Technical Which Panda do I have?

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Technical Which Panda do I have?

Pete. Another wee follow up to my last post. The engine ECU learns the angular relationship between the camshaft and crankshaft when the engine is running - which it gets from the sensors on both - and stores this info. If anything alters this relationship (like slackening and retightening the cam sprocket bolt I think) the ECU notices and will light up the engine warning light - MIL - on the dash. When you interrogate the ECU you'll often find it's logged a fault code for a missfire and you can waste lots of time and money looking for this non existent missfire! If the MIL lights up after a belt change, to let the ECU learn the new relationship between the two shafts, you need to do a "Phonic Wheel Relearn" which requires a good scanner, like Multiecuscan or The Fiat dealer tool. However I found that neither my Panda nor my boy's Punto needed this done following the renewal of their belts and I think it's because that cam sprocket bolt was never touched on either engine. From other posts people have made where their light has come on, it would seem it doesn't come on immediately on starting the engine but usually after a bit of driving around at main road speeds.
Hi puggit/pluggit (is that right?)
So you didn't touch the cam wheel bolt on yours or the pinto then, great, I won't touch it, I will just use the timing locking tools and back it up with the tried and trusted tipex method (sad fact of the day Mike nesbitt from the monkeys who's mother invented tipex passed through yesterday).

PS, my name is Steve, not Pete, pop it in Pete was the imaginary postman Larry grayson used reference, friend of slack alice
 
If you remember to connect all then sensors correctly before you first start the engine you shouldn’t have to do a phonic relearn on any post 2005 Panda as far as I know. We have seen one that was done at a local garage. Was this genuine or not is hard to tell when you are not doing the job yourself. I suspect they did something wrong when changing the belt and used the phonic learn as a get out clause to stop them looking stupid.


Not sure when Fiat made it unnecessary to do the phonic relearn
 
Hi puggit/pluggit (is that right?)
So you didn't touch the cam wheel bolt on yours or the pinto then, great, I won't touch it, I will just use the timing locking tools and back it up with the tried and trusted tipex method (sad fact of the day Mike nesbitt from the monkeys who's mother invented tipex passed through yesterday).

PS, my name is Steve, not Pete, pop it in Pete was the imaginary postman Larry grayson used reference, friend of slack alice
Hi Steve, It doesn't matter in the grand scheme of things but it's spelt PUGGLT, however I'm not "precious" about it.

If you don't slacken the cam pulley/sprocket (whatever you want to call it?) and then try to fit the new belt with both the cam and crank locking tools in place you'll find you can't get the belt teeth to quite line up because there's no slack to play with. You'll have to back off the crankshaft by a small amount - half a tooth is probably enough - then the belt will almost "fall" on. Of course check your marks and take two turns of the crank with a spanner/socket on the crank pulley to check for clearances before starting up although even if you've got it wrong the 1.1 and 1.2 up 'till 2011 were non interference so there's little to worry about.

The Monkees? not really my cup of tea but definitely brings back many happy memories of my youth - very sad all these guys are starting to depart. Doesn't half make you feel mortal!
 
Hi Steve, It doesn't matter in the grand scheme of things but it's spelt PUGGLT, however I'm not "precious" about it.

If you don't slacken the cam pulley/sprocket (whatever you want to call it?) and then try to fit the new belt with both the cam and crank locking tools in place you'll find you can't get the belt teeth to quite line up because there's no slack to play with. You'll have to back off the crankshaft by a small amount - half a tooth is probably enough - then the belt will almost "fall" on. Of course check your marks and take two turns of the crank with a spanner/socket on the crank pulley to check for clearances before starting up although even if you've got it wrong the 1.1 and 1.2 up 'till 2011 were non interference so there's little to worry about.

The Monkees? not really my cup of tea but definitely brings back many happy memories of my youth - very sad all these guys are starting to depart. Doesn't half make you feel mortal!
Hi puggLt

Quote - "You'll have to back off the crankshaft by a small amount - half a tooth is probably enough - then the belt will almost "fall" on." that would mean unbolting the crank timing tool for a short time to do this correct?

By back off you mean rotate the whole bottom crank sprocket AND crank a few degrees either way to get the belt to drop on the cam sprocket and NOT slacken it's bolt and freewheel it on the woodruff keyless crank? I'm sure that's what you mean.

I've done many belts over the years, I'm just checking there is nothing particular on this engine I need to do it, it sounds very straight forward

Thanks pete
 
Hi puggLt

Quote - "You'll have to back off the crankshaft by a small amount - half a tooth is probably enough - then the belt will almost "fall" on." that would mean unbolting the crank timing tool for a short time to do this correct?

By back off you mean rotate the whole bottom crank sprocket AND crank a few degrees either way to get the belt to drop on the cam sprocket and NOT slacken it's bolt and freewheel it on the woodruff keyless crank? I'm sure that's what you mean.

I've done many belts over the years, I'm just checking there is nothing particular on this engine I need to do it, it sounds very straight forward

Thanks pete
Absolutely. Leave the cam where it is - either with the locking tool still engaged in it's slot or with the tippex mark lined up if you're not using locking tools - then rotate the crankshaft - and it's sprocket, which is still bolted up solid to it of course - anticlockwise just enough to get the belt onto the sprocket teeth. Yes, if you're using locking tools, you'll need to take the top bolt out of the crank locking tool to free it up so the crank can be moved. The crank sprocket is keyed so won't rotate on the shaft if you slacken it's retaining bolt anyway, not that you'd want to in this instance. (It's only the cam sprocket that's keyless). If you've done belts before I'd be surprised if you find anything unusually difficult about this one - I find the most awkward bit is undoing the bottom 2 bolts which hold the engine mount to the front of the engine are the most fiddly bit and you'll probably need to jack the engine up and down a wee bit to "fiddle" it out from between the front of the engine and the inner wing. I like to support the engine with a trolley jack and thick sheet of plywood under the sump but take a careful look at your sump before you do this as these engines are famous for rusty sumps! If very bad it might be crushed!

Are you going to do a water pump as well? I would unless the pump has been very recently replaced as if it fails later you'll be taking the whole thing to pieces again - gives you the chance to renew the coolant at the same time.

I'd strongly recommend removing the spark plugs when you're doing this as it makes turning the engine over so much easier and reduces the chances of the crankshaft inadvertently moving due to any residual compression pressure in a cylinder.

Good luck and do let us know how you get on and don't hesitate to ask about anything you're unsure about.
 
Absolutely. Leave the cam where it is - either with the locking tool still engaged in it's slot or with the tippex mark lined up if you're not using locking tools - then rotate the crankshaft - and it's sprocket, which is still bolted up solid to it of course - anticlockwise just enough to get the belt onto the sprocket teeth. Yes, if you're using locking tools, you'll need to take the top bolt out of the crank locking tool to free it up so the crank can be moved. The crank sprocket is keyed so won't rotate on the shaft if you slacken it's retaining bolt anyway, not that you'd want to in this instance. (It's only the cam sprocket that's keyless). If you've done belts before I'd be surprised if you find anything unusually difficult about this one - I find the most awkward bit is undoing the bottom 2 bolts which hold the engine mount to the front of the engine are the most fiddly bit and you'll probably need to jack the engine up and down a wee bit to "fiddle" it out from between the front of the engine and the inner wing. I like to support the engine with a trolley jack and thick sheet of plywood under the sump but take a careful look at your sump before you do this as these engines are famous for rusty sumps! If very bad it might be crushed!

Are you going to do a water pump as well? I would unless the pump has been very recently replaced as if it fails later you'll be taking the whole thing to pieces again - gives you the chance to renew the coolant at the same time.

I'd strongly recommend removing the spark plugs when you're doing this as it makes turning the engine over so much easier and reduces the chances of the crankshaft inadvertently moving due to any residual compression pressure in a cylinder.

Good luck and do let us know how you get on and don't hesitate to ask about anything you're unsure about.
Hi

That's great thanks, I've read a few cambelt threads on here and at least one mentions that both the crank and cam sockets are woodruff key less. Thought it was a bit strange for the crank sprocket not to have a woodruff key.

The car has been maintained by the main dealer all its life if the previous owner is to be believed, I did ask her the question but she had no idea what they have done but it was always serviced ' on the dot' so the belt might have been done fingers crossed.

I've tried getting in touch with the service dept at the garage who have serviced it on at least ten occasions in the past week or so and with at least five promises to call back but nothing as yet I will probably pop in but I know people are still under the kybosh with covid absences.

I've made a sort of cradle to raise the sump but it lifts it by the sides, ie, where the sump joins the block where it bolts on so all of the weight is off the fragile sump, luckily mine has no rust.

Thanks for the pointers
 
Hi

That's great thanks, I've read a few cambelt threads on here and at least one mentions that both the crank and cam sockets are woodruff key less. Thought it was a bit strange for the crank sprocket not to have a woodruff key.

The car has been maintained by the main dealer all its life if the previous owner is to be believed, I did ask her the question but she had no idea what they have done but it was always serviced ' on the dot' so the belt might have been done fingers crossed.

I've tried getting in touch with the service dept at the garage who have serviced it on at least ten occasions in the past week or so and with at least five promises to call back but nothing as yet I will probably pop in but I know people are still under the kybosh with covid absences.

I've made a sort of cradle to raise the sump but it lifts it by the sides, ie, where the sump joins the block where it bolts on so all of the weight is off the fragile sump, luckily mine has no rust.

Thanks for the pointers
In my opinion these sumps are actually pretty robust. As long as the sump is not excessively corroded and you don't try to jack the engine up before you've undone the mount (so effectively taking the whole weight of the front end on the sump) I have never seen the slightest problem with jacking on the sump. My boy's Punto was actually quite "pimply" with rust when I did his and it survived without any drama. I wouldn't do it without a nice flat piece of wood between the jack saddle and the sump though!

This thread has made me think about the whole subject of changing these belts without slackening the cam sprocket bolt (As I said somewhere in previous posts I'm a great believer in letting "sleeping dogs lie" so I was keen to do it without slackening that bolt).

As I've previously said it only works if the cam sprocket has previously been correctly timed to the cam. I think if the car has always been maintained by a Fiat Main agent or specialist or if it's it's first change of belt - so the sprocket bolt will not have been touched since it left the factory - then you can safely assume the sprocket will be correctly timed. A car with a less certain past probably needs to be checked with the timing tools. Our Becky had a service history from the main dealer for her first few years, then a gap of about 3 years or so with no stamps in the book and then receipts from a garage up here in the central belt for the last 2 years before we bought her. She was in the low 60,000 miles with no record of the belt having been changed so, although I suspected she was still on her original belt, I bought the tools just to be sure and found that they slotted in just fine proving to me it was all set up correctly before I started.

I'm also aware of at least one post where someone tried to change their belt in this way - that is without slackening the sprocket bolt - by locking up the engine with the locking tools and then found it was impossible to fit the new belt without having slack in it which, when the locking tools were removed, resulted in the timing being incorrect when rechecked. Car Mechanics Magazine - a publication I hold in very high regard - seems to have encountered the same problem in their recent article where they tackled the job in one of their feature articles. I've thought about this a lot and I think the problem they encountered is because the locking tools lock the engine up with the crankshaft and camshaft positions as they are with a fully tensioned belt. So, if you are looking at the belt end of the engine (imagine you are looking at it from the driver's side of the car - Ie, radiator on your right and alternator to the left) then the run of belt on the right hand side, that is from the cam sprocket, round the water pump and down to the crankshaft sprocket, is going to be under full tension. If you slacken the tensioner the belt run on the left, that is from the crankshaft sprocket, round the tensioner pulley and up to the camshaft will go slack and you'll find you can remove the old belt. However if you now try to fit the new one with the cam sprocket bolt untouched and locking tools still in place you'll find it impossible to get the belt's teeth to mesh with the cam sprocket correctly unless you introduce some "wiggle room" by either turning the cam slightly clockwise or (my preference) turning the crankshaft slightly anticlockwise.

If you slacken the cam sprocket bolt, as recommended in the manufacturer's "official" way to do it, and keep the crank and cam locking tools in place - as you must to retain the timing if you slacken that bolt - then when you apply tension by rotating the tensioner pulley the belt will pull tight on the right hand side (water pump side) and cause the cam sprocket to rotate on the end of the camshaft (too much resistance on the crank for it to rotate) Then when the cam sprocket bolt is retightened the timing will be correct because the timing tools are still in place. If you do this DON'T TORQUE THE CAM SPROCKET BOLT WITH THE ANGLED LOCKING BAR STILL IN THE BACK END OF THE CAMSHAFT. If you do there is a very real danger you might fracture bits off the camshaft!

All this sounds so complicated doesn't it? especially if you are a person who only occasionally tackles a job such as this. Once you get the spanners out and stuck in it all becomes less fuddled. So, if you feel very unsure and are not clear about timing up 4 stroke engines just follow Andy Monty's guide (Grande Punto section guides) and you really can't go wrong. If you want to try doing it without slackening "that" bolt, then if you are sure the timing is correct before you start - either because the car's history is certain or because you use the tools to check it's all correct before you start - then by all means just buy some Tippex and carry on in the time honoured fashion. If, on the other hand you're now sitting thinking to yourself "4 stroke engines what does that mean" then I think your tools should stay in their box and you need to find a nice wee family garage to help you out.
 
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I have recently done the 1.2-60 cam belt. It's really an easy task if you ignore all the stuff you have to remove to get at the job.

The cam pulley bolt should be left untouched. With the old belt in place -
Lock the crank. **​
Paint mark the cam wheel and adjacent casing.​
Remove old cam belt,​
Fit the new water pump and belt tensioner.​
Fit the new belt around the pulleys.​
Tension the belt - align pointers within the tensioner using the special key and tighten the bolt.​

The belt tensioner pulls from one side, so setting the tension is likely to shift the timing by one tooth. The paint marks make this obvious. I simply refitted the belt one tooth "out" and retensioned. The timing marks now lined up.

** You can actually do it by paint marking the crank AND the cam so the relative alignment can be checked. But a locking tool kit is so cheap I just got one anyway.
 
In my opinion these sumps are actually pretty robust. As long as the sump is not excessively corroded and you don't try to jack the engine up before you've undone the mount (so effectively taking the whole weight of the front end on the sump) I have never seen the slightest problem with jacking on the sump. My boy's Punto was actually quite "pimply" with rust when I did his and it survived without any drama. I wouldn't do it without a nice flat piece of wood between the jack saddle and the sump though!

This thread has made me think about the whole subject of changing these belts without slackening the cam sprocket bolt (As I said somewhere in previous posts I'm a great believer in letting "sleeping dogs lie" so I was keen to do it without slackening that bolt).

As I've previously said it only works if the cam sprocket has previously been correctly timed to the cam. I think if the car has always been maintained by a Fiat Main agent or specialist or if it's it's first change of belt - so the sprocket bolt will not have been touched since it left the factory - then you can safely assume the sprocket will be correctly timed. A car with a less certain past probably needs to be checked with the timing tools. Our Becky had a service history from the main dealer for her first few years, then a gap of about 3 years or so with no stamps in the book and then receipts from a garage up here in the central belt for the last 2 years before we bought her. She was in the low 60,000 miles with no record of the belt having been changed so, although I suspected she was still on her original belt, I bought the tools just to be sure and found that they slotted in just fine proving to me it was all set up correctly before I started.

I'm also aware of at least one post where someone tried to change their belt in this way - that is without slackening the sprocket bolt - by locking up the engine with the locking tools and then found it was impossible to fit the new belt without having slack in it which, when the locking tools were removed, resulted in the timing being incorrect when rechecked. Car Mechanics Magazine - a publication I hold in very high regard - seems to have encountered the same problem in their recent article where they tackled the job in one of their feature articles. I've thought about this a lot and I think the problem they encountered is because the locking tools lock the engine up with the crankshaft and camshaft positions as they are with a fully tensioned belt. So, if you are looking at the belt end of the engine (imagine you are looking at it from the driver's side of the car - Ie, radiator on your right and alternator to the left) then the run of belt on the right hand side, that is from the cam sprocket, round the water pump and down to the crankshaft sprocket, is going to be under full tension. If you slacken the tensioner the belt run on the left, that is from the crankshaft sprocket, round the tensioner pulley and up to the camshaft will go slack and you'll find you can remove the old belt. However if you now try to fit the new one with the cam sprocket bolt untouched and locking tools still in place you'll find it impossible to get the belt's teeth to mesh with the cam sprocket correctly unless you introduce some "wiggle room" by either turning the cam slightly clockwise or (my preference) turning the crankshaft slightly anticlockwise.

If you slacken the cam sprocket bolt, as recommended in the manufacturer's "official" way to do it, and keep the crank and cam locking tools in place - as you must to retain the timing if you slacken that bolt - then when you apply tension by rotating the tensioner pulley the belt will pull tight on the right hand side (water pump side) and cause the cam sprocket to rotate on the end of the camshaft (too much resistance on the crank for it to rotate) Then when the cam sprocket bolt is retightened the timing will be correct because the timing tools are still in place. If you do this DON'T TORQUE THE CAM SPROCKET BOLT WITH THE ANGLED LOCKING BAR STILL IN THE BACK END OF THE CAMSHAFT. If you do there is a very real danger you might fracture bits off the camshaft!

All this sounds so complicated doesn't it? especially if you are a person who only occasionally tackles a job such as this. Once you get the spanners out and stuck in it all becomes less fuddled. So, if you feel very unsure and are not clear about timing up 4 stroke engines just follow Andy Monty's guide (Grande Punto section guides) and you really can't go wrong. If you want to try doing it without slackening "that" bolt, then if you are sure the timing is correct before you start - either because the car's history is certain or because you use the tools to check it's all correct before you start - then by all means just buy some Tippex and carry on in the time honoured fashion. If, on the other hand you're now sitting thinking to yourself "4 stroke engines what does that mean" then I think your tools should stay in their box and you need to find a nice wee family garage to help you out.
Hi, yes I saw the car mechanics feature too, it can be tackled two ways then;

use both locking tools and it's safe to undo the cam sprocket bolt to rotate the cam sprocket to allow the belt to align and 'drop on' to the teeth

Or as dave has mentioned, lock the crank with the tool then tippex the cam wheel, as long as the tippexd cam wheel lines back up after job done but I'm assuming if you have the crank locking tool you will have the cam locking tool too but I suppose the tippex method saves you taking the cam box off I reckon.

The crucial thing to do is to rotate it a couple of revolutions and make sure it's all still lined up. You could even tippex both sprockets regardless of where the timing is and as long as the two both match up after you'd be fine, if you got into trouble in the middle of it you would HAVE to refer to your cam tools to get a datum point.

I will do mine in the new year as I'm moving imminently and can't afford any down time with the car, it's crucial I'm still mobile at this time.

I might do a picture sequence I can post here (but I know of a couple already) or I might do a vlog a put it on YouTube.

I will persevere with the dealership and will confirm if it's had its belt done or not, I may take the top cover off to see the condition of the belt, you can usually tell an old belt from a belt that's relatively new.

All the best every body and merry Christmas 🎅
 
I have recently done the 1.2-60 cam belt. It's really an easy task if you ignore all the stuff you have to remove to get at the job.

The cam pulley bolt should be left untouched. With the old belt in place -
Lock the crank. **​
Paint mark the cam wheel and adjacent casing.​
Remove old cam belt,​
Fit the new water pump and belt tensioner.​
Fit the new belt around the pulleys.​
Tension the belt - align pointers within the tensioner using the special key and tighten the bolt.​

The belt tensioner pulls from one side, so setting the tension is likely to shift the timing by one tooth. The paint marks make this obvious. I simply refitted the belt one tooth "out" and retensioned. The timing marks now lined up.

** You can actually do it by paint marking the crank AND the cam so the relative alignment can be checked. But a locking tool kit is so cheap I just got one anyway.
Hi dave, yes my thoughts too, as long as the crank is locked and the cam tippex mark lines back up its job done, in theory just marking both sprockets at any position with tippex will suffice obviously making sure the marks line up after the obligatory 2 spins of the crank( how I've always done previous belts on previous cars but ALWAYS set to TDC first).
Using the crank locking tool gives you a datum point and that leaves you free to just concentrate on the cam sprocket timing.

All the best
 
Hi dave, yes my thoughts too, as long as the crank is locked and the cam tippex mark lines back up its job done, in theory just marking both sprockets at any position with tippex will suffice obviously making sure the marks line up after the obligatory 2 spins of the crank( how I've always done previous belts on previous cars but ALWAYS set to TDC first).
Using the crank locking tool gives you a datum point and that leaves you free to just concentrate on the cam sprocket timing.

All the best
The 1400 engine has to be set at 50% stroke with number 1 on the rising stoke. It's easy to get right by fitting the cam locking tool and turning the crank. The spring loaded pin will engage when the cam is in the right position. If the engine has been apart you would risk having it 180 out of phase. That might be "safe" (might not - I dont know!!!) but it certainly wont run.

I've always assumed the 1.1 and 1.2 also have to be set at half stroke but I simply fitted the crank locking tool without checking via the spark plugs.

The Mutijet locking kit includes a cam wheel holding tool. It's hugely important to hold the sprocket wheel while tightening the centre bolt. Fail to do that correctly and the chain will be damaged.

By the way Fiat Twin cams including the single and twin variator TS engines all have keyless cam pulleys. The cams are locked with shaped blocks that fit over the number 1 cam lobes. Again, you need a holding tool for torquing them up.
 
The 1400 engine has to be set at 50% stroke with number 1 on the rising stoke. It's easy to get right by fitting the cam locking tool and turning the crank. The spring loaded pin will engage when the cam is in the right position. If the engine has been apart you would risk having it 180 out of phase. That might be "safe" (might not - I dont know!!!) but it certainly wont run.

I've always assumed the 1.1 and 1.2 also have to be set at half stroke but I simply fitted the crank locking tool without checking via the spark plugs.

The Mutijet locking kit includes a cam wheel holding tool. It's hugely important to hold the sprocket wheel while tightening the centre bolt. Fail to do that correctly and the chain will be damaged.

By the way Fiat Twin cams including the single and twin variator TS engines all have keyless cam pulleys. The cams are locked with shaped blocks that fit over the number 1 cam lobes. Again, you need a holding tool for torquing them up.
Yes keyless cam sprockets have been around for a long time
 
Very interesting reading all of that, but how much more efficient is the engine with free wheeling pully's and /or 16 valve versions. My 17 year old with 66k on the clock is showing 44.7 to the gallon around town and is quite nippy. ( I know I could probably knock a bit off those figures as the computer is not that accurate ) but even so that's pretty good even by todays standards. The 1200 8 valve engine is a breath of fresh air to work on as opposed to my Mercedes which is a 3.5 ltr 24 valve engine. However that's chain driven and I'm told a bullet proof unit. But that's for another debate and another forum. :)
 
Oh... The chains on newer MB engines are really not that sturdy (due to emissions and pedestrian safety narrower chains are fitted).
And the 3,5 is notorious for balance shaft sprockets from a certain series being too soft. Oh and the highpressure fuelpump (direct injection) isn't faultfree.
But since this is a FiatForum I'll shut up now...

gr J
 
The Fiat Multijet cam chain is single row and will get to 100K miles but after that... A cam belt would be wider still, so I can only assume it was penny pinching to not fit a better chain. That said, the rockers are made to fail if the pistons hit valves so maybe the engineers found a few shekels to make them fail safe.
 
Oh... The chains on newer MB engines are really not that sturdy (due to emissions and pedestrian safety narrower chains are fitted).
And the 3,5 is notorious for balance shaft sprockets from a certain series being too soft. Oh and the highpressure fuelpump (direct injection) isn't faultfree.
But since this is a FiatForum I'll shut up now...

gr J
No balance shaft on the 276 engine and the chains were uprated.
 
Very interesting reading all of that, but how much more efficient is the engine with free wheeling pully's and /or 16 valve versions. My 17 year old with 66k on the clock is showing 44.7 to the gallon around town and is quite nippy. ( I know I could probably knock a bit off those figures as the computer is not that accurate ) but even so that's pretty good even by todays standards. The 1200 8 valve engine is a breath of fresh air to work on as opposed to my Mercedes which is a 3.5 ltr 24 valve engine. However that's chain driven and I'm told a bullet proof unit. But that's for another debate and another forum. :)
My merc Vito 2.2 is chain, breezed up to 300k with ease, does not uses water or oil between services. Any way I'm off as you say another debate for another forum
 
Very interesting reading all of that, but how much more efficient is the engine with free wheeling pully's and /or 16 valve versions. My 17 year old with 66k on the clock is showing 44.7 to the gallon around town and is quite nippy. ( I know I could probably knock a bit off those figures as the computer is not that accurate ) but even so that's pretty good even by todays standards. The 1200 8 valve engine is a breath of fresh air to work on as opposed to my Mercedes which is a 3.5 ltr 24 valve engine. However that's chain driven and I'm told a bullet proof unit. But that's for another debate and another forum. :)
What makes me laugh with the really modern engines is the 'easy slip' pistons and rings they install so as not to create friction on the cylinder walls to help it spin over easier to get good mpg and emissions.
This leads to piston blow-by that then mixes with soot diverted by the egr valve to the inlet manifold and because they are now direct petrol injection engines there is no petrol washing the valves or inlet tract clean so it just blocks itself up, on some models walnut blasting is part of the service. Rubbish.
 
What makes me laugh with the really modern engines is the 'easy slip' pistons and rings they install so as not to create friction on the cylinder walls to help it spin over easier to get good mpg and emissions.
This leads to piston blow-by that then mixes with soot diverted by the egr valve to the inlet manifold and because they are now direct petrol injection engines there is no petrol washing the valves or inlet tract clean so it just blocks itself up, on some models walnut blasting is part of the service. Rubbish.
Hi Steve. I remember the first time I "refreshed" an engine (think it was a 1600 Ford Pinto?) which had this type of ring. The gaps were acceptable but the rings slid in and out of the bores so easily I scrapped them because I thought they'd lost their tension! I fitted a set of Cords in their place which gripped well so I was "happy" but became a little less happy a few weeks later when a Ford friend told me the genuine Ford rings are all like that because they are low friction! The engine was fine though and eventually became my demo stand mounted engine which I used in my community ed evening classes.

Although retired I still have a number of garages where I'm a "weel kent face" and drop in regularly for a chat - and cup of tea if I'm lucky and their're not too busy. They know the passion I have for cars so sometimes show me "interesting stuff" lying about the workshop and I've noticed some pistons with the black (Molybdenum?) anti friction pads on their thrust sides, are showing wear such that the aluminium of the skirt is showing through. Of course I don't know how many miles might be on them - many have suffered damage due to getting intimate with their valves - but I wonder how long it takes to wear like this and does it really make that much difference anyway?

Inlet tract carbon fouling on direct injection petrol engines is a great interest of mine. Of course it's been quite a problem on diesels for many years. I'm particularly into VAG "stuff" and I've seen manifolds (and EGRs) so clogged with carbon you wouldn't think the engine could run like that. Some interesting procedures are tried by some:

I've been running Archoil 6900-P Max in the Ibiza since she was new. This product: https://www.powerenhancer.co.uk/archoil-ar6900-p-max-advanced-petrol-synthesis.html claims to reduce inlet carbon fouling. Who knows, and I doubt if it'll eliminate this "scourge" but It'll be interesting to see how long she goes before I get any symptoms.
 
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