Technical Timing Belt- Too tight or too loose?

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Technical Timing Belt- Too tight or too loose?

As someone who wants to (eventually) get around to changing his own timing belt, this has been interesting reading! Did you also change the water pump everson38?
 
As someone who wants to (eventually) get around to changing his own timing belt, this has been interesting reading! Did you also change the water pump everson38?
Hey house.

Thanks for the words of encouragement lol. I can say I would tell anyonentongive this ago. Very satisfying when done right. I plan to do a little write up / things I've learnt during this process.

In regards to water pump I never changed that, as I was rectifying another garages mistake but luckily they did the water pump right. But that would be the easier part of the job , so shouldn't be an issue to do [emoji3]
 
Hey everson. I've been incommunicado for a week as we've been away and I don't take my laptop with me when on holiday - Don't have any "smart" devices either just a very old "steam driven" phone which doesn't do data etc. So I'm just catching up on the forum and I'm very glad for you that you've successfully finished your belt and it's all turned out well - congratulations!

I've been reflecting on a few things which have arisen and I've come to the conclusion that doing belt changes on modern engines are best accomplished with a full set of locking/timing tools. Whereas older engines (especially where the sprockets are keyed to their shafts) could be reliably done with the "tippex" method, you have to really know inside out exactly what you are doing and why if you're to try it on a late model engine with "free" sprockets.

You were a bit puzzled about the belt alignment and tension I think? (after you'd rotated the crank a few revs you found the belt wanted to run closer to one edge of the pulley rather than in the middle). As I think judderbar points out, the belt running position on the pulley is controlled by the flanges on the water pump.

P1070228.JPG

I took this picture of the belt on the Panda before I changed it and you can see how it's running towards the rear of the cam pulley - Please ignore the tippex marks!:

P1070240.JPG

There's really nothing you can do about this (well I suppose you could shim out the pump somehow but I wouldn't) My boy's 2012 Punto 8 valve was just the same by the way. As the belt finds it's "settled" position during these first few revs you will very likely see a change in the belt tensioner pointer position and you can then retension it before finally refitting the dust covers. The whole idea of these spring tensioners though is to maintain a constant working tension on the belt and compensate for changes in centre distances between the crankshaft, camshaft and water pump due to expansion caused by temperature changes in the metal of the engine as well as minor differences as the belt settles and suffers wear. So if you check the position of the pointers when the engine is cold you'll find it's different when hot, and again after maybe 40,000 miles they won't be lining up as they did when fitted new. That's all OK though, that's why it's spring loaded!

Another observation, substantiated by Bernie, is that if you make reference marks (Tippex) on the belt, pulleys and casings and then rotate the engine, you will have to turn the engine through quite a number of complete revolutions (I'm too thick and actually can't be bothered, to work it out) before they will all line up again. The crank pulley (sprocket if you like) and it's casing mark will line up every rev of the crank. The cam pulley and it's casing mark will line up every two revs of the crank (2:1 ratio, as we all know) but the marks made on the belt corresponding to the marks made on the crank and cam pulleys will not return to their relative positions for many revs of the crankshaft. As Bernie points out this is good engineering practice for component life. If any mating components, gear wheels, ball/roller races, etc rotate so that faces frequently contact in the same place they will wear more quickly so manufacturers arrange for this to not happen. I was told at college that one of the reasons why a Rolls Royce wheel bearing was so costly was that it was designed so that the "repeatability factor" was 10 times less frequent than the bearing in my old Ford Anglia! He went on to say that meant that if you put a paint spot on the Anglia's roller it might return to the same part of the race track every 10 revolutions of the bearing whereas the RR bearing would only do it every 100 revs! To this day I don't know if I believe him - He's been dead for many years so I'll never get the chance now!

Anyway, Good Job! as the Yanks would say. There's nothing like the feeling you get from successfully completing a project like this is there? Please do keep us informed of any more tasks you may undertake. For me they are the most interesting posts which appear on "our" forum!

Kind regards, and again, jolly well done!
Jock
 
Hey guys, so finally got a moment to try recap abit on my whole process of this and share some tips and lessons learnt.

Firstly though want to givea special mention to all who help me, but some went above an beyond to get me to finish line: Boost, Berne, Jock and Judder. a MASSIVE THANKYOU and for putting up with my posts and direct DM's. I felt like a naggig 5 year old trying to get their fathers attention. But in doing so, i feel i have a new found learning and taken my diy skills to another level.

So here we go

1) I recommend that before even considering this job, just do some general watching on youtube and some reading if you prefer about the whole purpose and procedure of timing belts and changing them. I watched every video i could find from english to italian to polish about fiat based timing belts - alpha romeo , 500's, grande punto. I then went onto watch VW (purely because there is alot of vids on them brand) and watched those. Just grasp why / what / how a timing belt is.

2) Find similar models - In a job like this not having an exactly video on your exact engine and model always leaves some doubt. But after my initial learning i was able to find a video on a bravo tjet (in polish) to get somemoments of "thats exactly same on my car". Ford Ka shares similar to GP timing belt / water pump. Dont just type in Grande punto - adapt once your learning is in.

3) Get all the tools required - do not cut corners on tools, as you will need them, i found I need to buy pulley holder, EXTRA LONG telescopic ratchet, Allen key set, Locking tools. Use the correct tool for the job, the amount you will save in cost and time compared to going to a garage its amlsmot as if the tools are free anyway.

4) FIAT LOCKING TOOLS: Big point here - buy the locking tools obvsiously, but dont use the bolts to hold them in place (specific talking the crank loocking tool) I found that my actual crank bolts compared to the ones in the kit just went in nicer, one bolt sheard off (where in hindsight now - i realised i could of used lower timing belt cover bolt). The are just not up to standard, use what came off

5) Removing engine mount - I found that you can leave this on past the point where the elearn tells you to take it off, i left mine on with lower and upper covers off removed (just be gentle with lowercover as it sort of hooks under the mount) The reason why i say leave it on is just to get a feel of how the beast looks from the top and underneath, without worrying about the engine being supported. I rotated the engine a few times in this state to get a feel for compression and how it moves. a type of safety net b4 you plunge in

5) JIGGLE it around(LOCKING TOOLS) - You dont think it, but the most minor of movement when fitting locking tools makes all difference. moving it that 000000.1mm can work wonders. but the bolts and cam locking tool should go in nice and easy by FINGERS.

6) JUST STOP - There were times where i just kept going, especially when i got stuck and posted on here and it felt like 4 days for a response but in reality it was couple hours. If you get to a good point, down the tools and come back with good confidence. If you get stuck, down tools and come back and ask for help and WAIT. i ended up trying to get thebelt to sit in middle of cam numerous times, but if i had of waited would have found out...NOPE not gonna happen, wasted time, effort and worried mself for nothing.

7) Check, check, check and check - Getting close to the end it is easy to want to rush, but i putmy locking tools in and orated my engine over numerous times, so that i knew if something went wrong it wasnt the timing.i could almost do it with eyes closed.


8) FIRST start up - You will be terrified lol! my car was off the road for 2 weeks and one weekn of that was doing the actual job, this caused my car to not sound the best on startup but i put that down too oil falling of everything by now. but she is back to normal and sounds strong
 
I particularly like your points 5,6 and 8. I learned, long ago, that when things aren't quite going as you think they should, make a nice cup of tea and sit quietly for a wee while. If you do this problems often seem to resolve themselves and you are less likely to break something.

I honestly couldn't say how many belts I've done in my life, but I still remember the feeling of apprehension (maybe it was terror?) when the time came to twist the key on the first customer vehicle I ever did unsupervised. I still to this day find myself holding my breath and doing a little "butt clench" at that critical moment!

Best wishes to you for the future
Jock
 
I did like point 5 too ! (not that I disliked the others...).

Rewarding yourself, should it be by a cup of tea, a cigar or a rough-cider pint, is essential !
Making a break and closely inspect things/work your brain will most of the time bring you the solution. Had it yesterday trying to open a connector on my Scirocco: it ended up I just had to gently lift a (very small) plastic tab and the shield would slide off nicely...

On the other side you sometimes have to use the persuasive tooling, like prybar, sledge hammer etc. but before going that way try to have confirmation from more experienced people !

Job well done Emerson !!

BRs, Bernie

If someone here helped You fix -or better, understand- your issue, hit the thanks icon @ bottom right corner, it's free and makes us feel helpy ;-)
 
I'm installing a new timing belt and having some trouble getting the timing perfect... I'm having similar problems that everson38 did back last year, so going to post here rather than make a new thread.

My engine is the 1.4 16V, and I am using the special locking tools. The problem I'm having is everything seems "in time" up until I put the new belt on, tension it, then rotate the crank twice. After that, things are slightly out - the camshaft locking tool doesn't fit as the timing hole hasn't fully lined up with the window..

I think the problem is my understanding of the process for the camshaft pulley. I loosen it to fit the belt, then tighten it up to 120Nm. Then proceed to tension the tensioner to the max, rotate the engine twice, loosen the tensioner and get the notches lined up, then rotate engine again. It seems no matter what tension I set, things aren't lining up.

Getting the tensioner perfect isn't something I've been able to do. I get the two notches lined up and do the nut up hand tight, then torque it to 25Nm, but then the notches have moved... Do I need to tighten the nut to 25Nm all whilst holding the tension in the right place, using the fork? Basically hold it in the perfect place with one hand, and torque with the other?

I've gone through the process a few times and arriving at the same result. Basically, the pistons aren't quite level when the camshaft timing hole comes into view, it seems to be about half a turn out :bang:
 
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I'm installing a new timing belt and having some trouble getting the timing perfect... I'm having similar problems that everson38 did back last year, so going to post here rather than make a new thread.

Hey Pal, sorry to hear your having issues, but reading my key points previous, just take a break and call it a day, watch someore videos etc . In regards to your tensioning process, the steps are correct. I had the same issue though, when it cam to steps of loosening the tensioner to line up the notches and then re-tighten, I found the final tightening always moved. You have to hold it with the fork and get it as tight as you can, I found using my 1/4" torque wrench was just too big for.me.to tighten one way and hold with the fork the other. If u try tighten with a 13mm.wrench I found I was able to tighten but also see the notches before they started to move. They will move if you just try to tighten it down with a torque wrench, u can only the tighten so much before they shift. So go as far as you can before that happens and then rotate the engine twice , I did it about 4 times and then put locking tools in to ensure all.timed up

My engine is the 1.4 16V, and I am using the special locking tools. The problem I'm having is everything seems "in time" up until I put the new belt on, tension it, then rotate the crank twice. After that, things are slightly out - the camshaft locking tool doesn't fit as the timing hole hasn't fully lined up with the window..

I think the problem is my understanding of the process for the camshaft pulley. I loosen it to fit the belt, then tighten it up to 120Nm. Then proceed to tension the tensioner to the max, rotate the engine twice, loosen the tensioner and get the notches lined up, then rotate engine again. It seems no matter what tension I set, things aren't lining up.

Getting the tensioner perfect isn't something I've been able to do. I get the two notches lined up and do the nut up hand tight, then torque it to 25Nm, but then the notches have moved... Do I need to tighten the nut to 25Nm all whilst holding the tension in the right place, using the fork? Basically hold it in the perfect place with one hand, and torque with the other?

I've gone through the process a few times and arriving at the same result. Basically, the pistons aren't quite level when the camshaft timing hole comes into view, it seems to be about half a turn out :bang:

Hey Pal, sorry to hear your having issues, but reading my key points previous, just take a break and call it a day, watch someore videos etc . In regards to your tensioning process, the steps are correct. I had the same issue though, when it cam to steps of loosening the tensioner to line up the notches and then re-tighten, I found the final tightening always moved. You have to hold it with the fork and get it as tight as you can, I found using my 1/4" torque wrench was just too big for.me.to tighten one way and hold with the fork the other. If u try tighten with a 13mm.wrench I found I was able to tighten but also see the notches before they started to move. They will move if you just try to tighten it down with a torque wrench, u can only the tighten so much before they shift. So go as far as you can before that happens and then rotate the engine twice , I did it about 4 times and then put locking tools in to ensure all.timed up
 
Hey Pal, sorry to hear your having issues, but reading my key points previous, just take a break and call it a day, watch someore videos etc . In regards to your tensioning process, the steps are correct. I had the same issue though, when it cam to steps of loosening the tensioner to line up the notches and then re-tighten, I found the final tightening always moved. You have to hold it with the fork and get it as tight as you can, I found using my 1/4" torque wrench was just too big for.me.to tighten one way and hold with the fork the other. If u try tighten with a 13mm.wrench I found I was able to tighten but also see the notches before they started to move. They will move if you just try to tighten it down with a torque wrench, u can only the tighten so much before they shift. So go as far as you can before that happens and then rotate the engine twice , I did it about 4 times and then put locking tools in to ensure all.timed up

thanks everson38, had a break now back on the tools. Didn't get very far though as the little tensioner fork tool has broken! Circlip pliers are the next best thing i have access to, although they are nowhere near strong enough to hold the tension - the heads keep slipping out! might have to order a new fork tool
 
thanks everson38, had a break now back on the tools. Didn't get very far though as the little tensioner fork tool has broken! Circlip pliers are the next best thing i have access to, although they are nowhere near strong enough to hold the tension - the heads keep slipping out! might have to order a new fork tool

Yep the same happened to me, my fork prong bent, bit it shows how hard we must of been trying to tigthen. After that I was still able to use it but had to hold it a certain angle. Yes I would order a new one for sure. But try to just align the notches and then they tighten with a wrench as much as it can just before the notches start to.love again, I had to do this a few times just to get a feel of when I knew how much tension it will take before the notches start to move. My car was all n the air for about a week doing 6 hours a day on this, so don't worry, I believe if O can do it, honestly anyone can do it. If u want u can do video of anything that you are struggling with, email them to me and I can upload them to YouTube for so that people can properly see, I feel that really helped when getting feedback on my stuff.
 
Yep the same happened to me, my fork prong bent, bit it shows how hard we must of been trying to tigthen. After that I was still able to use it but had to hold it a certain angle. Yes I would order a new one for sure. But try to just align the notches and then they tighten with a wrench as much as it can just before the notches start to.love again, I had to do this a few times just to get a feel of when I knew how much tension it will take before the notches start to move. My car was all n the air for about a week doing 6 hours a day on this, so don't worry, I believe if O can do it, honestly anyone can do it. If u want u can do video of anything that you are struggling with, email them to me and I can upload them to YouTube for so that people can properly see, I feel that really helped when getting feedback on my stuff.

Thanks everson38, I'm going to persevere for now but got an MOT coming up so could do with getting the job done asap! I feel like I'm almost there but maybe getting something wrong.

I've just been out and redone everything and same problem, crankshaft is in time but camshaft is slightly out :( The guide I'm following (Gates) says to check the timing (with the tools) after turning the crank twice after tensioning the tensioner to the max. I noticed Haynes and eLearn don't say to do that, only to check it all times after you've tensioned the tensioner the second time (not to the max, to the notches)

The only bit I'm unsure about is slackening the camshaft pulley. I'm not sure why you need to do that, 'cos the camshaft is all locked in place already? I'm using the camshaft pulley locking tool that you bolt to the cylinder head. With this tool in place, it's still possible to move the camshaft pulley slightly as the tooth of the tool isn't exactly the same width as the belt tooth - so maybe that's why it's a little out?

I'm going to undo it all and try again! I'll try take some pics or a video
 
Guides section -> "Timing belt" thread (1.2 8V EVO 2 Engine Cam Belt replacement). It's about 8V engines, but idea is the same...
You don't mess with the camshaft/VVT wheel ("eLearn" bull$hit). And you set the tensioner once.
Water pump (bearings) is also responsible for belt tension or how (where) it rides the pulleys.
That's all. It is still 80's technology, simple engines (F.I.R.E. family).
Most servicing, scheduled maintenance can be done old way, DIY at home.
Besides tools, make your own paint-marks, everywhere (belt<->wheels/pulleys), count the teeth.

If it's still wrong...YOU are doing something wrong. Or parts are incorrect ones (belt - number of tooth?) or timing tools.
 
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Guides section -> "Timing belt" thread (1.2 8V EVO 2 Engine Cam Belt replacement). It's about 8V engines, but idea is the same...
You don't mess with the camshaft/VVT wheel ("eLearn" bull$hit). And you set the tensioner once.
Water pump (bearings) is also responsible for belt tension or how (where) it rides the pulleys.
That's all. It is still 80's technology, simple engines (F.I.R.E. family).
Most servicing, scheduled maintenance can be done old way, DIY at home.
Besides tools, make your own paint-marks, everywhere (belt<->wheels/pulleys), count the teeth.

If it's still wrong...YOU are doing something wrong. Or parts are incorrect ones (belt - number of tooth?) or timing tools.

Your comment interests me. Are you advocating changing the belt without slackening the cam sprocket bolt? If so I whole heartedly agree with you BUT - You need to be sure the cam timing is correctly set up before you start. Why? Because all you will achieve is the same timing as before you started so if someone before you has failed to tighten the pulley in the correct position in relation to the camshaft itself all you will just be achieving is what was already there. I was very interested to explore this when I did Becky's belt a wee while ago. You can read all about it here: https://www.fiatforum.com/panda/459903-beckys-timing-belt-ongoing-saga.html?459903=#post4338582

Then a wee while later i did the belt on my boy's 1.4 8 valve Punto which you can read some comments on here: https://www.fiatforum.com/panda/460629-timing-belts-again-becky-her-pal.html?460629=#post4344018

I can't think of any reason why it's any different with the 16 valve - of course the twin cams look different but the basic operation is the same, no? You do need to check that the timing is all correct before you start though because if it's wrong before you start and you are not slackening and realigning the pulley, then it's going to be wrong when you've finished. Some people have said to me "Oh but you are not taking manufacturing differences in the belt into account" My reply is that I believe modern belts are so accurately made that this is not a factor worth thinking about - certainly not on an every day "cooking" engine.

I'm a great believer in letting "sleeping dogs lie" and I think in this instance if you can leave that cam bolt alone by checking your timing before you start that's definitely the way to go!
 
Made some progress yesterday. I was doing something wrong, either with the cam pulley or the tensioning - although I'm not exactly sure what. I started over, and made sure to tension the belt before torquing the cam pulley bolt (I may have been doing those two things the other way round before).

All nicely in time now :) I do think you guys are right about not needing to loosen the cam pulley. I believe it's to make it easier to fit the belt, but it didn't seem to make much difference to me. Mine was marked up with tip-ex from a previous job so I used that to put it back to how it was originally aligned, but I had the cam locking tools in place anyway so not sure if that was really necessary. Does it matter how the pulley is positioned if you have the cams locked? I assume it's only important to pay attention to the pulleys position if you are relying on marking it with tipex against the head and don't have the locking tools..

Now onto the next problem: I think the threads in the cylinder head for the engine mounts are stripped as the bolts won't tighten :bang:
 
I think you've just stated here what your problem was caused by. If the belt is not fully tensioned BEFORE you tighten the cam sprocket bolt then further tightening of the belt is almost bound to alter the relationship between the crank and cam shafts.

If you have the cams locked and your crank positioned correctly (on your 16 valve engine that's done with the tool through the plug 'oles so you set the pistons all half way up/down the bores I think? then the position of the sprocket will be dictated by the tightened belt.

I remember on both engines (our own 1.2 non VVT panda and my boy's 1.4 VVT 8 valve Punto) that the bolts holding the engine mount to the front of the head were very tight indeed. Had to put a length of pipe over the spanner/wrench to slacken them. (I say spanner/wrench because I couldn't get at one of the bottom bolts on the Panda even with my "fancy" compact Vortex sockets and had to use a combination spanner with the length of pipe to get enough leverage) I remember they nearly all made a quite alarmingly loud "crack" as they first moved!

Ps, My guess would be that you should at least be able to elevate the engine enough with a jack to drill the holes out for helicoils without disconnecting the gearbox mount I think? but I've never tried it so don't take that as "gospel"
 
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Made some progress yesterday. I was doing something wrong, either with the cam pulley or the tensioning - although I'm not exactly sure what. I started over, and made sure to tension the belt before torquing the cam pulley bolt (I may have been doing those two things the other way round before).

All nicely in time now :) I do think you guys are right about not needing to loosen the cam pulley. I believe it's to make it easier to fit the belt, but it didn't seem to make much difference to me. Mine was marked up with tip-ex from a previous job so I used that to put it back to how it was originally aligned, but I had the cam locking tools in place anyway so not sure if that was really necessary. Does it matter how the pulley is positioned if you have the cams locked? I assume it's only important to pay attention to the pulleys position if you are relying on marking it with tipex against the head and don't have the locking tools..

Now onto the next problem: I think the threads in the cylinder head for the engine mounts are stripped as the bolts won't tighten :bang:

Hey , how you getting on with thing, did you manage to rectify your stripped bolts?
 
Hey , how you getting on with thing, did you manage to rectify your stripped bolts?

Hey everson. I've put everything back together and the engine is running normally and the car drives fine (just short test drive round the block). I've used some blue threadlocker on the mounting bracket bolts for now. I think putting a helicoil in might be a job for the garage as I'm not 100% sure I can jack the engine up enough to get access to the lower bolt holes
 
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