Technical Car stuck in limp mode after timing belt change

[lukeedukee]

Hi,

Sorry, it's long I know but I thought context would be helpful here.

I decided it was time to finally bring my beloved Punto to the mechanic as I felt it needed some TLC. Since the car recently hit 60K miles on the clock I wanted to get the timing belt and water pump changed. I also drive from Poole to Southampton for work every day which is roughly an hour's drive meaning, I'm very reliant on my car.

Brought it to the greaser on Saturday and they changed it out for me. They said though that the previous belt jumped 2 teeth or so but wasn't enough to cause damage to the engine or anything. This left me with the EML flashing since the car is not used to the new belt being in the correct position. They stated it was a sensor issue and that they would save that job for another rainy day so I agreed since nothing was wrong with the car. Well... that was until I drove it.

The engine appeared to be in limp mode. Slow acceleration, wouldn't even touch 60mph unless going downhill. Uphill was a major struggle since the speed went from 70mph all the way down to 50mph with the accelerator all the way down. Shifting down didn't do **** either. So... I called the mechanic and explained the issue. They replaced the sensor yesterday and also did some relearning on the phonic wheel.

This brings us to today. I picked it up early morning as I needed to get to work, I noticed the EML was still on but wasn't flashing this time so I thought this would suffice for now as long as the acceleration problem didn't persist. Drove it and to my surprise... no improvements whatsoever. Same poor acceleration. I pretty much just feel like I paid an additional £122 for the EML to stop flashing. Currently, I have paid a total of £400 for everything and the issue is still not fixed which leaves me feeling pretty pissed off as you can imagine.

Called the mechanic after I got to work this morning and explained that the issue is still going on. I told him that I'm not willing to spend any more money until everything functions as it was before the belt change. He's booked me in for Saturday next week now to have a look.

I personally feel like the car is absolutely fine and that the errors need clearing. Once that's been cleared, then it should be out of limp mode. I'm by no means a car expert but that's my theory.

If you were in my situation, what would your next move be? what would you check for?

Many thanks in advance,

Luke

 

[varesecrazy]

Hi

A phonic wheel is the commonest thing needed..

But normally its just the belt change.. a fraction of a millimetre difference in length between new and old

Im not convinced that 2 teeth out can be your issue.. as likely it was GOOD before.. and the shift now is wrong


IF you struggle..
Look out 'small car services' up the M27 from Soton

Huge FIAT experience


Member @s130 might know of somebody else in that area..?

 

[Pugglt Auld Jock]

I have to start by saying that, as I can't physically examine the car myself, I can only make an educated guess as to what's going on here. So, do I have this straight? The car was driving fine before you took it in to get the belt changed? Now you've got it back it's not driving at all well and the check engine light is on? The garage told you the belt was 2 teeth out BEFORE they changed the belt? This would imply that it's now built back together with the cam timing either 2 teeth advanced or retarded when compared to how it was before AND the check engine light is on.

Charlie (varesecrazy) is entirely correct to say a "phonic wheel relearn" is often needed after a cam belt change - in effect this is an ECU reset to accommodate the new cam belt - but, although the check engine light is often lit when this is needed after a belt change, it doesn't seem to affect engine performance as long as the belt is correctly fitted.

First question is what year is the car. I'm assuming it's post 2012 as you're in this section of the forum? If so, and without being able to examine the vehicle, I can only make an educated guess at what's going on here but I'd put money on the belt being incorrectly timed. There have been a number of posts on this forum about how easy it is to get the belt on by at least one tooth out, especially on the newer engines - post 2011 - which have no timing marks on the cam sprocket and should be timed with special locking tools. It's possible to do the job without these tools but you need to be really sure the timing is correct before you start and familiar with the setup to get it right. I wouldn't be advising a home mechanic to try it without the tools unless very experienced.

So where do you go now? Well, I think, from what you are saying, that this is most unlikely to be sorted with a new sensor and a phonic wheel relearn (ECU reset). It needs to be established that the relationship between the crankshaft sprocket and camshaft sprocket is correct and this can only really be accurately checked by using the timing locking tools - which, I'm sorry to say, involves a considerable amount of dismantling so you can get at the crank sprocket and camshaft itself to install these tools (so the engine mount and belt covers also the cam cover all need to come off again) In this instance, where there is a big question mark over the timing, using the locking tools is going to be the only way anyone can be sure it's all set up right. Until it's absolutely certain that this timing relationship between the crankshaft and camshaft is correct and a phonic wheel relearn subsequently performed to reset the ECU could you then say with certainty that it's not the timing setup which might then be causing the CEL to illuminate and give you poor performance. If the timing was out by 2 teeth with the old belt fitted the car would have been driving very poorly before you took it in to them.

I assume they are going to look at the car for free on Saturday? If they start suggesting spending more money I'd be seeking a second opinion elsewhere.

So what do you think fellow forum members? This has got to be an incorrectly timed belt don't you think?

 

[varesecrazy]

@lukeedukee


IF it ran well for the last 3 years..
and drove to 'the mechanic' without issue a few days ago

Any 'Adjustment' to the timing raises concerns.. as it was obviously 'happy' before

Its far from uncommon for work to be undertaken without all the Kit..and knowledge


A friend spent more than your punto is worth with 2 separate garages ..

Due to them using 'half the tools' required to time his Diesel correctly.

A 3rd garage with the Standard AND Option timing tools did it properly



You need to take it back and get them to recheck their work.

Then IF its no better.. get them to give you a full written Statement of Parts changed.. work carried out etc


Get back to us either way

 

[s130]

I have to start by saying that, as I can't physically examine the car myself, I can only make an educated guess as to what's going on here. So, do I have this straight? The car was driving fine before you took it in to get the belt changed? Now you've got it back it's not driving at all well and the check engine light is on? The garage told you the belt was 2 teeth out BEFORE they changed the belt? This would imply that it's now built back together with the cam timing either 2 teeth advanced or retarded when compared to how it was before AND the check engine light is on.

Charlie (varesecrazy) is entirely correct to say a "phonic wheel relearn" is often needed after a cam belt change - in effect this is an ECU reset to accommodate the new cam belt - but, although the check engine light is often lit when this is needed after a belt change, it doesn't seem to affect engine performance as long as the belt is correctly fitted.

First question is what year is the car. I'm assuming it's post 2012 as you're in this section of the forum? If so, and without being able to examine the vehicle, I can only make an educated guess at what's going on here but I'd put money on the belt being incorrectly timed. There have been a number of posts on this forum about how easy it is to get the belt on by at least one tooth out, especially on the newer engines - post 2011 - which have no timing marks on the cam sprocket and should be timed with special locking tools. It's possible to do the job without these tools but you need to be really sure the timing is correct before you start and familiar with the setup to get it right. I wouldn't be advising a home mechanic to try it without the tools unless very experienced.

So where do you go now? Well, I think, from what you are saying, that this is most unlikely to be sorted with a new sensor and a phonic wheel relearn (ECU reset). It needs to be established that the relationship between the crankshaft sprocket and camshaft sprocket is correct and this can only really be accurately checked by using the timing locking tools - which, I'm sorry to say, involves a considerable amount of dismantling so you can get at the crank sprocket and camshaft itself to install these tools (so the engine mount and belt covers also the cam cover all need to come off again) In this instance, where there is a big question mark over the timing, using the locking tools is going to be the only way anyone can be sure it's all set up right. Until it's absolutely certain that this timing relationship between the crankshaft and camshaft is correct and a phonic wheel relearn subsequently performed to reset the ECU could you then say with certainty that it's not the timing setup which might then be causing the CEL to illuminate and give you poor performance. If the timing was out by 2 teeth with the old belt fitted the car would have been driving very poorly before you took it in to them.

I assume they are going to look at the car for free on Saturday? If they start suggesting spending more money I'd be seeking a second opinion elsewhere.

So what do you think fellow forum members? This has got to be an incorrectly timed belt don't you think?

Well as has been said. All was OK before the cam belt job so this has to be the key issue. If not a mechanical timing issue then the cam phase sensor has been damaged/moved. This can happen when general purpose camshaft sprocket locking tools are use and their fingers protrude to far into the rear of the sprocket(s).

Unlike older Fiats there are now little or no timing marks on more modern Fiats. Correct timing can ONLY be guaranteed if all the appropriate timing tools are used. Unless a small local garage are into Fiats then it is highly unlikely they have the correcting tools (of which there are quite a few with Fiat engines these days) so they will either a) purchase for the job b) rent or c) mark everything up and hope for the best.

 

[lukeedukee]

I have to start by saying that, as I can't physically examine the car myself, I can only make an educated guess as to what's going on here. So, do I have this straight? The car was driving fine before you took it in to get the belt changed? Now you've got it back it's not driving at all well and the check engine light is on? The garage told you the belt was 2 teeth out BEFORE they changed the belt? This would imply that it's now built back together with the cam timing either 2 teeth advanced or retarded when compared to how it was before AND the check engine light is on.

Charlie (varesecrazy) is entirely correct to say a "phonic wheel relearn" is often needed after a cam belt change - in effect this is an ECU reset to accommodate the new cam belt - but, although the check engine light is often lit when this is needed after a belt change, it doesn't seem to affect engine performance as long as the belt is correctly fitted.

First question is what year is the car. I'm assuming it's post 2012 as you're in this section of the forum? If so, and without being able to examine the vehicle, I can only make an educated guess at what's going on here but I'd put money on the belt being incorrectly timed. There have been a number of posts on this forum about how easy it is to get the belt on by at least one tooth out, especially on the newer engines - post 2011 - which have no timing marks on the cam sprocket and should be timed with special locking tools. It's possible to do the job without these tools but you need to be really sure the timing is correct before you start and familiar with the setup to get it right. I wouldn't be advising a home mechanic to try it without the tools unless very experienced.

So where do you go now? Well, I think, from what you are saying, that this is most unlikely to be sorted with a new sensor and a phonic wheel relearn (ECU reset). It needs to be established that the relationship between the crankshaft sprocket and camshaft sprocket is correct and this can only really be accurately checked by using the timing locking tools - which, I'm sorry to say, involves a considerable amount of dismantling so you can get at the crank sprocket and camshaft itself to install these tools (so the engine mount and belt covers also the cam cover all need to come off again) In this instance, where there is a big question mark over the timing, using the locking tools is going to be the only way anyone can be sure it's all set up right. Until it's absolutely certain that this timing relationship between the crankshaft and camshaft is correct and a phonic wheel relearn subsequently performed to reset the ECU could you then say with certainty that it's not the timing setup which might then be causing the CEL to illuminate and give you poor performance. If the timing was out by 2 teeth with the old belt fitted the car would have been driving very poorly before you took it in to them.

I assume they are going to look at the car for free on Saturday? If they start suggesting spending more money I'd be seeking a second opinion elsewhere.

So what do you think fellow forum members? This has got to be an incorrectly timed belt don't you think?

You are correct indeed. The car is a 14-plate fiat punto pop+ which isn't seen all that often. I guess it's more similar to an Evo than anything else. So the car was driving fine before the belt change but now the engine light is still on even after the phonic wheel relearn they did. I'll plug a fault reader into it as well before I take it to the mechanic to see what error it spits out. They were pretty damn certain it's been installed correctly as they assured me twice.

I might see what happens once the EML is cleared and then drive it for a bit. If the issue still persists then I would agree with you that the belt has most likely not been timed properly since limp mode is then ruled out. I will make it clear to them that I'm not planning on spending any more money with them until it is fixed. Overall though the garage has provided a very decent service over the years and had no issues with them but thank you for taking the time to help out, I appreciate it and I will take it on board.

Luke

 

[lukeedukee]

@lukeedukee


IF it ran well for the last 3 years..
and drove to 'the mechanic' without issue a few days ago

Any 'Adjustment' to the timing raises concerns.. as it was obviously 'happy' before

Its far from uncommon for work to be undertaken without all the Kit..and knowledge


A friend spent more than your punto is worth with 2 separate garages ..

Due to them using 'half the tools' required to time his Diesel correctly.

A 3rd garage with the Standard AND Option timing tools did it properly



You need to take it back and get them to recheck their work.

Then IF its no better.. get them to give you a full written Statement of Parts changed.. work carried out etc


Get back to us either way

I agree, I was just unsure once they fitted it because I didn't know if the ECU affected the acceleration to try and protect other components from getting more damaged. The engine light never came on in my car since I bought it so I wouldn't know.

I am sorry for your friend and I hope I won't fall into that situation. I might just tell them if all else fails, they'll have to put it back into the position that the old belt was in as I never had an issue.

Thank you for your time.

Luke

 

[varesecrazy]

Im sure it wont take much to restore 'normal service'

Do keep us informed

 

[lukeedukee]

Im sure it wont take much to restore 'normal service'

Do keep us informed

I will do, thank you. I will also post what the error is when I plug an error reader into it

 

[lukeedukee]

Alright guys.

So a miracle just appeared to happen. For a moment; the car drove as normal with the same acceleration as before. I test it on the dual carriageway and it went to 60 then 70 then 80mph perfectly. So it clearly can’t be a timing issue right? It has to be an ECU issue. Unless anyone else has any other ideas? The acceleration went from amazing to bad again and it switches between the two every 10 minutes or so.

Let me know what ideas you have

Luke

 

[varesecrazy]

Is the MIL on constantly..??

Remember.. it went that well ALL THE TIME before they moved the belt 2 teeth

 

[lukeedukee]

Is the MIL on constantly..??

Remember.. it went that well ALL THE TIME before they moved the belt 2 teeth

It is on constantly yes. I’ll try and do a reading today as well and let you know

 

[lukeedukee]

The error’s are as follows:

P0016 - Cam/crankshaft pos. correlation sensor A - Bank 1

P0340 - Camshaft pos. sensor A - Bank 1 circuit malfunction

 

[portland_bill]

The error’s are as follows:

P0016 - Cam/crankshaft pos. correlation sensor A - Bank 1

P0340 - Camshaft pos. sensor A - Bank 1 circuit malfunction

P0016 suggests the phonic relearn needs doing again, although if it is 2 teeth out now, that'll never correct itself with a relearn. The physical timing still needs checking with the correct tools.
P0340 appears to be the cam sensor either not sending a signal, or a signal the ECU is not happy with. Might just be a confirmation of the P0016, or could be a damaged sensor.

The wiring from the crank sensor clips into the cam covers, so is disturbed when the belt is changed. Check it at the tightest points for any obvious damage. Official method suggests removal of the crank sensor, to avoid damage, but usually they just fail completely if damaged.

It is good practice to also remove the cam sensor for the cambelt job, as it can be damaged if struck. Check it for damage, and its wiring too.

I'd still be checking the physical timing first though.

 

[varesecrazy]

I am reading the top fault as 'timing error'

Again something you didnt have before they shifted the belt.

Check the GP cambelt timing threads..is it the same error code?

 

[lukeedukee]

P0016 suggests the phonic relearn needs doing again, although if it is 2 teeth out now, that'll never correct itself with a relearn. The physical timing still needs checking with the correct tools.
P0340 appears to be the cam sensor either not sending a signal, or a signal the ECU is not happy with. Might just be a confirmation of the P0016, or could be a damaged sensor.

The wiring from the crank sensor clips into the cam covers, so is disturbed when the belt is changed. Check it at the tightest points for any obvious damage. Official method suggests removal of the crank sensor, to avoid damage, but usually they just fail completely if damaged.

It is good practice to also remove the cam sensor for the cambelt job, as it can be damaged if struck. Check it for damage, and its wiring too.

I'd still be checking the physical timing first though.

I don’t understand though why it’s performing really well one minute and then the other it’s performing like trash. Surely the acceleration problem would be permanent if there’s a timing issue.

Or is it truly just a sensor issue that’s stopping it from performing well? If the faults were cleared, do you think it would be fine? I’m just struggling to understand that one thing

 

[lukeedukee]

I am reading the top fault as 'timing error'

Again something you didnt have before they shifted the belt.

Check the GP cambelt timing threads..is it the same error code?

it’s just that error with the cam/crankshaft sensor. It’s also only one of the sensors that’s playing up.

See the previous post as I’m a bit confused to why it performs well one minute and the other it performs terribly

 

[Pugglt Auld Jock]

it’s just that error with the cam/crankshaft sensor. It’s also only one of the sensors that’s playing up.

See the previous post as I’m a bit confused to why it performs well one minute and the other it performs terribly

Damaged wiring to camshaft sensor? - easily done if you're a bit rough when teasing the loom out of the channel in the top cover. might be a wire broken inside the insulation which is sometimes making contact and sometimes open circuit? Crankshaft sensor dictates ignition timing whereas camshaft sensor modifies (fine tunes) it. A serious open circuit on the crankshaft sensor will likely result in a non running engine. Intermittent continuity to the cam sensor might explain your running well some of the time (contact made) and some of the time running poorly (contact broken or in a high resistance state.)

 

[lukeedukee]

Damaged wiring to camshaft sensor? - easily done if you're a bit rough when teasing the loom out of the channel in the top cover. might be a wire broken inside the insulation which is sometimes making contact and sometimes open circuit? Crankshaft sensor dictates ignition timing whereas camshaft sensor modifies (fine tunes) it. A serious open circuit on the crankshaft sensor will likely result in a non running engine. Intermittent continuity to the cam sensor might explain your running well some of the time (contact made) and some of the time running poorly (contact broken or in a high resistance state.)

Ah I see that makes a lot more sense. I’ll get them to check it next Saturday as I don’t really have the tools to check it personally. Thank you for the insight though as that clears a lot of things up.

Do you think it is still a timing issue in this case or do you think it’s more of a sensor issue or maybe an accident that happened during the timing belt change?

 

[varesecrazy]

Referring back to my friends 'hard to diagnose' car:

After a cambelt change

It got timing correlation errors (top vs bottom)

It had the timing checked : ' its fine '

Changed top and bottom sensors with new genuine parts ( no improvement)

Blamed the ECU...New ECU..

They were lost..??
I told him they were just throwing parts at it.. get a 2nd opinion


NEXT GARAGE : factory trained supposedly


timing : 'fine'

Bad ECU : Replaced.. then 2 more !!

Obviously ECU ok..it can only deal with what it 'sees'..


Sent to electrical specialist :

Called 20 mins later ..' its perfect electrically'...
'I will check the timing next'


1 hour later : 'Its fixed' I couldnt get the timing kit to line up at the time.. PHOTO..
SO shifted pulleys so tools now fit..

Now timed properly and no errors.'


Car has now been great for 6 months

It spent longer in 2 garages who couldnt time it correctly..!!

Back to your Punto:

You already know theyve changed the timing... and blamed a bad sensor


Get that '2 teeth' cleared up before spending ANY money...!!