Technical Engine issues after cambelt replaced

[Geostanton]

Hey guys, my fiat is giving up on me.

I had the cambelt replaced two weeks ago as it was due (I was not having any issues with the engine before). The first time I drove it after being replaced, I started to lose speed and it began jolting forward when I slowed down to pull over. The engine light came on but after switching the engine off and then back on, it started as normal.

I took it back and they were unsure what had happened and no fault had been registered. It had been heavily raining so this was mentioned as a cause as it had been sat for a while (I was on holiday when it was fixed).

It has happened again today, this time while on a dual-carriageway (scary). Fortunately, I turned it off and on and it drove as normal again.

Anyone have any idea what could be causing this? I’m nervous that as it drives as normal, I’ll take it back and think it’s been fixed, only for it to happen again somewhere I can’t pull over.

 

[varesecrazy]

Probably only did half a job on the Cambelt change..
They have to plug it in so the sensors get the new belt timed correctly

See this post from @AppleFarmer

Fiat 500 1.2 8V timing belt replacement / error code P0016-76 | FIAT 500 (2007+)

Hi. I replaced the timing belt on our 2016 Fiat 500 1.2 8V (VVT-engine). I've replaced timing belts before, but not on any cars that have VVT. I used the locking tools to lock the crank and cam (valve cover off). I had downloaded the instructions from AutoData. The instructions did not mention...

www.fiatforum.com

 

[John202020]

Most probably the belt/timing is out take it to a Fiat dealer, honestly

 

[chris3234]

Definitely would say belt has been installed incorrectly properly. Atooth or 2 out given the power issues

 

[puntodeltathema]

As others have said, this engine (or rather the engine management) is quite sensitive to not being timed absolutely correctly (some of the "correct" timing tools can also be problematic in use), and a "phonic wheel" relearn is a must, with the procedure being executed before the engine is started for the first time after the belt change, and followed absolutely to the letter (e.g in Multiecuscan software).

Another common issue is to forget the replacement of the 4 O-rings in the cam cover which are part of the oil supply circuit to the variable valve timing variator. That will throw up certain errors (and in my experience does tend to give jolting and hesitation). And if your engine light has been on, there should be codes stored.

Unless your garage is the kind to take advice, it may be best to take it to a Fiat specialist.

 

[vexorg]

Most probably the belt/timing is out take it to a Fiat dealer, honestly

That's quite a costly option, not sure I'd recommend that. Many other garages wont be keen on fixing someone else's problem, I'd suspect they'd say they want to redo the whole belt replacement.

 

[Geostanton]

As others have said, this engine (or rather the engine management) is quite sensitive to not being timed absolutely correctly (some of the "correct" timing tools can also be problematic in use), and a "phonic wheel" relearn is a must, with the procedure being executed before the engine is started for the first time after the belt change, and followed absolutely to the letter (e.g in Multiecuscan software).

Another common issue is to forget the replacement of the 4 O-rings in the cam cover which are part of the oil supply circuit to the variable valve timing variator. That will throw up certain errors (and in my experience does tend to give jolting and hesitation). And if your engine light has been on, there should be codes stored.

Unless your garage is the kind to take advice, it may be best to take it to a Fiat specialist.

I forgot to mention that when the engine light comes on, it is flashing. I took it back again today and the code still hadn’t been stored.

When I mentioned the flashing, they said that they think it is spark plugs or coils rather than the belt? I’m a bit hesitant to change these incase they aren’t causing the problem

 

[varesecrazy]

I forgot to mention that when the engine light comes on, it is flashing. I took it back again today and the code still hadn’t been stored.

When I mentioned the flashing, they said that they think it is spark plugs or coils rather than the belt? I’m a bit hesitant to change these incase they aren’t causing the problem

So..,

You've had a few replies, all reinforcing the same basic message

To do this task correctly, you need access to both mechanical locking /timing tools

AND electronic kit to teach the ECU/ engines brain the new positions of components

What kind of garage have you used..?

Do you think they have access to this equipment..

 

[puntodeltathema]

A flashing light points towards the phonic wheel relearn being needed. (This learns the relative positions of the camshaft and crankshaft rotary sensors with the new cambelt). Procedure is to disconnect the battery for a decent period - at least a few hours or overnight - then without starting the engine but with ignition on and scanner (e.g. Multiecuscan (MES) connected), clear any fault codes which are present. Then start the phonic wheel relearn procedure (this will make the engine light flash constantly), start the engine, do not touch the throttle pedal until the engine has reached working temperature (the exact temperature is stated in MES, think it is 80 degrees from memory), then rev smoothly up to 6000 rpm and let it return to idle. Repeat twice. After the third time the flashing light should go out. (If not, try it again). Let the engine idle for 10 seconds, switch off, wait 60 seconds, then restart. All should be OK...

If you have any unclearable (red) errors then this procedure won't work (not least as the engine won't rev to 6,000 rpm in limp mode), and if a "cam-crank correlation" or "camshaft assembly position" error is present and isn't clearable, that suggests the timing is too far out to be "learned", and will need to be reset mechanically e.g. using the correct locking tools. Once that's done, the relearn procedure can be carried out.

If you have someone near you with MES (see the register on this forum) they may be able to help without trying to coax your garage into doing all this...

 

[vexorg]

If the timing was out, or cam sensor upset (btw you don't need the electronic part for timing belt), then would the engine die?

Any decent ecu would go into safe mode or limp mode, with basic settings to keep the engine running in a reduced manner.