Cam belt out of timing

b****rlugs said:
My 1.4 petrol had all the above and a throttle body clean and VCDS adaption cleared them. Not now seen for a 1000 miles or so. Good luck with the diagnosis.
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My first suspiction was the throttle valve. I did a thorogh clean of the throttle valve and made vcds adaptation. Replaced all gaskets. No change. Still jerking. I also switched to another used and cleaned throttle valve (vcds adapted after mounting on the car) There was no change at all. The car was still jerking. I guess it is nothing wrong with the throttle valve in my car.
 
BJohan said:
The car is like jerking at light throttle. It is impossible to run at constant speed. It starts to jerk and the only way to make it stop is to accelerate or take the foot from the throttle. If you don't do this it's jerking like crazy and sometimes the instrument panel lights starts to flash ABS, EPC and beeping a warning sound. Sometimes it goes into limp mode so you cannot rev more than 1200 rpm.
View attachment 64665
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Just a thought, when I had EGR problems (exhaust gases leaking into the intake system) on another Audi, the car behaved just like that.
In your case I would correct the timing first just to be able to exclude that from the list, even though just one tooth out of sync would hardly cause this much problem I would have thought.
 
Joga said:
Just a thought, when I had EGR problems (exhaust gases leaking into the intake system) on another Audi, the car behaved just like that.
In your case I would correct the timing first just to be able to exclude that from the list, even though just one tooth out of sync would hardly cause this much problem I would have thought.
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Did you get any error code? Can I just take away the electrical connection to the EGR to test if this is the fault? I guess there would be some error code, but would that close the EGR?

I already have replaced the EGR with a new one (not oem). I also adapted the EGR.
 
I also had a similar problem with a 1.4 petrol. Kept getting an air leak detected fault code. Tried all the usual things like egr valve, checking hoses for splits etc. I finally went to a specialist who used a smoke tester and diagnosed a leaking inlet manifold. We replaced it with a secondhand one. Whilst under the car, we also noticed an oil leak which was a split in the oil filler pipe. Both of these were the source of the air leak and cured the problem. My advise would be to engage the help of a specialist with a smoke tester, as you can spend ages trying to hunt down air leaks.


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Davidkinton said:
I also had a similar problem with a 1.4 petrol. Kept getting an air leak detected fault code. Tried all the usual things like egr valve, checking hoses for splits etc. I finally went to a specialist who used a smoke tester and diagnosed a leaking inlet manifold. We replaced it with a secondhand one. Whilst under the car, we also noticed an oil leak which was a split in the oil filler pipe. Both of these were the source of the air leak and cured the problem. My advise would be to engage the help of a specialist with a smoke tester, as you can spend ages trying to hunt down air leaks.


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Amazing. A split in the oil filler pipe can cause air leak? Thanks!
 
BJohan said:
Did you get any error code? Can I just take away the electrical connection to the EGR to test if this is the fault? I guess there would be some error code, but would that close the EGR?

I already have replaced the EGR with a new one (not oem). I also adapted the EGR.
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In my case it was a car without electronics (old one) so, no error codes.
Sorry I dont know in which position (open or closed) the valve is in when not electrically connected.
 
BJohan said:
Hello guys!
This is my first thread in this forum. I am from Sweden so forgive me if my english is not perfect. I have an Audi A2 2001 with petrol 1.4 engine. I bought it very cheaply because it had a lot of faults. I was hoping I could fix it for my daughter who recently took her drivers license. I have spent a lot of time fixing everything and trying to find out whats is wrong with the engine. It is running badly (surging) on low throttle at constant speed. I also hesitates when you start from a traffic light. At high revs and speed and during accelleration it runs fine. There were two error codes intermittently for the oxygene sensor after the cat (now replaced) and 17961 (Barometric / Manifold Pressure Signals: Implausible Correlation). I have replaced a lot of sensors, ignition coil, spark plugs and cleaned the throttle body. Replaced EGR and even tried swapping to another throttle body and gas pedal sensor. I have cleaned the crank house ventilation and replaced the rubber hose. Replaced canister valve, intake manifold pressure sensor, cam speed sensor, crankshaft speed sensor, knocking sensor, new intake gaskets and injector gaskets because I thought it was some vacuum leak. I have also calibrated the throttle body with VCDS. Still it runs like crap.

A few days ago I checked the cam belt timing, and it was out of timing! Maybe this is the main cause? It seems like it has slipped a tooth. I knew I had to replace the cam belt soon, but my strategy was to get the motor running well first. The belt has never been replaced during 250 000 km (155 000 miles). Now I am afraid that the slipped cam belt may have caused damage to valves or pistons. I did a compression check and it was perfect. The engine is ticking rather heavily but I thought that was due to a bad hydraulic lifter.

Now to my question; Do I just replace the cam belt and set the timing right, or do I have to take the head off and check the status of the valves and pistons? Can the motor survive slipping a tooth on the cambelt without damage?
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I've had similar problems when I bought my A2 1.4 petrol. It run badly (surging) up to 2000rpm, over this rpm it run ok but never a fault code.
The cam belt had been replaced recently before I got it. After some time it needed a new head gasket.
I then discovered that the exhaust cam shaft where one tooth wrong in alignment to the inlet cam shaft.
Now it runs perfect with no surging and a perfect idling.
 
I have replaced the cambelts now. Both belts were out of synk. The short belt connecting inlet and exhaust camshaft was not synked. The short belt looked rather new so I suspect it has been replaced before incorrectly. Also the long belt was out of synk with the inlet camshaft. (Who did this? I hope it wasn't a workshop charging money) I used a special tool to connect the inlet and exhaust camshafts during replacement, to be absolutely sure about the timing. Now the engine starts much easier and idles very steady (before it was vibrating and could stop during idling). The engine feels also more powerful and is easier to drive. 90 % of the jerkyness is gone, but a some are unfortunately still there at low throttle and constant speed. There are no error codes and I have already replaced almost every sensor you can replace including new EGR valve (adapted). The Throttle body is cleaned and adapted with vcds. New coil and spark plugs. I earlier also replaced the TB with a used one and it was no difference. I even replaced the throttle pedal with no difference.
Any suggestions? I can live with the car as it is now, but it would be nice to have it running really smoothly.
 
I found on my 1.4 petrol if you disconnect each coil pack one at a time and undo the wiring harness so you see all 4 wires mine had splits in them so you could see bare wire. I got a heat shrink kit and covered them up it's now running a lot better. Might be worth a look.
 
BJohan said:
What do you mean? Please explain.
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How old is the exhaust (they last a long time, but not for ever)?

When I purchased my AUA 1.4 four years ago, it was just under 70k miles and the exhaust was seriously choked up. I replaced the whole lot, and the car drove like new again.
 
Graham2704 said:
I found on my 1.4 petrol if you disconnect each coil pack one at a time and undo the wiring harness so you see all 4 wires mine had splits in them so you could see bare wire. I got a heat shrink kit and covered them up it's now running a lot better. Might be worth a look.
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steve_c said:
How old is the exhaust (they last a long time, but not for ever)?

When I purchased my AUA 1.4 four years ago, it was just under 70k miles and the exhaust was seriously choked up. I replaced the whole lot, and the car drove like new again.
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Mine is at 250 000 km (15 000 miles). I have no idea if the exhaust is replaced. Can you test it in some way?
 
BJohan said:
Mine is at 250 000 km (15 000 miles). I have no idea if the exhaust is replaced. Can you test it in some way?
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It's not exactly easy but here you go:

There are three elements that cause excess constriction inside the exhaust. The first is carbon build up, which can often be cleared by driving consistently in a lower gear than normal, and preferably over long journeys. With mild steel exhausts, the second is rust, which is a curse, particularly with petrol engines used mainly for short journeys. And finally there's deterioration of the catalytic converter, with a variety of causes.

A deteriorating exhaust will increase fuel consumption, and the engine will have less power, particularly at low RPM.
 
Can bad lifters cause the engine to jerk? At least one lifter is ticking quite hard. Can this affect how the engine runs?
 
steve_c said:
It's not exactly easy but here you go:

There are three elements that cause excess constriction inside the exhaust. The first is carbon build up, which can often be cleared by driving consistently in a lower gear than normal, and preferably over long journeys. With mild steel exhausts, the second is rust, which is a curse, particularly with petrol engines used mainly for short journeys. And finally there's deterioration of the catalytic converter, with a variety of causes.

A deteriorating exhaust will increase fuel consumption, and the engine will have less power, particularly at low RPM.
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Steve, how do you diagnose this as a fault?
 
BJohan said:
I have replaced the cambelts now. Both belts were out of synk. The short belt connecting inlet and exhaust camshaft was not synked. The short belt looked rather new so I suspect it has been replaced before incorrectly. Also the long belt was out of synk with the inlet camshaft. (Who did this? I hope it wasn't a workshop charging money) I used a special tool to connect the inlet and exhaust camshafts during replacement, to be absolutely sure about the timing. Now the engine starts much easier and idles very steady (before it was vibrating and could stop during idling). The engine feels also more powerful and is easier to drive. 90 % of the jerkyness is gone, but a some are unfortunately still there at low throttle and constant speed. There are no error codes and I have already replaced almost every sensor you can replace including new EGR valve (adapted). The Throttle body is cleaned and adapted with vcds. New coil and spark plugs. I earlier also replaced the TB with a used one and it was no difference. I even replaced the throttle pedal with no difference.
Any suggestions? I can live with the car as it is now, but it would be nice to have it running really smoothly.
Click to expand...
Just out of general interest, would you happen to have any pictures eg from the sync tool and the job itself?
 
Here are some pictures
IMG_9202.jpg

IMG_9203.jpg

IMG_9201.jpg
 
I disconnected the cables to the EGR valve and the engine runs perfectly! Even though I have a new EGR valve there must be something wrong with it. A mechanic said it has to be a Pierburg original EGR. Nothing else works. My EGR is not Pierburg. Can that be the problem? Do anyone have experience from another brand of EGR?
Now the check engine light is on so I guess it will not pass MOT without an EGR. Should I replace it with a Pierburg?
 
Yes it must be a genuine egr valve
Have you adapted the new egr to the car, this is absolutely needed but unlikely to work if not a genuine egr valve

Paul


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