Hi all,

 

looking for some suggestions on what to do next on my vRS.

The cars started juddering quite badly on idle. 
it started off by pulsing but now nearly does it constantly, but only when the engines cold. Once up to temp, seems to smooth itself out.

I first noticed it after it had the clutch and DMF changed a few months back.

 

list of things I’ve had done recently -

DMF and clutch

Genuine timing belt

EGR clean

changed thermostat and coolant temp sensor

New aux belt as last one snapped

 

The car smokes quite badly for a standard car (bar a straight through and FMIC), black smoke under heavy load.

 

any suggestions on what else I should look at?

I’ve seen an injector loom could cause lumpiness, bought I would’ve though that’d happen all the time, not just when cold?

happy to be proved wrong though, cheers!

I'd check the torsion value since you've had the cambelt changed recently, I suspect the timing is out slightly.

16 minutes ago, sepulchrave said:

I'd check the torsion value since you've had the cambelt changed recently, I suspect the timing is out slightly.

Thanks for the suggestion, I’ll ask my mech to see if he can check that when it’s in next. Would you expect it to stop juddering when warm if the timing is out?

12 minutes ago, mothyw1998 said:

Thanks for the suggestion, I’ll ask my mech to see if he can check that when it’s in next. Would you expect it to stop juddering when warm if the timing is out?

 

PD engines are incredibly sensitive to timing. You can also replace the ECT sensor since they're cheap to do.

3 hours ago, mothyw1998 said:

I first noticed it after it had the clutch and DMF changed a few months back.

 

list of things I’ve had done recently -

DMF and clutch

Genuine timing belt

EGR clean

changed thermostat and coolant temp sensor

New aux belt as last one snapped

 

The car smokes quite badly for a standard car (bar a straight through and FMIC), black smoke under heavy load.

 

 Could you supply a timeline starting with when you bought the car, how did it run then, how long did you own the car before the issue started, when the above items of maintenance were carried out especially relative to each other, who fitted the straight through and FMIC (unsure why this would be done on a standard engine). Are you sure it has not been mapped especially as with the old EDC15 ECU a cheap generic Ebay or similar "tuned" map can be uploaded at home.

Strange that the issue started before the clutch and a new DMF were fitted, but the issue has developed after this.

 Has it been scanned with VCDS or another VW specific scanner. It is possible with EDC15P programme to read a downloaded map and run a power curve to identify expected power.

38 minutes ago, KeithCheetham said:

 Could you supply a timeline starting with when you bought the car, how did it run then, how long did you own the car before the issue started, when the above items of maintenance were carried out especially relative to each other, who fitted the straight through and FMIC (unsure why this would be done on a standard engine). Are you sure it has not been mapped especially as with the old EDC15 ECU a cheap generic Ebay or similar "tuned" map can be uploaded at home.

Strange that the issue started before the clutch and a new DMF were fitted, but the issue has developed after this.

 Has it been scanned with VCDS or another VW specific scanner. It is possible with EDC15P programme to read a downloaded map and run a power curve to identify expected power.

Thanks for the response! 
 

A big point I did miss out was that it had a new turbo a few months back too.

 

I bought the car last august and it ran spot on, however was still quite smokey. I was the 2nd owner on 81k so car was none standard and owned previously by a more elderly person who looks to have done around 5k a year.

 

was serviced a few months back, new fuel filter, air filter, oil etc. 

 

turbo was done first last august, got it back and it ran fine, however still Smokey. Then started getting a judder in 6th and revs shot up on accelerating so new DMF and clutch put in around February which sorted that issues. Then the standard SMIC started popping off and all the pipes were done for, so decided to stick a FMIC on to stop the issues with the SMIC.

 

I changed the fuel filter around the same time I had the clutch changed, not sure if something there could’ve been done wrong or a dodgy filter installed?

 

Ill be getting it booked in with my mech to take a look, but just a bit confused by it as it only happens when cold engine. 
 

Id suspect timing due to have a cambelt change, but again only happens when cold so would’ve thought it’d do it both hot and cold.

 

I have thought about sticking a new loom in, but would’ve thought that’d bring up an engine light?

 

I’ve got a new fuel pump relay fuse coming, as was getting an intermittent code for that

 

cheers!

Check that the fuel temperature sensor was reconnected properly when the fuel filter was changed, it's in the top of the filter housing I think. It may also have failed leading to overfuelling and wouldn't throw  code like the ECT sensor wouldn't. If in doubt replace them, they're cheap parts.