rough idle after 2 minutes from cold start ??

Phelpsy24

Guest
I have recently bought a 2006 Seat Altea 2.0 TDI PD with a BKD engine.

The car starts perfectly and ticks over smoothly for approximately 2 mins before becoming very lumpy and rough whilst idling. The rough idle only stops after 5 mins driving when the engine warms up at which point car idles smoothly again. It drives faultlessly the whole time as long as your moving.

I have done a bit of research and am stumped ! I have read numeous threads with similar problems which have been fixed by changing EGRs, MAFs, adjusting timing, changing faulty pumps and injectors but none with exact same symptons as mine as it runs perfectly on start up and once warmed up.

There is no smoke from exhaust, the car has only done 37000 miles and has been serviced regularly (not by SEAT). I have tried an ' italian tune up' ( fun but didnt fix it !). I have borrowed a VCDS which shows not fault codes at all.

Anybody experienced same problem and know how to fix it ?? Any help much appreciated :)
 
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Phelpsy24

Guest
Took it to helpful VW specialist who ran diagnostics on the car. No fault codes came up but it was showing 'number 3 cylinder lazy in smooth running adjustment'.

He told me that SEAT may have done a 'campaign' to recall loads of 2.0 PD engines with faulty injectors.

Does anyone know if this is true and whether my car is likely to be covered by this now being 7 years old but only covering 37k miles ? Also, the car hasn't been serviced by SEAT so I suspect that will be used as a get out clause by SEAT.
 

cleverspoon

Active Member
Sep 17, 2011
686
2
don't know too much about that engine, but with the pd150 if one cylinder is out on the idle adjustment it can be due to low compression on that cylinder, and ive read of a few injector seals failing, causing low compression in the cylinder (as the pressure weeps out past the injector). try researching to see what symptoms faulty injector looms give, as these can be common to fail.

if you can get a compression test done this should indicate if you have low compression in cylinder 3 or if its an injection fault.
 

Phelpsy24

Guest
Thanks for the advice cleverspoon. Wierdly, the idles smooths out a liitle if I have the heated rear windscreen on ! Can't figure out how they are linked but must be somekind of an electrical fault ??
 

cleverspoon

Active Member
Sep 17, 2011
686
2
When you use electrical items/ ac the compressor/ alternator put strain on the engine at idle so the engine will compensate to maintain idle. You may notice revs pick up slightly when ac is on, im guessing it adds more fuel to maintain idle.
It may be a dirty injector, and as it opens up its ok, have you tried some injector cleaner? I usually mix it stronger than it says and go for a blast
 

cleverspoon

Active Member
Sep 17, 2011
686
2
Good shout on the flywheel, when you say rough idle do you mean rough as in loads of noise/ vibration or rough as in engine sounds like its missing a beat?
 

Phelpsy24

Guest
Tried out putting engine under electrical load and turned on aircon, radio, heated window and it seemed to work ! Idle was much smoother ;). Interested in trying some injector cleaner. I'm sure this thread has been covered but anyone recommend make of cleaner and is it harmful to seals and other components. I' ve read conflicting threads and none the wiser !
 

Merger18

Active Member
Jul 20, 2016
1
0
Do timing when car is warm and blanking plate to block off the egr did this to mine today and now perfect
 
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