Lumpy Start When Cold - Not Glow Plugs
 

So, here we go, next challenge team!

2008, Mk 3 D5. Approx. 100k miles.

When starting from cold, lumpy and when very cold reluctant bit still goes. Once warm, no noticeable issues.

All glow plugs replaced and symptoms did not change one bit.

So, any common faults?

I haven't tried injector cleaner yet - any success stories and recommendations as to which one to use?

Thanks in advance.

Do a leak off test?

When was the fuel filter last changed?
When was the oil last changed and what spec and viscosity oil did you use?

Fuel filter done about 10 months ago as was oil and air filter. Using SHELJ Helix 0w-30 as specified.

Going to run some Forté through it next week and see how that goes.

Not done a leak off test, I guess that will be next.

What colour is the exhaust smoke when it's cold? Is there more of it than normal (ie hot)? There will be some steam when cold as it burns off condensation in the exhaust etc so please ignore this bit and concentrate on the smoke.

Also what does the engine sound like? Is it "extra clattery" above what it used to be when cold or is there a sharp knocking noise?

Was it a gradual onset or did it happen overnight?

My P2 D5 was occasionally lumpy on start up . It was the hydraulic valve adjuster letting by while standing overnight. The lumpy-ness was accompanied by a tappet rattle for a few seconds then all was ok . As it had done 150k + I started using 10w-30 oil and it was fine from then on . One thing about that engine is that the oil stayed very clean , not the usual black diesel soup. I used to keep some back for use in a lawn mower . Positive re-cycling :teeth_smile:

Hi. My car is a 08 xc70. We have had it 8 years and it does exactly the same thing as yours. We have the glow plugs checked and they are all okay. Never got to the bottom of what it is but it run no problem once it is running. It does irritate me why it does it.

Thanks David. I suspect it’s the injectors but can’t be sure without replacing them or checking them at a diesel specialist. Have you looked into this?

I has your always done it?