Car shaking when Cranking the engine disappears when warmed up..

Richie_0000_

Registered User
Joined
Jul 8, 2015
Messages
13
Reaction score
0
Points
1
Hi all!

New to the forum and wondering if any of you could help.

I have an audi a4 b7 2.0tdi (140) which iven owned for a few months. Great car but ive noticed that when I start the car in the morning when the engine is cold the car shakes quiet badly whilst cranking then the starter catches the flywheel and it starts with a puff of white/blueish smoke then everythings fine. strangely enough if i start the car let it run for a minute but not fully warm then start it again it still shakes whilst cranking and keeps starting this way untill the car has reached 75-90'c. Once its reached that temperature when i turn it off and start its perfect no shaking whatsover. Now i dont think this car was regularly serviced as the fuel filter was really dirty as was the air filter so i changed them both a while ago made a difference to the pick up but still have the starting issue. Then I thought it could be the glowplugs so had it scanned with vagcom and two of the glowplugs where at fault. changed all four hoping it would fix the problem but it was still the same. Now when i changed the old fuel filter i poured out the diesel that was in it into a glass jar and it looked like there was oil floating at the bottom of it so thinking maybe the fuel is contaminated with oil, tandem pump? I ran liqui moly through the injectors and the moly that was returning from the engine was nearly black very dirty so dont know if its just soot from the injectors or not. Im thinking maybe valve stem seals but would the initial start not clear the oil straight away and wouldnt affect subsequent starting? It definately seems to be temperature related. There seems to be some blow by from the oil filler cap smoking and what not. dont know if the two are related tho. As ive said no drive-ability problems just the starting.
Any help will be much appreciated as im at a loss!
Thanks
Richie

 
Just a guess here but maybe try changing your coolant temp sensor or fuel temp sensor. I've heard these can cause some temp related running issues and also escape vcds scans even when faulty.
 
Thanks for the reply SDHa4Sline, yeah I was thinking of changing the cool temp sensor cuz its a cheap part to replace. ill try that next!
 
I'd do them both tbh, both reasonably cheap parts and at least you could rule them out. Good news is fuel temp sensor is a piece of **** to get to, bad news... the coolant temp sensor is a real bitch to change!
 
  • Like
Reactions: Richie_0000_