2001 TDI Misfires when cold, lots of smoke

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Just finished getting this 2001 Jetta TDI Auto roadworthy for a friend of mine. 525000km, but it runs great with the exception of a cold start problem.. hoping to get some opinions/advice on.

After the car is warm, even luke warm after sitting for 3-5 hours, it fires up within a half a second on the starter and runs great. When cold, after sitting all night it starts within a half second, but misfires and smokes white (extreme smoke). The car will stumble, misfire, and smoke white some days only 30 seconds. Other days it will sit there idling for 5 minutes doing this. Start driving it and the symptoms clear up right away.

Ambient temp is 15*C or warmer in the mornings right now
Compression is 375-390psi on all 4 cylinders. Tested after the sitting for 3-4 hours (still luke warm, i guess)
Coolant temp sensor is new
Fuel temp, coolant temp and ambient temp are nearly identical on the scan tool after sitting overnight
Glow plugs are new, although shouldn't be needed at this temp
No trouble codes stored
Timing is perfect, slightly advanced on the graph. T-belt is new. Installed professionally
Injectors were swapped with a known good set (from my own car)
Fuel filter is new
IQ is about 4.6 when warm

The car has great power and drive ability besides this problem. I have been running diesel purge through it (undiluted) to see if something in the pump may magically clear things up. To no avail yet.

I guess I have only the pump to condemn now. Anybody have any other ideas?
 

kshaws21

Well-known member
Joined
Jul 11, 2014
Location
Georgia
TDI
2003 Jetta Tdi
Have similar issues myself, I hope someone clears this up for you. Mine smokes as you state on startup for 30 secs to two minutes then clears right up.
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Well I ran the engine on diesel purge yesterday.. and left the engine hooked up to the can of diesel purge (rather than the vehicles fuel system) while sitting over night. Started this morning, no misfire, zero smoke, even without the glow plug harness plugged in.

I'm going to drain the fuel filter and inspect the fuel pickup in the tank. This is a weird one!
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Well I think diesel purge is very easy to ignite, which clouded my diagnosis.

I did a cold compression test after sitting overnight and this is what I found:

Cylinder 1 - 320psi
Cylinder 2 - 400psi
Cylinder 3 - 380psi
Cylinder 4 - 400psi

Looks like cylinder #1 is my smoky misfire culprit.

Rebuild time..
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
Well, low compression lead me to take the engine apart. And upon visual inspection, all 4 rods were very obviously bent.
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
No. My friend bought the car with this problem. There was some pitting on the pistons, and previous owner told me it had a "new" turbo in the last couple years.

Maybe hydro lock, debris in the engine for sure (something caused the pitting), i'm not sure what exactly caused it.
 

BobnOH

not-a-mechanic
Joined
May 29, 2004
Location
central Ohio
TDI
New Beetle 2003 manual
Yea, it clearly had an "event" Too bad people can't fess up to this sort of thing, could of saved you a lot of trouble.
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
A set of used rods, new rings, a hone, con rod bearings, and cylinder head rebuild... starts like new.. even this morning at 5*C
 

Yblocker

Veteran Member
Joined
Sep 1, 2010
Location
Oakland, CA
TDI
1997 Passat
Nice.
Did you hone the cylinders in the car or did you pull the engine?
I just did a hone (deglaze) in the car and am waiting for for my cylinder head and pistons...
 

Mavrick

Veteran Member
Joined
Feb 16, 2012
Location
Ontario
TDI
2003 VW Jetta TDI
I did it in the car. You can remove 1,2,3 oil squirters but #4 there is no room, you have to be careful. I nicked mine with the hone, but it was minor and I was able to bend it back to the right position.
 

Trcoelho

Active member
Joined
Sep 8, 2014
Location
Saskatoon
TDI
Jetta MK4
Could you measure the piston heights top and bottom to determine if there are bent rods? If so, where could I find the correct measurements to compare mine to?
I have had a turbo blow on me, car has 350,000km, and I'm getting a fair bit of white smoke during engine warm up( partial due to over fueling).
All my cylinders have fairly low compression (300-350).
 
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