My '81 240D has 238K miles on the original engine. When starting, it blows blue smoke for a few minutes until some heat builds up, then goes away.
I've taken a compression test (after it has warmed up) and the cylinders register from 350-410 PSI (24.5-28.5 bar). I have not adjusted the valves yet. I bought the car about 2 months ago and don't have previous service records. There is also a lot of blow by when I undo the oil cap too.

From the research that I've done, the compression seems to be OK?

Does this sound like a valve seal problem? And if so, can the valves be remedied without pulling the head off the motor? And are there any special tools needed to service the valves for this problem?

Thanks,
Andy

 

The compressions looks OK, but not great.
Engine purge would be the first thing I would do.
Valve adjustment never hurts, although I don't think some misadjustement would cost excessive smoking.

 

Sounds to me like a leaky injector....

 

I thought BLACK smoke was an indicator of FUEL/injector problems? Mine is BLUE smoke, which to my understanding is OIL burning?

Andy

 

It can look BLUE if it is un-burned fuel. Sometimes the injectors will bleed down overnight causing excess fuel in the cylinder. When you startup it will smoke like crazy. I don't know how to check it other than smelling it.

 

stupid question from a stupid newbie


what to you mean about a engine purge?


purge the fuel lines at the injectors??

if so what would this help

Thanks

Higgins

 

I had a similar issue with my '82 240 until I replaced my glowplugs. The new glowplug kit (Bosch) came with an updated version of the glowplug relay which heats the system for a longer time before cranking, then keeps the plugs lit for a short while after the engine has fired to help reduce fuel smoking. Solved my problem nicely. Might be worth a try if it's been a while since you serviced your glowplug system, and it certainly beats tearing your engine apart. Good luck.

 

defeinately a fuel supply problem.

 

purge refers to using chemical solvents to try to clean up the pump, injectors etc. look at dieselgiant.com for more info. regards, hugh