# E87 120D cold start and coolant problem



## rinzE87 (Mar 5, 2021)

Hi guys,

2005 E87 120d M47

Symptons are:

VERY hard to start when engine is cold (15-20 seconds paired with white smoke and diesel smell)
High pressure in Coolant after only a minute or less after cold start.

(I have no history on this car myself so don't know when the problem started and if there is a correlation)

First the cold start problem:
-Glow plugs are new and tested for proper resistance
-No glow circuit related codes/errors

It takes about 15-25 seconds for the car to start when cold. Cold starts are paired with a lot of white smoke and diesel smell.
Once it's warm it starts okayish, in my opinion it could be better but it start within 1-2 secs.

So my first thought was that the coolant pressure and hard cold start are related because of a head gasket problem. Since loss of compression would cause hard starting and would also explain the pressure bluid in the coolant system BUT..

Compression on all Cylinders checked out: 300psi/20bar on all 4 on a cold engine

Coolant system:

So far I replaced the thermostat, radiator and ET cap.
No signs of coolant in oil or oil in coolant

Also the coolant system holds pressure when tested on 17PSI for at least half an hour and drops only a couple PSI overnight. This would rule out any leaks from the head gasket and EGR cooler. I flushed the coolant and used the proper bleeding method when filling it up.
I do seem to have air in the system every morning and when I run it with the expansian tank bleeder screw open it keeps giving air bubbles. I find it hard to believe that this air is still just air pockets being trapped in the system. I've bled it for hours now.. But there is no sign of leaks or combustion gasses pressurizing the system.


I'm a bit lost so I hope you guys have some suggestions!

Cheers


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