low boost when engine hot

[sfedek]

Originally Posted by Evert

Good news, I've found the problem. It's the EGR gasket, or the lack there off.

I've disconnected the vacuum line to the EGR and now it runs fine. My explanation is as following:
When the engine is cold, the EGR stays closed, so it runs like normal
When the engine gets warm, the EGR valve opens. Exhaust gas now takes the path of least resistance and blows out through the gap where the gasket is supposed to be. This means less exhaust to the turbo resulting in less turbo spool, meaning less boost, resulting in a shitty running engine.

The warmer the engine gets, the more the EGR valve opens and the shittier the engine runs.

Good news Evert.

Eddy

[layback40]

Originally Posted by Evert

Mate, if you want to be scared with what can go wrong on your VM, just search for all the other threads that I have started so far.

To date I have had to:
- Replace all four cylinder heads
- Replace the starter motor
- Replace the vacuum sensor
- Replace the diesel primer pump
- Replace pushrods after I bent one
- Replace the power steering lines
- Replace the number 1 injector that has the built in sensor
- Replace the coolant hoses on the waterpump


All of these were due to problems that I couldn't pinpoint straight away and took me quite some time to identify and fix.

I'm getting close to the point of taking my car to the wreckers and asking them to crush it or schred in from if me, just to make me feel better...

Does not sound good.
If you sold it, the new owner would probably get a very good jeep. Every thing that could go wrong has been fixed.
The only thing on your list I have done is to remove the starter as the connection from the solenoid to the field was loose. PITA of a job to get it out !!

[amlav]

That is good that you finally found the problem.
As far as I remember there was a suggestion to replace the EGR gasket (as it was found out by your friend that part of it was blown.)
Just to show you that sometimes is easier to start with the obvious signs.
Cheers,
Andrei

[Deezelweazel]

Congratulations to you Evert.
Now put an oil cooler on it and drive that thing!