Not enough boost! - PeachParts Mercedes-Benz Forum

bgkast · #1 06-05-2007, 04:29 PM

I am starting a new thread about this boost problem...

Quote:

Originally Posted by Bajaman

Sorry to high jack this thread, but I have the opposite problem. I can't get over 10 psi with the wastegate disabled. The shaft seems to spin freely. A little lateral play and undetectable axial play. So besides a stuck wastegate is there anything else to look for? Do mufflers ever get clogged?
(82 300td fed)
bb

I have the same problem as you on my turbo'ed 240D. I get 8-9 psi normally, and 12 if I disconnect the wastegate hose. I also have a free spinning turbo with no unusual play. I also suspect the wastegate and plan to remove the cover and see if the shaft can be moved. If it seems OK I will replace the spring with a spare. It seems possible that carbon build up could be preventing it from closing fully. I don't think the muffler is to blame (I have a straight pipe on mine).

Anybody have any other suggestions?

Thank you.

Caduceus · #2 06-05-2007, 04:36 PM

Stuck open egr?

Bajaman · #3 06-05-2007, 04:51 PM

Quote:

Originally Posted by Caduceus

Stuck open egr?

I thought of that too, so I blocked it off. No change.
bb

Caduceus · #4 06-05-2007, 04:54 PM

Where are you guys measuring boost from?

bgkast · #5 06-05-2007, 06:19 PM

Quote:

Originally Posted by Caduceus

Stuck open egr?

What EGR?

My boost gauge is "T"ed into the ALDA line just before the ALDA.

Brian Carlton · #6 06-05-2007, 07:23 PM

I decided to throw in the towel and get a boost controller. Enough of the variation in boost all the way up to maximum.

Set the controller for 11 psi and be done with it.

bgkast · #7 06-06-2007, 12:50 AM

Quote:

Originally Posted by Brian Carlton

I decided to throw in the towel and get a boost controller. Enough of the variation in boost all the way up to maximum.

Set the controller for 11 psi and be done with it.

I got a ebay ball and spring boost controller and installed it with no noticeable change in boost even with it tightened all the way up. That is when I tried running without the wastegate hose attached and found I could only hit 12 psi with the wastegate disabled.

Bajaman · #8 06-06-2007, 08:51 AM

Quote:

Originally Posted by bgkast

I got a ebay ball and spring boost controller and installed it with no noticeable change in boost even with it tightened all the way up. That is when I tried running without the wastegate hose attached and found I could only hit 12 psi with the wastegate disabled.

This is exactly what I did (except I made my ball and spring controller), and I can only get 10 psi. sans wastegate hose. Maybe I'll find time this weekend to take the wastegate apart.
bb
ps Boost is measured from a port in the intake.

winmutt · #9 06-06-2007, 02:41 PM

Overboost solenoid is removed right?

bgkast · #10 06-06-2007, 03:19 PM

Check.

winmutt · #11 06-06-2007, 05:03 PM

Quote:

Originally Posted by bgkast

Check.

For SNG put the boost gauge right into the port on the manifold. Just to remove it as an issue. Also have you checked for leaks? I would go through the externals before looking at internals.