testing the turbo

[CJ]

I have a 1991 300d 2.5 and after reading a few forums hear, I wanted to make sure that my turbo is working properly. I have no reason to check this, other than the fact that after doing some reading, other turbo diesels are faster. My car does not leak or consume oil nor does it run rough, etc..
What do you think??

[SW]

I am not familiar with the turbo setup on your car, but the first thing to do would be to use a pressure guage and confirm that you have boost going to the manifold. Then, make sure the boost levels are within spec. Although I heard that the turbodiesels that came after the w123's had non adjustable wastegates. I could be wrong.

[CJ]

SW,
Silly question, but specifically how do I do this? Can I just hook up a test guage to the line into the turbo boost switch? I notice that on my friends 1984 300SD I can definately hear his turbo whistle when it spools up, but on mine I hear nothing. Any other testing procedures would be helpful.

[SW]

CJ,

There was a post in the Tech Help back in November by a guy named Richard Easley, he provided a link to his sight that tells you how to check your boost. Do a search for his posts or a search or "boost check" and you should find it. However, the procedure he has is mostly for 617 turbo engines. But I am sure it should help you get started. Good luck and keep us posted.

Hello CJ,

I do not think we are supposed to hear anything. On my 124 300D 2.5, the turbo works but I do not hear anything. I think its because the newer diesels are better designed.

[CJ]

Thanks. I did go ahead and clean out the turbo boost valve as recomened in this site listed below, but I did not clean the black box.

Check out this guys 2.5!!!

http://www.mindspring.com/~houlihan/merc/banjo.htm

http://www.mindspring.com/~houlihan/mb.htm

[engatwork]

Really good job on the links.
Jim
'95 E320
'97 Honda CRV