EGR hissing air

[Micko66]

Hi All,

I've recently picked up a '95 6G74 24 valve GLS Paj as a project for my son and I. It's clean and straight and fairly unmolested with 316,000 k's.

My previous Paj was a NH GLS, 6G72 12 valve with a Magna engine I swapped into it.

This "new" one has a few issues, tach doesn't work, clutch slips and a few other minor things.

One thing at a time.

There is a very definite air hissing sound coming from where the end of the EGR diaphragm arm opens at the inlet manifold. (see pic) Is this normal?

The engine doesn't idle well and seems to be lacking power.



Micko

[Micko66]

Or is it perhaps not an EGR system?

[TimTams]

Seems like a vacuum leak. That'll cause the rough idle for sure... I'd be looking to pick up a replacement EGR from a wrecker.

[Micko66]

After some more investigation it seems that the 24 valve 6G74 has dual length inlet tracts. That diaphragm controls butterflies in the inlet manifold that switch from the longer inlet tracts (for low end power) to the shorter inlet tracts (for high end power).

Does this seem right?

And has anyone else experienced a leaking butterfly bush at the front of the manifold?

[stumagoo]

yes this could be correct (the butterfly leaking) it is not uncommon for these t fail and bits of butterfly to go through the engine..... if you have any suspicions about that part of the engine pull the manifold and check - well that is my advice anyway.

[Micko66]

Good advice. Thanks. :-)

[hichamaziz]

reply

thank you for post.

[hichamaziz]

re

you should change it