wicked squeaks, possibly TPEFI related

[George M. Dailey]

Dope!! When I got this engine out of the '89 Formula one Fire bird, it had
two PVC valve looking things in the valve covers. I broke one while
installing the motor and assumed it was a PVC valve and replaced it with one
identical to the remaining valve.

If you are sure this is not a negative pressure crankcase, this must be the
problem. A bright ray of sun light shines on my bald spot, but it begins to
dim! 

I used all of the original air ducting and air cleaners from the Fire Bird.
There are no "before MAF connections", that I'm aware of on this setup, that
could serve as an engine vent. My 3.8PFI set up does have one after the MAF
and no PVC at all. 

Presently, I have the driver side PVC valve connected to the fitting at the
base of the TPI manifold also on the driver side. The passenger side valve
is connected to the fitting at the back driver side of the plenum.

Since a negative pressure crankcase is a no no, I will remove the second PVC
valve and add a vent with it's own filter. I hate to imagine the damage I've
done to the seals and sealing surfaces not to mention the dirt that has been
ingested.

Thanks to all that responded.

GMD
I was begining to think that this motor was the most leak free I had ever
owned! Oil can't leak out of a vessel under vacuume.


At 12:54 PM 9/17/97 -1000, you wrote:
>
>
>----------
>> I've got a weird one here. Every one I've asked so far has been stomped. I
>> drove my '89 5.7L TPI '58 chevy truck to Atlanta last weekend, 100mph
>> plus...420 miles one way from my home...so I'm perty sure it's not a
>> mechanical engine noise. The following is what I know. I think it's the
>EGR
>> valve or diaphragm resonating.

>Sounds like you're developing vacuum in your crankcase, which is a no-no. 
>You said that you checked BOTH pcv valves, but the crankcase ventilation
>system is designed to have ONE pcv valve and one vent tube to the filtered
>side of the intake line.  Try removing one pcv valve from the valve cover
>while the engine is running.  If the squeak dissappears, vent your
>crankcase and remove the redundant valve.
George M. Dailey
gmd at tecinfo.com