Is 3.8 Litre L-67 prone to Intake Manifold leaks.

[Bazza]

Hi Everyone:

I am just curious to know if the 3.8 L67 (VIN 1 series engine) is prone to manifold leaks like the L36 engine?

I have noticed some sepage on the top of the intake manifold since I flushed & changed coolant this fall. I have lost a bit of coolant out of the reservous but not much since the change.

I have the SSEI model, and wondering how many hours the job to replace the intake manifold gaskets? What else should I be replacing when I have thinsg apart?

Bazza

[00Beast]

Yes, the intakes are just as prone as the L36, we just don't have the EGR eating at the coolant passage in the Intake, since we have the aluminum S/C as our UIM. It would be wise to change to the aluminum framed gaskets. The job is ~ 2 days, one for tear down and clean up, and another for re-assembly.

[Bazza]

Ed:

Thanks so much for the reply.

As per my usual luck I noticed the coolant at -40 Celcius. This will not be a fun job in an unheated garage. I guess it will be off to the parts and liquor store!

[00Beast]

Be sure to get the aluminum framed gaskets, not the stock nylon gaskets. That's just asking for trouble. We're doing my gaskets this weekend.

[Phyrestorm]

I hear you on that 00Beast, I'm moving into my new place in January and right after that im putting that garage to good use and hopping right into mine and replacing both the UIM and LIM. Not to thread jack or anything but does anyone else have any other suggestions while it's apart? Methods? Cleaning? Or anything in particular?

[00Beast]

I hear you on that 00Beast, I'm moving into my new place in January and right after that im putting that garage to good use and hopping right into mine and replacing both the UIM and LIM. Not to thread jack or anything but does anyone else have any other suggestions while it's apart? Methods? Cleaning? Or anything in particular?

You're replacing the S/C?? On the Supercharged motors, the supercharger IS the UIM. I think you are confused with that.

[Archon]

This techinfo article is a good place to start. As stated, the supercharger takes the place of the UIM. For the supercharger gasket, get the Felpro which come with the 2 coolant O-rings that you will have to pay extra for at the dealer.
http://www.pontiacbonnevilleclub.com/fo ... =53&t=3591

[Bazza]

Hi Everyone:

I managed to get the job completed in what looks like perfect timing. I did find a small amount of coolant in the oil. (A couple of ounces) I changed & flushed oil twice & keeping my fingers crossed there was not any serious internal damage done.

I 1st noticed the coolant leakage on a very cold -40 day (This is the time when things seem to break) I had removed the Dex Kill this fall & it appears that the failure of the manifold gaskets 1st appeared when the cold weather hit.

Anywa, I would like to thank you all for the responses & those that took the time to do the step by step instructions. It was all a big help!

[00Beast]

That's what we're here for. Did you replace the Valve Cover gaskets at the same time? If not, and they ever go bad, you're going to have a much harder time with the intake and S/C on than w/o.