Howdy. First time poster...

I've been having problems with a coolant leak in between the intake manifold and supercharger on my Series I L67 from a '95 SSEi. The intake manifold and supercharger came from the same engine (which was supposedly in good running condition). I picked up a gasket from Advance, which is pictured below. I tried the Advance gaskets twice, which leaked A LOT of coolant into the intake. When I removed the */C, there was a pool of coolant in the manifold. Tons of white smoke. It backfired once and there was coolant up in my cone air filter. There'* been a trickle of coolant between the two, under the throttle body.

I was thinking that Advance was giving me the wrong Felpro gasket, so I tried one from a local GM dealer, but it'* designed exactly the same. To me, it looks like coolant in the cavity in the supercharger (and a tiny one in the manifold) is leaking into the boost valve area. I've tried it both with RTV and dry. Surfaces are smooth. I've checked for cracks and warping. I prepared them to be near sterile.

Tonight I made my own gasket, but I can't get the car to run for over a few seconds and still getting tons of white smoke. I haven't checked to be sure if its leaked with "my" gasket but I have a good feeling it is. It has NOT leaked from the rubber O rings (which are also new, came with the Advance gasket).

What do you guys suppose is wrong? Thank you.

Er, from the looks of it, you are/were missing 2 yellow O-rings that seal those driver-side holes between the LIM and the supercharger. And from what I understand, these O-rings do not come with the gasket set. Anyone know where to get these?

Go to the dealer and get an OEM AC Delco gasket.
While you're there, get both yellow coolant o-rings mentioned.
Don't sand or buff the top surface of the manifold. That'* bad news.


See the o-rings? That'* your problem. Sure hope you're changing your oil. If any of that coolant gets past the rings into your bottom end, your motor is trashed.

Drain your oil TODAY. As in NOW.

The Felpro supercharger gasket comes with the two o-rings. It comes as a kit.

Noooooo! I do have the two yellow O rings that came with the Felpro, and I did use them. They're not in the photos cuz I just wanted to show what the gasket and the surfaces looked like. And I did use them. Made sure they were seated right and all. I didn't do the sanding or whatever on the surfaces...was there when I got the engine. It'* really smooth and you can't feel it.

There are some potential fitment issues regarding FelPro supercharger gaskets on a Series 1.

F14, what year is your car (92-95 obviously)????? Please put that information in your signature.

And what did you do with the yellow o-rings if they didn't come with the kit? Did you notice the old rings when you took it apart?

It'* a '95. Will edit my signature.

I bought a genuine GM gasket earlier today but returned it because the cut outs were exactly the same as the Felpro. And yes, I did properly use the new O rings in the kit and were certain they were seated right before torquing it down to the suggest 19-22 ft/lbs

Your problem is the lack of 0-rings. Not the gasket fit in that area.

That'* a low-pressure bypass to the LIM when you're at idle or out of the throttle, and if it leaks, it leaks to dead areas.

One more thing:

I'm serious about draining your engine oil. I'd also strongly suggest dropping your oil pan and drain it completely. There is a great deal of risk here if you get water into the oil. The 95-05 L36 engines suffer from this quite often.

Will do an oil change asap.

What do you suggest I do about the O rings, if they are leaking? I've used 2 brand new sets of those O rings, but its leaked every time. Should I use RTV in conjunction with them? The surfaces in the area of the O rings have a very slight bit of corrosion. Not substantial. Is this an issue here?

I haven't been more stumped in my years as a plumber, 1500+ Explorer posts, and 2000+ Reatta posts :(