Unusual 3.8L Intake Manifold Leak?

I had the plenum failure in a series II 3800 and there was no external leak. Cylinders filled with water, hydrolocked, etc.

Yours doesnt sound at all like what I experienced.

Now, I have torn down those engines and have to say that the gaskets can also look pretty darn bad.

Double check and find the location of your leak before you go too much further.

My thinking exactly, and glad I didn't proceed with the notion, as originally planned, to just start pulling everything preventing the removal of the UIM. Turns out to very nearly definitively be that pictured "right- angled black plastic" Coolant Bypass Elbow/Tube, and apparently not all that uncommon a failure either. Looks like a relatively easy job, though I'm having an issue with removing the "alternator/serpentine belt tensioner mount/heater core hose outlet" assembly. The heater hoses and all three bolts fastening it to the engine are out, it's loose and wobbles, but just won't fully detach for some still unknown reason. If anyone has any hints or ideas, I'm all ears ;^)

SF

My 1995 Old 88 with a 3.8L developed a coolant leak with the belt tensioner a few years back so your '96 may be leaking in the same place. Symptoms were coolant drop in the reservoir, and coolant dripping on the garage floor from the left side of the engine, viewed from the front of the car.

For what it's worth, my Olds is coming up on 99K miles and is still running with the original intake manifold, but it's had green coolant for all of it's miles.

Hope this helps.

Bob

My kid recently replaced that on his '95 Bonneville (maybe Grand Prix) with the 3800.. He's due to come over for dinner soon. I'll ask him, but it might be a different set up.

--Vic

He won't change it until it warms up. It lost about a quart over the winter. He's had them off before. Says the el (your pic) is all that is holding it. Pull it straight back. Only the el o-ring is holding it in. This is the VIN K series II engine. BTW, you can pick up those els at local (Murrays) parts store around here.

--Vic

Yes, this is the VIN K, Series II engine.

The results of my online research would seem to indicate that there are 2 right-angle elbows, one from the "tensioner" to the LIM, another from the same to the front cover, used on this application. However, and although I've still yet to fully remove the item, it appears that the latter described tube is in fact a straight shot from the unit into the cover, and likely the culprit in preventing extraction (the other el simply loosely dangles).

Thanx to all, who so kindly responded, for their time, advice and efforts.

"snuckfoe" wrote in news:7q6El.21471$%k2.3076 @newsfe07.iad:

"alternator/serpentine

(picture

(picture2),

I have same exact car which had the same problem. The belt tensioner is water cooled & the plastic elbow pipe between the coolant & the Intake manifold was cracked & leaking coolant. The whole tensioner assembly has to be replaced.

Yes, we also had to do that. The tensioner flew to pieces which we were "on the road", and when that happens, power steering, alternator, brakes, etc stop working.

You would think that you could buy the tensioner without the integrated plumbing, but that is apparently not the case.

Luckily we cratered near a dealership that had one, and the repair was a couple hundred bucks. or so.

I offer a followup should anyone care or be at all interested.

Still being unable to remove the multi-function belt tensioner assembly, being careful not to damage the somewhat delicate, thin walled, cast aluminum device itself or anything else in its cramped-quarters surroundings, I had begun to consider other possible and dreaded scenarios that I may have had to resort to to affect repairs. Among them were pulling and replacing, as a unit, not only the tensioner assembly (~$100 locally), but also the multi-function water pump housing/front timing chain cover assembly (no doubt multiple hundreds of dollars) the latter of which would require a type (that I don't possess) of harmonic balancer tool for both removal and re-installation of the latter.

No matter what I had tried I just COULD NOT remove the tensioner from the front cover. But lo and behold on Sunday morning, things progressed from sucks ass to success after providing a straighter pull by jerking on a strap wrapped around the heater core oulet passage (that runs through the tensioner) just before it takes a right angle turn and enters the front cover (see pic). Then, finally, voila, seperation!

Again, my thanx for your all your responses and info guys.