Had to top off the tank today, it was about an inch low.
I'm gonna be swapping on a ported M90 case this weekend, what can I look for to determine if it was leaking from an intake gasket, other than standing coolant?
Also, where else could coolant leak without showing? LIM gaskets are aluminum, and I know the head gaskets are fine...oil looks fine too. No drips on the ground, no visible leaks on the hoses, no coolant on the heads.

Also, not sure if it'* related, but my coolant temps are spiking to 200+ on a 180* T-stat. I think it'* the fans, because the temp drop down to 183ish once I'm rolling. How would i check to see if the high-speed relay is out?

Finally, the car has to go in to the dealer for a belt(damn motor mount goes THROUGH the belt...). Should I just have the dealer look for the problems while it'* there?

I'm not sure if your car has the lower coolant elbow, the one from the tensioner to the water pump, but those can start to slowly leak for some time before they leak enough to start leaving much evidence. Of course, the LIM can leak coolant into the engine, but yours would be the first reported problem of that with the new gasket.

Is it warm enough to turn on the A/C and have it run? That should turn on the fans. If you have access to a scan tool, you could turn them on with that. You could also find a relay with the same number in the fuse block, and try swapping them to see if there is a change.

Let me know what you find, bud.

I did the aluminum LIM gaskets on the wife'* '04, and it started leaking coolant again. I tracked that to a pinched o-ring on the upper plastic coolant elbow (totally my fault, and faint but visible on the side of the motor).

I also did my '98 LeSabre, and it is very slowly starting to lose coolant (though I think that may be either that my epoxy-filled-rear modded L67 TB may not be sealing against the UIM gasket so well, or that I was too cheap to buy a new UIM gasket ...obviously not going to be the exact same issue on your PAU).

One place you might want to check is the yellow LIM-to-TB o-ring coolant seals?

If you find anything in your investigation, let us know.

OK, so possibilities are upper coolant elbow(that'* the one under the */C snout right?)
Lower coolant elbow(where would that one be?)
And the O-rings on the */C gasket or TB gasket.
I'll check the various hoses when I have the top taken apart this weekend as well.

If I don't find a leak from one of those, I guess I'll have to bite the bullet and pull the LIM to check those gaskets...
BTW, I can't find my damn Chilton'* and I don't want to buy one when I have an FSM on order. Does anyone have all the torque specs I'll need to pull the */C, swap the case, and re-install it?

#1 in this diagram is the lower one. It comes off the tensioner and goes into the water pump.


I believe all of the torque specs you want are in techinfo.

Hmm, do those elbows flex? Can I get them out and back in without taking that bracket out? Or am I gonna be doing a lot more work than I bargained for?

Unfortunately, they do not. They're made of pretty much the same material as the original LIM gaskets. You have to remove the tensioner to replace them, but it'* not a bad job...maybe 30-60 minutes.

OK, I'm gonna tyr to pick those up, and we'll tackle that too, this weekend. I think I'm gonna go ahead and do the radiator hoses as well, they feel pretty soft now.
Gadzooks, this thing is mounting up.
Screw it, I'm gonna try to tackle that dam belt, too. I gotta do the hockey puck mount, too, so It'* gonna be on jack stands anyway.

OK, something is odd here. Went to Advance Auto parts and Haydocy Pontiac to get the pieces needed.
Haydocy'* parts guy couldn't find a part'* number for the lower coolant elbow, and the diagram for his catalog didn't show one for the L67...

The design of the tensioner assembly changed from using one plastic elbow in the early models to two in later years. That is perhaps why the parts man could not find the lower elbow for your car for the water pump / tensioner assembly joint. If you have the older design, there is a cast aluminum nipple integral to the tensioner assembly that pushes into the water pump and seals with an o-ring. That may also be the cause of your leak. The coolant elbows should be available from any parts store that carries the "Help!" line of parts. About $6. The dealer will have the o-ring for the water pump connection.

You want to be careful to clean the sealing surfaces for those o-rings on the water pump and the LIM. If you find pitting, you will want to install the new ring with a good dollop of rtv silicone. If the aluminum is clean and smooth, just use some silicone grease to ease the installation and prevent damage to the o-ring.