Page updated on 05-22-2018

95 lesabre coolant leak???

02-23-2007, 10:23 AM
I have a 95 leabre with 145000 miles on it. It has started leaking coolant from what appears to be the lower intake gasket and maybe the upper intake gasket. However i called some places about it and some said that i might be a plastic tube on the belt drive side of the motor? Does anyone know about what plastic tube they are talking about? The car is leaking on the tranny side of the motor, it is an L engine with the aluminum lower intake with the plastic upper plenum. It looks like maybe both the upper plenum gasket and the lower are leaking? ? There is coolant in between the front valve cover gasket and the intake. So thats why i thought it was just the lower intake but any info would be great. Also how much does the intake cost to fix? :shakehead

Why did i buy a GM:banghead:

02-23-2007, 09:45 PM
Look behind the alternator and you'll see the heater hose going to it. I'll bet the local buick dealer will have plenty of new metal ones to sell you for about 14 bucks. You may need to use a large easy out to remove it. I used an easy out and it stripped because it was plastic and brittle. Then I used a hack saw blade and cut it long ways until the blade just touched the metal threads. Do this cut 2 more times and you can break it apart to remove it.

02-23-2007, 10:25 PM
My son has a 96. It is the plenum and upper and lower gaskets. You are getting antifreeze in your oil and if you don't get it fixed soon, the engine will likely seize (sp?). In any event, it's at least a $1,200.00 fix.

One other possibility is the water pump may be shot. My guess tho, is the former is the problem. This problem is inherent in the 3800 series II engine. GM is well aware of the problem and has refused to fix it.

At least two class action lawsuits are pending about this. One I believe is in Washington (state) federal court and other down south some where.

It has its roots in the antifreeze coolant GM was using back then that basically turned to gunk in some engines.

Good luck!

02-24-2007, 09:25 AM
Let’s not confuse the 1995 Series I engine, with the 1996 Series II engine and the infamous UIM coolant leaks, caused by the EGR tube heat. From what you described here, There is coolant in between the front valve cover gasket and the intake This would more than likely be a LIM gasket leak, around the area of the water jacket in the head & manifold. This type of leak, usually seeps coolant to the outside of the manifold and not into the engine. The other areas mentioned, “plastic coolant bypass fitting & water pump”, do not leak in an area that would allow coolant to settle on top of the manifold! All you need on the Series I manifold, is a new LIM/UIM & TB gasket set. Clean everything well, install new gaskets and use the proper torque setting & sequence to reinstall manifold.:iceslolan

BTW, if you still have the plastic coolant bypass fitting, replace it with a metal one, while you have things apart.:icon16:

Add your comment to this topic!