99 Grand Am 3.4L

[dksob81]

I am working on a 99 Pontiac Grand Am 3.4L. Last summer I replaced the LIM and it is still losing coolant it is puddling under the intake manifold, I have replaced about a dozen of these LIM gaskets and well lately about the last month it started overheating and now it looks like coolant is puddling under the intake manifold. And the CE light is on - something about a misfire...

Do you think the LIM Gasket went bad again or head gasket leaking. I didn't know about the common head gasket problem or I would have replaced it at the same time.

[J-Ri]

I would clean the gaskets up on that part of the engine and pressurize the system to see where it's coming from, If not done correctly, if the manifold is defective, or if you got a bad replacement gasket, the lower intake manifold gasket can go bad a second time (especially if you don't flush the coolant).

[dksob81]

I just pressurized the system to 15 psi and let it sit for about 25 minutes and no change in pressure, I then increased the pressure to 18 psi and the radiator hose on the T-Stat starts to leak at this pressure but this can't be whats causing the puddle under the intake.

[xeroinfinity]

IT could be the hoses that runs to the bottom of the TB.

And sometimes if you dont use enough silicone sealant on the block/intake area, it will start blowing out and leak under pressure.

Good Luck.

[J-Ri]

You may want to use UV dye then, some leaks are so small you'll never see them with a pressure test. The engine may have to be hot, cold, vibrating, etc. to make it leak.

[Jrs3800]

The last time this was done was the lower intake pitted at all around the coolant ports?

These gaskets are install dry, but I like to run a thin film of High Temp Black or Copper around the coolant ports if there is any evidence of pitting and allow it to set up a hair.. The same would go for the heads as they too are aluminum.. The gasket is designed to seal a smooth surface, if there is pitting on that surface you could have sealing issues..

Kind of a ghetto way to do things but it works..

And just being curious, is there an Updated Gasket from GM concerning the 60* V6 engines?

[dksob81]

No there was no pitting at all. I am going to start tearing her down 2morow to replace the HEAD GASKET and redo the intake gaskets. I read somewhere about updated torque specs does anyone know what they are?