LIM Gasket

**black plague815** · 06-23-2011

Will a bad LIM Gasket cause performance problems?

**matt5112** · 06-23-2011

i'd venture to say yes.

but primarily it can cause you to chuck a bearing or hydrolock the motor if it gets bad enough.

**Kejross** · 06-23-2011

FIX IT!!!!

"An internal combustion engine works by compressing an air/fuel mixture in a cylinder and igniting it. But air and fuel can be compressed, water cannot be compressed.
When water gets into the cylinder and the cylinder tries to move towards the valves to compress the air/fuel mixture for ignition it is stopped by the water. This can cause the piston arm to bend, it can blow the valves out, it can literally blow a hole in the engine block." By Matt Finley, About.com Guide

**black plague815** · 06-23-2011

I plan on fixing it, it is a very minor leak. after running for hours it is only a couple dots of coolant. I dont think any gets into the cylinder, no smoke from burning coolant. but yea def. gonna get it fixed

**matt5112** · 06-23-2011

an external LIM leak is rather uncommon.

Most common external leak are the coolant elbows that connect the water pump to the heater core to the LIM.

**black plague815** · 06-23-2011

Originally Posted by matt5112

an external LIM leak is rather uncommon.

Most common external leak are the coolant elbows that connect the water pump to the heater core to the LIM.

It is leaking there but I can also see oil underneath the supercharger, on the very top of the intake

**matt5112** · 06-23-2011

on the top of the LIM the only oil it'd be exposed to is from the s/c. not the motor oil.

Theres a plug on the front of the snout, i'd remove that and check the level. when the car is level, the fluid should be up to the bottom of the threads of the plug hole.

if that was your issue, siphion the remaining fluid out, remove snout, clean with brake clean, use anaerobic sealant between the snout and rotor pack, (good time to replace your coupler with a green one) fill with two bottles of GM supercharger fluid.

**black plague815** · 06-23-2011

So if the LIM gasket was bad I would be getting white smoke out of the exhaust from cooland in the cylinders?

**brandonl2000** · 06-23-2011

Originally Posted by matt5112

i'd venture to say yes.

but primarily it can cause you to chuck a bearing or hydrolock the motor if it gets bad enough.

he's right. fix it immediately. i've chucked a bearing, it's not fun. it'll leave you sitting on the side of an interstate at 9:30 at night.

**black plague815** · 06-23-2011

Originally Posted by matt5112

on the top of the LIM the only oil it'd be exposed to is from the s/c. not the motor oil.

I guess I have some figuring to do then

**brandonl2000** · 06-23-2011

Originally Posted by black plague815

So if the LIM gasket was bad I would be getting white smoke out of the exhaust from cooland in the cylinders?

most likely. your concern is when it's in the oil pan. cus then you got coolant touching those precious materials.

if you have plastic lim gaskets, who cares if it's leaking or not? replace it NOW.

while you're at it, do valve cover gaskets too. knock it all out. your car will love you.

**matt5112** · 06-23-2011

Originally Posted by black plague815

So if the LIM gasket was bad I would be getting white smoke out of the exhaust from cooland in the cylinders?

Thats the sign of a bad leak.

Generally a small leak would be slowly disappearing coolant with no visible external leak.

Coolant pressure test would reveal if you had any leaks in the system.

Agreed on the replace it all idea. Valve cover gaskets, LIM gasket, s/c fluid change, s/c coupler change, TB clean, coolant elbows.

It'd pretty much eliminate most of the issues people have with these motors aside from wear and tear.

**black plague815** · 06-23-2011

we looked the oil over pretty good during the last oil change it has no coolant in it. Not milky or anything like that. And it allready has the aluminum gasket.

**black plague815** · 06-23-2011

but it really sound like I have a supercharger leak or something, and that elbow needs to be replaced.

**brandonl2000** · 06-23-2011

it's probably just oil on the top of the LIM just from usage. cus if the LIM has a small leak, not only will it seep coolant but it can seep oil. and it could have seeped oil on top of the LIM and that's what you see...

edit: nvm, you haz alum. gaskets. i fail lol

**matt5112** · 06-23-2011

Oh, if you have Al gaskets i wouldnt worry about it until you started missing coolant.

your gaskets can fail yet not show signs of coolant getting into the oil.

I'd look around the blower and look into those elbows.

Elbows are $5 at your local parts store in the help! section. get a green coupler if you decide to take the snout off (ebay or ZZP) GM supercharge fluid is $5 a bottle (need two) at your dealer.

**black plague815** · 06-23-2011

I just went outside to take another look, I have a little bitty pool of oil in front of the supercharger above the valve cover, I dont know how it got there, but it is motor oil not s/c oil.