IM Gasket R&R

ADDZ71 · March 11, 2005

I just had mine replaced. Afterwards, oil began leaking off the back of the engine. I took it back after this developing over a month or so. They said they fixed it and that it was a seal around the Distributor. What do you guys think? Is this part of the R&R for an Intake gasket that they just forgot?

Thanks,

Ben · March 11, 2005

Could be both, but I'd first suspect the intake manifold gasket.

Wacky design changes, mainly for ease of manufactur and assembly. Stupid design and think first year engineer right out of college and no wrenching experience, nor will there ever be.

The Vortec intake manifold bolts are ***NOT*** square to the sandwich of parts, but at an angle. Straight up so the robotic head can just come down and not have to angle itself to the old way.

Since those bolts are angled, there is a sliding action going on when those bolts are tightened. Why their torque is so low.

It's been fixed on the NBS with a boss incorporated into the gasket. Here's a picture of one of the new gaskets. Took the picture while visitiong Stillen and reviewing their new brake designs and a prototype "car" is all I can say for now.

It's from a $70K Caddy getting a Whipple installed (another $30K).

Also, the OEM gasket has an "O-Ring" incorporated and the above "sliding" messes up the o-ring, so it deforms and leaks over time. Again, the "newer" OEM gasket has solved this.

Here's a picture of one from a 5.7L engine.

Silverhair · March 13, 2005

Good point about the intake manifold leakage. I replaced the intake gasket on my '99 Yukon last year with about 124K on it. I was leaking water (a small amount), and finally found it was coming from the passenger side rear of the engine. The gasket had failed. This is my first look at this website, and have already found alot of good info! I try to do most work on my vehicles and found that using a digital camera is a real good idea when in uncharted territory. Another leak is occurring now, so I am going to look real close at the water pump! It's got 146K on it, so I'm sure that things are starting to wear out. No transmission problems yet, however, I change fluid about every 25-30K. I have been real pleased with my Yukon and will probably keep it 10-15 years, maybe more! Keep up the good work!