Intake Manifold O-rings

[CriticalB]

I've taken the plunge and started a VOD cleanup. All said, it's not too bad in there. I found a few copper sealing rings and an old grill clip from the engine cover. I found the air filter box bolt I dropped the first week I owned it, as well as what I believe is the bolt it had replaced I will have to replace the heater pipe and a few hoses and clamps, but overall it could have been a lot worse.

I ordered the intake o-ring kit from DMC, and my assumption was the 6 rings go between the block and the intake manifold. They're the right size, but the existing rings appear to be flat instead of rounded and fill the entire recessed area perfectly. Is that because the rubber flattens over time under pressure, or does it really not matter? Or am I missing something altogether and these rings go somewhere else?

[opethmike]

The new o-rings will get squished down when you re-install the intake.

[NckT]

Yes, they flatten over time.

My personal preference on reinstallation is to use clear silicone sealant to hold the new O rings in place and create a guaranteed seal between the cylinder heads and inlet manifold.

On my car I also used a heat gun to dry the "valley" area, vacuumed any remnant dirt/ dust, and then used motorbike air cooled cylinder engine black paint to protect the top of the alloy of the engine to help prevent any future rot due to any water ingress.

Take your time in removing the long bolts that hold the V coolant pipe to the cylinder head. I tapped the head of the bolts a few times with a small hammerr to help shock loose the threads before undoing them as they are prone to snapping.

Good luck with it all, it's not as bad as people make it out to be.

[Jonathan]

My o-rings were squished flat when I took them out too.

53950

[opethmike]

My o-rings were squished flat when I took them out too.

53950

Dang dude, those have to be some of the flattest I've seen!

[Jonathan]

Dang dude, those have to be some of the flattest I've seen!

Oh yea. For this and 100 other reasons just like it, the car thanks me for finding it and making her like new again.

In other news... we still have at least one thread on the forum here today that hasn't been overrun by BOTS. Whaddupwiththat?

[CriticalB]

Dang dude, those have to be some of the flattest I've seen!

This is why I was in doubt:

53963

[mluder]

My personal preference on reinstallation is to use clear silicone sealant to hold the new O rings in place and create a guaranteed seal between the cylinder heads and inlet manifold.


Plus one on this - Top tip is to use clear silicone on all the engine o-rings when you reinstall.

Cheers
Steve

[DMC1890]

I had a coolant leak on the back of the water pump (cockeyed hose), and pulled the intake manifold to get to the hose. I did not replace the intake O-rings. I didn't think they were that old since I had replaced them 3-4 years ago. Now I've got an apparent massive vacuum leak. I tried a smoke test and all I could see was a bunch of smoke from 'somewhere' under the manifold. I bought a cheap borescope camera, thinking I would try the smoke test again this weekend to pinpoint the leak sources.

Should you just always replace those O rings when re-installing the manifold?

[kings1527]

I had a coolant leak on the back of the water pump (cockeyed hose), and pulled the intake manifold to get to the hose. I did not replace the intake O-rings. I didn't think they were that old since I had replaced them 3-4 years ago. Now I've got an apparent massive vacuum leak. I tried a smoke test and all I could see was a bunch of smoke from 'somewhere' under the manifold. I bought a cheap borescope camera, thinking I would try the smoke test again this weekend to pinpoint the leak sources.

Should you just always replace those O rings when re-installing the manifold?

I've removed the intake probably about eight times or so and that's what I've done with the exception of one or two times. Cheap and easy to do and prevents stuff like what you're describing from happening.