Resurfacing intake manifold?
 

Hey All,

I'm just having a hell of a time getting my intake manifold to seal at the head. I've tried the OEM gaskets, the Lindsey gaskets, OEM gaskets with permatex copper spray on them, and now doubling up OEM gaskets and it just keeps leaking when I pressurize the intake. :banghead:

The surfaces on the head look perfect, the surfaces on the manifold look less than perfect, but they seem like they should be ok. All I can think is there's got to be some irregularity I'm not seeing, maybe a little bit of a warp? Or maybe a high/low spot?

So, I'm wondering: Has anyone had luck resurfacing the intake manifold? Anything I should know before pursuing that as an option? Anyone experienced a similar problem?

Thanks!

Yes. Been in your shoes in a past 2.5. We used: http://www.permatex.com/products-2/p...sealant-detail

Pauley doubled up intake gaskets for a different reason, but this seemed to help. I'd try Permatex on both sides of the stock gasket without torquing, allow to setup, then torque to spec. Likely will seal up your intake.

Hope this works as it did for me a decade ago.

G

Get the manifold to some shop that has a lapping stone. It should seal perfectly if lapped properly. Or you can glue it with loctite or permatex.

This new formula may allow immediate tq to spec. Didn't read their instructions, but this stuff worked in my intake for years.

This will work, but sounds like you are looking for an immediate remedy.

Are you sure it is not hitting anything around the throttle body?

Thanks, George! Does this stuff work a lot better than the copper spray stuff? I may give two gaskets +permatex a shot :)

I'd really like an immediate remedy, but really it can take its time if it means getting it done properly.

It's definitely not hitting anything at the throttle body. I do have some concerns that it might be contacting the oil feed to the turbo... For some reason, every hydraulic shop I could find in my general area could not figure out how to adapt from 1/4" NPT to 12x1.5mm without using two fittings, so it's a little taller than I'd like. I've checked as best I can to make sure it's not hitting though. I put a piece of paper on top of it and then bolted the manifold down and was able to pull the paper out without trouble. It's really really close though.

Did you spray around the intake gaskets at idle to see where it's sucking. The intake is a vacuum, and you'll immediately see the hoover effect. WD-40 or engine starting fluid works fine - at idle.

I used the method of pressurizing the intake with ~10psi form the compressor and spraying the intake down with soapy water and looking for bubbles.

That said, I also discovered that the leak I thought was the manifold was actually the cam tower gasket. Since there were a ton of bubbles coming out around the manifold runner, I assumed it was the intake... I guess that's the downside of using the pressure method - it puts air in places it wouldn't normally go.

So, there's a small leak at the cam tower gasket and I R and R'd the intake manifold about 8 times to try and solve it :banghead:

Ah well, at least it's "solved" :)

Yes. It's used as a gasket material. I'd try this unless you're willing to make sure each surface mates as came from Stuttgart.

http://www.permatex.com/products-2/p...er-grey-detail

I think the above material will do the job. If it were me today, I'd find where it's leaking, and then have the uneven surface machined to fit using OE gaskets. Twenty years ago when I was modding my cars, including these 951's, I choose the remedy that worked while doing my own wrenching on a budget.

I wouldn't share this without knowing this will likely work, as long as the manifold is leaking at idle. Test where it's leaking first, but use the permatex on both sides of the gasket on all ports. The lower tolerance (leaking-sucking) port will not squeeze as much permatex as the other three. Won't know/see this as it's likely in the .1000ths. This won't be a band-aid fix, and likely last for years.

The only way you'd know if your cam housing had a leak is oil escaping from the pressure while driving or what you did forcing air into the system. Why were you looking for a leak in the first place? If not oil, or a ****ty running motor, why look for something that's not causing issues with drive-ability or seeping fluid?

Stumped.

Ahh, yes. I suppose I didn't explain what led me to this in the first place. Sorry about that :icon107:

My car runs fat under boost. It always has. I've been chasing this issue down every road I can think of and, based upon some skillful M-Tune log reading by Joshua, it was deduced that I likely had a vacuum/boost leak. So, I began searching for vacuum leaks using the method I described.

On the last round of the taking it apart and putting it back together, I did discover that one of the small vacuum lines that connects to the banjos between runners 3 and 4 had a sizable split in it. I replaced it, but I've still got to go do some logging runs to see if that's solved anything.

Hope that clears up the confusion. Thanks again for your help!