[Magnum2K]

Hi-

I have been lurking for a while and have gotten a lot of useful info here but now I have a question.

I know that you can diagnose an intake leak by seeing a puddle of oil through the throttle plates. I looked in mine and saw no puddle per se but there is a film there and some oil on a lip of the intake on the right side; just a little line of oil.

If I have a real problem it would be much more evident, right? Any other signs I should look for? I wonder because the oil was a qt low between oil changes with no external leak or smoke.

Thanks!
M2K

 

[Rick99]

The only way that oil would get into the upper intake would be through a plenum pan gasket leak. If you've been going through that much oil and you see oil in your upper intake, I'd say you have a leak.

The main problem caused by the plenum pan leak is that the oil getting burned in your cylinders eventually carbons everthing up and results in pre-ignition or "ping", which reduces performance and can cause more serious engine damage over time. In case you don't know, if you have "ping", you'll tend to hear it when you accelerate hard (ie onto the highway) or go up steep grades. It is a sound like someone dropping a bag of marbles on a hardwood floor and it's pretty hard to miss.

Replacing the plenum gasket is a significant job, but not beyond the competant DIYer. The prevailing theory around here is that the problem is caused by the fact that the stock plenum pan is made of steel and is attached to the aluminum intake manifold. Since these metals expand and contract at different rates, over time a leak will result. The solution is to install a new gasket together with an aftermarket aluminum plenum pan. (Someone else here should be able to point to the source of such a pan if you're interested.) Whether you do it yourself or have a pro do it, it would be a good idea to have the aluminum pan installed.

 

[Magnum2K]

(Someone else here should be able to point to the source of such a pan if you're interested.)

I am, thanks for the info. I may have caught a problem before it got too severe.

 

[WarrensD]

Hey M2K, this is also a nice time to consider a FM t-body & an M1 intake (never leak again). You'll see very impressive HP gains with your existing mods if you also add a CAI.

 

[Rick99]

Here's the link for the place that sells the plenum pan kit:

http://www.hughesengines.com/

 

[Magnum2K]

Man guys, thanks again for the info. I spent a lot already so I can't say I can dish more out for a new intake. Any sites with good prices on one?? The money only stretches so far.

Am I risking damage to my new cat right away if I only have a slight leak?? The truck will ping slightly if I'm pullin my boat under load. I'm just wondering how much I should drive her. I just did a plug change and they were all a nice light brown color.

Oh btw, will the M1 and 51mm FM TB give me good torque for towing? I could search for it but I'm feelin lazy since you are looking here anyways

This is M2k and I approve of this message.