View Full Version : Intake Manifold Leak

04-12-04, 08:49 PM
I finally fixed my oil leak! I'm so excited! Let me give you some history....kinda long winded.....

I finally bought my 1995 Corvette about 2 years ago. I've always wanted a Corvette since I was little. About 3 months after I bought it, I noticed it dripping oil. Not much oil at all, but it was dripping. About a half dollar sized spot, every few weeks. I needed to investigate.

I've had it on a rack several times and noticed it dripping from the same spot, where the engine and trans meet. I was told by serveal mechanics that I had a rear main seal leak. I took their word for it and figured when I saved up enough money to fix it, I would. It wasn't leaking bad, so I figured no rush.

Well it started to get nice outside early this year and the temps around here got into the 60's one weekend, so I decided to change the oil in the Corvette. While changing it I noticed some oil seeping from the heads. I had my mechanic friend (Josh) come by to confirm. I'm thinking great, more money to spend on this car. Well, there not leaking bad, so I'll wait and save some money. If I'm gonna do it, I should go buy the LT4 kit and do it while I'm in there......

I finally saved up the money for the parts to do the rear main seal a few weeks ago. I talked it over with a friend of mine who works at a shop, to get it in and fix the leak once and for all. I bought the parts from a local Chevy dealer for about $300.

After I bought the parts, I figured I'd ask a Chevy tech to see what type of trans fluid to use. I was introduced to the Corvette tech there. I told him what I was planning on doing with the rear main seal. I told him that I was also seeing seepage from the heads. He told me to check the intake manifold. When it leaks it drips down the back of the motor and looks like a rear main leak. He said that he's never seen a rear main leak. Sure he done rear main seals, but when he's doing a clutch. He also said that the oil was not leaking from the heads, it was from when the intake leaks, the engine is tilted so the oil runs down the heads. He said that the heads can't leak because there's no oil in ther to leak out. WOW, I'm thinking I want to talk to this guy all day, but I have to get on my way.

I called Josh and told him I talked to this tech and he told me where to look for the leak. Josh came by that night and confirmed the intake was leaking. OK, I need to buy more parts. Josh went to Chevy to get the parts for me the next day. He talked to the Corvette tech too! I spent $50 in parts and Josh had asked all the right questions. He told us to get the 2 side gaskets, the silicone sealer, a PCV valve, and a check valve. He also said to check the throttle body gasket, which I needed to find on Saturday once we had everything apart. Just another $5.

So we wake up a bit late at 6:15 AM. We wanted to be at the shop by 6:30, but we made it there by 7:00. Get the car pulled into his bay and start planning the disassembally. We get a plan, and start working. The motor is still a bit hot, but we keep going. We get everything removed from the intake manifold, except the AC and fuel lines, which were kept on. Time to take the manifold off. We pry it gently so the seals loosen and flip it backwards onto the windshield. Josh cleaned this thing to perfection, the block too. The Corvette tech said to make sure it's "REALLY CLEAN" and he's been right so far. Time to find a TB gasket, drive there, drive back. OK, now lets finish this thing. We got the side gakets on, and Josh applied the silicone sealer. I held one side of the wiring, a co-worker, the other side, and Josh placed the manifold on. Perfect. We put on the manifold bolts, and torqued them down in the correct sequence. We cleaned the TB and got everything put back together in no time. OK, start it. Josh took the keys and fired her up. He shut her off and we cleaned the underside to get all that grime off. Cleaned her up and went home. Josh kept reminding me to not get on the throttle for 24 hours.

EASTER! Sunday moring, time to finish my home project before we've got to go to see family. I take the car out to go to Home Depot at 9:00 AM. It's been almost 24 hours. NO, gotta wait till noon. So I get ready to go to visit family, I'm telling my girlfirend to hurry up, she always late anyway. We get in the car and start heading out. I finally get to rip her good. I rip out at stop sign, spinning the tires to about 5000 RPMs, slam second, hit 3rd, and start to ease her down. I have to say that I do notice some power increase. Not like raw power, but the car feels stronger. I've never had power in 3rd gear, and it seems to be there now. I've also noticed my oil pressure is consistant while driving now, about 40 at idle, 80 while driving, and it used to change when driving.

I've included two picks from when we had everything apart. I have to say that I'm very happy that I got this done, and fixed the right problem. I'm not embarrased to leak on anyones driveway now. My Corvette is top shape, thanks to a very friendly Corvette mechanic and a good friend who took the time to really help me.

Thanks for reading!

04-12-04, 09:00 PM
Sounds like you have a great couple of friends. Good going, and thanks for the run-down. :beer

04-12-04, 09:09 PM
It's really great when you have people willing to help. This was the biggest job I've ever done on a car, and was a bit nervous. It was a lot of fun learning new things, and we did everything by hand. It was a great experience.


04-13-04, 02:30 PM
I live not too far away. Have no need for work right now and do most myself when needed but just in case ----- Would you mind sharing the name of the shop and of the Corvette Tech?
Others might be interested too but if you don't want to go public with the info, I would appreciate an email.

04-13-04, 04:15 PM
Hey, how about that? I just finished the same job a week ago. I think that you will find a lot of satisfaction doing your own work on your '95. Good job!