Scooter70

I've got a bad oil leak that developed at Watkins Glen. My diagnosis was an intake gasket failure since that was where it looked like it was coming from. Here's what it looked like in the garage at The Glen.


Here's the front corner where the last pic is taken:


Is this normal?



So what do you think? Will changing the intake gasket (and distributor & gooseneck gaskets) fix the leak? I've been looking around under the motor and everything else looks ok, with the exception of the light coat of oil.

Thanks in advance,
Matt

burners

How are the mating surfaces? Has the engine block been decked, heads milled? If so has the intake manifold been machined to account for it? I would go a little lighter on the RTV near the corners next time. Did you get an idea of where it was coming from, exactly?

Scooter70

I don't know anything about the motor other than the fact that it's been in there for close to 10 years. I did have the intake off probably 6 years ago, but it was fine until lately. Unfortunately, I couldn't pinpoint where the oil was coming from. There was no blowout of the gasket, but there was some oil pooled up around the intake bolts. (I hate those chromed 12 point bolts!!)

Boofers

Mmmm Blue Light :cheers:

Tominator

You haven't just switched to sythic oil by chance?

Scooter70

Nope. Castrol GTX. To add to the car's issues, it's been burning oil at a pretty high rate lately (~a quart every 50-100 miles). While I have the intake off, should I yank the heads and have a look-see under there? I just want this motor to make it though this summer without too much work or expense. If it's hosed right now, I think the car will just sit in the garage until the snow starts falling, when I'll order a new crate motor. I'm getting tired of wrenching and not being able to drive lately.

zwede

Did you use sealer on the intake bolts? Several of them go into oil. Doesn't look like the gasket failed. Look into the intake ports and tell us what the valves look like. How much deposits? 1Q/100 miles is massive. You should have blue smoke if it's an internal leak and some sizeable puddles if external.

Scooter70

Blue smoke.... check! It got worse as the loud pedal got closer to the floor. When I reved the car up, I could spit oil out the sidepipes.... I guess it couldn't burn all of it!
Puddles.... no more than the average Vette. Definitely not the cause of the massive consumption.

Deposits on the valves.... check!



A few of the valves look like there's a pile of built up sludge on them. Now where do I go from here??? Should I just retire this thing or can it be saved for not a lot of $$?





[Modified by Scooter70, 1:34 AM 7/16/2003]

69stingray

I think it is time for a 383 with AFR heads.



If you are burning that much oil, it must be pouring into the combustion chamber. It could be coming from a leak between the intake manifold and the cylinder head.

If it increases with RPM, does that mean it is blowing by the rings? :confused:

Scooter70

Is that the general concensus? It's hosed?

Zach - Don't tempt me. If I wasn't going to be starting on a bathroom and home theater in my basement the end of this month, I'd have someone building me an AFR 383 motor it right now.

pingdashf

AFR 383 vs. Bathroom and Home Theater. Thats tough.

TedH

You may have been experiencing some oil seepage through the intake to head gaskets. I have similar problem; on decelleration with vacuum high, the oil is getting into the combustion chambers. I saw it when I had it on the dyno. Big puff of blue smoke when the tuner let off the gas and the engine coasted down. No blue smoke otherwise. The RTV may have let go resulting in the leak at The Glenn. Good insurance to go ahead and replace the valve cover gaskets also.

zwede

Well, the intake ports & valves don't look oily enough to explain 1Q/100 miles. To me it looks like it's coming in past the piston rings.

Scooter70

Ted: It's more on acceleration than decel. I was thinking it was the rings like Zwede said.

Zwede: If it is the rings, would that explain sludge on the intake valves? I'm sure it could be a combination of the rings and the valve seals that were pretty bad when I replaced them last year.

I think that the second bathroom & HT are going to win out this month. Since it looks like this thing is not going to get put back together, I'll probably start pulling it apart more and getting ready for a crate motor when I get some free time.

bigvette1

What Markus says makes sense. If you are sucking oil into the intake the runners will be moist or wet with oil. At a quart/100 miles they will be soaked.

Do you have only some cyliners that are fouled out? If so, you could have a cracked or egg shaped guide where oil is leaking into the cylinder.

Did you run a compression check both wet and dry?

If the heads are magional and some of the rings may be bad, it sounds like a rebuild time. If you want to keep on the road this summer and fall, find a good used engine, drop it in and rebuild the #'s matching one this winter.

Roadster71

Try the simple solution first, replace the intake manifold gasket. My 71 was smoking pretty good and thats what it was.

burners

I would agree that it is probably the rings and that is why you blew oil everywhere when you were at the Glenn. All the high rpm built up pressure in the crank case. From what your situaton is I would just put it back together and drive it until winter. Just don't run it real hard.

Tominator

If it was me I would wrench it back together and run straight weight oil 30 (or some type of really thick oil) and drive it till I got the new crate engine.

bloodvette80

beer cases make excellent support blocks....... :lolg:

Scooter70

Those were the empties from Saturday. (It was a pretty good day.)

Thinking about this thing is giving me a headache. Maybe I need to find more of those....

I think I'm going to clean it up, reassemble with some new gaskets and see what happens. What's the worst thing that could happen? (knock on wood)