Fushae

At first I thought I had a rear intake gasket leak. I've been having an issue with keeping the coolant full and small oil leak. But I suspected that both issues were independent of each other.

Recently, I've noticed the oil leak has gotten worse, incidentally after I had the oil changed. There was no evidence that the leak was originating from that lower part of the engine. Thus my conclusion that it was the rear intake gasket.

That was until the other day when I checked the oil and the very top of the dipstick was milky white. Also I've noticed it starting the smoke out of the exhaust pipes. That seems to be a new symptom as well. Now I'm thinking my coolant leak and oil leak are the same issue which typically means head gasket.

Is there anyway the rear intake gasket can explain milky white substance on the dipstick?

Mishawaka

Sounds like a blown head gasket to me.

Sleazy Rider

somehow/somewhere, you are getting water/coolant into your oil. head gasket is usually the culprit.

antfarmer2

another vote for head gasket and will be doing the intake as well.

touyech2883

Check the four corners of your intake could just be blown intake gasket they can push coolant into the engine valley and into the intake runner, but usually they will show an external leak as well when there that bad.

1984Z51auto

Sure sounds like a head gasket. Probably will show up if you run a compression test as a low cylinder/low cylinders on one bank. Look for a really clean spark plug when you run the test. That can be another sign.

aklim

One would think so. Everytime my head gasket on my other car blew up, there it was. Vikingtrader did that and there was no compression issue. About 150 across the board plus or minus 10, IIRC. Pressurize the cylinder for replacing valve stem seals and the coolant was bubbling. Maybe OP should try that? IDK.

l98tpi

Sounds like ole number seven has given it up. pull the spark plug in the number 7 cylinder and see if you have coolant in there. Number 7 is the rear most cylinder on the driver side if you didn't already know. Good luck.

aklim

For his sake, I hope it is the gasket. Heads get expensive when they break.

VikingTrad3r

yup. do this. ensure your coolant system is full (use water if u dont freeze as you will be draining soon). ensure you have fluid in your overflow tank

put the air to the 7 cyl and u should get bubbling coolant bthere is a vid of mine doing that in my thread.

just me or are we getting a tonne of blown head gaskets lately? me included!

maybe people just drive them then deal with em over winter so it just loojs lije that.

Joe C

I pretty much don't have a clue, and just kind of curious, so what is the price range for taking a L98 C4 into a shop for a blown head gasket? i'm assuming a dealer would be worst case, and thinking parts should be minimum, as long as nothing is broken. labor rates, i'm guessing, might be between $50-$100 per hour, and I can see some repairs exceeding the value of the car. if I had to guess, i'm thinking the average repair for a blown head gasket might be in the $2000 range (parts and labor) - ??? another issue with taking a C4 into a shop is the experience, or should I say, the in-experience of the tech doing the work. you have to ask yourself, how many dealer mechanics, even though they might have good, basic, mechanical skills, have actual hands-on experience on a 25-30 year old corvette.

antfarmer2

take your time and do it yourself. no one else will give they same care. and once you leave the shop if anything is wrong you must have done it. and your wallet will be much lighter.

Joe C

I am doing it myself -- been wrenchin' on C4's for some 20 years now. I was just curious what the cost WOULD be. to be honest I don't trust shops to change my frickin' oil. here's my latest example - my garage is tied up with some major work on my 85. I needed an oil change on my 90 - a bit overdue. so, I take my 90 into a local mom and pop garage for lube and oil - supposed to have been in business for some 30+ years. I told them upfront, 10W30. I get the car back, and on the invoice, it reads 5W20, and none of the front suspension was lubed. they did check the transmission, but not the differential. so, it's bend-over, thank you, and that will be $29.95! i'm not sure if people are just idiots, or they just don't give a rats-***. dealerships aren't much better!

crowz

As mentioned if its the heads it can get real expensive.....

These are pics of the heads on my formula firebird's lt1 when the previous owner let it sit and idle and run all the coolant out of it.

Joe C

- OUCH! that hurts just looking at it....

SJW

That definitely hurts the eyes.

Live well,

SJW

crowz

Believe it or not the local shop here rebuilt them. Pulls consistent mid 12's in the 1/4 afterwards too

One thing that it does though is "burps" into the coolant when I cut it off after long trips so it may still have a few issues....

Going to replace the heads next time I feel like fooling with it just to be on the safe side. Wife and I were leaving for a trip at the time and I needed it done fast and didn't have time to wait on new heads to come in so I gambled. Again it did fine for a good bit of time after the rebuild job they did on the heads for me so I got my moneys worth at least. Just time to do it right now.

Vic'89

1K is my guess.

Vic

VikingTrad3r

where i live in canada its equivilent to 2700 usd. bleh.

IacobucciB

Probably a blown head gasket. Common on cast iron block, aluminum head SBCs, notably LT1s. Everyone knows the corrosion that can take place between steel/aluminum (that white powdery stuff and pitted mating surface) that can accumulate. Usually the head gasket serves as a buffer between the two metals, but it can also happen through age, mileage etc like any other head gasket. Pull the plugs, if one looks aesthetically cleaner than the others it's most likely that cylinder. If you're gonna pull a head, the intake's coming off, so might as well check for leaks there before you pull it apart completely