JWASR64

I'm looking at a 95 C4 with 77k mile, it drops about 4 to 6 drops of oil on the ground overnight. Looks near the back of the motor, and can be smelled after driving to temp. When on the ground looking under the car the oil pan appears moist, not covered in driplets. I didn't see any clear sources, but hoped for common spots on this year model.

Please advise of any other areas of problem I should look over before purchase.

Thank You in advance.

BA

ovrebo1

Rear main?

Spray/ clean everything. Poof with baby powder. Guaranteed you'll find your leak.

FASTAZU

You may also want to check the front and rear of the intake another very common area for oil leak on the LT1-LT4.

Tom400CFI

Valve covers or rear wall/intake manifold joint. That is where my '92 was leaking oil.

Time to dig around back there w/a flash light.

POLOVETTE 94

A common oil leak on these is the rear of the intake, usually on the passenger side, I believe. It will run down the bell housing all the way to the ground. Or the rear main.

JWASR64

Are the above mentioned easy fixes, or more on the labor intensive side on
this motor ?

FASTAZU

The LT1 intake is very easy to remove, Do a search many posts and how to's here.

Richard Raichert

If it is rear intake doesn't that involve draining all coolant? (with the Opti being the big danger from coolant)

enventr

antfarmer2

It is best to pull both knock sensors when draining only way to get it all. And no danger to the opti. A lot of crud collects there.

RUU

No coolant passages in LT intake.

FASTAZU

"Quote"
The LT1 series Gen II small block Chevrolet is very similar to the standard small block. They use similar internals, exhaust manifolds and oil pans. The main difference in the LT1 is the reverse cooling design, which cools the cylinder heads first, then the block. Because of this, there is no water that passes through the intake manifold. Coolant is transferred from head to head by a steam line on the back of heads. The thermostat is located on the water pump. Also, the water pump is cam-driven, rather than belt driven. In 1996, an LT4 was available in the Corvette. The LT4 had the same features as the LT1, but had larger valves, larger intake ports that were located higher, and an intake to match. The LT4 also came with a more aggressive cam to enhance the better heads.

csthews

There is a youtube video where a guy goes through this step by step. There are coolant hoses going to the throttle body, so in this video, and in the FSM, they specify draining the system. I just removed my intake, and I didn't drain anything. I just unbolted the throttle body and moved it to the side.

Removing the intake is fairly simple. A lot of brackets to remove and you have to pull the injectors. If you do this, you might want to buy or borrow a fuel line disconnect tool. I got a set from Harbor Freight for $13. The gasket kit is only around $15, so the job is fairly inexpensive.

If you do this, remember there are 12 bolts on the intake and not 10. I lost 3 good hours out of my life learning this valuable lesson.

csthews

Another fairly common place for a leak is the oil pan gasket itself. If the leak is coming from the back, I find it very difficult, if not impossible to tell if it originates from the seal or from the oil pan.

1993C4LT1

My car leaked A LOT. Forum told me to feel back of the intake. It was the intake gaskets. No need to drain the coolant.

CRUSIN1

Just replaced my intake manifold gasket last weekend. Very easy job.

96GS#007

If you're mechanically competent, it takes 90 minutes or a bit less to R&R an LT1 or LT4 intake.

Very easy to run a finger along the back edge of the intake manifold to check for leaks. It should be bone dry.

B17Crew

After you have disconnected the two fuel lines on the right side of the engine, what’s the safest way to cover the lines so you don’t have fumes escaping into the space you’re working in?

Thanks in advance.

B17Crew

1993C4LT1

I don't even remember what I did. Think I cut up a microfiber towel and pushed it in slightly.

96GS#007

You don't disconnect the fuel lines. You pull the rail from the intake and the lines are flexible enough that you can flip the assembly backwards and rest it on the windshield.

I was swapping injectors in this shot, but you get the point....