lackryaa

Hi everyone,

Thanks in advance for any help you may provide. Any comments welcome!

This is a 1996 Chevy Cheyenne with 4.3L vortec V6. Has 173,xxx miles on it.

I've been searching for a coolant leak for about 3 months now. Finally decided just to get the pressure tester and find the leak. Found it within 5 minutes. These things are handy aren't they?

If you will refer to the pictures, the leak is coming through a tiny hole on a cover of some kind on the block on the driver's side right next to the crank pulley. The orange dot right in the middle of the black circle.

My question is, what the hell is this thing? Pretty tough looking for a part diagram with this part pointed out.... And how bad is it that coolant is leaking through there? I am typically a DIY so I don't mind getting into it myself. Just need to know what I am getting into.

Also, should I go ahead and replace the intake gasket with the upgraded Fel Pro? I have no idea if the previous owner replaced it (got it at 100k 8 yrs ago). Seems like a good opportunity to do it while having some stuff out of the way to fix this freaking leak...

custom_car_man87

If its behind the crank pulley, which it looks like, then that would be your timing cover, unless im just looking at something else.

lackryaa

That's what I thought it was. I can't find an exploded view of that area.

The most important question I need answered is why the heck is there coolant in that area? Was it designed this way? All these things I need answered and can't find a good source so I came here.

Also, it leaks pretty good. I had a tester at 5 psi, and it was dripping pretty quickly. Imagine what it does at the designed pressure (what 16 psi or so?) I noticed my temp wouldnt reach 190 on the gauge, only 175 or so. Perhaps due to the reduced pressure capability of the system.

But again, why is there coolant in that area? If it is the timing cover then, well, I've got big problems don't I?

thonyyang

When you said pinhole size leak, I automatically thought of the little weep hole on the water pump that tells you it's going bad. I don't know if the 96 chevy's had the weep hole but that was my first guess since that trucks got some miles on it. From the pictures, all i could tell was that it looks like it's pooling in that area, not necessarily that it's leaking from there, but to there.

Look and see where the water pump is and see if it's wet near that hole if you got one.

If it is leaking from that hole though and if that is the timing cover like customcarman87 says, it might be your lower intake manifold gasket that needs replacing. I can't really tell by the angle you were taking the pictures and what part that really is.

custom_car_man87

You shouldnt have coolant behind your timing cover. But like the previous post mentioned, the water pump is directly above the crank shaft pulley. Most water pumps have a weep hole at the bottom. From the pictures you attached, we wouldnt be able to see that weep hole. Its possible that the water pump is leaking and running down the front of the timing cover, and that is where you see it at. Use your pressure tester again, pump it up to about 16-18 psi and look around the area of the water pump, its the big pulley that is attached to the fan. If you see water dripping or running anywhere behind that, you probably need to replace the water pump

lackryaa

Hi,

More details.

I guess my brain was believing what my eyes were seeing. It's not coming from the timing cover.

Went ahead and took the front stuff out so I could see where the leak is coming from.

I have two pictures. From what I can tell it is the Intake Manifold Gasket although, I can't see the mating line bw the manifold and the block so it's a guess. Really hoping its not a Head Gasket since way more stuff will be involved with that.

The weep hole appears dry so I guess we can rule that out.

What do you guys think from seeing these pictures?

Thanks guys!

custom_car_man87

Thats still a little tricky to see. Best bet, if you want to be sure of what it is, take that bracket off to the right of the water pump. If i can remember correctly, its really not that difficult to remove. That will give you access to see whats really going on. You might be able to get a small mirror around there and check it out as well.

lackryaa

Case solved, it is definitely the Intake Manifold Gasket. It was leaking right under the Power Steering Pump Bracket so it was near impossible to see it with the bracket on.

Well, going to order me a felpro metal core/rubber edge intake manifold gasket.

I'm going to replace the water pump while I'm in here. Any recommendations on water pumps?

Going to get rid of the Dex cool coolant as well.

Anything else I should replace while I've got all this stuff out of the way?

Fishinfooleric10@aol.com

Why would u get rid of dex cool? I heard without the dex cool it will make the the blocks corrode and all GM products had to have that coolant in them. Correct me if I am wrong, but I thought that is what they had to have.

lackryaa

Yes, IIRC GM used to recommend their own DEX COOL, pretty sure they still do (for obvious reasons) but there are a lot of pages like these exposing dex cool for what it really is... This is just one of them, look them up and see if you agree with them... I sure do. There is a lot of brown mud build up and always wondered "Why the hell?"


For your viewing pleasure!
Dex-cool Contamination