Where the heck is this coolant leaking from? (Page 1/6)
Patrick APR 12, 06:44 PM
My '88 Formula suddenly started leaking coolant. A lot. This is a Fiero that had sat for several years, but I've resurrected it and it's been fine for six months or so. It's leaking from the water pump area, but apparently not from the seal in the hub/impeller area. It's absolutely dry behind the pulley. When the engine is running the coolant really comes out fast, but it'll also drip out slowly just sitting there when the engine is cold. The car is undriveable in it's present condition.

When I'm under the car, I can see coolant dripping down directly from the middle of the front of the block/timing chain cover behind the harmonic balancer. What's above there that would leak so badly? Obviously the water pump is up there, but if the seal in the hub/impeller area is fine, what else would suddenly let go like that? A gasket? Seems unlikely unless a bolt has worked loose.

Just wondering of course if there's any chance the water pump doesn't need to come out.

[This message has been edited by Patrick (edited 04-12-2014).]

Dodgerunner APR 12, 07:56 PM
My guess is the area behind the large radiator hose that comes off the pump toward the front of the car. The gasket is very narrow there. I had one come loose there and start to leak bad. Took me a while to figure out where it was leaking since it was very hard to see and ran down off other places.
It's actually the timing cover to block gasket where the water passes through.

[This message has been edited by Dodgerunner (edited 04-12-2014).]

schw32m APR 12, 11:53 PM
Other place to check is the water pump front seals. The little hole in the casing where the pump shaft is has the tendency to leak as well
phonedawgz APR 13, 01:08 AM
The little hole is called the 'weep' hole. It is located after the seal but before the bearings. It allows the fluid to leak out before being pushed through the bearings. All rotating seals will end up leaking some. This way a tiny leak doesn't cause the water pump bearings to fail early.
trotterlg APR 13, 01:09 AM
The timing cover gasket that connects the heads to the timing cover and then to the pump are very bad actors. They leak often, and mostly when the pump is changed without clamping the top of the cover. If you do not clamp the cover it will pull the cover back and seperate the gasket from the block. Then in a little while you will end up with a coolant leak. Very common problem. Larry
84fiero123 APR 13, 12:40 PM

quote
Originally posted by phonedawgz:

The little hole is called the 'weep' hole. It is located after the seal but before the bearings. It allows the fluid to leak out before being pushed through the bearings. All rotating seals will end up leaking some. This way a tiny leak doesn't cause the water pump bearings to fail early.



ditto

just means the thing is gone and needs replacement that's what happens when it leaks out the weep hole. Get an inspection mirror under there to be sure but I bet that's what it is.

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

[This message has been edited by 84fiero123 (edited 04-13-2014).]

Raydar APR 13, 01:17 PM

quote
Originally posted by Dodgerunner:

My guess is the area behind the large radiator hose that comes off the pump toward the front of the car. The gasket is very narrow there. I had one come loose there and start to leak bad. Took me a while to figure out where it was leaking since it was very hard to see and ran down off other places.
It's actually the timing cover to block gasket where the water passes through.




This.
My 3.4 sprung a (slow) leak here. If you can get the car up on ramps or a lift, you can see it dripping down the big coolant hose.
Other than pulling the balancer, it's not too bad a job. You get to work mostly through the wheel well. Fun.
Go ahead and replace the crankshaft seal in the timing cover, while you're in there.

They may try to sell you the wrong water pump gasket in the gasket kit. (Most 2.8s, by this time, were using reverse rotation water pumps.)
I forget how I resolved it. Either asked for an 87 timing cover kit, or just bought the water pump gasket separately.
BrittB APR 13, 03:19 PM
How do you clamp the timing cover?
Patrick APR 13, 03:55 PM
Thanks for all the responses, guys. It's much appreciated.

I'll be shuffling three Fieros in my back yard to position the Formula in a location on the driveway where I can more comfortably work on it. As I had stated earlier, I don't think the seal at the hub/impeller is leaking as the backside of the pulley is completely dry. The leak might be at the gasket location that's been mentioned a couple times. Hopefully I'll know a lot more by the end of the day!

Doing some research here about this task, I came across several references to the danger of potentially creating a coolant leak between the timing cover and the block, which has been touched upon here...


quote
Originally posted by trotterlg:

The timing cover gasket that connects the heads (block?) to the timing cover and then to the pump are very bad actors. They leak often, and mostly when the pump is changed without clamping the top of the cover. If you do not clamp the cover it will pull the cover back and seperate the gasket from the block. Then in a little while you will end up with a coolant leak. Very common problem.




How is this clamping accomplished? I hope to be at this stage a little later today.

I grabbed some images I found and altered them a bit. The first two images were originally posted by ManMadeChickens in This thread, and I lost rack who originally posted the third one.

What is the purpose of the gap that I've indicated with a question mark? Shouldn't there at least be a stud with a nut on it used to hold down the timing cover below the water pump at that location?




I've added numbering in this image to match it up with the third image.






quote
Originally posted by Dodgerunner:

My guess is the area behind the large radiator hose that comes off the pump toward the front of the car. The gasket is very narrow there. I had one come loose there and start to leak bad. Took me a while to figure out where it was leaking since it was very hard to see and ran down off other places.
It's actually the timing cover to block gasket where the water passes through.



Just to clarify, I suppose it's more than the water pump that needs to come off if this is the issue? The timing cover as well?

[This message has been edited by Patrick (edited 05-13-2024).]

Raydar APR 13, 04:09 PM

quote
Originally posted by Patrick:
...
Just to clarify, I suppose it's more than the water pump that needs to come off if this is the issue? The timing cover as well?



Unfortunately, that's where mine was leaking. Between the timing cover and the block. Sounds like others have had the same issue.

I would be inclined to fill up the coolant, back the car up on ramps, leave the engine running, and climb under and have a look. (Or if you have someone nearby with a lift, it would be even better.)
Check between that large coolant hose and the block. It's where I saw the drips on mine.
At first I thought the hose clamp was loose. No such luck.