Big Mysterious Coolant Leak :O

[Chirpbark]

After the car's been sitting for a while, because of broken bearings, I ran it a little just to keep the engine healthy, and it appears the coolant leak is a lot worse. Seems to be coming from directly under the timing belt cover, dripping off the top of the oil pan, pooling on the splash guard nearer the driver side, and spilling everywhere. It doesn't seem to be coming from the water pump, but I can't necessarily reach or see all the way under it. Hose isn't leaking in that spot either. Why why why?

Also, I've added the car to gofundme: http://www.gofundme.com/e6cxxk; I just don't have the tools, time, or cash anymore to deal with it myself

[Chirpbark]

I just need my reply deleted, the original post can stay. And yeah, figured crowdfunding was worth a try.

Anywho, wondering if it's even possible for coolant to leak from the bottom of the timing cover on these cars?

[irowiki]

Yes!

The o-ring between the water pump and the block is probably bad.

It's the hole right above the tensioner.




You might want to replace your timing belt and maybe your water pump while you are at it.

I can list you all the gaskets and o-rings I ended up needing if you like.

[Gottolovem]

If it's leaking from the bottom of the water pump it will "wick" down the front of the block and appear to be coming from the timing belt cover check the pump first.
If it's there the repair is much less work

[Chirpbark]

Good, thx. So it definitely can't be coming from through a crank or cam seal? And probably not a block crack or hg? It can probably leak a cup within an hour

[irowiki]

You might be better off taking the timing belt cover off...

[Chirpbark]

Oh wait, the hole is actually behind the cover? Dang, just noticed that. I may need that gasket list eventually...

If I just wanted to replace the one seal for now, can that be done by only removing the top cover & water pump?

[irowiki]

You'd have to remove the alternator belt, and the pulley from the water pump. Then the upper timing cover will come off.

At which point you'll need to probably put the pulley and belt back on, start the car, and watch for leaks (unless it is obvious)

[irowiki]

I actually have a spare seal I'd be willing to drop in an envelope for you.

[Petros]

it is very unlikely the block is cracked or leaking, the only place for coolant to leak in that area is that large o-ring behind the water pump housing, the water pump shaft seal, and perhaps the o-rings on the by-pass and heater supply tubes comming out of the back of the water pump housing. These o-rings are usually very reliable, lasting many decades without problems, but when a car sits for many years without running they can dry out and crack. If the sourse is from behind the timing cover (and not dripping down from some other location) it is almost certainly from that large o-ring that Irowiki pointed out between the front of the block and the back of the water pump housing.

It is not too bad of a job to do yourself, you will need 10, 12, and 14 mm sockets and combination wrenches. There is no need to touch the valve timing belt (unless it is bad and needs to be replaced anyway, but that is a much more complicated job since you have to break the big front pulley bolt loose and than use a puller to get the front pulley off). This big o-ring is only a doller or two.

It would be a good opportunity to replace the water pump, they are not costly but they do last a long time, 100k miles typically, and are easy to replace later when you have the money.

You might try putting in a can of Barrs Leak, stop leak and see if that stops it. Not likely it will fix a bad o-ring, but it only cost a few dollars, no extra work (you dump it in the dradiator and run the engine for a while). It will not harm anything if it does not work, and if it does, it will allow you an interim repair so you can earn some money to get a few tools and do a proper repair later.

It is REALLY important you NEVER allow the engine to get hot at all. even the upper part of the temperature gauge below the red zone is too hot, and will compromise the head gasket. If the head gasket is damaged from overheating, there is no fix other than to do major repairs to replace the head gasket.

good luck.

[boisesr5]

4 years later, I have the exact symptom. Coolant appears to be pouring out of the oil pan gasket behind the big front pulley. It's still leaking an hour after I turned the car off, after having only run it for 30 seconds. Also, on the drive where everything went bad the pump belt broke.

Irowiki if you're still around do you have that gasket list? I'm going to pull the belts and water pump to see what I can see, unless Iro and Petros have other suggestions...

[oldfaithful]

Th O Riingbehind the water pump housing it sounds like.

[boisesr5]

Turns out the pully shaft was wobbly, pump failed and leaked. I replaced the pump, but did not take the extra step to get to the O ring. So far so good.

[Petros]

when the bearing in the water pump goes bad it usually causes the water pump seal to leak (the shaft wobbles as it rotates and allows leaking). Replace the pump with a new one, not rebuilt, if possible. the rebuilt ones do not last very long in my experience. if that solved the problem than you are good to go.

sometime the water pump housing will develop a leak behind it, where it is bolted to the front of the engine block. that is also a fairly easy repair, you will need a new o-ring, and it is a bit more involved to get at, but only a little more work than changing the water pump.

sounds like you have it solved, keep an eye on your coolant level until you know for sure.