Car eats coolant like a fat person eats donuts!

[surfer63]

Hello,
I recently did a tuneup on my '92 SVX and replaced both O2 sensors and was finally able to pass smog. It has around 170K. The problem is, it's been overheating. I never let the needle get above 75%. I've been able to keep the temperature down by blowing the heater and/or shutting off the car when necessary.

The thermostat, radiator, and cap are brand new. There are no visible coolant leaks anywhere. However, I keep having to add coolant, it's like it's a blackhole that leads to nowhere. If I let the car run for awhile to bleed the air out of the cooling system, it seems like the bubbles never stop, but finally the coolant level does get full at the radiator.

The real mystery happens only when driving the car. I'll drive the car for an hour, shut it off, let it cool, and I'll have to add more coolant again. The temperature has been fine, but only if I add coolant every day. The reservoir level remains the same and like I said, there are *no* external leaks that I can find.

Also, which probably does not make a difference, there's a minor oil leak coming from one of the front seals on the passenger side. I say minor because I rarely have to add oil to the car between oil changes, if at all. Apparently, the guy who did my timing belt last time either stripped some threads, or just left off a bolt, and I visibly see one of the seals is damaged. Either way I can tell I had a bad mechanic. I'll be doing all the work myself from now on since, in the words of Fox Mulder, TRUST NO ONE!

My question is, do I have a major seal problem? I don't find any coolant in the oil, or any oil in the coolant. There's no unusual colors coming from the exhaust pipe. I'm stumped! HELP! My SVX is a money pit and I hate my life!

[redlightningsvx]

What does your oil look like,smell? Maybe head gasket but i'm unsure?

[surfer63]

I didn't drain all the oil, I drained about 1/2 quart to look at it, but it looks black like normal (for my car, 1000 miles after an oil change). I can't find any traces of oil in the coolant either. I've had temperature issues with the car, but I'm careful never to let it get above 75% on the temperature gauge. The whole reason I watch the needle so closely is because I'm worried about the head gasket and mechanical damage. Despite my efforts, could I have blown a head gasket?

[SVXMAN2001]

Is there a noticeable fume color coming out of your exhaust? From my experience, on the most severe end of things you have a faulty head gasket (which I highly doubt). SIDE NOTE: Antifreeze gives off a white smoke, when I dealt with my radiator issues, where my fluid was literally spewing from the radiator spout, once it got into the engine bay there were plumes of white smoke, could barely even see.

On the other hand, your thermostat may be defective, where did you purchase it? Are you sure it is installed correctly? There is a small hold/pin that needs to be at 12 o clock when installed, if not the thermostat will not operate correctly. I have heard of a few members having purchased brand new thermostats both from autozone/advanced auto parts/pep boys AND Subaru that were defective from the start, i'd start there. Also, when you had the timing belt done was the water pump also done? this could also be a culprit, seized waterpump.

Other than that, when you fill up your radiator (50/50 split, half water half antifreeze) make sure the heat is on.

[surfer63]

Previously I had bought one from Advance and it was complete crap. The gasket they gave didn't fit right either, causing the thermostat housing to leak. I recently replaced it with a genuine subaru thermostat, and it's installed with the bleed hole on top. I also haven't noticed any white smoke/steam from the engine bay or the exhaust or any unusual smells.

My previous mechanic *claimed* to do the water pump and timing belt (it was about 10K miles ago) but after inspecting his work I don't trust anything he said.

I tested the brand new thermostat in a pot of water before I put it in the car and it opened like it was supposed to. Should I go ahead and replace the water pump, timing belt, and cam seals? What symptoms would I see if the water pump were seized? I've heard of water pump seal failure, but never seizing up.

[kwren]

blown head gasket

[SVXMAN2001]

kwren, i agree that it could be a blown head gasket, however, I am only reluctant to suggest that that is the primary culprit due to its significant cost to replace (if one isn't able to tear down the cylinder head by themselves) AND i was told by numerous members that I had a blown head gasket about a year ago only to later find out my overheating issue to a faulty thermostat.

Surfer, just for piece of mind, there are a number of blown head gasket threads on this forum, perhaps searching them might give you some more insight. There are a variety of ways to test if you have a blown head gasket (is the top hose rock hard when the engine is running?).

Since the timing belt was put on 10k miles ago and you didn't immediately have overheating issues I wouldn't see the need for installing new timing belt (I could only see the timing belt causing overheating issues if it wasn't aligned properly, and if it weren't you would have immediate overheating issues), may be worth the effort to take a look at the water pump though.

Are you sure the radiator itself is good? how many miles are on it? Is it suffering from the notorious top crack along the plastic part?

So, so far you've ruled out that you have a faulty thermostat, next is to check the water pump and radiator itself.

As for how to tell whether or not the water pump is seized, I wouldn't really know to be honest, however, i would assume that it wouldn't rotate as freely as it should.

[OrangeOkie]

New radiator and water pump solved ALL of my cooling issues.

[surfer63]

how can i test the water pump without taking everything apart?

[TomsSVX]

look at it... When pump seals go bad it will leak coolant from the vent holes to let you know before a big failure. If the water pump seems to be leaking, then it most likely has internal seal failure.

Head gasket failures in the SVX rarely mix oil and coolant. More often they leak compression from the cylinders into the coolant system... This will push coolant out of the overflow... So, check the frame rail under the battery. If it is stained with coolant, the head gasket is more than likely the culprit.

Tom

[kwren]

right on TomsSVX

that would also keep the radiator from sucking the coolant back in with a decrease in coolant temperature as it is designed to do.

A seized water pump would take about 5 seconds to reveal itself. like Tom said, it would probably be leaking long before it got that far.

You can easily check the condition of the radiator.

Hope it works out ok for you, sorry

(am doing my head gasket this weekend)

A first for me... wish me luck... Keith