Overheating - water pump?

[CornerHard]

Hello, I have an 83 Subaru GL with EA81 that's been overheating recently. The issues started with leaking coolant, which I narrowed down to a hairline crack in the radiator close to the lower radiator hose connection. After sealing it up with JB weld, things seemed fine, but a short trip to the library saw my engine temperatures rising above normal (about 3/4 of the way up the temp gauge), and coolant started exploding out the top of the coolant overflow container. Every time the car gets up to temp and I start driving around, coolant starts spurting out the top of the reservoir, even though the top driver's side of the radiator is cool to the touch.

 

A couple details:

 

- I just replaced the thermostat after the issue started, but it didn't change anything

 

- Compression is between 160-170psi for all cylinders

 

- Since this issue started, I've noticed that the intake manifold gaskets appear to be leaking a bit of coolant

 

- When the car gets to the point where coolant is exploding out the coolant reservoir, I also get lots of steam coming out the engine exhaust

 

- If I take the oil dipstick out while the engine is running and the car is warm, I can see steam come out

 

My guess at what is going on:

The water pump is bad, so the coolant just builds up in pressure on the driver's side and pushes coolant out the reservoir, despite the radiator being cool to the touch by the radiator cap. The extra pressure has caused the intake manifold gaskets to start leaking, which is making steam come out the exhaust.

 

Am I on the right track here? Any other suggestions as to what's going on?

[ruparts]

Hi,

from what you describe it indicates a head gasket or cracked head allowing some compression and high temp from the cylinders into the water system inside the engine. if it does the over flow before it even gets warm you have pressure getting into the water. even if the water pump were bad it would have to get up to a higher temp before water would overflow. Best thing to diagnose it is a cooling system pressure test, just a little hand pump with guage for pressure , goes on the radiator in place of the cap, and if it don't hold pressure then you have a leak inside probably. almost any shop , even auto stores have them, might check it for free since it is such a simple test.

good luck with it

[Uncle Ed]

A better test is the block or combustion gas test. Its a chemical test that changes color when exposed to exhaust gases. Check your local radiator shops, for most of them its standard equipment. But head gaskets are a good bet.

 

Ed

[GeneralDisorder]

Water pump's rarely fail in that way - so rare that I have yet to see one. Either they work and leak out the weep hole, or the bearings totally give out and the seize, or just chew the bearing right out of them and gush coolant all over. If it's not leaking them it's not the water pump.

 

Most likely the head gaskets or you haven't got all the air out of the system. If the radiator was bad enough to crack it might just be clogged inside from corrosion - you may need a new radiator as well.

 

GD

[CornerHard]

I didn't have time to do too much troubleshooting myself, so I dropped it off at a shop, and they verified exhaust gas is pressurizing the coolant. Sad times!

[GeneralDisorder]

EA81 head gaskets are the simplest things around. Can easily be changed in an afternoon. Get yourself a set of the Fel-Pro perma-torques from Autozone - should be about $30 for the pair. Get a set of intake and exhaust manifold gaskets at the dealership and borrow or rent a 1/2" torque wrench. Pull the heads, have them milled flat ($35 - $40 per head) and reinstall them. Torque them to a final torque of 65 Ft/Lbs and you will never have to do them again.

 

GD

[vagen]

while it's apart have your radiator looked at it is not unusual for these to become plugged. it happened to my younger brother's EA81 hatch he had just 2-3 tubes trying to cool his whole engine.