Yet another overheating problem -- 1992 Corolla DX

[karugs]

OK, this is another thread about an overheating 1992 Corolla DX, 3-speed automatic if it makes any difference.

Conditions: New radiator installed, no leaks in radiator area, automatic transmission cooling hoses, nor radiator hoses (upper/lower). No leak to the front of the engine, leak is behind engine. It seems to originate from the area between the intake manifold, engine head, and starter area. I suspect one of the culprits to be the headgasket, but I can't figure it out exactly. Exhaust smoke is blue, and exhaust tip is covered in moisture (don't know if oil, water or coolant). When driving, car emits blue smoke even when warmed up. Oil dipstick seems to show no signs of coolant.

Symptoms:

1. When engine gets to operational temperature, the coolant leak is imminent and can easily be seen from below the car. Below operating temps, it has no leaks. So now I suspect that it's after the thermostat, right?

2. Leak is like a dripping faucet, and alot of coolant is lost. It's not a drip, drip, drip. It's alot more. It seems that the loss of coolant increases when the engine has just shut off.

3. Leak comes from under the intake manifold, behind engine, right where the intake manifold meets the head of the engine. When we shut off the engine, the coolant seemed to move backwards up the intake manifold plenums halfway through.

4. There is a hose coming from the heater valve to the pipe going to the water pump, it shows signs of coolant leak... but I can't figure out exactly because that hose is too far from #3.

5. Starter seems to have drips of coolant on it (top part) so anything on top or around the starter might be cause. We suspect a hose that comes from the thermostat, going behind the engine, and into a tube that leads to the water pump. But since it's so crowded in there I can't fully determine it. If anybody has any good diagrams I would love to point it out.

Please help! We would like to know what the possible causes are. A ripped hose? Headgasket? Also, if anybody would recommend a good mechanic in the Anaheim, CA, area, I would appreciate it alot. Yes I know it's Easter Sunday, that's why we ran out of luck looking for an open shop.

Thanks!

[JohnelP]

I would suggest to have a look at the water pump,too.

I have the water pump changed by the previous owner, so I can not help you with the exact symptom, but might worth a check. Water pump is on the rear side of the engine, exectly at the end of the hose you are talking about (the hose that passes the starter, too),

Headgasket - I don't believe... Do you have water in the oil dipstick? Headgaskets failures are rather associated with white smoke, not blue smoke. Problems with the start? If not, I would exclude the headgasket. For the blue smoke, you don't really want to fix it, trust me. Better change the car.

[karugs]

JohnelP, I understand your concern regarding the blue smoke (valve stem seals). I was just playing safe to mention it here just in case it is related at all. No problems starting up. Dipstick seems not to be contaminated with coolant.

I checked the water pump and seems to show no signs of leak. Also, since when the thermostat opened, the leak started. So this is a sign that the coolant is circulating, right? If so then the water pump is working. But there are no leaks on the right side of the car, where the water pump is. Also, I checked the general area of the water pump and all seems to be dry save for the rubber hose that comes from the tube going to the water pump. That same rubber hose goes to the heater valve area, and was showing signs of coolant but no leaks (like the coolant just splashed onto it).

A look into another car to purchase isn't too far, in fact my mom already mentioned she wants to replace the car already. But I'm concerned that she won't be able to use it, and I'll drive her around with my car (the Corolla is her car).

By the way it already has 207,8xx miles and by my own reading of receipts, has had at least 5 owners (spanning from Arizona, Nevada, Bakersfield, Long Beach, and us in Anaheim)

Thanks again

[foodaa]

Before the new radiator was installed, was the coolant leaking?

Blue Smoke = Burning Oil
White Smoke = Coolant/Water leaking into combustion chamber
Black Smoke = Rich fuel mixture (Too much fuel)

[cobrajet25]

There is a metal pipe that runs from the trans end of the engine under the intake to the water pump inlet in just the area you described. I think there are hoses that come off of this pipe and go to the heater core. You might want to check these hoses (and the pipe itself) if you see water leaking in the area behind the intake. The pipe is difficult to see if you are not looking for it, and it sounds like your leak is there. It could also be the o-ring that seals the pipe to the water pump (which is on the pulley end of the engine, not the back). Regards, Aaron

[karugs]

Foodaa,

Yes, coolant was also leaking, that's why we replaced the radiator (one of the radiator metal tubes for the transmission cooler lines was loose and leaking coolant). After replacing the radiator alongside that metal tube, the leak was gone.

However, this new leak is behind the engine, not from the radiator area. The radiator is fine now, no leaks at all in that area.

It seems that the blue smoke isn't related to the coolant loss, since it's burning oil? (another matter)? I guess it's also safe to say that the head gasket is intact because white smoke will indicate oil/coolant mixture, and we have blue smoke.

Aaron,

Exactly what I meant to say, that metal tube goes to the water pump and runs just beneath the intake manifold, hence it being difficult to see. That rubber hose going to the heater valve seems to have coolant drops on it, but I checked before starting the engine and it was dry. I will check that O-ring on the water pump end of the tube. I will also contact my local mechanic to make an appointment tomorrow, or Tuesday if he's busy.

Ok to clarify, the heater valve will have two or three hoses going out of it. One of them goes directly forward and into the engine, near the area where the metal tube from the transmission end starts. The other rubber hose goes diagonally into the metal tube that ends at the water pump. This is the hose that has coolant drops on it, but the other one that goes directly forward into the engine is bone dry.

Also, near that large metal tube is a large rubber hose, like the size of the radiator hoses, starting from same spot where the large metal tube originates from, and curves behind the engine. I was also thinking this could be the culprit because exactly below it is where I saw alot of coolant flowing like a faucet.

Do you think the mechanic would charge an arm and a leg for this job? It seems the intake manifold has to be removed. If so then I would suggest replacing all the hoses while he's at it.

By the way do you know what that metal tube is for? The one that comes from the transmission end going to the water pump? Should it carry hot coolant for the heater hoses? I noticed the coolant that came out was steaming hot.

Thanks again.

[Flashmn]

By the way do you know what that metal tube is for?´

Its the inlet pipe for the waterpump.

[REN69]

so this car has 200,000+ miles on it... when's the last time the waterpump was replaced??

[karugs]

Ren, I have no idea. It seems either I overlooked the receipts or didn't show any signs of it. Do you think it's the water pump? The main leak was far from it...

Thanks Flashmn. So it delivers hot water or cold water to the pump? I'm going to call the mechanic to see if he's available, hopefully the rain would cooperate and makes things easier for me (like keep the car cool )

Thanks again. I'll keep you updated. I hope it's just a minor repair...

[karugs]

Ok so we bought all 3 heater hoses, and two radiator hoses, plus 1 large hose. Grand total: $300 (parts & labor). Waiting for delivery of hoses on Wednesday at the Toyota dealership, then once there I'll pick it up and head to the mechanic. Hopefully that's it...

Also we'll have the transmission flushed - $36 for 12 bottles of ATF and $20 labor. Good?

[foodaa]

Just hope your problem is not a warped head/block.

[JohnelP]

Just thinking, that in some other models it happens ofter for the interior heater matrix to fail.

[karugs]

But the mechanic saw the hose was leaking...? We already made an appointment for tomorrow since the parts arrive in the morning at the dealership. I pick it up and head to the shop to have it done... pray it is just a hose!

Foodaa, I hope the same too!

John, where is the interior heater matrix located?