Blown Head Gasket? Block Seal? - Toyota Nation Forum : Toyota Car and Truck Forums

89_3SFE · 07-19-2006, 10:19 AM

I've got a 3SFE engine in my car and it's leaking coolant right behind the front passenger side tire. It looks like it's coming from the water pump, but my mechanic couldn't tell right off the bat. He replaced the water pump 2 months ago and he's going to pull the timing belt cover off today to see where the leak's coming from. He did a pressure test and noticed a lot more leaked from that area than if he just ran the car. He said it could be a bad water pump. He didn't say anything about a head gasket leak until I brought it up and he said that it could leak from the outside and not into the engine. What do you guys think?

Also, if the head gasket is bad, I heard of this stuff called Block Seal that I could use to seal up the gasket. How does that work, and does it work at all? How do I apply it and what steps do I need to take to ensure that I do it right? Also, how long does the seal last?

Thanks everyone!!

Mike Gerber · 07-19-2006, 02:20 PM

"he said that it could leak from the outside and not into the engine"

It can. I had this happen on an 86 Camry with a 2SE engine. The cure was to remove the head and replace the head gasket.

I'm not familiar with Block Seal, but to me, if something sounds too good to be true, it probably is. Maybe someone who has heard of or used it will pipe in here.

Mike

Kep · 07-19-2006, 02:35 PM

From your description I would expect your problem to be the water pump. The head gasket might be leaking into the timing belt / water pump enclosure but the odds are against it.

As far as block sealer goes, I am a fortunate user of it. I used CARGO block sealer. I had a small leak (maybe topped off my coolant every other week with a quart or so and had a small puff of water vapor out the exhaust on start up only). The way this stuff works you needed to drain the antifreeze and use plain water. When you put it in and circulate it (a couple of hundred miles) it reacts to air and clogs that area up. Just for grins I pulled the thermostat so it wouldn't get gummed up. Once your through you flush it out and refill the antifreeze and put back the thermostat. It held up for over three years until a lady T-Boned me last night. For that matter, it probably is still good. Anyway, if the water pump is leaking this stuff will clog up the axle and make the water pump worse.

However, I still vote for a damaged water pump.

Kep.

Mike Gerber · 07-19-2006, 02:56 PM

"However, I still vote for a damaged water pump."

Me too.

Mike

Doctor J · 07-19-2006, 03:16 PM

Please read my latest responce on Celica forum.

89_3SFE · 07-19-2006, 04:11 PM

For those of you who think it's the water pump, can it go bad that fast? My mechanic replaced it 2 months ago and I think it's weird it already broke, if it is the water pump that broke.

Doctor J · 07-20-2006, 08:54 AM

Could you please go to the Celica forum and read my responce to the thread posted yesterday.
It gives detailed explanation what part exactly fails if it was a shortcut in a pump replacement.

89_3SFE · 07-20-2006, 09:20 AM

Quote:

Originally Posted by Doctor J

Could you please go to the Celica forum and read my responce to the thread posted yesterday.
It gives detailed explanation what part exactly fails if it was a shortcut in a pump replacement.

I did read it, and thank you very much for your information. I can tell you know what you're talking about. I'm surprised that my mechanic would skip that step because he and his crew seem like rather thorough guys.

I talked to them last night and the secretary in the office said that she overheard the mechanics saying something about the thermostat housing. Doesn't that come with the whole water pump assembly when you buy a whole new water pump w/housing and all?

Mike Gerber · 07-20-2006, 09:46 AM

"I talked to them last night and the secretary in the office said that she overheard the mechanics saying something about the thermostat housing. Doesn't that come with the whole water pump assembly when you buy a whole new water pump w/housing and all?"

No, the thermostat housing is an entirely seperate item. If you follow the upper radiator hose back from the radiator and in to the engine block you will see it. It has 2 nuts screwed in to 2 studs coming out of the block.

Mike

Doctor J · 07-20-2006, 11:28 AM

Mike, the thermostat housing on 3SFE and 5sfe engines is bolted to the water pump body (engine end of the lower radiator hose) this housing also has the rad. fan switch threaded into it. It is a separate part that is transfered to the new water pump body. The thermostat housing has a counterbore at the the flanged end that houses the thermostat gasket. Occationally, the aluminum on the flange surface corrodes, which allows coolant to leak. The housing needs to be inspected. If leaks are due to minor pitting, epoxy filling may help, as well as applying OEM toyota black seal packing RTV to the flange in addition to the gasket. Other option is to get a good used housing from the wrecking yard.

89_3SFE · 07-20-2006, 11:32 AM

My mechanic called back and said that it's a cover between something and the engine block that's leaking so he's going to try some stop leak. He says it has worked loads of times and he has some great stuff. What are all your opinions about this stop leak stuff?

The car leaks hardly at all when it's running on its own power but when he pressurizes it 10 psi more than the engine can do, it leaks more. Is that a good sign that this stop leak stuff should work? I think I caught the leak fairly early, so I'm optimistic, but I wanted to see what you guys thought. Let me know.

Doctor J · 07-20-2006, 12:09 PM

If mechanic will just add a stopleak to the cooling system, it may plug the radiator resulting in overheating. Could you please ask him one more time where is the leak? What kind of cover was he talking about?