Overheating Engine, No Heat, Good Thermostat
- Thread starter Von Hayek
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WAIT!
This absolutely needs to be addressed first.
Until you do, you can't accurately diagnose anything. You can't monitor coolant levels, you can't isolate the source of the overheating (the leak itself may be the problem), anything.
Please pinpoint that leak asap.
Curtis
- Thread starter
- #24
Well, I tried with a mirror at every angle I could find and simply could not observe the back of the head where it meets the block.
I'll pressure test again this afternoon and I see if I can find the source of the leak, but it was fruitless before.
When you pressure tested, what did you set the PSI to?
- Thread starter
- #26
17 psi
Factory is 13 PSI. You likely blew out several fittings that were never designed to take that pressure. I would also expect fittings/hoses that have not yet failed will do so down the road in the not too distant future..
Between the stop leak and running a high PSI, if this were my vehicle I'd be completely replacing pretty much the entire cooling system. Radiator, hoses, etc etc etc.
I think stop leak is about one of the worst things you can do to an engine. It might help you in the short term, but I've never heard of it being good in the long term.
If you can't see the leak, there is a very easy way to isolate it's location. Get some white paper towels and clean off the areas that you are expecting to be leaking. Then stuff or tape clean paper towels in small sections to the areas of suspect, and do your pressure test again. Observe which paper towels are now red with coolant, and you have your leak. Based on what I have seen from your responses, I would start with the block/head junction at number 6 and go from there. I am speaking from experience when I say that the troubleshooting portion of the head gasket job, is much easier than the labor involved in replacement, and confirming that you do not have an externally leaking HG is much less expensive than assuming that you do.
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- #29
Factory is 13 PSI. You likely blew out several fittings that were never designed to take that pressure. I would also expect fittings/hoses that have not yet failed will do so down the road in the not too distant future..
Between the stop leak and running a high PSI, if this were my vehicle I'd be completely replacing pretty much the entire cooling system. Radiator, hoses, etc etc etc.
I think stop leak is about one of the worst things you can do to an engine. It might help you in the short term, but I've never heard of it being good in the long term.
The factory service manual calls for 17.1 psi for a pressure test.
That is one excellent suggestion. Trying that next.
I just pulled the hose off of the back side of the hard pipe that runs along the passenger side of the engine. That hose runs to a T which splits off to both heaters. With the valve open, I ran water down that hose and it came pouring out of the block drain, then the hard pipe I yanked the hose off of, and eventually the radiator. I don't think I have a blockage. It was free flowing.
I agree that you probably didn't hurt anything. I might have started at 13 first to see if that was enough to cause leaking, but no biggie either way.
The factory service manual also assumes that everything is up to FSM spec, which it's obviously not in your case since it's leaking.
One of the very few cases where I disagree with the FSM. But only because I've seen more than one case of people testing at around 17 PSI, and either blowing something then or having leaks shortly down the road.
To be clear, I don't think that testing at 17 PSI is the end of the world. I think it's likely that it stressed components and shortened their life (maybe even caused your leak), but they would have likely been components to fail down the road anyway.
17 Psi isn't too much. If the part can't take that, it would fail at the time it was pressurized.
- Thread starter
- #33
OK, just spent the afternoon until dark and this leak will not be detected without dropping the transmission.
I took a point and shoot camera and jammed into the firewall and up above the bell housing but to no avail.
I laid a piece of cardboard on top of the engine so I could lay on it. I put my forehead up against the firewall and could not see the source of the leak with a light and a mirror.
I tried the suggested method of putting a paper towel on the back of the head, but getting one's hand back there is not possible.
I am certain that I looked at all of the hose connections going into the firewall and running to the rear heater pipes. This leads me to believe by process of elimination that the leak must be coming from between the head and the block. There is simply no other source of coolant that could be reaching the top of the bell housing.
Add that to the fact that the radiator is new, the thermostat is new, the water pump works, and there are no symptoms of a blockage, and I don't see where else there is to go.
I took a point and shoot camera and jammed into the firewall and up above the bell housing but to no avail.
I laid a piece of cardboard on top of the engine so I could lay on it. I put my forehead up against the firewall and could not see the source of the leak with a light and a mirror.
I tried the suggested method of putting a paper towel on the back of the head, but getting one's hand back there is not possible.
I am certain that I looked at all of the hose connections going into the firewall and running to the rear heater pipes. This leads me to believe by process of elimination that the leak must be coming from between the head and the block. There is simply no other source of coolant that could be reaching the top of the bell housing.
Add that to the fact that the radiator is new, the thermostat is new, the water pump works, and there are no symptoms of a blockage, and I don't see where else there is to go.
Well, there is at least one case here of a member discovering an external HG leak that way. He had the tranny out for unrelated reasons, took a look at the back of the motor, and went, "Holy crap!"
The head gasket is toast. In some cases there is a pressure buildup that prohibits coolant from circulating through the heater cores. I seem to remember one of Semlin's symptoms when his head gasket blew was no heat.
Dang Dan, nail in the coffin. You can get back there, take the hood off, put a nice sturdy 2 x6 across the two fenders and get on top. I would still confirm. If you have water coming out of in between the head and block, you will be able to find it.
I had an external leak, towards the back of the block on the exhaust side. This was three months after I replaced the HG. I started losing water and started investigating when I found the leak. I found out later that my "unwarpable block" was indeed warped. I did not bother to have it checked when my head was off getting refurbed. Turns out a perfectly flat head does not mate well with a warped block. I can only imagine what the PO history of my rig was.
Not trying to scare you, from what I hear, my case is fairly rare.When my head gasket went for the second time at 182k I had no heat. Number 6 cylinder was where the gasket failed. Also some electrolysis at the same spot. I chose to buy the short block for Toyota and rebuilt the head. $7845.00 later it runs pretty good.
Been having similar issues with mine. Done all what you have. Could it be a transmission heating up on you?
- Thread starter
- #40
Thanks Dan. You'll be getting a call later from me.
What, is this a jinx!?
No, I have a boiling radiator. Transmission works very well.
