Updated the Update Over Heat***. Engine bay heat

[Dari Desilva]

Thank you. I did the search while I was in the 70-Series Tech, so I expected it to find threads within that series. It makes sense now....this is why the 70-series section has 1000s of threads. Cool, thank you. I am out of this.....sorry for the spam. Good Luck.

 

[dannyvp]

Well I overheated again.
I have a new 3 row radiator, coolant was at the correct level. New temp sensor.
I have around 50 miles on the job, all of a sudden, running hot.
Last oil change was clear, no color at all in it.
when I pulled over, coolant was boiling, reserve bottle was full and had popped its top.
Coolant was bubbling out of the collection between the carb and the intake manifold.

only thing I have not done is replaced the thermostat, bc it’s only 3 mts old.

 

[BlackCat]

Well I overheated again.
I have a new 3 row radiator, coolant was at the correct level. New temp sensor.
I have around 50 miles on the job, all of a sudden, running hot.
Last oil change was clear, no color at all in it.
when I pulled over, coolant was boiling, reserve bottle was full and had popped its top.
Coolant was bubbling out of the collection between the carb and the intake manifold.

only thing I have not done is replaced the thermostat, bc it’s only 3 mts old.

You said in an earlier post that the top end was rebuilt. Meaning the head was gone thru and a new head gasket installed? If so, is it possible the head gasket is installed backwards? It would block coolant passages and cause overheats. I’m not 100% sure a 2F gasket can be installed backwards or upside down, but I know a lot of other motors they can be. Just something to think about.

 

[dannyvp]

I installed it. I don’t think it was backwards. I don’t know if it can be.

 

[Gretsch]

There's only one reason why a hot 2F will spew white smoke out the tail pipe after the coolant boiled inside the engine. A hot engine won't blow white smoke if everything is ok.

Coolant got into the combustion chamber/s somehow- and that never should happen.
Keep an eye on it and carefully watch the coolant level in the overflow tank. If the tank keeps losing coolant, there's an internal coolant leak inside the engine from either a blown gasket or crack in the head.

Did I miss the part where you post the results of the pressure test as @NeverGiveUpYota suggested early on? I looked back through this and couldn't find additional mention of the test to see if your system can hold pressure. Maybe I missed it.

One of two new dowel sleeves. These are critical to precisely align both the head gasket and the cylinder head.

Head gasket Toyota OEM or something else? I too am not sure if you can install it incorrectly or not. I thought the alignment dowels prevented that. I also thought I read where the dowels can get bent not allowing the head or the gasket to line up properly. The dowels I think are critical for proper head\gasket alignment.

Inlet hose - 150
Outlet hose - 150

You posted that the upper and lower radiator hoses were the same temp. Shouldn't there be a difference in temp between the two if the thermostat were installed\working properly. Was the thermostat Toyota OEM or something else? Was the rubber O-ring placed on top of the thermostat when installed?

Do you get heat when turning the heater on?

 

[NeverGiveUpYota]

A quick recap straight from @dannyvp via text, he had not done a pressure test.
“I replaced the radiator, hoses, coolant, temp sensor instead of testing it. I also did a compression test. Head was magnafluxed and planned tho shop had said it was w/in spec. New digital torque wrench and had retorqued. Headbolts reused.”

 

[dannyvp]

Heat worked when turned on.
I remember the gasket was aligned with the pins.
gasket was a SOR if I remember correctly. (I can’t remember if that was the intake gasket that was a sor or the head)

 

[dannyvp]

Here’s the head gasket I installed.

 

[OSS]

Here’s the head gasket I installed.

That thing is a POS. If it's the SOR head gasket it's definitely a POS. They should be fined for selling those. It is not "fine" no matter what they tell you, it's a disaster time bomb. I'd know, I installed one of those Ps O S... and a couple years later had to install another HG. The second time I used the Toyota gasket.

The Toyota 2F gasket looks like THIS:

But after saying all that negative stuff about the POS SOR HG, I can't say that it's the cause of your overheating problem. I do know that the coolant flow through its holes is MUCH different than the Toyota gasket. The coolant flow through the head therefore is different as well.

Whatever you do, plan on some time in the not too distant future, replacing that cheapo wrong gasket with a genuine Toyota HG.

 

[dannyvp]

That thing is a POS. If it's the SOR head gasket it's definitely a POS. They should be fined for selling those. It is not "fine" no matter what they tell you, it's a disaster time bomb. I'd know, I installed one of those Ps O S... and a couple years later had to install another HG. The second time I used the Toyota gasket.

The Toyota 2F gasket looks like THIS:

View attachment 2112878

But after saying all that negative stuff about the POS SOR HG, I can't say that it's the cause of your overheating problem. I do know that the coolant flow through its holes is MUCH different than the Toyota gasket. The coolant flow through the head therefore is different as well.

Whatever you do, plan on some time in the not too distant future, replacing that cheapo wrong gasket with a genuine Toyota HG.

I think that’s an OEM one. I think. I think the SOR one is the intake gasket I put on.
With a new radiator, hose, coolant, temp sensor and a thermostat 3000 miles ago, what could cause running hot and overheating like this?

 

[NeverGiveUpYota]

There’s an obvious difference in how those gaskets look in each photo... here’s mine from the dealer that’s been tucked away for safe keeping.

 

[dannyvp]

There’s an obvious difference in how those gaskets look in each photo... here’s mine from the dealer that’s been tucked away for safe keeping.

View attachment 2112953

oh yea, sure is!
Can I borrow that for a bit.

 

[John McVicker]

And yes, you can install the OEM HG incorrectly...ie.backwards.

There is a ‘lip’ which sticks out on the rear of the head (lip goes towards the firewall). If you put the lip @ the firewall, you will have done it correctly.

 

[dannyvp]

And yes, you can install the OEM HG incorrectly...ie.backwards.

There is a ‘lip’ which sticks out on the rear of the head (lip goes towards the firewall). If you put the lip @ the firewall, you will have done it correctly.

so the lip in the wrong location will cause overheating?

 

[John McVicker]

so the lip in the wrong location will cause overheating?

Yes. There is a reason that lip is there.
If the HG is installed upside down/backwards you will be covering up some of the holes in the head. Effectively blocking some of the coolant passages.

 

[dannyvp]

Yes. There is a reason that lip is there.
If the HG is installed upside down/backwards you will be covering up some of the holes in the head. Effectively blocking some of the coolant passages.

i was looking at the FSM and it doesn’t mention it, I don’t doubt you at all. I also wonder if the block has some passages blocked maybe.

 

[dannyvp]

I do not pass a pressure test of the cooling system. It will not pump up and hold pressure. I can’t see a leak, but I can hear it bubble or fizzle.

 

[BlackCat]

I do not pass a pressure test of the cooling system. It will not pump up and hold pressure. I can’t see a leak, but I can hear it bubble or fizzle.

Unfortunately, I think you know what direction this is going. My next step would be to pull each spark plug, crank each piston around till it’s up at TDC, and see if you can shine a flashlight in the spark plug hole to see if you have any steam cleaned pistons. Or pressure test the cooling system without spark plugs in it and see if your “fizz” noise gets louder.

 

[dannyvp]

Well I started the truck after I cleaned all the coolant off to see if I could find a leak. The coolant is running (not dripping) out of the exhaust manifold and down the muffler.
I also removed the valve cover to see what it looked like.

 

[BlackCat]

Well I started the truck after I cleaned all the coolant off to see if I could find a leak. The coolant is running (not dripping) out of the exhaust manifold and down the muffler.
I also removed the valve cover to see what it looked like.

View attachment 2113598

View attachment 2113599

Case solved. Looks like you’re doing a head gasket again. Be careful running it, if it’s leaking that bad it could hydro lock a cylinder and bend a connecting Rod.