Help! Overheating issues after new head gasket, can't figure it out

[calinaki]

flow direction

Question on the thermostat placement for the 3vZE: I always thought that the thermostat opened and then allowed flow through it in the direction of the radiator. However, I heard that the flow from the engine is into the top of the radiator and then the cooler fluid is out the bottom of the radiator to the thermostat. So my question is, how does the thermostat "sense" the hot temperature if it's in contact with the 'cooled' flow off the bottom of the radiator? The jiggle valve would also allow a small amount of flow from the bottom of the radiator, through the tstat to the opposite side of the tstat. Am I thinking about this correctly??? THanks for any clarity! I can't find a flow path diagram anywhere for this cooling system.

 

[CharliePR74]

I read part of the thread and then came to check on my runner's engine pics (replaced my heads gaskets exactly a year ago). I remember being very cautiously right in that step, installing the gaskets as they were going to be buried underneath those heads for a good amount of time! Can't recall it but I think they came with some stamped info specifying at least the side they were supposed to be placed. Other than that, I compared them against the old ones and it wasn't that tricky. You can see from the picture, both sides are almost identical but one orifice that is missing on the left side (the one on the right side, pointing forward). I think is very difficult to block a passage due to their configuration. Just thinking positively!

Didn't have heating issues with mine. Check your temp sensor/wiring. Sometimes sensors and wires start to give headaches as they get moved around during this type of job. Maybe is something simple, fan clutch, clogged rad.

Do a simple test. Remove the thermostat but re-install the bottom hose connection housing to the engine, disconnect the top hose from the rad and try to pressurize the engine from bottom to top. Water should come out if gaskets were installed the right way... Hope that helps.

 

[4runner15]

Conclusion to problem

Conclusion

"I discovered that my problem was that I had switched the head gaskets when doing my HG job. That was my conclusion after eliminating most, if not all, of the probable causes.

Some explanation.. The two head gaskets are nearly identical with the exception of one hole the size of a nickel. This hole is where coolant passes through and if the gaskets are swapped, that coolant hose is blocked. Hence, coolant does not flow through the system. This explained why the lower hose remained cold (with thermostat in).

It may be hard to believe since the only solution to confirm this would be to tear it down again to check whether or not this be the case. I'd say if all else fails and you've eliminated all possible causes, do what you need to do."

 

[gio-geno]

Conclusion

"I discovered that my problem was that I had switched the head gaskets when doing my HG job. That was my conclusion after eliminating most, if not all, of the probable causes.

Some explanation.. The two head gaskets are nearly identical with the exception of one hole the size of a nickel. This hole is where coolant passes through and if the gaskets are swapped, that coolant hose is blocked. Hence, coolant does not flow through the system. This explained why the lower hose remained cold (with thermostat in).

It may be hard to believe since the only solution to confirm this would be to tear it down again to check whether or not this be the case. I'd say if all else fails and you've eliminated all possible causes, do what you need to do."

Hello there
Did changing headgaskets solve your problem?

 

[Toyotayoda]

Hello there
Did changing headgaskets solve your problem?

yes it did. the cylinder head gaskets are marked for left and right

 

[gio-geno]

yes it did. the cylinder head gaskets are marked for left and right

Thank you.
I have been trying to solve this overheating for months, I hope changing headgaskets will help.

 

[FordF150]

Get a new radiator

 

[firebirdguy]

Get a new radiator

did you read the 3.5 year old thread captnsolo? it was the head gaskets mixed up causing the issue, why would he need to get a new radiator??

 

[Snopy886]

Swapped HG over heating issues

1997 4runner..Hi thank you for this helpful information. I am having the Sam exact symptoms and after reading I took a look back at my pictures and found it is just that, HG installed incorrectly/ swapped .