‘98 3.4L coolant leak

[JFrog]

I’ve started loosing coolant on my 300k T4R. I originally thought it was dripping from the heater control valve but I’ve replaced it with a new one. It’s running down the very back of the motor on the passenger side and looks like it’s coming from just under the new control on top the motor. I just can’t see where without taking everything off the top of the motor. Wouldn’t that be too high to be the head gasket? I can see the larger heater hoses and they appear to be dry....input? Any input? Thanks, folks!

 

[nobb]

Do a UV dye test.

 

[spartacus]

I’ve started loosing coolant on my 300k T4R. I originally thought it was dripping from the heater control valve but I’ve replaced it with a new one. It’s running down the very back of the motor on the passenger side and looks like it’s coming from just under the new control on top the motor. I just can’t see where without taking everything off the top of the motor. Wouldn’t that be too high to be the head gasket? I can see the larger heater hoses and they appear to be dry....input? Any input? Thanks, folks!

there is a coolant bypass tube that runs under the intake manifold in the cavity between the heads it is connected to the motor with a flange that is sealed with fipg and overtime might leak and pool coolant in the cavity that leaks from the back of the motor. if you have a long mirror tool you can see if there is coolant pooling in that area.

 

[curryT4R]

Does the 5VZ have a coolant valley pan? It could be leaking and dripping down the back.
I know the 1MZ and 3MZ engines had problems with leaking coolant valley pans and they are of similar design to the 5VZ.

 

[JFrog]

there is a coolant bypass tube that runs under the intake manifold in the cavity between the heads it is connected to the motor with a flange that is sealed with fipg and overtime might leak and pool coolant in the cavity that leaks from the back of the motor. if you have a long mirror tool you can see if there is coolant pooling in that area.

A mirror.....damn, why didn’t I think of that?! I’m an idiot! Thanks!

 

[Outsider1]

Hello, I changed the lower intake plentum gasket along with the coolant hose gasket. When I opened it up there was fluid there. What should I do, I’m still loosing coolant

 

[nissanh]

Do you mean intake manifold gasket?

 

[gamefreakgc]

Hello, I changed the lower intake plentum gasket along with the coolant hose gasket. When I opened it up there was fluid there. What should I do, I’m still loosing coolant

There's a few gaskets that are used to contain fluid between parts. Sounds like you got the easy ones. The IAC gasket also holds fluid and could drip down (a bit messily though) and the head gasket can also leak into the valley if it fails.