86 2.9l cooling issue

[Cameron1591]

I just finished replacing the heads on my 86 2.9l V6 this weekend due to a head or gasket crack. It started up and ran fine the 1st day. Just the other night we were getting pounded with snow so I took it out to test the 4x4 in the fresh snow. I let it warm up for about 5 minutes, topped off the overflow coolant tank, then went for a drive. About five miles out I noticed my temp gage was almost to the high mark but still in the normal range. I stopped and shut it off to avoid overheating. Had the heat on full blast while driving and with engine off. Lots of strong cold wind to keep it cool from the storm as well.

It has a recently replaced thermostat, and both coolant sensors by the therm. Not showing any moisture on oil dipstick to signify head or gasket leak either. Also has a k&n cone filter in place of airbox.

Any idea what could cause this heat spike in such cool conditions?

 

[hende]

are you sure there is no air in the cooling system?

 

[Cameron1591]

No I am not sure.
How would I go about checking this and in turn correcting it?

 

[a31ford]

The aftermarket thermostats are NOT exactly like the OEM, you see, the OEM has a small "pin hole" to allow air to pass the stat, so what it gets is warm water, and NOT air built up behind (block side) of the stat.

ALL thermostats that I install in ANYTHING, get a 1/16" hole in the stat plate, AND oriented so the hole is at the top portion of the housing (UP).

It is quite possible that an air bubble formed behind the stat, this would explain the wierd condition..........

Greg

 

[Cameron1591]

With further inspection I found coolant in the oil. Only showing at the oil fill spout not the dipstick.
Also noticed coolant on the block under the therm housing and where the head and lower intake meet the block.
I do have a therm with the hole up top to release air and positioned correctly.

I just realized I never retorqued the lower intake after running the engine.
Would this cause the leak into the oil?
Or does it sound like a more severe problem?

 

[FritzTKatt]

Possibly. Did you properly put permatex around the coolant passages? Are you sure that you properly torqued the head bolts too?

 

[Cameron1591]

I followed the specs in my chilton manual for the bolts just missed the retorquing lower intake.

For the permatex I put it on the corners where the heads block and lower intake meet like the manual said. Was told by the parts store the gasket already had the sealing material for the coolant passages.

Should I have put some on anyway?
If so can I still do this with the current gasket?

 

[Cameron1591]

Well I believe I resolved the coolant leak issue. My problem was I forgot to retorque the lower intake after running the engine.
All the bolts on the passenger side were about 10 ft lbs loose driver side was about 5.
Its been running fine for the last 2 days with no signs of coolant leaks in the oil
Coolant level has stayed relatively the same.
Temp gauge hasn't gone past the high mark. Likes to get close initially then settle back down around half way.

Just wanted to thank you guys for ur input and advice.

I'm thinking of putting in a lower temp therm to help keep the temp down now.
Any suggestions on how much lower I should go?

 

[Reds 88]

Another little tip I like to do is fill my coolant system with very hot,almost boiling water. This allows the thermostat to open when filling the coolant system. This has always worked for me to help prevent air from getting in the system.

 

[freedom5]

Another little tip I like to do is fill my coolant system with very hot,almost boiling water. This allows the thermostat to open when filling the coolant system. This has always worked for me to help prevent air from getting in the system.

Another tip is to replace the thermostat with one that, if fails, fails open. they only cost about $2 more.

freedom5

 

[Reds 88]

^^^ Good tip there Freedom 5,I didnt know that. Thanks