M42 rad + M50 overheating woes.

[lolcantturn]

Got an M42 rad. Got an 80*C t-stat. Got a 14" IE Fan wired in properly. Brand new coolant temp sender (to the gauge)

When I'm on the highway, my temp gauge just climbsssss. The faster I go, the more the revs build up, the hotter it gets even with the heat on. The heat is basically fire.
When I'm idling, it'll stay right below the halfway mark.

what the heck is the deal? I left the rad cap off and the bleed screw off and let it idle for about 10mins with no problems and the heat on to let itself bleed through and it didn't overheat, but when i put the cap on and bleed screw on and drive normally it'll just heat up.

Thoughts?

[KenC]

Coolant lines into the heater core might be backwards.

[lolcantturn]

but my heat is super hawt, wouldn't it just not work ?

[KenC]

Do the heat output temps fluctuate at all? Hotter at idle than driving?

[lolcantturn]

Seems roughly the same. A little hotter driving but i guess that's cause my car's overheating haha.

[KenC]

It doesn't make sense that it cools down at idle. Is your t-stat stuck closed... or open?

[lolcantturn]

I have no idea. It's fairly old but came from a known working well never-overheated M20.

[sticksdaman]

Perhaps your drive belt is slipping? If your belt isnt under enough tension it may not be turning your water pump fast enough to keep up with the engine at higher revs. That may explain why at idle it's fine but at speed it isnt pumping enough coolant in/out fast enough to maintain an optimal temp.

[lolcantturn]

My drive belt is pretty darn tight. ill double check.

[trackjunkie21]

uhm why reuse a thermostat? It's a couple bucks and it's not worth the risk to use an old one.

[AndrewBird]

Your cooling fan isn't accidentally set to blow AWAY from the engine (forward), is it? Had a friend do this with a mechanical fan. Took him forever to figure out why the car was over heating.

[lolcantturn]

uhm why reuse a thermostat? It's a couple bucks and it's not worth the risk to use an old one.

Because carrace. I'll buy a new one it doesn't matter to me.

Your cooling fan isn't accidentally set to blow AWAY from the engine (forward), is it? Had a friend do this with a mechanical fan. Took him forever to figure out why the car was over heating.

Nope it's blowing air towards and through the rad, setup fine.

[328ijunkie]

Your biggest problem is the M42 radiator and the fact its too small and its a mother Fer to bleed properly.

[lolcantturn]

People run M42 rads all the time thoughhhh.

It is a bitch to bleed well though fuck.

[nrubenstein]

Did you elevate the front end while bleeding it? I'd start there.

the M42 radiator sucksass, but it doesn't suck so much ass that you can't drive the car with it.