so ive got this car im working on that was only supposed to be a tune and turned into much much more. anyway, with the engine running, the top hose gets hot and the bottom hose stays cold....ok so you think thermostat? me too. pulled the thermostat and tested it. opens fully in boiling water.

thought about blockages or maybe a bad water pump. pulled the water pump, which spins fine and looks brand spanking new on the inside. while i had the pump off, i poured water through the top hose and water came through the water pump feed port. while doing the thermostat i poured water through the radiator and it came out the lower hose which attaches to the thermo housing. I removed the cooling lines going to the heater core since he already had them removed and looped so that eliminated the heater core from being clogged up.

he has his cooling lines from the turbo being fed from the front cooling pipe that crosses over the front cover then the return that is under the front side of the exhaust manifold.

i pressure tested the system and it held 17psi for 45 minutes and never fell, nor did i see a leak.

the fans dont turn on due to the fan switch being bad, but i hooked the fans straight to the battery with it running. it gets up to about 210 and will stay there at idle (it did for about 15 min before i shut it down) but as soon as you start revving on it, the temp goes up.

he had the head replaced and a new headgasket. Unsure of the brand of gasket or history of head. I dont smell anything in the exhaust and it doesnt have any white smoke coming out.


any ideas before i pull this head off?

 

This sounds like a radiator that plugged inside. Did the fellow use any head gasket sealer stop leak recentley? Do the simple (cheap) things first I say. Just have the rad shop clean it.

 

Thought that too. Took the rad and fan from my race car and rigged it up. Same problem

 

is it building air in the system. remove the turbo coolant lines and cap them, then recheck. possible disturbance of flow?

 

Try to bleed the system as well. Also get a new fan switch.

When you run the system and have the rad cap off do you see coolant flowing?

 

I have bled it using the bleeder. Steady stream of water about an inch high with it barely cracked open so I know there is flow at least in that portion. I know the rad isnt clogged since I rigged mine rad and fan on it. Fan switch needs to be replaced but its not the source of the problem.

I.can read the temp through aem. It appears to be working fine even though he said the cluster temp gauge hasnt worked since he put the aem on. I know they pretty much either work or dont work or get stuck at one position. Starts off around 79 degrees which is about atmospheric when its dead cold

 

Hi again. It's sounding like you have hot exhaust leaking into clooing system. You can check that with palstic water bottle filled with water. Put a hose on the rad overflow and the other end into the water bottle. Then accelerate the engine several times if there are air bubbles in the water bottle ther is a leak. The hot leaking exhaust gas will supper heat the coolant beyound the rad capacity real quick. If you pull the head have it checked for cracks. They can hard to find when everthing is cooled off.

 

What did find wrong??

 

havent had time to work on it in the past week. Hoping to get some time tuesday