Gabe_

Alright, I recently swapped in my JDM b18c. If I don't drive around with my heat on, my car begins to overheat, but as long as the heat stays on, the car stays at normal operating temperature. Also, my lower radiator hose is always cold.

The car never overheated before with the old motor. I replaced the thermostat durring the swap. I am not low on coolant. The system has been bled.

Any ideas?

SpooN Man

Gabe try another thermostat. sounds like it's not opening at all.

Start the car with the rad. cap off. When it starts to heat up you should see a (slight) drop in the fluid levels. do you see any movement at all ? What about your water pump ?

Blkhatchbk

or just take the thermostat out. i had the same problem u did after i did that swap. also went back and double checked all the hoses just to be sure i didnt have a leak anywhere. havent had a problem since.

SpooN Man

That would only work for about 1 month in michigan.

On another note you could just drill a few holes in the thermostat. That should give you plently of flow to keep cool, but it will take forever to heat up.

Gabe_

I replaced the water pump when I did the swap... and I have another brand new honda OE thermostat right here. I suppose I will have to throw that in...

tonyxcom

DONT run without a thermostat.

Sounds like your cooling system isn't up to the job of cooling that motor. I would start with a larger capacity radiator.

DCStreetHtch

if either of your hoses are cold then you have air in your cooling system and it needs to be released... i hear this story all the time, happens to all. These is a small purge screw on the intake manifold side of the block...run your car up to normal opperating temp and do not turn on your heat. Open up the bolt a bit. have a towel handy because some coolent will spill out. BUT you will also notice little air bubbles too. Pump the hoses with your hand and these air bubbles should get pushed out. Eventually you will notice both hoses getting warm an the air bubbles will stop... then you are cool and good to go!
IM me for more details
-Bryan-

DCStreetHtch

notes:
Purge is on the back of the head... right aside the intake manifold ports (tranny side).
Fill your radiator to full after purgingthe air bubbles.
-Bryan-

NiiS

Uh, to purge the water system you have to find the bleeder valve located above the upper radiator hose(12mm)...While you lose fluid, simultaneously replace the water through the radiator and look for a steady stream of water from the bleeder, then simply close it off to make the system air tight.

NiiS

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tonyXcom &raquo;</TD></TR><TR><TD CLASS="quote">Sounds like your cooling system isn't up to the job of cooling that motor. I would start with a larger capacity radiator.</TD></TR></TABLE>

I agree with most of what you say, but this I have to differ, I have the same swap along with some internal work and I still use the stock EG radiator. So I`m going with air in the system or a thermostat

tonyxcom

well, he claims he bleed the system, so....

SkyeC

Stock radiator isn't the problem unless it is clogged up or broken in some other way.