Any help or ideas would be greatly appreciated.
03 RSX Type-S blew the engine. The engine is now rebuilt with OEM Type R pistons .25" over, Eagle Rods, Toda Head Package, port and polished head, K-Pro ecu (untuned at this point) the works for an all motor street car. Before the original engine blew, never overheated. Now when you drive the car no problems with overheating, however, once you take it above 5,000 the temp rises all the way to "H". After minutes of smooth driving the temp goes back down. But once you stop at a redlight or let the car idle, it overheats again. If you never take the car above 5,000 and stop at a redlight or let the car idle, it will not overheat. Once you cross that point (5,000 rpms), its like there is no return. The car has a brand new OEM waterpump, OEM thermostat, OEM temp. sensor, fan switch works fine and the fans come on. I have had a thermometer in the radiator when it "overheats" and the temp never exceeds 210 degrees. I am very knowledgeable about this car amongst many but I am stumped on this problem. If anyone has heard of this problem and knows a quick fix or any fix, please let me know. Thanks in advance.

 

Just a guess... but what about blow-by past the head gasket at high RPM/cylinder pressure? Might be enough to keep the coolant from flowing through the radiator. Any air accumulating in the coolant?

 

Did you bleed the cooling system to get all the air out after you did the rebuild?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by NJslvrtypes &raquo;</TD></TR><TR><TD CLASS="quote">Did you bleed the cooling system to get all the air out after you did the rebuild?</TD></TR></TABLE>

I think that air in the cooling system could be the problem. Bleeding should help

 

Yeah I bleed all the air I could from the system. Jacking the car up, turning on the heater full blast, mashing the hoses until all the air bubbles came out. I am starting to worry about the headgasket problem though. The head and block were both professionally decked and surfaced, and a compression check was performed. The check showed no leak down but of course that is just at turning the car over. I fear that at high rpms some cylinder pressure is getting through the head gasket somehow and causing the problem. The overflow tank can be empty and once it over heats antifreeze/water shoots out of the capof the overflow tank. To me, it looks like air is getting into the system, hence the headgasket is leaking internally. Anyone else?

 

I don't know how practical this idea is, but if you started with fresh new coolant, does anyone know if there is a way to test for combustion byproducts in the coolant? That would certainly rule in/out head gasket leaks.

 

Yeah, I did use new coolant and I took at look at the coolant after I removed it from the car to put in the new thermostat. Visibly, there is really is nothing there. I have seen blown head gasket cases where there is oil in antifreeze, but nothing like that coming from this car.

 

twke your car to a mechanic and drive him around to show him the problem, because the gauge utself could be messed up, after my rebuild my oil light stays on at idle but acura said that it was a short, so try looking at the gauge

 

chage your radator cap, i had the same problem on my brothers rsx