jungle

Hello, I recently put a massive radiator in my MY00 that looks just like the mishimoto and I have been keeping track of my coolant temp. When I drive on the highway it will drop to low 150's. If i'm VTECing for a minute or two at highway speeds it will sit around 155-165. Ive heard that the rev limited is lowered or VTEC doesnt engage below 3 bars on the AP1 and 3 bars is 159 or 160 degrees. Is this true?

Could my thermostat not be closing fully?
Could excessive cooling cause damage?

Thanks

flanders

Your thermostat should regulate the temps to stay the same as with stock radiator, sounds like yours is not working correctly.
Having the engine run cooler than what its designed for will cause excessive wear.
Its true there is a lowered rev limiter when engine is cold, but I think it might be even lower than the temps you are seeing.

s2000Junky

vtec wll start working when you hit 2 bars. If its still at one bar you will hit a brick wall on the rev limiter at 6k. Its shocking how abrupt if you arent expecting it. I think every new s2k driver not privy to this has experienced at least once. You would know it if you did.

RolanTHUNDER

A large radiator I can understand would lower temps considerably but would a 1.3 bar radiator cap lower temps significantly or just a bit/enough?

jungle

My guess is that either my thermostat is not working properly or the previous owner put in a lower temp thermostat. The mishimoto thermostat opens up at 154.4 but that would not explain why I ocasionally see it go below that when highway cruising.

Where is the coolant temp sensor located exactly?

flanders

It sits close to the firewall just where the upper radiator hose attaches to the intake manifold.
Pretty hard to reach or even see.

zeroptzero

The size of the radiator is likely fine, I suspect your thermostat is defective if oem, or too cold of a design if aftermarket. Your engine will make more power with higher coolant temps (180+) compared to what you are seeing. too cold is not good.