I recently had my head rebuilt in my ap1
While it was off I did a few up grades including new silicone radiator hoses and a mishimoto thermostat and I already had a mishimoto radiator ... The vehicle is N/a

With that being said here's my question
I read that it is not good to vtec the motor under 3 bars (160 degrees) well at idle the car will sit at 3 bars on the temp gauge but while driving it will go down to 2 bars is this bad ....

It this because of the cooling upgrades or is it because it's winter in Ohio and it's 15 degrees out or is it a combo of all of that

Mainly i just want to hear others opinions on if you guys think it's safe and why do you think it's doing this ? Has any one ever had this problem

 

i believe its a combo of all that, even though its cold it should still reach operating temperature, those cooling upgrades like the thermostat is prob. opening up much faster than the stock one.

 

I suspect you might have air in the system, and the car should not be driven until you get that fixed.

 

Thanks guys I think there is some air still in there I'm gonna try bleeding it more and let you guys know what happens thanks for the suggestions

 

Aside from vehicles with air cooled engines, no car has ever run cooler because it had air in the cooling system. Your issue with lower than normal operating temps is the low temp thermostat. Every time it gets to its opening temp, it lets a big gulp of super chilled water from a large volume radiator into the engine. This makes it close back and the flow of warmer water going into the radiator stops. Blocking the airflow to the radiator would help but going to a regular thermostat would be best.

 

I too have the Mishimoto radiator, thermostat, and fan switch with 2x SPAL fans. Mine will sit at 2 bars under normal street-driving when the ambient temps are below 60ish. If its hot out then the third bar will come on while driving normally. Or if I'm romping on it I can usually get the thrid bar to come on even if its cold out.

I'm not worried about it.

 

I read it's bad to vtec when it's under 160(2 bars)

 

Bump

 

In this instance its not

 

While 3 bars is a good reference to when VTEC is available it has nothing to do with VTEC; it's one of the great myths here. The VTEC solenoid operates based on oil pressure not water temperature. When the engine temp goes up the the oil thins out and the pressure goes down. It's this logic not water temp that controls the solenoid. On a stock car this is ~3 bars. Upgrade cooling can be good at two. If the ECU let's you V you are good to go.....it's monitoring oil pressure. If the oil pressure is too low, from thicker oil, you can cause damage; your ECU is programmed to prevent this.

Utah

Note: There are NO temp tests in the shop manual to troubleshoot VTEC.........ALL based on oil pressure and continuity (electrical).