Venomous S

I started my car in the AM as I normally do to go to work. The temp was around 65 F. So I get on the highway cruising at 70 and notice that from 3 bars the gauge jumps to its full scale in a matter of less than one minute. Respectively my digi gauge went from 190 to about 250 I think it was. So I pulled over right away and shut her down. Waited about 20 min and start it and notice the lower rad hose is a lot cooler than the top

I had just put a brand new low temp fan switch and thermostat (mugen)

kept driving to work with the coolant reservoir now full above its level and it was sorta fine, gauges showing 3 bars but digi gauge staying at 225 even at cruising speed. Once I got to work i let it idle for about 5 min. Car idled at 4 bars and at 230 constant, not dropping or rising with the fans constantly on.

There were times while driving that my digi gauge was jumping around at least 10 degrees
1. Could the system possibly have gotten air for the digi gauge to be jumping like that?
2. Could the thermostat have gone bad since the lower rad was a lot cooler than top?( but then the hoses seemed to have almost the same temp when touched.)



Thats the only thing i can think of

I do have a FMIC but its set lower than rad.(once cruising temps are normal 185-195) And I never had the temp rise suddently like that.

PWRMKR

It sound like the system still has some air trapped inside, after the stat install.

Am I stating the obvious that the lower (rad out) hose should be cooler then the top (rad in)?

Venomous S

I bled the system entirely but I guess it could be possible.

As far as the lower rad hose, i am talking a huge difference between hose temps when I touched them.

Tinker219

Your thermostat hasnt opened yet; I drove around for an entire evening thinking I had properly bled the system, but the heat was VERY VERY hot. Arrived at my destination, check the lower hose, very chilly. The upper hose was about to burst from the heat. So on the way back home, the heater fan was cranked, heat all the way up to try and get rid of some of the motor heat.

You may have bled the system with the heater core closed??? Thatll induce about a gallon of air rather quickly if you crack it open

Sideways

It's either air in the system or a non functioning thermostat. Did you burp it in two places besides the radiator cap? Heater on?

fltsfshr

If it was an old Chevy, I'd say you put the thermostat in upside down ...

I'm betting its a stuck thermostat.

fltsfshr

Venomous S

yeah I always bleed the system w/ the heater at max and i always open up the intake and heater bypass bleeder screws.

kane.s2k

This engine (and the damn B series honda engines) are a bitch and a half to get to bleed completely. Did you start the car let it go through 2 fan cycles so the thermostat opens, then let it cool and then bled again? That seems to be the only way I can get this thing to bleed out completely. As well as a jack to lift the rear and tilt the front to get all the air out of the heater hole (I pour rad. fluid through that hole and slowly so the air can escape with the radiator cap on).

Venomous S

WEll, normally I dont know how many fan cycles I go through but because I know this car is a byatch bleeding I normally bleed for an hour. But It just hits me that in a month the car hasn't overheated, and just today when its cooler, the car surprises me.

But no I dont' lift the car to give a tilt like that. I just open the bleeders, let it cool and repeat, but I guess that wasn't enough.

xviper

Did you install the stat with the hole at the top? Did you install it backwards?
As for the digi temp gauge, where and how did you install the sender?