Coolant Temperature Fluctuating Wildly

[DerekBell]

At cruise, the coolant temperature holds relatively properly. In stop and go traffic, it will frequently dip below normal and heater starts blowing cool. Occasionally it will dash towards the redline, 'check gauges' light illuminates momentarily, then settles back into the normal range.

I'm hoping that it is only the thermostat (192k miles, and I think it's the original), and will be installing a new one this weekend (parked until then).

Might these symptoms point to possibly other, bigger issues?

[ihatemybike]

That's usually a sign of low coolant.

[leadtrombone]

x2 on low coolant. Check your levels and work the air bubbles out.

Open the radiator cap and top off. Run the engine with radiator cap off. when the engine gets warm and the thermostat opens and the coolant cycles through all the spots you will probably see some air bubbles percolate up through the radiator.

as the weather got cooler i noticed my heater didn't seem to heat. Did that above and after a couple of bubbles the heat started pouring out the vents.


any better ideas.. For that matter is there a bleed valve in the system somewhere???

good luck

[Kabey's Van]

There is no bleed valve, but I agree with the trombone player and the guy that hates bikes.

[LiftedAWDAstro]

I would change the t-stat if it's original. Then top off the coolant level.

[DerekBell]

Turns out that I have a coolant leak up near the intake manifold. I had checked the coolant level not too long ago, and it was good. Therefore I thought that I was having another issue. Checked it again as per the input on this page, and sure enough - low.

I wasn't having the obvious signs of a leak, like a pond in the parking spot, 'cus it was only seeping out while under way and flowing over the top of the engine. Thanks for all that folks!

[reaper]

There is no bleed valve, but I agree with the trombone player and the guy that hates bikes.

LOL

[ihatemybike]

I did Green's intake manifold gasket last winter. Not to terrible to do. Having a garage to do it in helped.