My '92's coolant level is low, light coming on in dash.

Checked for leaks...hoses, waterpump, etc, none whatsoever.

Nothing in oil, nothing coming out of exhaust, hetar core ok.

Noticed a high level in the overflow, but low level (obviously) in the high press reservoir ( top, passenger side)....hmmmm

Any ideas?

 

The 92 system requires opening the two bleed valves when filling the system in order to "burp" it. It's very easy to get air pockets in the system. Did you recently have a cooling system flush done or replace radiator hoses? One bleed valve is on the thermostat housing and the other is on the driver's side of the throttle body down toward the botom.

When filling an empty cooling system, open these valves and add coolant through the surge tank. When coolant flow steadily out of the bleed valves, close them and fill the expansion (surge) tank to the rim. Be very careful to not allow coolant to drain down over the OptiSpark. That will ruin it and the repairs are not cheap! Use some aluminum foil to create a channel to allow coolant to run off to the sides.

Remove the pressure cap and fill the expansion tank. Start the motor and let temps get to where the thermostat opens; you should see the coolant level drop. Raise the RPM's to about 1100-1200 and keep filling the tank. Have somebody watch coolant temps to make sure the temps don't get too hot. When the coolant is just below the base of the rim on the filler neck and stays there, install the pressure cap. Shut the engine off and fill the plastic expansion tank with fresh coolant to the cold mark.

 

Thanks! Will do tomorrow, but I haven't done any work to the car, so it seems kinda mysterious as to why this happened....

 

Is your radiator cap good? If it is; check your recovery system for leaks, an small leak in the recovery lines/tank can cause the system to lose the vacuum needed to siphon the coolant from the overflow reservoir back to the system.

 

I suspected a leak in my recovery tank on my Dodge Dakota. I put a little red food coloring dye in the tank and sure enough, there on the driveway was a few drops of red. Worked for me.

 

I had a similiar experience in a 91. I finally noticed the upper connection in the pressure tank had a leak at pressure. There have been posts here on how to fix it using JB Weld. I followed the instructions and had no problems since. Hope this helps................

 

That could be it, although I didn't notice any leaks as of yet, I'll look again. Thats a good explanation though, my overflow is past the "full hot" mark when sitting off!!! I'll mess with it today. Thanks guys for the replies!

 

I forgot to mention that my recovery tank was dry and that I filled it with plain water with a little red dye.

 

Had a good run with the car today, about 70+miles, and she's running at a steady 196 degrees, and no low coolant level light.

What I did was pump the excess coolant out of the overflow container, and into the pressure reservoir above, and bled off any air at the water neck (stat) fitting.

Runs okay now, we'll see what happens....