While driving in the icy Canadian winter, the last day or two I have noticed my temp gage will go up into the high & stay there for a while. Then out of the blue the gage will drop back down to normal & not move. My fluid levels are all good in the rad & spare tank. I think my thermostat needs replacing. Any other thoughts?

 

What year and engine? Are you familiar with the headgasket recall on the late '80 thru early '90 V6's? Check your oil. Uusually you can tell if you're getting coolant in your crankcase by looking at the inside of your oil cap. What you described is a typical symptom of the headgasket problem. If your vehicle has not had the HG replaced, Toyota will do the repair at no charge, regardless of your mileage.

 

It is a 1989 4Runner with the 22RE 4 Cyl. I bought the vehicle a month ago, the guy who I bought it from had the head gasket replaced 5000km ago.

 

do a search for 2-stage or dual-stage t-stat. I think Roger Brown has the part number for it on his web site (do a memeber search). That is a know issue with 22RE's.

 

Here is the full scoop on the 2-valve t-stat that fixes the exact issue you are seeing:
- http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

 

The 2nd best thing I have done since purchasing my 4Runner has been subscribing to this board. Amazing..... you guys should charge by the hour for your info! You're saving me!!

 

Board members don't take cash. How old and where are the pics of your wife, g/f, sister and/or daughter?!?!?!

 

Also a good idea to check the anti-freeze mix ratio.

 

Went outside & checked coolant levels - they have gone down a little. I ran the vehicle with the rad cap off after topping it up to check for bubbling in the fluid. The exhaust is white, but seeing as it's -20C here right now, that's a bit of a poor test to see if I'm burning coolant. Would coolant levels dropping still be a symptom of a bad T-Stat or am I looking at a bigger problem (ie head gasket or worse?)

 

youll know if youre 'burning' coolant by the smell, very distinct. that would be a h/g issue and you might want to talk with the p/o about how it was replaced when he owned it.

lee

 

A cooling system pressure or chemical test would tell you if you have a cylinder to coolant passage leak:
- http://www.arrowheadradiator.com/hea..._leak_test.htm