my newly installed thermostat varies from 35% all the way to about 52%..based on how hot the weather is.

Should a change in temperature of about 15 degrees cause this degree of flux? i assumed they mechanic had put in a thermostat that oppened early...but now i'm not sure because oft he amount of change


I live in san diego...where the winters are cool (50-70 degree weather and the summers are hot (all the way to 90's)

my radiator is 2 years old...so it can't be.....but i will flush it anyways

my fan clutch is fine....i checked it today...

You probably have a partially blocked rad or a bad clutch fan. After shutting the engine off feel the back surface of the rad - you may find a cold zone or two. The fan, when the temp is high, should stop quickly with the engine if it is engaging properly. If it freewheels for any length of time, it is faulty.

You car does not have a temp compensation board. They came in - I think - in 1986 with the advent of the electronic speedometer, along with a nmber of other changes.

All the 240s I have owned of 1984 and older vintage have had these temp guage readings, when things were runing right.

First start in the morning, gauge needle moves (at about the speed of a sweep second hand on a wrist watch) from zero up to about 11 0'clock. Then it immediately starts downward, coming to rest at the 9 0'clock "normal" position. As long as running continues, the needle stays "welded" at normal.

Starts later in the day usually do not have the same readings, as the engine is warmed a bit.

The movement of the needle on the first start is completely expected, as reflects the action of the thermostat. If your readings are not close to these, something ain't right.

Thermostat in, but incorrectly.

Thermostat is, but not the correct temp type. Should be 92 C.

Thermostat not in.

Thermostat OK, and wiring from temp sender to temp gauge is flaky or messed up somehow. BTW, that wire (yellow) is one of the bundle with the crumbling insulation problem.

Hope this helps,

Bob

:>)

Do you mean your 'thermostat' varies, or the temperature indicated on the temp gauge varies? And the percentages - are those % of full scale on the gauge?

A 15 degree change in ambient temp would hardly cause the fluctuation it sounds like you're seeing. It could be from a bad 'stat, or - famous Volvo 200 problem - a flaky temperature compensation board in the gauge.

If all is up to snuff, once your car comes up to operating temp, the temp gauge needle should remain quite steady at the mid-scale location.

see..my old thermostat would fluctuate a lot....it would go from 1/2 on cool days..all the way to 3/4....so i changed it. Now it still varies....

what is the temp comp board...and how would i change it?

also...the coolant is new...the radiator is fine...two years old..nissen brand. No leaks....i'ts only the thermostat moving so much up and down that i'm concerned about.

i'm sure its not the thermostat..because the old one did the same thing...it must be something else.

THe only issue is...i thought only 1985 and older cars had temp comp boards...mine is a 1982 244 DL kjet?

thanks

Well, my '88 had a temp comp board, since it was replaced under warranty.

I think you need to do some research here on the Brickboard and read all you can on the TC board. Among other things it acts to dampen the needle swing to keep us staid and conservative Volvo drivers from having heart failure... there's even a 'bypass' which you can do at home or buy from IPD to minimize the *true* heart-stopping swings into the red zone.

Based on other cars I've owned, I think it's reasonable to expect a 25% variation in indicated coolant temp as you drive, more under extreme conditions (e.g., driving up a mountain at 8000 feet, like I do in Flagstaff). Volvo jsut doesn't want most of its customers to worry.