temperature gauge is all the way up 86 240

Well, yesterday I just needed to drive a short distance from home and
even though I needed some gas I decided to keep driving, I was very
tired and did'nt feel like stopping. The fuel guage was almost in the
red when I got to where I was going,and when I was leaving the car had
trouble starting. This was about 9am on a hot saturday. I got home and
slept for a while. I did'nt start it up again until about 7pm, and
again it would barely start and now the temperature had gone all the
way up to the red. I finally got the car to start and headed directly
to the gas station, filled it up and proceeded to drive two cities
away. The temperature gauge was all the way up the whole time, I
thought it might go down after driving for awhile, but it did'nt, and I
could feel that it wasn't at full power when I accelerated. I did make
it home though saturday evening.
Tonight sunday, I waited all day til the weather cooled down to try
again, started up OK, but again temperature guage went all the way up
immediatly. I test drove it to the gas station, still low power. Filled
it up, proceeded to drive home. Checked under the hood when I got home
and it was very hot in there, I could feel it on my face.
I just had a new radiator installed 2 weeks ago.
Any Ideas why the temp is so high?

 

Troll. If I'm wrong, sue me.

 

bad radiator
air lock in coolant
normal temp, bad temperature stabilizer board gadget
slipping fan clutch
pick one

 

Who put in the new radiator?
Perhaps a hose was not made fast?
Is there fluid in there?

 

A well respected volvo shop installed the radiator, and yes there is
fluid. I called the shop today and the guy said it sounds like an
electrical problem. Possibly a bad temp sensor.

 

Thermostat bellows sticking closed?

 

Since the temperature gauge is all the way up, even when the engine has
been sitting overnight, there's no doubt you have a wiring or gauge
problem. By the way, ignoring warnings like a high temp gauge is a good
way to ruin an engine quickly. Fortunately for you, the gauge reading
appears to be wrong, but if it had been correct, you'd be looking for a
new engine now.

--
Mike F.
Thornhill (near Toronto), Ont.

Replace tt with t (twice!) and remove parentheses to email me directly.
(But I check the newsgroup more often than this email address.)

 

Also, "trouble starting"; wouldn't crank, or wouldn't fire?

 

There's a little printed circuit board on the back of the instrument cluster
that provides bias to the temperature sensor and linearizes the result. The
board plugs into an edge connector and is trivial to swap out once you have
the cluster in your lap.

When it went bad on my '87 240 (pegged at zero) I replaced it with a new
board from Volvo for about $150 and that fixed it.

The board only has one component on it, an LM324 op-amp, which is a very
common single-supply utility op-amp. When the board went bad on my '89 240
(railed high), I replaced the op-amp for about $1 from Radio Shack and that
fixed it.

Of course, if the engine has real overheating problems, it isn't the PCB on
the sensor, but it did eventually go bad on both of my late 80's 240's

-RL

 

uhh...maybe lack of coolant?...