245 overheating

Hi there, my 1993 245 is overheating, the temp gauge was working
erratically, so I did not know for sure if it was overheating. Bypassed the
temp compensating board in the instrument cluster and started the car, put
the AC on and left it on my driveway for about 10 minutes, the outside temp
was about 86 degrees. The car did not overheat, and the gauge is just a
hair above 9. There is no coolant consumption and no air bubbles on the
coolant. The pump was replaced about 7 months ago with a new thermostat and
belts. When the car is hot, I feel the fan in the engine compartment
pulling air through the radiator, but when I shut the car the fan blades
feel like they are spinning too easily (viscous clutch ng?). My wife took
the car for a spin and noticed that the car was overheating when it was
climbing hills, the temp almost reached the red zone. turning the AC off
and putting the heat full blast cooled the car down. I checked the timing,
and it is good. I intend to check the engine compression, remove the fan,
hose the radiator from the engine compartment out, to clear any bugs, dirt
etc, then temporarily bypass the thermostat and JB weld the fan, so it is
always on.

Any suggestions, will be greatly appreciated.

arnold_perez13 at verizon dot com

 

My '89 240 overheating problem turned out to be a crack in the one of the
ruffles of the big black plastic tube between the air mass sensor and the
intake manifold. It took a year to find after trying all the usual
culprits. Once fixed, though, it never overheated again.

I recommend removing the big ruffled tube from the car and inspecting it
carefully all around.

 

You might be onto something there, I ordered the throttle body gasket
because there is a random misfire on idle, I am going to clean the TB, check
the idle control valve and replace the flame trap. I will check it out
tomorrow and will post. Thanks

Arnold

 

The viscous couplers don't have a very good life expectancy. A bad one will
allow the engine to overheat at idle on a hot day, and on low speed hill
climbing, but cool down rapidly (in a few minutes) once the air gets flowing
through the radiator again.

Your plan sounds pretty good, but JB Welding the fan clutch may be wasted
effort. I recommend replacing it, but aftermarket units are expensive
enough. Genuine Volvo units are downright expensive.

Mike

 

I applied JB weld to the fan clutch to have it engaged all the time, hosed
the radiator from the engine compartment out, checked the hose from airflow
sensor to the throttle, it did not have any leaks, replaced the flame trap,
and noticed that the hose had a tear that allowed unmetered air into the
engine, allowing it to run lean, and possibly over heating, but the most
important thing I noticed after I shut off the engine was a low hissing
sound coming from the coolant reservoir. Pressure was not being maintained
due to a faulty cap, borrowed the cap from my other 240, (I noticed the
system still had pressure from 3 days ago when I last ran it). Test drove
the car with the AC on, outside temp about 90, and the temperature gauge was
stuck at 9.

Thanks to all who helped.

I will keep an eye on the temp gauge, if it runs too cold in the winter, I
will get a new fan clutch.

Arnold

 

Thanks for the feedback. The cracked cap is common enough I'm surprised none
of us thought about it.

Mike

 

Take the JB weld off the fan clutch, that'll burn a lot of extra fuel and
make the engine slow to warm up resulting in accelerated wear.