Bought my daughter a 240 a couple of months back - since this is my first Volvo, I'm just starting to get familar with the way these things work.

Running the car, it shows nearly mid way on the temp guage - which I've read is somewhat normal with this car. But when I turned on the AC (and ran it here in the West TN heat of about 98 with 108 heat index) at about 75mph - and she nearly red lined on me. - - Needless to say, I WANT my AC!!

Didn't feel any loss of power, and frankly the heat from the engine compartment didn't feel what I would expect to be "red line hot".

Since I'm expecting that she's got the original thermostat (everthing else has been original) - should I change that first?? And if so should I go to an 87 instead of a 92?

Should I also look at changing the Sending unit since it may be falsely reading hot?

Or should I go the route of putting in a digital temp guage? If so, what are some suggestions for best look / performance?

Any and all input is appreciated.
Thanks
Charles

Both my 240's have done a similar thing with the cooling system in good shape. Next time it does this, flick the guage several times with your finger as hard as possible, good chance it will go down. With such treatment, mine will go from very hot to normal or even register too cool. As others have noted, there may be a problem with the cooling system, but the temp gauge is less than reliable.
Aaron

Does your car have the compensation board in place or have you bypassed it? Removing the board and replacing it with a jumper has always fixed a wonky 240 temperature gauge in my experience.

Randy

Do not assume your temperature gauge is giving you anything near an accurate reading until you remove and bypass the compensation board located in the cluster. Remove the cluster (Keep track of the where the wires go; the white wire with red stripe is not used unless you have a tachometer in the car) and follow the pictorial below to remove the board and install a jumper wire. The board is not replaced.

The easiest way to install the jumper is to use a short section of lamp cord pushed onto the two pins. Quick and easy.

Randy

There's a temperature compensation board that can be bypassed to tell you what the engine temp is really doing. Search IPD's (or this board) site for more info.

Though, when you have a repeatable cause/effect thing happening, it sounds like there's a real issue behind the scenes. I'd check the T-stat, radiator, and water pump condition.

-Ryan

--

Athens, Ohio
1987 245 DL 324k, Dog-mobile, E-codes
1990 245 DL 137k M47, E-codes, GT Sways/Braces, Dracos, A-cam
1990 744GLE 189K 16-valve project
1991 745 GL 304k, Regina, 23/21mm Turbo Sway Bars

Started up Vickie for a little drive this weekend - and the temp was red-lined before I got 5 miles from the house.

So I got back home and poped the thermostat. Yep, it was the original one!!! It had broken into a couple of pieces and was blocking the flow of coolant

(as I had mentioned in a previous post - she hasn't been run much this year - guess the pressure of driving 800 miles in 1 week was too much for that old rusted thermostat!).

I put in a "Zoned" special (195 degree) and filled it up with Coolant. After about 20 mintutes of idle with AC on - it was showing about 3/4 on the temp guage.

I'll probably drive her to work tomorrow on my 160 mile round trip. With the temp supoosed to be 100 and a heat index of 115 - We'll see if she does any better.

If she still gets hot, I may step down to a 180 thermostat. If that fails I may opt for a new radiator. Don't worry - just got in a new compensator board from Flee-bay and will swap it before I order the radiator!!!


(BTW - I had an old piece of Junk Mustang 2 (2.3 l) that always ran too hot. I swapped out everthing with no luck until I got to the radiator. The Radiator shop said the only thing holding it together WAS the rust. Put in a new one and she ran cool from then on! - - - thanks for Reminding me Brian!!)

Since you never know what you get when you buy used - I replaced the following immediately after purchase:
All belts including Timing belt
Cam, Crank and intermediate seals
Upper and Lower radiator hoses - (complete coolant flush)
Water pump (since I was in there with Timing belt)
plugs, plug wires, Distributor cap, rotor button
flame trap
tranny and brake fluid flushes
fuel filter, and of course air and oil.

Also had to change alternator since it wasn't charging (tried brushes first) and changed from R12 to R134 AC coolant.


I really hate pulling out the cluster - but I have done it (had to replace the odometer gear after breaking a gear with the trip reset button on my first fill up).

If I "jumper" the compensation board - what does it show?? Is a red-line actually too hot? BTW - what is too hot for a 240 in relatively good shape?

I recently had this problem w/ '89 240 when riding with air. I am in deep south so understand the heat index issue. I did the coolant flush and cleaning. That did not fix. I used a digital thermometer on the radiator connections and on the T-stat. Replaced the T-stat and that did not fix prob. I ended up getting a radiator put in ... and the car has been running fine in our heat.

Please install the bypass jumper.

Your car may or may not need a radiator or other components. However bypassing that compensator board with a short wire is - in my humble opinion - a required project for these cars. I do it on ours whenever we buy one. I don't wait for the driving family member to call me in a state of alarm.

It's quick to do, and then you have a temp gauge you can count on. It will be informative, going up a bit on upgrades and down a bit on downgrades, if you watch it.

The comp board was added by Volvo when US drivers complained of temp gauges going up and down. They were used to idiot lights on USA cars. the board's job is to stabilize the needle, turning it into a moving-arm idiot light. Unfortunately the comp board likes to fail, giving high readings.

If you use the push-on wire method, I recommend 16 ga. wire. The insulation sleeve is big enough to go over the pin.
--
Sven: '89 245 NA, 951 ECU, expanded air dam, forward belly pan reaches oem belly pan, airbox heater upgraded, E-fan, 205/65-15 at 50 psi, IPD sways, no a/c-p/s belt, E-Codes, amber front corner reflectors, aero front face, quad horns, tach, small clock.

I pulled the compensator board and installed the jumper (just did the push on) . Now I have a no-start issue.

Starter turns the engine over fine - not sure if it's a no-fire or a no-gas issue. Could this because I hooked up something wrong?? Maybe the computer not getting the right input now????

I will take the console out again tomorrow evening to see if I plugged something up wrong - it got dark on me while I was trying to install it.

Fixed the no-start. Not sure how I blew fuse #6 (main fuel pump) since I disconnected battery ground when I took out the console.

Oh well - it was easy.

Now with Compensator board out - (and jumper in place) - I'm reading about 1/2 - 3/4 on the heat gauge with the AC off. Still seems to heat up warmer than I would like when sitting in idle (with 87 thermostat and Tropical Fan clutch)

Sounds like I need a new radiator. - Any preferance on the brands available??

There is nothing wrong with replacing an 18 year old radiator, but perhaps yours is just restricted with two decades of debris.

They are not difficult to remove and once you have done that you can quickly determine if the air flow is restricted by holding it up to a bright light and looking for debris or restricted flow due to bent fins.

Much of the accumulated material can be removed by tapping the whole radiator on a concrete floor- front side down first (that is the direction it went in) and then the back side bearing in mind the necks can be brittle and easily broken. Resist the temptation to use a power washer of even a small solid stream from a garden hose as it is very easy to bend over the cooling fins. It is a time consuming job to straighten an area that has been damage- I am speaking from experience (grin).

Randy