Well I've been problem free (for the most part) since last year. Today the 240 started running really hot at stop lights and wouldn't cool down very well until it hit about 30mph. Never in the red on the temp gauge, but just under that by a sliver. Coolant is fine and full though I do have a slow leak at both ends of the lower radiator hose. No coolant in the oil or the transmission fluid.

I was just wondering if this is common for a 240 in warm weather since mine's run a bit hot during the summer since I bought it two years ago. If it is then is it advisable to put in an electric fan and just run a switch to the cab? I know that 240s could come with an auxiliary electric fan but mine does not have that equipped. If it isn't normal I've pretty much narrowed it down to the fan clutch being shot.

 

electric fans were added to the later models, I don't think they were even an option on the older ones.

our 87 240 has never overheated even in really gnarly bumper to bumper stop-n-go while its 100F outside.

I suspect your radiator may be partially plugged, or your thermostat isn't opening adequately, or something like that. or maybe your fan isn't moving air, it has a thermostatic hydraulic clutch thing that can give up. OTOH, if you're running your AC, that can add a lot of heat load to the engine at slow speeds. our AC hasn't worked in 20 years

 

My AC hasn't functioned since I bought the car. Switch doesn't work and even if it did the AC compressor is in no shape to turn. Makes it a pain in the summer months. Luckily the heat works in winter...a bit too well. Car can become an oven without even turning the blower on.

Last year I had some slight problems with running hot. At one point I pulled over at a gas station, turned the car off, and tried to spin the fan by hand. It went around once before stopping. And I'm likely to not suspect the thermostat because she runs fine at stops and such on cooler days. This problem only presents itself on warm days. Days above 80. Once you get moving the temp goes down though it takes a little while. Maybe a mile to two miles. Lower radiator hose has always leaked a bit on both ends and at the radiator from the hose that goes to the coolant reservoir.

How can I go about checking for radiator blockages? It seems that it's either that or the fan clutch. A bad thermostat would have it overheat. It never really OVERheats. Just gets REALLY warm according to the temp gauge. Like it never went into the red even after sitting for 15 minutes in stop and go traffic.

 

if your heat comes on really hot when the heater control is just a bit on, then its likely you have the old style heater valve and its thermostat thingie has failed. this is 240 specific.

remove the driver side felt kickpanel, and the plastic panel on the right side of the drivers footwell, on the center console.... the heater valve is jammed in there near the bottom.

see the pics on this page:
Volvo 240 heater valve : EuroPartsHouse Bargain Parts

if you have that first picture style, with the thin copper capillary tube, then yeah, replace. I used the heater valve kit that site sells, it works GREAT when properly installed.
Volvo 240 heater valve kit replaces 1348252 9131998 $59! Volvo 240 heater valve kit replaces 1348252 9131998 $59 [] - $59.00 : EuroPartsHouse Bargain Parts
[its actually the all metal valve out of an older Dodge pickup truck, I think]

if you have a dead AC compressor, I *highly* recommend disconnecting the wire to the AC compressor clutch so it can't accidentally try to come on, as that can end up frying a belt.

 

Oh I don't mind that the heater is a bit too warm. I just roll my window down a bit and it stabilizes the interior temp PERFECTLY. I mean I love this car enough to give her a name but she's a $900 beater and I'm on social security (mental/social disorder). So paying money to fix a problem that can be solved by rolling my window down an inch and a half just isn't in the cards.

As for the current issue of the 240 running a bit hot I'm also not likely to say that the radiator is plugged. The coolant is a bit darker than it used to be because of just normal running conditions but I've never noticed any sludge in the hoses or the reservoir. I had to drain it to change the water pump this last fall and the coolant just looked old. No sludge in it.

So I should first look at my fan clutch and then my thermostat, correct?

 

yeah, probably.

I will say, most good mechanics I know just automatically change the thermostat (and its seal) when they change the water pump, you're already halfway into there, so its just good insurance. volvo suggests water pumps every 120K miles (every other timing belt), which is probably good insurance.

 

You may have a partially obstructed radiator by what you describe: you don't need "sludge" or dark coolant, what plugs a radiator are hard chemical deposits. Try to feel around with your hand various spots on the radiator surface and if there are great temperature differences you have blockage.
Also, your clutch fan is bad if it spins half way.
If you suspect a "lazy" thermostat, just get rid of it--you don't need it in the summer, all it does is make the car warm up faster and risk a catastrophic overheating if it gets stuck. This past winter, as a test a went the entire Oregon winter with no thermostat in one of my Volvos, a '92 740 and the only effect was slightly slower inside heat. Considering the down side of a bad thermostat, if I had one car only, I'd never have a thermostat in there. Some cars you can't run them without one but the b230s are fine without the thing...
Also, I'd address that leaking hose you mention, remember that overheating is by far the biggest cause of death of Volvo motors, nothing to take chances with! That gauge routinely coming "close" to the RED is not a good way to live...

 

Two notes from experience. A failsafe or a failed thermostat would both allow the temp to get over service, but not boil over in non extreme conditions. Personal experience has also shown me that if as it starts to over heat you turn on the heater and the fan and the gauge doesn't fall, bang the dash above the fuel gauge. An unlikely but possible culprit is the gauge display converter. If the temp falls immediately then this may be your problem. (I've had a lot of relay issues in mine).

 

the temp gauge on most 2/7/9's has a 'temperature compensator' circuit on it, which is designed to keep the needle dead centered, as long as the temp was in 'normal' range. they (and many other car makers) did this to reduce neurotic service calls from people obsessing over 30% temp swings during normal range of operations.

on mid 80s 240s, this compensator was a separate little board plugged into the back of the instrument panel, IPD will sell you a jumper with instructions to replace this board so your needle reads linear temperature. last couple years, 240's no longer had the separate board. 7/9's never did, it was integrated into the instrument panel, and disabling it would be a board version specific operation, something I don't know if anyone has ever figured out.