I have a beautiful 87 240 wagon. 162k. lately, the temp has been running just shy of the red, which obviously worries me as I safely and stylishly transport my son, 2 dogs and beautiful girlfriend. (not listed in order of importance, except my son that is) So, the water pump is pretty new, the temp sending unit was replaced,as was the fan clutch. Using the heater has mimimal effect on the gauge. I bypassed the compensation board, and the antifreeze is clean and mostly new. i replaced the overflow tank but am worried about using the "green cap" as I read it has a higher pressure on it. Anyhow, short of replacing the radiator and spending needless money, I squeezed the upper rad hose as it seems to have no coolant in it after the car is shut off. It should force the antifreeze into the coolant tank. instead all i get is air at first. after i would squeeze, i'd hear air hissing into the overflow tank. hmmm. after that I could feel the hose get full, and the bottom hose would "pulsate" for the lack of a better term, so I deduced the rad isnt clogged to bad (?) anyhow, the hose clamps on all the hoses werent too tight so i tightened them down snugly, and voila, no more hissing. In addition, when the car was hot and I'd shut her off, the top hose feels/is hotter than the bottom, but not by much. Please help me keep all of them and myself happy, cool and stylish

 

Man, you got a tough one there. In the other thread you mentioned you had changed the thermostat, right? All I can think of is something is blocking the internal flow (unlikely) or maybe something weird with the water pump or rad. No leaking eh? Maybe the sensor is reading it wrong?

 

nope, no leaking ever. and my oil is..well...oily, not milky, so i deduce my headgasket is good. The temp sensor is new, and the water pump is about a year and 5-10k miles new also. SO, i'm thinking the rad may be partially clogged. The 'hiss' when I squeeze on the hoses is rather odd, like the coolant is draining back into the block. that seems to have stopped when i tightened them down and put the green overflow cap on. I'll drive her tomorrow after work. Now, onto the blower motor ugh!

 

I responded on your previous post and I just caught the high temp malignancy.
This started when I replaced the freaking thermostat, brand new. I think it sticks because the car will ride just under the red on streets and highways
when I coast at 35mph to 40 it goes back to normal (half way). When I go above it clogs again.

NOTE: aftermarket water pumps outlet is smaller than stock. the one I bought anyways.

My worst case senario is the Head Gasket.

 

That really is a worst case scenario haha.

 

I dont know if i buy into the sticking tstat legend. Sounds like you're not getting enough flow under load. Mine goes up to just under the red, maybe 3/4 and stays there. No difference anymore (last week there was) if i'm in traffic, idling or on the hwy. My heater on doesn't bring the temp down. I cant feel cold spots on my radiator though. UGH i'm tempted to put in a known working gauge. Last week it would climb into the red with the ac on, or in traffic. I swear it was better with the bad/funky compensation board and the dash slap method.

 

I really would confirm your actual coolant temperatures before you chase this further, especially if you have no other symptoms of overheating.
An infrared thermometer shot at the top hose will work (should read around 90 degrees c when at temperature) or a meat thermometer stuck into the radiator matrix at the top hose area will also work.

Regards, Andrew.

 

how is your timing marks on:
Crank shaft
distributor
Camshaft

I recently did the timing of these and the shh@#*t temp gauge needle never came down......what the hell......!!!!!!!!!!!!!! I will try another cluster to see.

 

I bought a car diagnosis cd.....and says to do the following:

when engine is cold

open the hood
turn it on and walk back to the egine
observe the two radiator hoses for a minute or two
see if either one of them collapses or as if an invisible hand were to pinch the hose...if so, replace the hose.

other than that the cd diagnosis was the water pump or thermostat....eehhhhee eehhh

 

Ive heard of collapsed hoses, though never seen it happen myself. I drove it today, and then felt the rad itself. I cant believe i never thought of that until i read it here, which is why forums are excellent. They are a combined experience of hundreds of people. I felt a large spot on the pass. side of the radiator that while wasn't "cool" i could tell it was 'cooler'. as the engine cooled, it was more pronounced. A wonderful day with the fiancee and kids delayed the installation of the new rad i ordered for 99 bucks. (i have some priorities straight) I'll let yall know what tomorrow brings. THEN onto the ac/heat blower motor. UGH oh and gonna back flush the system and add new antifreeze. Not gonna cheap out over 20 bucks of new coolant.

 

great.....! I got to replace mine as well.....

 

You are on the right track... "Cooler radiator spots" is the sign that you need a new radiator... it should all be uniformly the same temp...

 

#1. Go get a laser temp gun(borrow it from a shop or see if your local parts store lends them out or has a cheap one to purchase this will save you a TON of $$ in the long run. You DO NOT want to just start throwing parts at the car...mechanics don't do that they test first then replace. #2. Take the temp of the thermostat first point it at the nut closet to drivers side that holds housing in place. temp should read 180-190. #3. The take the temp of the radiator. You need to take temp of both sides. If the temp is the same or very close to the same on both sides then you have a bad radiator. If the degrees differ from one side to the other by 20-30 degrees then your radiator is just fine. #4 I would also replace the overflow cap to the black cap.#5 I would check for a head gasket leak to do this remove the overflow cap while car is running and hot if you see the coolant bubbling or overflowing from the resevoir if it is then you have a bad head gasket. If this is the case and you do not want to spend the $$ for a head gasket, Bars Leak head gasket repair works wonders but only if it is not blown to badly and you need to follow the instructions to a tee. Anyhow, the laser temp gun will be your savior because then you can really see what's going on....Hope this helps.

 

Thank you all for your good advice and input. I should have gotten the IR temp gun or whatever it's called. Anywho, new rad, flushed system, 82c thermostat, all is well. I let it idle in the drive for a long while, and gauge never moved past half way. Driving it it went a bit above, but not much. All is well. Now, onto the fan motor, ugh, Mississippi is HOT in the summer.

 

At the start you mentioned using a green cap (150Kg), you should install a black cap (85Kg) which is the correct one for Volvo 240 cooling systems.

 

When I hear about temp running high, the 1st thing I think of is a thermostat. Car part manufacturers change specs all the time for no reason and cause problems for people. They sell you a 92' thermostat and it is actually a 105' thermostat. My 1st stop would have been the ir temp reader.

In the future, my 1st test would have been to remove the thermostat and see if it ram warm. Glad this is behind you.

 

From a problem with not too many sources to track down (the cooling system I mean) I've learned a lot, thanks to many decades of combined experience from people who took time to answer. Looking back, the IR gun would have diagnosed my issue almost immediately, as it was a bad radiator, the thermostat also was of concern. I bought a wahler from fcp groton, and the constuction was SO much better than the same priced one from autozone. I also boiled it before installation, to verify it worked. now, without the temp compensation board/idiot light gauge, it goes up a bit and down a bit as the engine does it's thing, but all is well.

 

I run a green cap on my modified 740 turbo. No problems whatsoever. Higher cooling system pressure equal higher coolant boiling points, so they are a win as long as the rest of the system can handle the pressure (which even 20 year old cars can).

Regards, Andrew.

 

My 240 is having the same overheating issues. Replaced the water pump. The after market model had a better design. Replaced fan clutch. Did some repair to the fan shroud. Took the radiator to the car wash and blasted it clean. Drilled out the middle of the thermo to make it free flow antifreeze. Still over heats when car is fully warmed up and sitting in heavy traffic or the drive thru. Havent messed with the compensation board or replaced the Rad. After hearing your issues I think I'm gonna replace the rad next. Thank goodness my boyfriend is a mechanic!

 

#1. Go get a laser temp gun(borrow it from a shop or see if your local parts store lends them out or has a cheap one to purchase this will save you a TON of $$ in the long run. You DO NOT want to just start throwing parts at the car...mechanics don't do that they test first then replace. #2. Take the temp of the thermostat first point it at the nut closet to drivers side that holds housing in place. temp should read 180-190. #3. The take the temp of the radiator. You need to take temp of both sides. If the temp is the same or very close to the same on both sides then you have a bad radiator. If the degrees differ from one side to the other by 20-30 degrees then your radiator is just fine