Hello all,
I drive a 2008 AWD Volvo s40 t5 LHD... About a week ago after a few hrs of driving high way and city with decent breaks in the time, the cooling fan remained on when I parked... I thought well that's peculiar considering I have driven more/harder on hotter days and the fan didn't remain on. It was at least below 80 degrees Fahrenheit that day. I popped the hood, saw my coolant expansion tank had sprung a pressure leak... I had a crack at the top so I replaced that. Then today i drove maybe 80 min today back roads too and from school with hours breaks between and its cooling fan stayed on yet again... 77 degrees out... I'm wondering if anyone with the car/motor, has had weird cooling system problems? Or if this is even a red flag? I have had the car for going on 2 years now and this is abnormal for me. I havent noticed any fluctuations in the operating temp at all.

 

the fan is controlled by the engine's coolant temp sensor (located under the thermostat housing) so either the temp sensor is wonky or your car is running above the threshold to turn the fan on. There is a timing circuit to turn the fan off after xx minutes so if it fails to turn off and kills the battery, you could have a relay problem or a problem with the fan motor itself. Your case sounds like the engine is running warm - does the temp gauge do anything differently (say wanders or pegs higher than it used to)? the temp guage is also controlled by the ECT sensor so there's a few things to consider.

1) what does the coolant look like? still green or is it a brownish/rusty color?
2) does the upper radiator hose get very firm when the engine is running? (indicates a potential head gasket issue)
3) does the temp sensor do something new/odd?
4) what happens when you turn the heater on full - does it change the temp gauge?

At this point I'd consider doing a radiator flush (drain, refill with distilled water ($.79/gallon at walmart :-) , run the water till full temp, drain again and refill with fresh 50/50. Google around for correct procedures on fully draining and burbing the system after the refill.

I'd also consider putting in a new thermostat and ECT sensor. $75 in parts, hardest task is figuring out how the wire harness unclips!

Last is I'd look around for any signs of leaks - radiator seams, pop off the timing belt cover to make sure no water pump leaks etc.

 

There could be (probably is) air in your cooling system. This can mess with the sensors, causing the temperature sensors to report erroneously, causing your fan to run at those odd times.

I've never bled my V50's cooling system, but apparently Volvo suggests a vacuum bleeding process. Never did that, but it looks like fun...

 

So this poses me a BIG annoying question... What kind of coolant does this car take? Blue, green, orange? LOL. mt6127: What does this coolant look like to you? (I hope two pictures show here) To me, it looks like it is orange... When I changed the overflow tank I bought from FCP Euro, I also bought the coolant recommended for the car considering id need to top it off. Craps blue man, so I called the Bill gray Volvo dealer that is here and he said its to be blue... I just think it's interesting you asked if it's still green. I'm oblivious when it comes to coolant types, when I siphoned it out of the expansion tank it looked orange but green too so I wasn't sure if it was the green coolant that became "rusty"
The temp sensor has done nothing abnormal to me, I have never seen it go above operating temp. The only weird thing the car has done while ive owned it was last year in the cold months it seemed to take a while to warm up. Like 15-20 min of back roads to reach operating temp. I figured it was the thermostat. I was going to replace it this summer but didn't get the chance to financially, I heard its quite a pain to remove that airbox to gain access to the thermostat hence why I wanted to pay a shop to do it. If I remember right, the car 'could' start to cool a little from operating temp at idle in the very cold wintery months.

I turned the heater on high today and noticed no difference, I left it on for a couple min.

Habbyguy: Do you think air got in the system from replacing the overflow tank? I know I saw people saying the car does its self burping. I didn't drain the coolant completely so I didn't think I would need to. But ive let it run for a little without the cap on it and i tried to squeeze the top hoses I could get to... Ill have to look more into the burping method.

I drove quite a bit today and IT WAS FINE. I kinda hate the car lol. I also have intermittent AC super annoying.

 

How do I know if my reply gets approved? I sent one a few hours ago.

 

ha! I'm showing my age suggesting the coolant is supposed to be green. At least its not pink - that's for my wife's Toyota :-)

So there is a whole color scheme for coolants - particularly when they came out with the OAT formulas. As a wise man once said, "you can't tell the players without a scorecard" so best is to go to a dealer source and ask...

HP658 - I just noticed your post with the pics had the little mute icon so I approved it. usually once you get approval for a rich content thread (ie posts with links, pics etc) you shouldn't need approvals in the future...

 

Sounds like the OP might have sorted the problem (or the car burped up some air, which happens, too). ;-)

Intermittent A/C can be a million things, but our Volvos are very prone to the A/C clutch wearing to the point that the electromagnetic clutch can't pull the upper plate in reliably. Next time the A/C stops working, have a peek at your A/C pulley - if the front (away from the engine) part of the pulley is stationary, then CAREFULLY give it a little tap with a broom handle (or similar), in the center. If the problem is the clutch gap, that will be enough to engage the clutch (until you turn the A/C off, but now you know the problem). Lots of threads on how to deal with the clutch gap (really easy on our S40-style compressors).