T4 behaving differently
 

Evening all

I'm after some more advice please?

Lately I have noticed that my cooling fan is coming on every time the car is used. If i drive for more than 5 minutes the cooling fan is coming on, staying on for a few minutes, stopping and then coming back on. If i stop the car and turn off the ignition, the cooling fan turns off, but if i turn the ignition back on, the fan will restart for a minute or so. Is this normal and just a result of this weather? I have recently replaced my thermostat (genuine Volvo) and replaced my coolant with Prestone ready to use. The temperature gauge goes to half way very quickly from cold, and hasn't gone above this, even is slow traffic.

Also, with the latest heatwave I have started to use my aircon, normally i just open the windows and sunroof!! I have noticed that when i turn my aircon on, the ECC kicks out ice cold air, but my engine starts to idle erratically and the car feels like it surges in power when driving at speed. When i turn my A/C back off, the car returns to running normally.

Does anybody have any thoughts on this as i'm getting abit worried by it!!

Thanks as always
James

The fan running when it shouldn't can sometimes be caused by issues with the MAF sensor. Check connections, & give it a clean inside by spraying it with switch cleaner !

Hi,

I would bet the engine cooling temperature sensor is playing up...just a thought!

When was the Idle Air Control Valve & Throttle Body butterfly valve last serviced? I'd be checking those before replacing anything :thumbs_up:

Hi Liam

They were cleaned about 3 months ago, so wouldn't hurt to clean them again!

The fan coming on seems normal enough to me. With any kind of summer weather mine routinely comes on very regularly. It's loud enough that it's also somewhat annoying. What you want to watch is that the needle makes its way to 12 o'clock and then stays there firmly. if it starts to wander past 12 or doesn't make it's way to 12 then you have an issue.

As for the AC it's normal enough to feel the engine push a bit harder as the clutch kicks on. I would describe normal behavior as a bit of a shudder with each cycle of on off. You should not notice it while driving but if you are idling you would definitely notice it. Anything beyond a shudder and I would look into whether the compressor is on its way out and/or is insufficiently lubricated with compressor oil.

For what it's worth I've always found that my V40 performs best between 18-21deg C. When it gets very hot, it just seems a tad more sluggish to me. I've heard that this could be partially remedied with an aftermarket transmission oil cooler but I've got no appetite for such a thing.

Thanks pierremcalpine. The news that your car shudders on idle with the aircon on is really reassuring :)

Re the transmission oil cooler, do you have an automatic or manual car?

Also, the cooling fan comes on with the AC running to keep the gasses in the condenser cool. So your recent AC use and erratic cooling fan are probably linked.

As for the engine surging when the AC is switched on, my god, you've never experienced an early 1.8 NA Volvo engine with the AC running. It's so tragic it's almost funny. If I'm climbing a gentle hill in mine, in fourth gear doing around 40mph and the AC clutch kicks in, I literally have to change down a gear immediately. It's like someone has instantly dropped a 2 tonne weight in the back. I'd say around 30 of the 115 raging Swedish (ok, Dutch) horses take a dive.

Lord knows how bad an early 1.6 is with this system switched on. That's why I only really switch it on when the temperature gets past around 25 degrees. On the plus side, it's pretty good going that a 20 year old AC system is still going!

Wow i didn't realise!!! I'm still relatively new to the car so still learning but seems i have nothing to fear. If anything i'm lucky the T4 can afford to loose a few horse when at cruising speed!!! Thanks Martin :)