Source
r/e46•
elevatewave

High coolant temperature only when A/C is on

Hey guys,

My 2005 330ci (auto) is exhibiting abnormal behaviour when the AC is on.

Here's what's happening: when i drive the car, coolant temperatures are anywhere from 92-97. Normal right?

As soon as i turn the A/C on, the coolant temperature is fine during idle. But when i start driving the coolant temperature starts going up to 99,101, 102 even 104!!

The only thing i can think of that could be causing the issue is the electric fan conversion... but I've tested the fan with INPA and it seems to be working great. When i turn the AC on I hear the fan kicking into high gear.. when the AC is off I hear the fan spinning at a slower speed.

I've replace the water pump(last month) and the thermostat housing(today). The radiator was replaced a couple years ago along with the expansion tank. I had the AC recharged about a year ago. I've bled the system properly according to TIS and the car runs great without the AC on.

Not sure what else I can try here....

Any ideas?

Posted Jul 14, 2019, 11:26 PM UTC

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skuobiee•

Besides something that would affect at all times such as a tensioner, pulley somewhere, ac clutch not working good, i lean towards the electric fan. But i still have a clutch fan so i cant say from experience.

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elevatewaveOP330ci ZHP•

Thanks for the input. I wrote an update below.

You got me wondering if I should recheck my belt and water pump installation since I replace the WP and alternator..

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elevatewaveOP330ci ZHP•

Ya I did remove the front aux fan and shroud. I bought a used oe fan and tested with inpa.. seems to be working at full speed and half speed .

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elevatewaveOP330ci ZHP•

Thank you everyone for your input. Really appreciate the help

Update on everything. I checked the plug for the fan because i read that if the one pin doesnt make contact in the plug, then the fan won't kick into high gear for the AC. I unplugged and made sure the connection was tight as possible.

So now for the most part, the engine is cooling properly with the AC.

HOWEVER... I was still skeptical so i took it for a longer than normal drive. About an hour of driving. When i push the pedal down (on empty back road of course) and put the engine under higher load, I see temps rising again to 102 103 highest I got was 108 before I turned the heater on full and got the temps down.

If I drive moderately the temps seem to be on the lower scale... I can hear the fan kicking into high gear..

I'm thinking i may need to revisit my water pump and possibly my tensioner for any install errors that may have occurred when I did my alternator and WP replacement...

Could it be possible under high load the WP is not spinning fast enough?? This is the only thing i could think of. Either that or my rad is not cooling properly..

Or is it the transmission oil cooler causing the extra heat?

Really wonder what's going wrong with the engine cooling. On idle temps seem to be normal..

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elevatewaveOP330ci ZHP•

It runs perfect without AC on.. perfect temps

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elevatewaveOP330ci ZHP•

Well I'm not big AC guy, but after I did the electric fan conversion I wanted to monitor the temps to make sure it's all good..

That being said I'm really not sure if the problem was happening before the conversion/replacing the components. The only thing i replaced because of the issue was the thermostat. Thought that would help. I needed to replace the tstat anyway.

The voltage seems good when i check it with obd fusion. I have an android HU that links to the odb reader I have. I've been continuously monitoring everything ever since the conversion.. is there anything i should be watching for in regards to the voltages?

AC Is working and is ice cold!!

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elevatewaveOP330ci ZHP•

Thanks man. The problem usually occurs after about an hour of driving as well. The first 30-45 mins with AC on full blast are usually fine until more driving and at higher speeds. Especially with higher revs.

Yeah but when temps go past 105 I go into panic mode. Even at 102 I feel uncertain.. i feel like the engine should never go past 102 even on a super hot day.

I also don't trust the temp gauge at all due to the shitty buffer they came with. I don't want to test it to see if it will go past 108 since I would be asking for trouble at that point..

Good point, maybe i should reflush the system with perfect 50/50 mix just to rule out the possibility. For the most part it's a 50/50 mix but it's not perfect. I should really do another flush with full 50/50 coolant.

Re: bleeding. yes i ran heat on high with the vent controls on full heat (dots) and made sure system was fully bled. Did the bleeding procedure found in TIS. Confirmed that system was bled when water started pouring out of the little hole in the ET (won't do it if there's air in the system).

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tourima325i•

I thought/think that just detects air quality for the intelligent air recirculation...

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