S52 w/ AC cooling problems

[dude8383]

Stock is better. The resistors do fail on these cars... I'd say this is a "wear" item.

[Strelok]

So, interesting new development. The car has been running great, no overheating, but I realized the other day that my aux fan went out. On closer inspection, the zipties that were holding the low speed resistor in place have melted off, and the high speed fuse was blown. I'm guessing this resistor has gone out. Any thoughts on whether this is just a wear item or do I maybe need a different on to deal with the SPAL fan over stock?

[AndrewBird]

FYI, I've only got the stock AC condenser fan in my M50 powered E34 (no mechanical fan) with a mishimoto E36 radiator and a Stewart high performance water pump. With the AC on full blast in 90º weather, the temp never creeps up past half. I did also get a fan switch from an M42 powered car (lower temp).

[ATL_E30]

Put about 20 miles on it after tightening the hose, refilling and bleeding. Temp gauge hangs out just under 1/2 and hasn't touched 3/4 in stop and go. It hasn't been quite as hot this past week so it still needs more testing but I think it's good to go

Nice, would love to see/ride in it sometime. I'm debating on swapping my car or stroking the M20 so would be cool to see one first hand.

[Strelok]

Any luck?

Put about 20 miles on it after tightening the hose, refilling and bleeding. Temp gauge hangs out just under 1/2 and hasn't touched 3/4 in stop and go. It hasn't been quite as hot this past week so it still needs more testing but I think it's good to go

[ATL_E30]

Any luck?

[Strelok]

Pressurized as in combustion gasses from the cylinders are leaking into the cooling system and "over-pressurizing" it to the point that hoses pop off (or are extremely hard when running). Basically if the head gasket has a slight leak onto the cooling system, every time that piston comes up, it leaks pressure into the system. A cooling system runs at about 16psi-21psi, a running engine combustion chamber will see in the neighborhood of 200psi at idle/cranking.

I see. Well, I hope it's not that. When I re-attached the hose I noticed the clamp was pretty loose so I'm hoping I just neglected to tighten it.

[ForcedFirebird]

Pressurized as in combustion gasses from the cylinders are leaking into the cooling system and "over-pressurizing" it to the point that hoses pop off (or are extremely hard when running). Basically if the head gasket has a slight leak onto the cooling system, every time that piston comes up, it leaks pressure into the system. A cooling system runs at about 16psi-21psi, a running engine combustion chamber will see in the neighborhood of 200psi at idle/cranking.

[Strelok]

Hose shouldn't have popped off, even at 220. Time for a coolant system pressure test, you might be pressurizing the system. :(

Forgive my ignorance, cooling systems are the bane of my existence. Aren't they supposed to be pressurized? What would cause improper pressurization? Bad bleeding?

[ForcedFirebird]

Hose shouldn't have popped off, even at 220. Time for a coolant system pressure test, you might be pressurizing the system. :(

[Strelok]

Well I got the fan in and working, but I may have spoke too soon. I took it out for a test drive and it was running great, much cooler than before even in stop and go with the AC on full blast.

Since this is the first time I've had it off the stands with the new wheels and lip, I decided to drive to a nearby parking lot to take a few pictures. I left it idling while I took a few, and when I got back in I saw the gauge had creeped above 3/4. I popped the hood and grabbed my IR thermometer. To my dismay, the upper hose was reading about 220. The t-stat was at 210-ish. I walked over to check the lower hose and as I was about to get a reading it popped off the rad and sent all my coolant everywhere. I immediately shut the car off.

The gauge wasn't in the red but getting a 220 reading on the hose scared me into thinking I may have just lost my head gasket. It's currently sitting in the parking lot cooling down so I can go back later and fill it back up and drive it home.

[dude8383]

Interesting. The spal unit is rated at just over 1600cfm and is a good bit larger than the stock one. Do you know what CFM the stock one is?

I am not totally certain but its like 2000+ IIRC

[Strelok]

The diesel fan works perfectly with the Mishimoto radiators... they don't have the lip on em.

The stock a/c fan as Austin! has mentioned is more than capable of pushing the air that you need to keep the car cool. I've had my S52 E30 with a/c for the last 3 years now kicking ass in NYC heat. Never has it ever gone above the 1/2 way mark. The spal fans don't push nearly as much air as the factory unit does.

Interesting. The spal unit is rated at just over 1600cfm and is a good bit larger than the stock one. Do you know what CFM the stock one is?

I finally got this fan in. I initially trimmed the rad, threw the fan in, filled the coolant and fired to the car up only to find the fan was rubbing on the bottom of the rad. I took everything apart again in a fit of rage and ended up following the advice of one of the posters in this thread by putting the fan on the back of the clutch, then trimming the blades to clear the vanos and thermostat.



Lots of room for the rad but the vanos is damn close:


I'll be filling up and bleeding this afternoon, hopefully all goes well and I can finally get this thing off the jack stands

[dude8383]

The diesel fan works perfectly with the Mishimoto radiators... they don't have the lip on em.

The stock a/c fan as Austin! has mentioned is more than capable of pushing the air that you need to keep the car cool. I've had my S52 E30 with a/c for the last 3 years now kicking ass in NYC heat. Never has it ever gone above the 1/2 way mark. The spal fans don't push nearly as much air as the factory unit does.

[ForcedFirebird]

I regress based on that last post. 220 "is" too high. 215 should be max when fans bring it back.

It doesn't cost anything to completely remove the thermostat and take note of temps. Worth a try for the sake of science.....