Operating temps with Spal / Zionsville / other cooling improvmts

[zak78]

Driving around in 40F conditions with and without the 26" Spal hooked up-- cruising at 107C regardless, idling in traffic at 108C without the fan, idling at 107-108 with it, possibly 2 degrees hotter at most when parked at the Quickee Mart. During WOT blasts I see the same 107, maybe 108 for the blink of an eye, regardless. I'm guessing I'd see a slightly-greater difference in summer, but overall I'm struck by how little it seems to impact the overall temp. Also, this is using Z'ville's included fan shroud, which doesn't look like the best design.

A buddy is trying to sell me on an 8% overdrive pulley for the water pump, which seems negligible. I see that the Stewart pump has a good rep...but I'd like to hear some real-world numbers before pulling the trigger on that one (if only because changing water pumps is a PITA).

Any input is appreciated

[JimLev]

You must mean a 16" fan.
Last I knew Stewart only made WP for i6 engines.
Why an overdrive pulley, that's not going to drop the temp its the t-stat that sets the temp.
I'm using an under drive on the pwr steering and the WP.

[philly98540]

Yeah, as Jim said the engine temp is controlled by the t-stat. If you want cooler engine temps, you need to change to a lower temp stat. The cooling of the radiator temp is by the fan(s) and is separate from the control of the engine temperature. Don't bother changing your water pump or its pulley unless you see a reason to (which you dont).

[1823alex]

Does anyone know what the standard operating temp for an inline 6 is supposed to be?

Mine usually sits at 204.8f (96.8c) for the majority of the time and the highest I've seen is like 210 (98c). Is this normal? I do have a clutch fan delete right now so I've been watching temps like crazy, although it's still colder out so I'm less worried and my aux fan does operate. I'm mainly worried about stop and go and what temp do I need to worry about like just stopping my car and waiting for it to cool off?

[JimLev]

I'm mainly worried about stop and go and what temp do I need to worry about like just stopping my car and waiting for it to cool off?

I'd be worried too, those i6 engines just love to warp the heads.

[1823alex]

I'd be worried too, those i6 engines just love to warp the heads.

Yup that's why I've been watching the temps, at what temp do I need to start worrying tho?

[MotorMouth93]

The factory thermostat in the 540i opens at 108C but has a heater circuit to force it open earlier at the discretion of the DME. Just cruising, the temps you are seeing are perfectly normal and expected. If you want it cooler you can swap in an 88C thermostat.

The downside to the 88C thermostat is either a code for the disconnected heater circuit or a code for coolant temp too low, depending on the year of your car.

[Dave Sal]

Does anyone know what the standard operating temp for an inline 6 is supposed to be?

Mine usually sits at 204.8f (96.8c) for the majority of the time and the highest I've seen is like 210 (98c). Is this normal? I do have a clutch fan delete right now so I've been watching temps like crazy, although it's still colder out so I'm less worried and my aux fan does operate. I'm mainly worried about stop and go and what temp do I need to worry about like just stopping my car and waiting for it to cool off?

Can't answer your question but I'm running an 88 degree thermostat in my lowly I-6. In cooler weather such as winter and early spring I'm normally seeing 87 degrees in test 7. During the hot summer months it varies between 88-93 degrees, with the highest I've seen being 95 degrees while sitting in a drive through at a local Wendy's.

[crazy4trains]

Does anyone know what the standard operating temp for an inline 6 is supposed to be?

Mine usually sits at 204.8f (96.8c) for the majority of the time and the highest I've seen is like 210 (98c). Is this normal? I do have a clutch fan delete right now so I've been watching temps like crazy, although it's still colder out so I'm less worried and my aux fan does operate. I'm mainly worried about stop and go and what temp do I need to worry about like just stopping my car and waiting for it to cool off?

Those temps are right in-line with my in-line 6.

[zak78]

Yup, I do have an 88C T-stat. I also wired the fan to come on whenever the car hits full operating temp.

Philly and Jim, do you have aftermarket fans that aren't the Spal? I think I recall Jim have a Flex-a-Lite or something. Anything has to be quieter than this thing.

[JimLev]

I've got a 16" low profile Flex-a-Lite fan that is controlled by a PWM controller. It's mounted in the OE fan shroud.
It runs at 25% speed as soon as I start the engine, if needed the temp sensor will speed it up.
When the engine is running you can't hear it.

[MotorMouth93]

Yup, I do have an 88C T-stat. I also wired the fan to come on whenever the car hits full operating temp.

Philly and Jim, do you have aftermarket fans that aren't the Spal? I think I recall Jim have a Flex-a-Lite or something. Anything has to be quieter than this thing.

If your ktmp is 107C while cruising with an 88C thermostat then something is seriously wrong somewhere, it should sit between 90-93 under normal circumstances. What thermostat did you buy? If your numbers are consistently 107ish then it sounds like you don't actually have an 88C thermostat as that number is pretty much spot on the factory thermostat.

[jicaino]

88ºC thermostat here and a (overkill) Wizard cooling 20 liters radiator. Cruising temps of 87º to 91ºC and high load temps (several passes of full throttle w/o time to cool down) max. 99ºC.

If I'd have bought the 88ºC thermostat first I wouldn't have "improved" the radiator. What's wrong with our cooling systems is the dreaded thermostat.

Also have a 88ºC in the i6

[Uturn540]

Mine ran 94-95c all last summer with the 88c thermostat and no viscous fan. Then on a recent 700 mile round trip to Midland with outside air temp at 12-15c the engine temps were a consistent 102c which was just not right. After all the other helpful comments agreeing about something not being right I pulled the radiator back and cleaned all the trash that had accumulated between the radiator and condenser. Now the temps are running 87-90c. There is a opening on the left side of the condenser/fan assembly of the 540's that can allow the area between the radiator and condenser to become packed with leaves, grass, and anything else that is blowing around. I think that is one of those areas that is taken for granted until you start having issues.

[ninetyseven1]

I have an 87C thermostat in my 97 540i and im running 87C on the highway and about 90C around town. Sounds like your thermo is not opening or there is some serioius air in the system. Are both hoses hot? Is the system filled up? i used Jim's method of filling it. Remove expansion tank cap, When car is cold remove top radiator hose and fill until it wont take anymore ,then put it back on ,turn heater on and start the car and let idle for a while until its up to temp (88C+). Then put the cap back on while still running and drive. Maybe your fan is not powerful enough? Try the factory clutch fan after all of this if its still running hot. The factory fan is a 92C fan, which means it should engage at that temp. The factory fan is a power robber but works well at keeping temps low.

[jicaino]

Mine ran 94-95c all last summer with the 88c thermostat and no viscous fan. Then on a recent 700 mile round trip to Midland with outside air temp at 12-15c the engine temps were a consistent 102c which was just not right. After all the other helpful comments agreeing about something not being right I pulled the radiator back and cleaned all the trash that had accumulated between the radiator and condenser. Now the temps are running 87-90c. There is a opening on the left side of the condenser/fan assembly of the 540's that can allow the area between the radiator and condenser to become packed with leaves, grass, and anything else that is blowing around. I think that is one of those areas that is taken for granted until you start having issues.

This is a very very good suggestion. Take a look:

IMAG0708.jpgIMAG0709.jpg

[zak78]

Mine ran 94-95c all last summer with the 88c thermostat and no viscous fan. Then on a recent 700 mile round trip to Midland with outside air temp at 12-15c the engine temps were a consistent 102c which was just not right. After all the other helpful comments agreeing about something not being right I pulled the radiator back and cleaned all the trash that had accumulated between the radiator and condenser. Now the temps are running 87-90c. There is a opening on the left side of the condenser/fan assembly of the 540's that can allow the area between the radiator and condenser to become packed with leaves, grass, and anything else that is blowing around. I think that is one of those areas that is taken for granted until you start having issues.

Man. Dead on. In converting from standard to //M front ends, I hadn't picked up the very-important, lower-front cover that otherwise keeps away debris (not to mention what looked like a dead weasel). THANK YOU for the common-sense reminder. Now I'm crusing at 88 degrees again. Edit: There was also some air in the system that I'd forgotten to bleed with the last round of hose replacements. It wasn't so apparent at first...then I jacked the nose into the air and yup, bubbles galore. Live and learn.

[vien]

just my 2 cents on my set up i have a custom spal 16inch fan with temp sensor opening at 185f, i also have the 88c stat mine is 01 no codes at all that only fo rthe 02-03 model years. right now with my set up in florida heat driving all day my temps top at 204f and average 199f.