engine oil thermostat

[maicol76]

Is there someone who knows what the opening temp of the oil thermostat is?

I'm considering to exchange oem with low temp thermostat for Hot~~ summer track driving.

[dparm]

Are you having problems with oil temps getting too high, e.g. 300+?

[macdude357]

It's at the bottom of the oil filter housing. Total PITA to get to.

[maicol76]

The point is 'what the opening temp of the oil thermostat is?'

[MSY]

Thermo is useless on this car as it runs wide open already and thermo would not help

[roastbeef]

If it's as open as it gets, nothing is going to change.

I think bimmerworld makes a bypass and claim to get better cooling through efficiency (zero obstruction of flow), but the car would take a long time to warm up and is not recommended for street cars.

[Richbot]

WAG based on watching the OEM gauge in cold weather when it finally opens on the highway, is 195-200ish *F because in cold weather it'll drop significantly after warming up to around there...but that's a WAG

Paging dogbone I bet his data reveal...something

[macdude357]

I bought the bimmerworld oil diverter. I'm going to install it before my next track day. My plan is to simply cover up part of the oil cooler grill when driving on the street to prevent over-cooling.

[bigjae1976]

Originally Posted by macdude357

I bought the bimmerworld oil diverter. I'm going to install it before my next track day. My plan is to simply cover up part of the oil cooler grill when driving on the street to prevent over-cooling.

Not sure that would work. Once the oil reaches operating temp then oil temps will likely go over 210.

It can work if you let the car idle and warm up for a couple of minutes.

The diverter valve doesn't do anything to reduce temps. If it does, it maybe buys me another minute or two.

[dparm]

Originally Posted by macdude357

I bought the bimmerworld oil diverter. I'm going to install it before my next track day. My plan is to simply cover up part of the oil cooler grill when driving on the street to prevent over-cooling.

So basically this?

[macdude357]

Originally Posted by bigjae1976

Not sure that would work. Once the oil reaches operating temp then oil temps will likely go over 210.

It can work if you let the car idle and warm up for a couple of minutes.

The diverter valve doesn't do anything to reduce temps. If it does, it maybe buys me another minute or two.

I actually tested this already by taping over the grill. Oil temps didn't climb over 210 or so when I was cruising at freeway speeds. I generally only use my car for one of three things. Driving to/from work (short commute where the oil temps barely reach 210 anyhow), driving to/from the track and driving on the track. I can "tune" the amount of air getting to the oil cooler for the longer drives to/from the track by adding/removing tape.

I'm interested to hear more about the diverter not really reducing temps though. On the E9x platform or your E46? Stock oil cooler?

Seems like these solutions (upgraded coolers, diverters, etc.) seem to help some but not others. Could be that my theromostat isn't working properly and not sending as much oil through the cooler as it should, so if that's the case, then the diverter should help. Other guys that run E9x at the same tracks don't seem to be having the cooling issues I'm having and most of them have more mods (stickier tires, aero) and you'd think that would create even more heat.

[maicol76]

Thanks for helpful information, guys~

I'm using a low temp coolant thermostat(71C. stock is 79C). After installing it, engine oil temp is lower than before...at least 5C. I'm very satisfied with this coolant thermostat. DCT fluid temp is also lower than before.

[dogbone]

Originally Posted by Richbot

WAG based on watching the OEM gauge in cold weather when it finally opens on the highway, is 195-200ish *F because in cold weather it'll drop significantly after warming up to around there...but that's a WAG

Paging dogbone I bet his data reveal...something

As far as what the AIM shows for oil temps with the OEM diverter---I find the oil gets to operating temps in a single warm up lap. Once it's up to temps and the hard driving starts, the temps don't really drop. (Obviously, the supercharger doesn't help as far as heat goes.)

Here are some oil temp charts from a few tracks. The numbers are not important here. What we want to look at is how the temps trend over whole sessions. In the first three charts at Laguna Seca, Chuckwalla and Buttonwillow, the temps go up and generally stay up unless I take a cool down lap. A possible exception is at Buttonwillow, where in the first two sessions of the day, the temps drop briefly after the second lap, but it doesn't do it the rest of the day.

At Auto Club Speedway, you get a temp drop at the beginning of each lap because the speeds are so high. You’re crossing the start/finish at 150mph and that really does have a cooling effect, but then they go up again once you hit the in-field.

Laguna Seca


Chuckwalla


Buttonwillow


Auto Club Speedway


So I don't see any obvious moment in the data where you can say the OEM oil diverter opened and temps dropped. Bimmerworld claims in their sales pitch on their website that the OEM oil diverter might not ever fully divert maximum oil into the cooler. If that's true, then the Bimmerworld diverter could be fairly useful. But the install is a big job. At least four hours for a real mechanic (and my supercharger doesn't make it any easier)....I bought the Bimmerworld diverter, but I have not had it installed yet. The best time to do it would be when replacing all the belts, but I did that a year ago, so I'm not super eager to tear the front of the car apart at the moment.......

[Richbot]

OFHG eventually starts leaking on these, probably? That'd be as good a time as any

[Visceral]

What is an "excessive" oil temperature at the track? 260? 280?

[dparm]

Originally Posted by Visceral

What is an "excessive" oil temperature at the track? 260? 280?

300+, especially if that's being sustained.

At a certain point, when the temps are really high, the pump may not be able to provide enough pressure since the oil is so thin. This is why I stress the importance of an oil pressure gauge.

[bigjae1976]

Originally Posted by Visceral

What is an "excessive" oil temperature at the track? 260? 280?

Depends on the oil's specification. You don't want to go far over 300.

[Visceral]

Hmmm. OK. I was worried about 260 going on 270.

[bigjae1976]

Originally Posted by Visceral

Hmmm. OK. I was worried about 260 going on 270.

I'd say ideal is 240-260 in most cases. 280 isn't great but it's not bad. You're entering the danger zone at 300. Keep in mind, your oil temps are fluctuating a lot more than the OE gauge is telling you. If the gauge says 300 , your actual temps could be higher.

[Visceral]

Originally Posted by bigjae1976

I'd say ideal is 240-260 in most cases. 280 isn't great but it's not bad. You're entering the danger zone at 300. Keep in mind, your oil temps are fluctuating a lot more than the OE gauge is telling you. If the gauge says 300 , your actual temps could be higher.

I have that AIM Solo 2 and Smartycam, remember...

[bigjae1976]

Originally Posted by Visceral

I have that AIM Solo 2 and Smartycam, remember...

Lol...sounds like you need to buy another one!

I was looking at oil and water temp data and comparing it to where I was on the lap and RPMs. Learned a lot!

[dparm]

Originally Posted by bigjae1976

Keep in mind, your oil temps are fluctuating a lot more than the OE gauge is telling you. If the gauge says 300 , your actual temps could be higher.

Correct, the gauge is showing the temperature in the sump. In areas like the bearings, it's even higher.