M535i oil cooler questions

[Robert Bondi]

I've acquired a used setup from a Euro E24 and am in the process of deciding what I will clean up and use and what I will buy new. A few questions after initial inspection:

1. I know the filter head contains a thermostat element. It seems like a good thing to renew now, but I'm not sure that it actually has its own part number?

2. A bit of residual white/red paint helps me match cooler ports with line connections. On the other end, I'm still not sure which port is which on the filter head; there are no words or arrows either. One port is straight up and parallel to the filter housing, while the other is sort of at a 45 deg angle. Anyone know which is which? I might figure it out by taking apart the filter head and housing to follow passages; haven't gone there yet.

Why am I doing this? I need to post my project pics, but I'm now running a freshly rebuilt and modified M30B34. Since I've had oil pressure and temperature gauges for many, many years, I see my oil T can easily run 20-30 F hotter and consequently that thinner oil can go to somewhat lower pressures than the 3.0L engine did. I already run pretty much every coolant system upgrade under the sun, so not much room for improvement in that area.

[wkohler]

The E24 cooler lines are different than the E12 ones. I have an E24 that still has this setup in tact and will trace the lines to see which ends up where. My M535i setup is still out of the car and I can show the difference in the lines too if that helps and also a photo of the bracket on the left frame rail.

[thomas_m535i]

1. I know the filter head contains a thermostat element. It seems like a good thing to renew now, but I'm not sure that it actually has its own part number?

2. A bit of residual white/red paint helps me match cooler ports with line [..] passages; haven't gone there yet.

Hi Robert,

I've a M535i E12 with an oil cooler (should be the same as you're referring to).

About point 1 (filter head contains a thermostat): thanks, this is good info. Are you entirely sure about that by the way? I thought so too, but couldn't tell for sure when examining the filter housing.

2: I can't check at the car right now, but judging from my restoration pictures it is as follows in my car:
- The oil line closest to the engine (90 degrees angle) goes to the upper port on the cooler (45 degrees angle).
- The other oil line further away from the engine (90 degrees angle) goes to the lower port on the oil cooler (90 degrees angle).

I hope this helps.

[Robert Bondi]

The E24 cooler lines are different than the E12 ones. I have an E24 that still has this setup in tact and will trace the lines to see which ends up where. My M535i setup is still out of the car and I can show the difference in the lines too if that helps and also a photo of the bracket on the left frame rail.

Chris,

Sure. Any pics would be of great help. Since the 530i never had an oil cooler, none of my manuals help me very much on this project.

Since the filter head and the cooler seem to have been shared between the Euro E24 and M535i, it at least seems that the ports connected should be the same even if the lines are a little different.

[Robert Bondi]

Hi Robert,

I've a M535i E12 with an oil cooler (should be the same as you're referring to).

About point 1 (filter head contains a thermostat): thanks, this is good info. Are you entirely sure about that by the way? I thought so too, but couldn't tell for sure when examining the filter housing.

2: I can't check at the car right now, but judging from my restoration pictures it is as follows in my car:
- The oil line closest to the engine (90 degrees angle) goes to the upper port on the cooler (45 degrees angle).
- The other oil line further away from the engine (90 degrees angle) goes to the lower port on the oil cooler (90 degrees angle).

I hope this helps.

Not entirely sure about the thermostat, but I ran across it discussed multiple times in the archives and seems to make sense.

I'm a bit confused on the port routing you mention since the only port I'd describe as 45 degrees is on the filter head, not the cooler?

[Robert Bondi]

Update:

Following some tuning advice, I've seen surprising improvements on the hot running 3.7L engine just with timing adjustments:

1. I was running quite a bit of advance as legacy from my earlier engine. I'd pretty much had it that way since reading an old post years ago from Peter Florance on dialing in more advance until it pings, then backing off. I returned the ignition timing (at the distributor) back closer to stock.
2. I removed/capped the vacuum advance lines of the 80-81 528i setup that modify the spark timing at the distributor too.

Weather is getting cooler, but I was amazed to see the water temp barely exceed 1/4 on the temp gauge and oil < 180F. If this keeps up, the oil cooler really won't be needed and I may shift focus to another project.

FWIW, I've studied and dissected my E24 oil cooler setup and figured out my plumbing questions. The annotated pictures at the link might prove useful to others. My filter head definitely has a tstat - Wahler told me it's speced at 90C. When the tstat opens, filtered oil is diverted through the oil cooler before heading back to the block. Like the water tstat, the element really needs to be present for proper flow - 4 holes are present in the tstat passage and only two should be open at a time.

https://www.flickr.com/photos/robertbon ... 1003183145

[PatinaBeforePolish]

Robert,

Very interesting, thanks for the pics. How did you determine the flow in the block ports?

[Robert Bondi]

Robert,

Very interesting, thanks for the pics. How did you determine the flow in the block ports?

Yeah, that would have been a bit tougher to figure out. For the block, the BMW blue factory manual shows the flow pattern associated with the oil filter element.