Added OEM Oil Cooler System, Now Low Pressure Under 1800 RPM

E28 technical advice asked and given! Troubleshooting, modifications and more.
Post Reply
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Added OEM Oil Cooler System, Now Low Pressure Under 1800 RPM

Post by BuzzBomb »

So I test fitted an oil cooler setup from a Euro 535. Now, the oil light stays on below around 1800 RPM.
Were there any modifications done to Euro M30B34 engine blocks to maintain oil pressure at idle while using an oil cooler? Any other ideas?
Karl Grau
Posts: 9708
Joined: Mar 10, 2006 7:34 PM
Location: Sandy Eggo

Post by Karl Grau »

Did you get the car warm enough that the oil cooler thermostat opened?
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Post by BuzzBomb »

I don't know. I idled it for a couple of minutes. But even so, would the oil light be on during idle up to that temp?
epearce
Posts: 136
Joined: Feb 01, 2013 6:08 AM
Location: Australia

Post by epearce »

Oil pressure light shouldn't be on whilst idling.

The thermostat in the oil filter housing if operating correctly would be closed under the mentioned conditions. It should only operate if the oil temp is high.

Sounds like there is something up with your filter housing.
ahab
Posts: 6174
Joined: Jun 11, 2006 9:12 AM
Location: Chalfont, PA

Post by ahab »

Don't forget to fill the cooler by pouring oil into the hoses before connecting it. In most cases during street driving, it's unlikely you will get the oil hot enough to open the thermostat. I forgot to fill the cooler when I installed mine and a few thousand miles later it was still empty, indicating the thermostat had never opened. Thankfully. I don't think any of this relates to your low oil pressure however. It sounds like some kind of bypass valve problem, like using a B34 canister on a B35 block.

I'm not aware of any problems using a US B34 block with a cooler, mine was a Euro block but I did mount one to a US block the other day and should be able to start the engine in another couple of days.
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Post by BuzzBomb »

ahab wrote:Don't forget to fill the cooler by pouring oil into the hoses before connecting it. In most cases during street driving, it's unlikely you will get the oil hot enough to open the thermostat. I forgot to fill the cooler when I installed mine and a few thousand miles later it was still empty, indicating the thermostat had never opened. Thankfully. I don't think any of this relates to your low oil pressure however. It sounds like some kind of bypass valve problem, like using a B34 canister on a B35 block.

I'm not aware of any problems using a US B34 block with a cooler, mine was a Euro block but I did mount one to a US block the other day and should be able to start the engine in another couple of days.
I'm guilty of both of these. I didn't fill the cooler. It did take over 6 quarts finally though, so I'm pretty sure it's full now. As far as the filter head issue, I'm thinking that is more likely the problem. The block is a transitional B35. Feb 89 e24, so originally a B34 style filter head, but I don't know if it was different internally. The block casting uses the #12 gasket. This cooler head is completely open, and uses the #2 gasket.

Image
ahab
Posts: 6174
Joined: Jun 11, 2006 9:12 AM
Location: Chalfont, PA

Post by ahab »

The cooler will only fill when the oil is hot enough to open the thermostat and allow the oil to flow into it. If that didn't happen then there is no oil in it. An M30 with a filter will take nearly 6 quarts on its own. You might want to pull a cooler line and check for copious amounts of oil. As for the block, a B34 housing on a B35 block (which an 89 E24 has) will result in low oil pressure at idle. Search for demetk's post on the issue.
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Post by BuzzBomb »

ahab wrote:As for the block, a B34 housing on a B35 block (which an 89 E24 has) will result in low oil pressure at idle. Search for demetk's post on the issue.
In his thread, he just used the e34 upright housing to solve his issue. Is there a mod/fix to run a B34 oil cooler on a B35 block?
demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Post by demetk »

BuzzBomb wrote:
ahab wrote:As for the block, a B34 housing on a B35 block (which an 89 E24 has) will result in low oil pressure at idle. Search for demetk's post on the issue.
In his thread, he just used the e34 upright housing to solve his issue. Is there a mod/fix to run a B34 oil cooler on a B35 block?
Yes, that was my fix, although you do have me concerned enough about the type of gasket in there now for me to revisit that fix.

There is a b35 oil filter housing that has oil cooler ports.
wkohler
Posts: 50921
Joined: Oct 05, 2006 11:04 PM
Location: Phönix, Arizona, USA
Contact:

Post by wkohler »

To run the B34 housing on a b35 block, you need to plug a hole in one of the chambers. It should already be threaded.

The plug is a DIN 908 screw plug. M10x1. Just thread it into the hole. It will tighten and seal like an NPT fitting. Done.

If you have to have BMW parts, the part number is 11 12 7 539 543.
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Post by BuzzBomb »

I had to drive a long way to get this. I really hope this works.
Image
johnnye23
Posts: 5059
Joined: Sep 27, 2006 3:47 PM
Location: Auburn Ca
Contact:

Post by johnnye23 »

Is the oil level okay after the cooler was filled ?
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Post by BuzzBomb »

Installed. Oil pressure as it should be. Thank you W.C.K.
Image
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Post by BuzzBomb »

johnnye23 wrote:Is the oil level okay after the cooler was filled ?
Still full at the stick, but I haven't ran it more than a few mins total since it's been installed. I'm carrying a few extra quarts in case the thermostat hasn't opened yet.
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Post by BuzzBomb »

demetk wrote: Yes, that was my fix, although you do have me concerned enough about the type of gasket in there now for me to revisit that fix.
If your casting looks like mine, deeply consider getting gasket #12.
demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Post by demetk »

BuzzBomb wrote:
demetk wrote: Yes, that was my fix, although you do have me concerned enough about the type of gasket in there now for me to revisit that fix.
If your casting looks like mine, deeply consider getting gasket #12.
I will be checking it this weekend. Thanks for the info on the plug. I'm assuming this info is in the archives somewhere?
BuzzBomb
Posts: 1668
Joined: Aug 21, 2011 12:14 AM
Location: SoCal

Post by BuzzBomb »

demetk wrote:
BuzzBomb wrote:
demetk wrote: Yes, that was my fix, although you do have me concerned enough about the type of gasket in there now for me to revisit that fix.
If your casting looks like mine, deeply consider getting gasket #12.
I will be checking it this weekend. Thanks for the info on the plug. I'm assuming this info is in the archives somewhere?
Don't know. I looked briefly but nothing came up that was as helpful as Chris' comment in this case.
demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Post by demetk »

BuzzBomb wrote:
demetk wrote:
BuzzBomb wrote:
demetk wrote: Yes, that was my fix, although you do have me concerned enough about the type of gasket in there now for me to revisit that fix.
If your casting looks like mine, deeply consider getting gasket #12.
I will be checking it this weekend. Thanks for the info on the plug. I'm assuming this info is in the archives somewhere?
Don't know. I looked briefly but nothing came up that was as helpful as Chris' comment in this case.
Same here. It's amazing how he retains all of this information. Deep respect Chris!
wkohler
Posts: 50921
Joined: Oct 05, 2006 11:04 PM
Location: Phönix, Arizona, USA
Contact:

Post by wkohler »

Thanks. Glad I could help. :D
ahab
Posts: 6174
Joined: Jun 11, 2006 9:12 AM
Location: Chalfont, PA

Post by ahab »

No deference to Chris, Shawn D posted the plug info a while back. I had forgotten its significance in this situation. Anyway, as usual, Chris did not and and even pulled out some part numbers!

I would take a cooler line off and fill the cooler manually (and, it was actually Chris who brought that to my attention when I installed mine too!). I suspect that the cooler will fill as oil exits the journals and re-enters the sump, however the last thing I would want when the temps are good and hot is an interruption of flow as oil is diverted to the cooler via the now open thermostat.
wkohler
Posts: 50921
Joined: Oct 05, 2006 11:04 PM
Location: Phönix, Arizona, USA
Contact:

Post by wkohler »

All the info is in the archives. Shawn posted different pieces at various times as the question was asked a couple of times in different ways - mostly in a "does it work" kinda way, so I can see how it might be tough to find it all. Now it should all be in one place. ;)
demetk
Posts: 8431
Joined: Aug 09, 2007 8:58 AM
Location: CT, USA

Post by demetk »

Couldn't wait so I checked mine on the 88 535is today.

The b35 oil filter canister that I installed has gasket #12,

Image

So that's good.

AND ... the block has the plug,

Image

I'm assuming one does not go with the other? Opinions welcomed.
Post Reply