[Orion4]

I need to replace the o-rings on the oil cooler lines connecting to the bottom of the Thermostat on my 13 335i N55. I have a slow leak there. What is the torque setting for the single long bolt the connects the dual line assembly to the thermostat? See images. Can't seem to find the spec. Thanks

[Polo08816]

Originally Posted by Orion4

I need to replace the o-rings on the oil cooler lines connecting to the bottom of the Thermostat on my 13 335i N55. I have a slow leak there. What is the torque setting for the single long bolt the connects the dual line assembly to the thermostat? See images. Can't seem to find the spec. Thanks

Are you talking about bolt #9?

If so...

https://www.newtis.info/tisv2/a/en/f...lines/IOeIjLRo

https://www.newtis.info/tisv2/a/en/f...lines/IJkdGaYA

seems like it's 8Nm. I wouldn't worry about it too much. Hand tight is sufficient.

[Orion4]

That's it! 8NM. Found it late last night and completed the o-ring swap. Tightened to 8NM via my torque wrench and went for 20-30 min drive.



Still seeping at that connection. It's coming from the drivers side engine oil pipe/o-ring area. Verified that no oil is coming from any other location or gasket above or around it.



Thanks!

[Polo08816]

Originally Posted by Orion4

That's it! 8NM. Found it late last night and completed the o-ring swap. Tightened to 8NM via my torque wrench and went for 20-30 min drive.



Still seeping at that connection. It's coming from the drivers side engine oil pipe/o-ring area. Verified that no oil is coming from any other location or gasket above or around it.



Thanks!

That's bizarre. If you replaced the o-rings I don't know why it would continue to seep...

[Orion4]

I'm going to initially assume I received a defective o-ring. Just picked up a couple of more and will change those this afternoon.

[Polo08816]

Originally Posted by Orion4

I need to replace the o-rings on the oil cooler lines connecting to the bottom of the Thermostat on my 13 335i N55. I have a slow leak there. What is the torque setting for the single long bolt the connects the dual line assembly to the thermostat? See images. Can't seem to find the spec. Thanks

Originally Posted by Orion4

I'm going to initially assume I received a defective o-ring. Just picked up a couple of more and will change those this afternoon.

Out of curiosity, which group/diagram of parts is that picture to the right out of? I can't seem to find it and I think I'm missing the bolt #12, 13, or 14.

[Polo08816]

Originally Posted by Polo08816

Out of curiosity, which group/diagram of parts is that picture to the right out of? I can't seem to find it and I think I'm missing the bolt #12, 13, or 14.

Nvmd, I found it.

https://www.realoem.com/bmw/enUS/sho...diagId=17_0654

[Orion4]

Still no luck resolving the seep. Dissembled the Cooler Lines from the Thermostat, removed the o-rings, thoroughly inspected both matting surfaces for debris (none found) and cleaned surfaces. Inspected underneath area with mirror for another source of the leak including thermostat housing where it mates to the OFH. Nothing noted. Installed the 2nd set of new o-rings (confirmed the correct P/N) and reassembled. Ran engine at idle for about 8-10 minutes and seep reappears!


Images are 90 degrees CCW out of correct Perspective.

Guess my next step is to replace the Thermostat Gasket that mates to the OFH. Can't for the life of me find the source. Frustrating for something that should be straight forward,

[Polo08816]

Originally Posted by Orion4

Still no luck resolving the seep. Dissembled the Cooler Lines from the Thermostat, removed the o-rings, thoroughly inspected both matting surfaces for debris (none found) and cleaned surfaces. Inspected underneath area with mirror for another source of the leak including thermostat housing where it mates to the OFH. Nothing noted. Installed the 2nd set of new o-rings (confirmed the correct P/N) and reassembled. Ran engine at idle for about 8-10 minutes and seep reappears!


Images are 90 degrees CCW out of correct Perspective.

Guess my next step is to replace the Thermostat Gasket that mates to the OFH. Can't for the life of me find the source. Frustrating for something that should be straight forward,

Have you ever replaced the OFHG (both gaskets) in the life of the car?

[Orion4]

Replaced both about 40-45K ago. Didnt replace the Oil Cooler o-rings at the time (didn't realize they are single use items at the time). That's one reason i have assumed they are the culprit.

[scorpionhunk]

Hello everyone I am new to this site and in the past been looking at these forums for help .I bought an BMW 330d 2013 F31 a week ago while bringing the car back to home all was fine until next morning I wanted to check engine before cold start and than found thick greyish oil in my coolant bottle and one big fat radiator pipe was cracked a bit from top side where there are 3 connectors 1 goes in radiater 1 small pipe goes in coolant bottle and third is towards oil filter housing in engine , I called my mate who knows about cars and a family friend who used to be a mechanic , They advised me to clean the oil mess from coolant bottle and flush the whole system as best as I can and told me that it could be oil cooler itself or gaskets inside gone leaked. I went in BMW to get brand new oil cooler (heat exchange) and 2 gaskets which one goes between engine and oil cooler and the second one goes between another heat exchange which is on top same place after getting it fixed from my local mechanic. Now mechanic said the same thing regarding faulty oil cooler or gaskets but I didn't knew there are 2 heat exchanges near oil filter housing until BMW guy told me. When the car was ready he said the system needs to be flushed again after few days . When I was flushing the system again next morning I opened 2 pipes that connect with right side of heat exchange both were water inlet pipes and found out that oil is still coming through second small pipe on right. Can some body help me in this big problem now although i made a big speech about it but this is my first thread so kindly forgive me if I didn't put it right?

[BashShah]

Originally Posted by scorpionhunk

Hello everyone I am new to this site and in the past been looking at these forums for help .I bought an BMW 330d 2013 F31 a week ago while bringing the car back to home all was fine until next morning I wanted to check engine before cold start and than found thick greyish oil in my coolant bottle and one big fat radiator pipe was cracked a bit from top side where there are 3 connectors 1 goes in radiater 1 small pipe goes in coolant bottle and third is towards oil filter housing in engine , I called my mate who knows about cars and a family friend who used to be a mechanic , They advised me to clean the oil mess from coolant bottle and flush the whole system as best as I can and told me that it could be oil cooler itself or gaskets inside gone leaked. I went in BMW to get brand new oil cooler (heat exchange) and 2 gaskets which one goes between engine and oil cooler and the second one goes between another heat exchange which is on top same place after getting it fixed from my local mechanic. Now mechanic said the same thing regarding faulty oil cooler or gaskets but I didn't knew there are 2 heat exchanges near oil filter housing until BMW guy told me. When the car was ready he said the system needs to be flushed again after few days . When I was flushing the system again next morning I opened 2 pipes that connect with right side of heat exchange both were water inlet pipes and found out that oil is still coming through second small pipe on right. Can some body help me in this big problem now although i made a big speech about it but this is my first thread so kindly forgive me if I didn't put it right?

Please start your own tread, your issue is not the same as OPs.

[Orion4]

Well, finally ran this leak 'to ground"! It was the one place I didn't check (of course). It was the seal between the end plate and the housing.

[markeys]

Originally Posted by Orion4

Well, finally ran this leak 'to ground"! It was the one place I didn't check (of course). It was the seal between the end plate and the housing.

Old thread, but worth a shot since I have the same issue. Do you have a part number for that gasket between the end plate and housing?

[Orion4]

There is no gasket, per se. The thermostat housing end cap screws down to the housing which has an integral rubber seal embedding in the housing seat. All I did was remove the end cap, clean off the mating surfaces on cap and housing and re tightened. Couldn't find a torque setting, so "judged" how much pressure to loosen and tightened to about the same with a little "extra". Don't "gorilla arm" it! Solved my issue. Did same about 8 months later when I installed the BMS Sport Cooler Valve. No leaks-so far.

[markeys]

Originally Posted by Orion4

There is no gasket, per se. The thermostat housing end cap screws down to the housing which has an integral rubber seal embedding in the housing seat. All I did was remove the end cap, clean off the mating surfaces on cap and housing and re tightened. Couldn't find a torque setting, so "judged" how much pressure to loosen and tightened to about the same with a little "extra". Don't "gorilla arm" it! Solved my issue. Did same about 8 months later when I installed the BMS Sport Cooler Valve. No leaks-so far.

Got it thanks for that info!

I found this thread in the e90 forums with a similar issue on the n55 oil cooler. Someone used a generic o ring 43mm OD 37mm ID 3mm width to solve it.

I figure the oil thermostat end plate that they sell can work for the e90 n55 and f30 n55, so I'm giving this a try to see how it does.

[kvrlitos]

Real quick do you mean that there is no gasket to put on? Like I should remove mine, I’ve been fighting the issue for like 2 weeks But for the cap of the thermostat, did you change it out or just clean it off?

[Orion4]

My end-cap had an integral rubber matting surface as part of the cap. That was the culprit. Replace the end-cap, if you can find that part independently. This is what I installed: https://burgertuning.com/collections...thermastat-lid

[BashShah]

There is an O-Ring that will work:

43mm OD, 3mm thick o-ring

See this Post: https://www.e90post.com/forums/showthread.php?t=1550526