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Check both the hose that goes from the oil filter housing to the oil cooler. You referred to this as the radiator which it does looks like. I had driver side one with a pin hole that squirted oil out. The hose was saturated with the oik though....
GL
Same problem and still no clue where the oil leak is coming from
Well, I have the same problem and I already did extensive troubleshooting. My serpentine belt is spraying the leaked oil around and since the sprayed oil is everywhere, it is hard to say where the leak is coming from. I already removed the fan along with the serpentine belt and cleaned the engine front with brake cleaner and compressed air 3(!) times. I also added UV dye to my engine oil after the first cleaning and now I know that:
No leaks from 2 oil filter housing gaskets - both replaced and all bolts torqued to the specs. Cleaned the area and the black light shows no traces of oil whatsoever near the oil filter housing.
No leaks from the 2 oil inlets and hoses coming from the radiator to the oil filter housing (o-rings replaced, 6mm hex bolt is tightened properly)
No leaks from the front seal - when I removed the crankshaft belt pulley there was no oil residue in the area.
BTW, this is urgent. The N52, N54 and N55 all have a crankshaft pulley that is very very close to the engine block. If the serpentine belt comes off, it sometimes gets wedged between the pulley and the block and the engine continues to turn and the belt comes apart and pieces of it get pulled into the engine through the front main seal. At this point you either junk the car or get a new engine or spend a lot of time and money cleaning the engine. You can surf for this and see that this is a real possibility.
Yes, it is my engine oil. As I mentioned, I did added UV dye and now my engine front glitters light-green particles when I point my UV flashlight there.
BTW, this is urgent. The N52, N54 and N55 all have a crankshaft pulley that is very very close to the engine block. If the serpentine belt comes off, it sometimes gets wedged between the pulley and the block and the engine continues to turn and the belt comes apart and pieces of it get pulled into the engine through the front main seal. At this point you either junk the car or get a new engine or spend a lot of time and money cleaning the engine. You can surf for this and see that this is a real possibility.
Thank you for pointing me to that thread. Seems like a very similar problem. Though if I remember correctly my engine oil cooler radiator base was pretty clean the last time I removed the fan. I mean I doubt it is leaking and the fan is spraying the oil around. It feels more like the serpentine belt is doing the main job of spraying oil. Anyway, I'm going to pay extra attention to the oil cooler radiator - planning to remove the fan and inspect everything again this coming weekend.
Also, talked to a fellow mechanic and he thinks I should not exclude the old crank seal as a culprit. Honestly I don't think it is my case but I'm thinking to replace the seal anyway as preventive maintenance. @twh. thank you for pointing out that it is an urgent problem. I've read multiple horror stories already about how the serpentine belt is eaten by the engine. Really would like to avoid this scenario. So determined to find the root cause and get it fixed. I own my 2008 535i for more than 7 years already and it is in immaculate condition. This oil leak problem is driving me crazy but once fixed it will be a happy marriage again
Yes, it is my engine oil. As I mentioned, I did added UV dye and now my engine front glitters light-green particles when I point my UV flashlight there.
Thank you for pointing me to that thread. Seems like a very similar problem. Though if I remember correctly my engine oil cooler radiator base was pretty clean the last time I removed the fan. I mean I doubt it is leaking and the fan is spraying the oil around. It feels more like the serpentine belt is doing the main job of spraying oil. Anyway, I'm going to pay extra attention to the oil cooler radiator - planning to remove the fan and inspect everything again this coming weekend.
Also, talked to a fellow mechanic and he thinks I should not exclude the old crank seal as a culprit. Honestly I don't think it is my case but I'm thinking to replace the seal anyway as preventive maintenance. @twh. thank you for pointing out that it is an urgent problem. I've read multiple horror stories already about how the serpentine belt is eaten by the engine. Really would like to avoid this scenario. So determined to find the root cause and get it fixed. I own my 2008 535i for more than 7 years already and it is in immaculate condition. This oil leak problem is driving me crazy but once fixed it will be a happy marriage again
Wow, it's been 9 years since this first posted. The neighbor with that car has moved away but I still remember what happened.
His serpentine belt got shredded and wrapped itself around the crank shaft pulley and ruined his front main seal. I bought three different seal pullers to replace the seal and the only thing that worked was a factory designed seal puller that took six weeks to get here. You cannot do a seal replacement any other way. What a poor design. I have lent out the tools a few times for other DIY posters to replace their N60 front crank seal.
After working on that car, it's stupid designs, and the difficulty of getting to the twin turbos, and the direct injection fuel pump, I have lost all interest in owning a modern BMW. The very large ugly looking kidney grills of the last couple years sealed the sentiment. My work truck is a 2006 BMW 530ix station wagon, non-turbo, port injection.
Hey folks, found it and fixed it!
Just to follow up on my "mysterious oil leak" story, decided to still replace the front main seal, ordered the replacement toolkit from amazon. It worked just fine, managed to pull the old seal and install a new replacement one. Again, I did not see any leaks or oil residue around the old main seal and I could not imagine how the oil would leak and get sprayed around if the leak is in that area. Also inspected the auxiliary radiator and did not see any leaks there. Cleaned the engine front again with brake cleaner and compressed air, gave it a ride and... got the same result, oil is sprayed around. Was quite upset and thought about giving up and scheduling an appointment with the shop and ready to pay more $ for this endless oil leak search. Still, the next day decided to have another look at the oil traces and what seemed suspicious is that my oil cooler return hose (the one on the right if you look at engine) was moist compared to the oil cooler flow hose (on the left). I removed the auxiliary radiator again and inspected the return hose, and here we go, I found the bloody leak! A tiny hole on the back side of the hose right where the fabric wrap hides it. See the attached photo and a small cut in the orange circle.
Ordered a new hose (had to shell $149 + tax for it), replaced it and now I'm a happy camper again!
Looking back I should admit it was a hard case. How that tiny hole developed itself? Not remembering that I did something wrong or pierced it accidentally. Plus it was really hard to find the source of my problem because the radiator fan and serpentine belt did a good job in a cover-up mission for this criminal. Anyway, thanks everyone for chiming in and helping!
@yelcab2, while I totally support your sentiment about the ugly kidney grills in modern BMWs, I can just partially agree about the stupid design. I worked on a few other cars and I could say I've seen worse. After replacing both turbos on my N54 and recent carbon buildup cleaning I'm determined to keep my 2008 535i for as long as I can. Great engine (yeah, after all the typical issues I had to address), adequate steering/handling, rear-wheel drive, and a 6-speed manual, please tell me which other car I should trade it for?
Hey folks, found it and fixed it!
Just to follow up on my "mysterious oil leak" story, decided to still replace the front main seal, ordered the replacement toolkit from amazon. It worked just fine, managed to pull the old seal and install a new replacement one. Again, I did not see any leaks or oil residue around the old main seal and I could not imagine how the oil would leak and get sprayed around if the leak is in that area. Also inspected the auxiliary radiator and did not see any leaks there. Cleaned the engine front again with brake cleaner and compressed air, gave it a ride and... got the same result, oil is sprayed around. Was quite upset and thought about giving up and scheduling an appointment with the shop and ready to pay more $ for this endless oil leak search. Still, the next day decided to have another look at the oil traces and what seemed suspicious is that my oil cooler return hose (the one on the right if you look at engine) was moist compared to the oil cooler flow hose (on the left). I removed the auxiliary radiator again and inspected the return hose, and here we go, I found the bloody leak! A tiny hole on the back side of the hose right where the fabric wrap hides it. See the attached photo and a small cut in the orange circle.
Ordered a new hose (had to shell $149 + tax for it), replaced it and now I'm a happy camper again!
Looking back I should admit it was a hard case. How that tiny hole developed itself? Not remembering that I did something wrong or pierced it accidentally. Plus it was really hard to find the source of my problem because the radiator fan and serpentine belt did a good job in a cover-up mission for this criminal. Anyway, thanks everyone for chiming in and helping!
@yelcab2, while I totally support your sentiment about the ugly kidney grills in modern BMWs, I can just partially agree about the stupid design. I worked on a few other cars and I could say I've seen worse. After replacing both turbos on my N54 and recent carbon buildup cleaning I'm determined to keep my 2008 535i for as long as I can. Great engine (yeah, after all the typical issues I had to address), adequate steering/handling, rear-wheel drive, and a 6-speed manual, please tell me which other car I should trade it for?
Good work on the fix and even better to report it. As for your BMW sentiment, oh well, we are all different. I would not recommend Audi either so if you are a German car fanatic, I really don't know what else to buy.
06-09-2017, 12:31 PM
