Afraid to fix OFHG leak for fear of Rod bearing/engine seizing

[passthetongs]

Hi everyone, this is my first thread. I own a '11 35i with 122k miles. I've been reading about horror stories of people having their engines seizing after an OFHG service. Mine is definitely leaking as there is oil buildup around the front of the housing, but not enough where I have to continuously add oil. I recently noticed a squeak in my auxiliary belt due to a failed tensioner that was bouncing violently. I had the tensioner, belt, upper and lower pulleys replaced. I have heard that a leak from the OFHG can cause the belt to slip and get sucked into the engine. I can't decide if I should just keep driving with a leaking OFHG or get it replaced and risk having the engine seizing/ rod bearings spun.

[smass]

Some mechanics have posted to the E90 forums "that they have changed 100s of these without issue". Hopefully this issue will not affect the majority of N55 out there. Are you doing the work your self? If so just be very clean when removing the old gasket.

[passthetongs]

Yes if I were to get it done then I would do it myself. So hypothetically, if I were to ignore the leak, if I routinely cleaned the serpentine belt and pulley off then could i ignore the leak? I know there’s a possibility that the coolant and leak into the oil chamber through the seal but I change my oil every 5k miles.

[TheeE86]

Originally Posted by passthetongs

Hi everyone, this is my first thread. I own a '11 35i with 122k miles. I've been reading about horror stories of people having their engines seizing after an OFHG service. Mine is definitely leaking as there is oil buildup around the front of the housing, but not enough where I have to continuously add oil. I recently noticed a squeak in my auxiliary belt due to a failed tensioner that was bouncing violently. I had the tensioner, belt, upper and lower pulleys replaced. I have heard that a leak from the OFHG can cause the belt to slip and get sucked into the engine. I can't decide if I should just keep driving with a leaking OFHG or get it replaced and risk having the engine seizing/ rod bearings spun.

I have experienced replacement on 4 vehicles, one on N54 535, two X5 N55 and 335 n55. No issues. I hose off the oil and coolant from engine after I reassemble. Just remove the belt before and clean up well after if your worried.
Also, I noticed some of the non-bmw branded gaskets from ECStuning.com seemed low quality in my opinion. Good luck

[klargo]

My STRONG advice is that you replace leaky gasket as soon as possible and replace belt no matter how good it looks. Also check pullys and tensioner. I bought a used X5 with 30k miles on it and noticed the leaky oil cooler and housing at 50k. I replaced gaskets but didnt replace belt because it looked fine once I cleaned it off and I'm used to these things going for 75k or longer. Two days ago with 56k miles the belt came off, shredded and tangled behind the harmonic balancer. I'm pretty sure some of the belt entered the engine because the crankshaft front seal is completely gone and I had to fish some of the belt out from around crankshaft and seal. I called the BMW service dept (who is well aware of this issue) and they advised me not to drive car until inspected due to possible oil starvation and engine seizure. They estimated $3500 to do the inspection and work required. I loved the car until this happened now I regret ever purchasing it. I've lost serpentine belts off other cars but never saw one shred like this and I would never believe it could enter engine until I saw this myself. The car is parked for now I'll try to DIY when I get the time. There is a thread on X3 blog (shredded serpentine belt) about this but surprisingly not on the X5 forum that I can find. BMW knows leak from oil cooler compromises belt but has never engineered a fix.

[boneca]

Originally Posted by klargo

My STRONG advice is that you replace leaky gasket as soon as possible and replace belt no matter how good it looks. Also check pullys and tensioner. I bought a used X5 with 30k miles on it and noticed the leaky oil cooler and housing at 50k. I replaced gaskets but didnt replace belt because it looked fine once I cleaned it off and I'm used to these things going for 75k or longer. Two days ago with 56k miles the belt came off, shredded and tangled behind the harmonic balancer. I'm pretty sure some of the belt entered the engine because the crankshaft front seal is completely gone and I had to fish some of the belt out from around crankshaft and seal. I called the BMW service dept (who is well aware of this issue) and they advised me not to drive car until inspected due to possible oil starvation and engine seizure. They estimated $3500 to do the inspection and work required. I loved the car until this happened now I regret ever purchasing it. I've lost serpentine belts off other cars but never saw one shred like this and I would never believe it could enter engine until I saw this myself. The car is parked for now I'll try to DIY when I get the time. There is a thread on X3 blog (shredded serpentine belt) about this but surprisingly not on the X5 forum that I can find. BMW knows leak from oil cooler compromises belt but has never engineered a fix.

oh wow, sorry to hear this, what a nightmare

[racermp]

WTH, is this real? I changed alot of ofhg and never had an issue.


Yea stupid design, not changing it leads to belt shredding. Been there.

[klargo]

I didn't know about the shredded serp belt entering engine issue until it happened to me and I Googled my issue which is what led me to this forum. Surprisingly theres nothing in the E70 but there is in the E90 and other forums. Basically the belt shreds and wraps around the crankshaft and continues to wrap like line on a fishing reel until forced into the crank oil seal where the timing chain grabs it and winds it up in there. The belt is forced aft because of the harmonic balancer in front being larger than the pulley. My oil seal was completely trashed and I had a piece of belt sticking out between what was left of seal and the crankshaft. I was going to just replace the seal and the belt but then I found the forum which I'm glad I did. I guess people have suffered loss of eng. oil press and eng seizure due to clogged oil pickup. I took off valve cover today and sure enough I had 2 pieces of shredded belt approx 8 inches long in the timing chain area. Luckily not wrapped around anything or hurting nothing that I could tell. I still have to remove the oil pan to remove pieces and clean the pick up tube so as not to risk oil starvation. My BMW service center were well aware that this happens and even have an inspection procedure for it. They quoted $3500 to do the inspection and recommended car not be started until completed. I'm doing all myself so far spent $800 on parts and a seal installation tool. Not looking fwd to R&R oilpan in my driveway which requires disassembly of suspension, driveshafts and undercarraige. (all wheel drive). Search this forum for "shredded belt" and you will find pics and info.

[klargo]

Also, in regards to the title of this thread - "afraid to fix OFHG leak". Fixing a leak is never a bad thing. You should be afraid NOT to fix to leak. If your OFHG is leaking fix it ASAP, remove the serp belt and clean all residual oil from front of engine. Clean all pulley grooves and make sure the pulleys and tensioner are in good shape. After all clean and dry reinstall a new (quality) belt and inspect area every so often to make sure no leaks on the belt. Beleive me you do not want to deal with the expensive and time consuming problem I encountered just because I chose not to replace the belt after I fixed the leaky OFHG. On a positive note I'm just thankful I didn't drive the car with possible clogged oil pick-up tube.