[325eyeguy]

On my way back home from las Vegas last Tuesday afternoon. Made it about 20miles back into California when we hit traffic and my coolant light, battery light, and engine overheating light came on, I also lost all power steering. I pull over pop the ol hood and see the serpentine belt is off the pulleys!! It wasn't completely off nor did it look ripped or torn but something obviously messed up(BTW 120°f outside) .

I got It towed to the nearest and only mechanic in the desert. For some background info I have had oil leaks in my engine for the past few years, I recently replaced the valve cover gasket and was planning on doing the oil filter housing gasket soon, and I wanted to check out the cylinder head gasket too. the three mechanics at this rundown shack of a shop tell me that the belt likely came off from the amount of oil on all the pulleys, but they insist the leak is the main cause, which i don't agree with because if it was then I probably would of had this happen a year ago (although I'm not eliminating that possibility) . I would think it would be from a broken tensioner or broken pulley (from what I researched myself) or a combination of oil leak plus heat (?).

Now I live 350+ miles from this shop so it would be ideal for me not to spend another $500+ on a truck/trailer to get the car back to my garage in San Diego. They already slammed me with a $50 a day storage fee + $94 just to look at it so being the broke college student that I am I'd like to not give these guys all my money.

I asked if cleaning the oil from the pulleys and replacing the belt would hold up for my drive back but he said that would not last and he is also not comfortable doing that type of cleaning on my car. The guy handling my car sounds trustworthy but you never know now a days.

I also plugged in my code reader as I was driving (minutes before I pulled over) and no codes were thrown. If anyone has suggestions/advice or is in a similar situation would appreciate any feedback!

Thank you!!

2005 325i auto 108,000 miles

[bimmerlove335]

To me it sounds like it could be a combination of things.

I would definitely agree that if there was oil on the belt and pulley that could cause this in a heartbeat. If you have oil on your belt, IMO you have a ticking time bomb on your hands.

The pulleys could also be an issue, this is easy to tell just by turning them by hand and seeing if they have any play.

I would address the oil leaks! The oil filter housing gasket is almost guaranteed to go out after 60-80k miles and will leak directly on the serpentine belt.


Hope this helps, Nate

[SHEEDI]

hmm engine over heating and coolant could be water pump.

[Efthreeoh]

Not sure how long you ran the car with the belt not running, but these cars lose battery power very quickly once the alternator is not making electricity. Because the water pump is electric, the ECU may have shut down the waterpump as part of the battery losing power. I have no idea how much oil is leaking on the belt, but you said you've had a leak for over a year, so it must be a mess. I'd have the belt and tensioner replaced, bring a few cans of brake kleen, and drive the car back home.

BTW, an no offense, but "BMW" and "broke college" student is generally not a good mix. Just sayin'

[325eyeguy]

UPDATE: thanks everyone for your responses ive been very busy the past week so i wasnt able to read through and make individual replys......

ANYWAYS the status of the car is that i have replaced the belt after checking all the pulleys and tensioner. i cranked it today for the first time in like 4 days and immeadiatley coolant started to spray from the upper radiator hose (puncture was on bottom side of hose right above alternator pulley) so i need to replace that hose and also i noticed the belt started to slightly slip off the tensioner pulley so looks like ill be replacing that too. no other visual failures or leaks that i can see, once im able to keep the car running for more than 15sec im gonna put some uv dye in there to find that oil leak.

gonna get my parts from ecs tuning cause the local autozone doesnt have the tensioner i need and i thought i might as well get all the parts in one order to try and save money. i will update agian once the new hose and tensioner are installed

i also found something kind of offputting: the coolant ive been using the past year is pink and the coolant that is in the lower radiator hose is green (yikes). i read online that micxing coolant colors is very bad (?) so im gonna do a flush once i get the car running.

[ZeeVaughn]

Originally Posted by 325eyeguy

UPDATE: thanks everyone for your responses ive been very busy the past week so i wasnt able to read through and make individual replys......

ANYWAYS the status of the car is that i have replaced the belt after checking all the pulleys and tensioner. i cranked it today for the first time in like 4 days and immeadiatley coolant started to spray from the upper radiator hose (puncture was on bottom side of hose right above alternator pulley) so i need to replace that hose and also i noticed the belt started to slightly slip off the tensioner pulley so looks like ill be replacing that too. no other visual failures or leaks that i can see, once im able to keep the car running for more than 15sec im gonna put some uv dye in there to find that oil leak.

gonna get my parts from ecs tuning cause the local autozone doesnt have the tensioner i need and i thought i might as well get all the parts in one order to try and save money. i will update agian once the new hose and tensioner are installed

i also found something kind of offputting: the coolant ive been using the past year is pink and the coolant that is in the lower radiator hose is green (yikes). i read online that micxing coolant colors is very bad (?) so im gonna do a flush once i get the car running.

If you haven't already ordered the parts I would use fcp euro, they have great shipping and a lifetime warranty on everything they sell.

Also I would just stick with BMW brand coolant, pick some up at the dealer

[juld0zer]

Dont use red/pink coolant. Only the blue if you can't get BMW coolant.

As others stated, leaky oil filter housing dribbles straight onto the serpentine belt and degrades the rubber, weakening it and causing it to slip. The slippage chews away at the plastic idler and tensioner pulleys and deposits melted rubber on the metal pulleys. The oily serpentine belt also slings oil everywhere - the top radiator hose is in direct line with the slinging oil. Just like the belt itself which is made of the same EPDM synthetic rubber, it weakens when contaminated with motor oil. Under enough pressure it will balloon and possibly explode. If your belt happened to let go it may have whipped a hole into the weak hose?

Oil filter housing gaskets when left to leak for a long time can also cause oil and coolant to mix.

[ptpending]

please keep in mind that almost 20 years as head gasket is leaking is due clogged engine breather subsystem
ie engine head gasket and other gasket made not from metal or some ceramic material but from something like silicone sealant, so they keep specified pressure until engine breather is working, when breather is clogged oil is pushed thru all gaskets
so in case of the N51, N52, N54 engine it is recommended to check breather membrane in engine head cover (intake manifold) and replace it or replace this membrane using aftermarket parts
N54 is less exposed to this problem due forced induction system
335d engine also have breather system but it is have another design
N52 engine prior 2006MY have separate breather, no in intake manifold