Vacuum hose leak and Engine Compartment

[Comanche]

My Check Engine light for my 2001 BMW X5 came on so I hooked up a Pocket Scan to find out what was causing the issue. The scanner listed two fault codes, PO171 System Too Lean (bank 1) & PO174 System Too Lean ( Bank 2). I was checking for vacuum leaks and took off the engine cover and noticed two vent hoses collapsed and cracked (see part #5 in the diagram below). I was able to replace the one closest to the front of the vehicle, but I can not reach the one in the rear. I found some information from a thread on X5World that mentioned you can access them by removing the hood seal and cowling along the back of the engine. If anyone has a diagram, directions, pictures or web site that show how to remove this I would greatly appreciate it. The X5 runs great about 97% of the time, however occasionally when I start the vehicle it will ideal ruff for about 10 seconds and then it will be fine. If I reset the codes the check engine light comes on somewhere between 50miles and 120 miles.

If anyone has any other recommendations that might resolve my problem I would be very grateful.

Comanche

[jp99]

I posted detail on pulling the center section out to get at those hoses fairly easily for replacement -

[jp99]

Quote:
Originally Posted by ThrasherFan
Seba/JP99,

I've got the same 2 crankcase vent hoses at the back of the engine on my 4.4 that have deteriorated and causing Mixture Control faults. Did you replace these on your own? If so, could you share how you were able to access these hoses for removal and replacement?

Thanx!


The center plastic component just above those hoses comes off - it holds the pollen filter and, at firewall, fits into two ventilation ports. Once off, you have ready access to the back end of those rotten hoses.

1. Pull the long rubber gasket that seals the area - runs parallel to the firewall the width of the engine compartment.
2. Pull rain catchers (or whatever they are) on each side of the pollen filter area - pull straight up - each is about the size of your hand - they are snap-in, vertically.
3. Locate large nut that holds your battery positive cable in place - locate similar nut on the other side of the engine - that one does not appear to hold anything. Remove nuts, pull the plastic housing straight back off the bolts and lift out. Bolts will stay in place. That center housing, with pollen filter on top, comes out as one large piece - note how it fits back in at the firewall.
4. You should have easy access to the back ends of those hoses. In my case, the back ends had standard BMW hose clamps while the front, top ends had crimped clamps. The crimped ones come off readily with a screw driver to pry at the crimp point or, better, pry the wrapped part of the clamp up and back.
5. Replace hoses, reverse assembly procedure. I bought the two hoses at local dealer and got, also, two clamps to replace the crimped ones.

Ran quieter and smoother, took care of P1159 and P1161 fault codes. The replacement hoses are modified from the original but the parts guy had no idea if they were any better. I doubt it - looks like something that needs to be done every 4 or 5 years.

Good luck - post back if you have a problem. Fun project.

[mysweetx5]

[QUOTE=jp99;187754]Quote:
Originally Posted by ThrasherFan
Seba/JP99,

I've got the same 2 crankcase vent hoses at the back of the engine on my 4.4 that have deteriorated and causing Mixture Control faults. Did you replace these on your own? If so, could you share how you were able to access these hoses for removal and replacement?

Thanx!

I also experienced two faulty codes on my 2001 X5 4.4i and I never knew if these hoses in the back of the engine could have been the cause. After several other tests: cleaning (Air mass sensor, checking some other vacuum for leakage and replacing all 4 O2 sensors, but still having those two ignoring codes alone: P0171/P0174 and unable to detect where this leak is coming from.

Now, as I look @ those hoses behind the engine, one of them which is the big one seems to be pretty muggy, slightly melted flat. Now I'm very focusing on replacing them and the fuel filter gas as they might be the issue for those two codes (P0171/P0174) wish someone would post a few pic on how to access behind the engine @ those hoses.


The center plastic component just above those hoses comes off - it holds the pollen filter and, at firewall, fits into two ventilation ports. Once off, you have ready access to the back end of those rotten hoses.

1. Pull the long rubber gasket that seals the area - runs parallel to the firewall the width of the engine compartment.
2. Pull rain catchers (or whatever they are) on each side of the pollen filter area - pull straight up - each is about the size of your hand - they are snap-in, vertically.
3. Locate large nut that holds your battery positive cable in place - locate similar nut on the other side of the engine - that one does not appear to hold anything. Remove nuts, pull the plastic housing straight back off the bolts and lift out. Bolts will stay in place. That center housing, with pollen filter on top, comes out as one large piece - note how it fits back in at the firewall.
4. You should have easy access to the back ends of those hoses. In my case, the back ends had standard BMW hose clamps while the front, top ends had crimped clamps. The crimped ones come off readily with a screw driver to pry at the crimp point or, better, pry the wrapped part of the clamp up and back.
5. Replace hoses, reverse assembly procedure. I bought the two hoses at local dealer and got, also, two clamps to replace the crimped ones.

Ran quieter and smoother, took care of P1159 and P1161 fault codes. The replacement hoses are modified from the original but the parts guy had no idea if they were any better. I doubt it - looks like something that needs to be done every 4 or 5 years.

Good luck - post back if you have a problem. Fun project.

[jp99]

No pics taken - none needed. Read and follow the instructions at the bottom of your post - else scan for all posts by 'jp99' as I did a fuller post on this several years ago.

It's a common problem on that year - possibly other years - of the X5.

[mysweetx5]

Originally Posted by jp99

No pics taken - none needed. Read and follow the instructions at the bottom of your post - else scan for all posts by 'jp99' as I did a fuller post on this several years ago.

It's a common problem on that year - possibly other years - of the X5.

If this hoses in the back of the engine are really the cause of my trouble codes: (P0171/P0174 vacuum leak all this time, I will definitively get on his tail to fix this issue for sure, once I've been working and serviced my X5 4.4i all the time.

[fast4d]

pollen filter?

it's a oil separator for the crankcase vent

[Hal88]

Originally Posted by fast4d

pollen filter?

it's a oil separator for the crankcase vent

I think he meant the microfilter housing, (pollen filter) it needs to be removed to access the hoses.

[Hal88]

Ok, changed mine today, it is so much easier to do by taking out the whole microfilter assy like JP99/Thrasherfan suggested, the hardest part for me was tightening the screw on the lower hose clamp, it took me about an hr. 'cause I'm slow and I work in my parking lot.
BTW I wasn't getting any codes but the hose was cracked in two places, one of them was pretty big and still no codes, oh well.

If anyone out there hasn't checked these hoses lately maybe you should, my old one was like chewing gum and it was falling apart.

[elric75]

I also these hoses go bad on my '00 4.4 back in 2005, so yes appears to be yet another Known Flaw in X5s (KFX).