2002 X5 P1349 Misfire & High Crankcase Pressure

[MHRX5]

I've had a couple BMW's over the years and love the brand, the way it drives and German Engineering.

I got an 2002 X5 3.0i last year, it had several problems, leaking valve cover gasket which I had to replace the valve cover as well, DISA valve was falling apart and leaking. A couple times I filled up with bad 92 octane fuel and got on the freeway only to smell bad burning fuel then the engine would bog down like it was missing on 1 cylinder until I stopped the engine and restarted it then it would run better until climbing a hill and the engine would bog down again and run rough, always could be reset by a restart. All this would go away when I filled the tank with good fuel.

I recently had to change the Battery, Alternator and the Crankcase Ventilation system (oil separator) and all plastic hoses and new Intake Boot... It fired up running better than ever before. I took it on a highway drive for about 50 miles and it was getting 24 MPG and running really great. Then on the way home getting back on the highway it bogged down again and I pulled over, restarted and it kept bogging down. I limped it back home and haven't driven it since. When I got home the auxiliary fan motor burned up like it was over heating or something but didn't ever turn on. Now my A/C won't work either as a result of the fan not working.

I can start the engine, it runs rough at start then rougher after about 30 seconds. I get a code P1349. I have swapped #4 Coil with #1 Coil to rule out a bad coil. I have replaced all spark plugs with NGK Iridium Plugs. I pulled the dipstick out and cleaned the oil return tube and reinstalled. My Air Equalizer has 3 drilled holes in the back, why anyone would do that I can't figure it out, I epoxied the holes closed while waiting for a new one. When it's running Im getting louder than usual Intake Valve noise, very rough idle, the crankcase pressure builds up and is hissing in several places until I relieve the oil filler cap.

I can do most repairs myself so I've ordered several parts to replace:

DISA Valve w/O-Ring
Air Equalizer for Intake Manifold
Throttle Housing Gasket

Should I start looking at fuel pressure, pressure regulator, or something else. I will have to replace the auxiliary fan as well. I don't want to just keep replacing things arbitrarily. I would appreciate any wisdom regarding these issues Im facing.

Is there a good inexpensive Scanner Tool that would assist me in finding my specific problems? I have a simple ODBII scanner but it's limited.

Thanks!

I forgot to add my High Crankcase Pressure issue, I can hear the hissing of the pressure releasing from the oil separator return tube where it connects with the dip stick. Should the crankcase pressure be so high? Shouldn't the positive pressure just return to the oil pan and work it's way back up through the engine and cycle through the system? Is there another part of the breather system I should check for blockage or fault.

My Vehicle: 2002 BMW X5 3.0i 245k miles

[MHRX5]

Today I got a Fuel Pressure Gauge and did a test. I got a consistent reading with the ignition on and running of between 40 - 50 psi. I shut off the engine and the pressure didn't leak for over 5 minutes. Im satisfied it doesn't need a fuel filter, pressure regulator or fuel pump.

[MHRX5]

I got the Air Equalizer for Intake Manifold in today and when comparing the new part to my old part I see a major difference, all 6 return tubes that seat in the Intake Manifold are sealed shut, like someone crammed a piece of plastic inside so they wouldn't return air to the intake.




Notice the white epoxy I placed over 3, 1/4" holes that were drilled in the rear, Why would anyone drill holes in a part that needs to be vacuum tight and connected to the intake system. Maybe this car has had vacuum leak issues in the past and the only solution was to block the 6 tubes and release the pressure by drilling holes.


I installed this new part and the engine didn't want to start, I cranked it 5 times before it finally limped to start. I shut it off and tried again and it started more quickly. I guess it takes a few minutes for the computer to understand the vacuum difference. It ran smooth for about 15 seconds then started to misfire again but the crankcase pressure problem is now gone. Yippy!


I hate to keep throwing money at this but I got to get it running right soon, this is my only vehicle at the moment.


I am still waiting for my new DISA Valve to come in and I will replace the throttle body O-Ring also.


Should I check or clean the Idle Control Valve? Should I replace the O2 Sensor? What else could be causing a P1349 Code and making the engine run so rough. I have excessive valve noise on Cylinder 4 also when I rev the engine a little.

[MHRX5]

I received the DISA Valve today and installed it, It runs better but when it warmed up it was running rough again at idle. It runs like it should when I push the throttle but it idles rough. I still get a P1349, I have reset it the restarted and get the same code. I drove the car and it has little power.

So to recap, I have replaced:

DISA Valve
Air Equalizer for Intake Manifold
CCV / Oil Separator Valve and All Hoses
Cleaned the Dipstick Return tube
Swapped Coil #4 with Coil #1
Replaced all Spark Plugs

Why would I still be getting a P1349 Misfire Cyl. 4 Fuel Cut-Off

Anybody have any advice?

[MHRX5]

Here is my old DISA Valve, you can see how it was broken and rubbing against the Intake Manifold journal where it seats. Also the O-Ring was pinched in the process.

[MHRX5]

Well Day 11 in this saga, I replaced 1 PreCat O2 Sensor today, cleaned my idle control valve and replaced the throttle body O-Ring. Still getting P1349 code and running rough at idle and little power when driving it.

The engine runs smooth for first 10 seconds then misfires and throws the P1349 code, running rough at idle and when I throttle up.

To recap, here is all that i've done:

New DISA Valve
New Intake Boot
New Air Equalizer on Intake Manifold
New Oil Separator (CCV) and all Hoses
New Spark Plugs
Switched Coils to rule out #4
New Throttle Body O-Ring
Cleaned Idle Control Valve
Checked Fuel Pressure, 47psi key on, 50+psi engine on
Checked for vacuum leaks

Could I need a different O2 Sensor or Could bad fuel, low octane fuel be causing this?

Im surprised nobody in this forum has any advise for me?

[MHRX5]

Ok, today I installed another pre-cat O2 Sensor and replaced brittle vacuum hoses connected to the vacuum control valve air pump on the back of the intake manifold. No change, clear code and restart engine, runs smooth for about 30 seconds then idle drops and begins to misfire, the MIL illuminates with P1349 again.

Could I need both Post-Cat O2 sensors also, or should I continue looking for an intake leak? Is there a way to clean injectors or should I just replace them? Can I test the coils with a simple OHM Meter? The engine runs very well for 30 seconds when codes are cleared which makes me want to rule out all ignition component problems. Must me a sensor or vacuum leak triggering the ECU to cut fuel to cyl# 4.

Can anyone help me?

[MHRX5]

Today I installed 2 new Post-Cat O2 Sensors with 4 inches of snow on the ground (my son was willing to lay under the car and do the work for me), and I still get the same results. It's as though I have done nothing to the engine at all.

At this point I am feeling I must still have enough of an intake vacuum leak to cause the ECU to think there is a lean condition and throwing the P1349 Code. I clear the code and restart the engine and it runs smooth for a few seconds then the idle drops and the MIL illuminates at the moment the engine starts to run rough. If I throttle up the engine it runs smooth for about 30 seconds until the Code returns and the throttle drops on it's own.

I hope all these details of the work I've done will be helpful to someone in the future. If I can find the solution to my problem before I have lost all my patience, I will have the confidence to keep the car, knowing I can diagnose and fix nearly anything on this car.

Can anyone tell me what the ECU checklist is when it first starts, maybe I can track down my problem if I knew the specific details and sensors that affect the ECU's management of the engine.

[will308]

I'm looking to buy an X5 for my daughter. I am following your thread to see what ends up fixing your issues in case they show up in hers. I would suggest searching the e39 and e46 sections to see if they're others who have this issue with that engine...I believe it's the same M54 that is shared with the 530, and 330.
good luck...

[MHRX5]

I have learned a lot about this engine in the process and still haven't found the problem. I have always liked the straight 6 engine but this fly-by-wire design has me stumped. Putting all the control to the computer to run the engine makes it more difficult to diagnose without checking and testing every component in the system. My car has 246k miles and no record of previous maintenance. I don't know if any of the parts have ever been replaced so I find myself replacing them anyway so I can rule out those parts in the future.

I read the thread about replacing the CCV system with a PCV valve so I decided to do it. I disconnected the tube at the Valve Cover, the Air Equalizer and Dip Stick and capped off the Dip Stick and large connection at the Air Equalizer and pushed those parts aside incase I decide to reconnect them. I used the old CCV tube at the Valve Cover and added a 3/4" ID tube and PCV valve then a 3/8" ID tube and connected to the smaller original CCV tube that stretches across the intake connecting to the rear of the Air Equalizer. I ordered a catch can online and will splice that in when it arrives and drain the can back to the Dip Stick to complete this modification and recirculate the oil.

I started the car and it is so much quieter now but I can still hear hissing sounds coming somewhere near the rear of the Intake and between Cyl 3 and Cyl 4 around the Air Sensor in the Intake Manifold. It's running much smoother then ever before but still misfiring on Cylinder 4, I pulled the #4 plug it looks like it hasn't fired at all.

I am still getting a misfire code P1349.

I will keep looking for a vacuum leak.

[lanbrown]

I know you have swapped the coil, but have you checked the wiring for the #4 cylinder? As in, is it really firing at all? The coil could be good, but the wiring up to it is not.

[MHRX5]

I know you have swapped the coil, but have you checked the wiring for the #4 cylinder? As in, is it really firing at all? The coil could be good, but the wiring up to it is not.

Thanks for your input, I believe I can rule out the #4 Cylinder wiring being faulty. When I reset the ECU and restart the engine it runs smooth, firing on all 6 cylinders then after about 20 to 30 seconds the MIL illuminates and the RPM's drop slightly and the familiar thump of a misfire returns. I also reset the ECU restarted the engine and pulled the #4 Plug from the Coil and the rpm's dropped exactly as before but it took another 20 seconds for the MIL to illuminate.

I would check the #4 Plug with my OHM Meter if I knew what I was looking for. Any advise on how to do this would be helpful.

Thanks!

- - - Updated - - -

I'm looking to buy an X5 for my daughter. I am following your thread to see what ends up fixing your issues in case they show up in hers.

I really like driving this unique SUV, when everything is working well I feel very safe and confident driving it on long trips. I've driven 7 or more hours at a time with no problems several times. This car has 246k miles and after reading the carfax report I learned it was in a front-end collision in 2010, when I bought it nearly a year ago it was leaking oil all over the place from the valve cover and hissing vacuum from everywhere. I have to assume after the collision it was probably sold at auction and then rebuilt in a hurry for sale. I paid cash for it assuming I could fix whatever was the problem and then have years of fun driving my dream car for years to come. I still believe this.

I feel that buying a car from someone who has records of previous maintenance would surely make future diagnoses and repairs much quicker. For instance, I don't know if my O2 Sensors or Fuel Filter or DISA Valve or CCV System have ever been replaced, I have no previous records of maintenance for my car. So I am throwing money at my engine because I just have to assume if the part hasn't been replaced in the appropriate scheduled time, then it will probably need to be changed soon anyway.

I have been hearing a whistling sound coming from under the car on the passengers side for about 2 months so now I am thinking I need to just replace the fuel filter and rubber vacuum return hose to the Fuel Pressure Regulator and maybe my problem will be solved.

Could a low vacuum return to the fuel pressure regulator cause enough of a lean condition to trick the ECU to cut-off fuel to Cylinder #4.

[lanbrown]

You could put the #4 plug into a different cylinder to see what happens; if the problem moves with the plug or stays with the cylinder.

How old are the plugs and what model are they? I see that you say NGK Iridium but they have several different models.
http://www.e46fanatics.com/forum/sho...d.php?t=675317

Have you checked the gap as well?

I would think an issue with the fuel pressure regulator in anyway would impact more than just cylinder #4.

[MHRX5]

I rented a compression gauge today, here is what I found.

Cyl #1 - 175psi
Cyl #2 - 180psi
Cyl #3 - 180psi
Cyl #4 - 20psi
Cyl #5 - 180psi
Cyl #6 - 180psi

My suspicion is my #4 piston rings are gummed up or stuck to the piston journals and not seating against the Cylinder Sleeve correctly. If I had a bent valve or poorly seated valve I wouldn't have any compression at all. Right?

Here is a similar problem and solution by this BMW Mechanic, I am trying this now: https://www.youtube.com/watch?v=_Vo4fm0JDPY

I will report back tomorrow with my findings.

[MHRX5]

Well I have done everything I can to fix my problem but I still have only 30psi on Cylinder #4. I may or may not still have an intake vacuum leak but at this point, what's the point, I still have low compression on Cylinder #4 and my ECU still throws a P1349 code, Misfire cylinder 4 with fuel cutoff. The engine is running better than before on all other cylinders except for the misfire on cylinder 4. I can idle the engine for about 10 minutes then my phone OBDII app says my engine is overheating but my dash gauge is normal.

I think I have to look at my valves and or head gasket. I guess I will remove my head and prepare to replace the head gasket and maybe an exhaust valve.

Any advise for me or anything else I should consider or that I should do while I have the head off?

Remember I have 246K miles on this car, I want it to run well for another 100K if possible.

[HeliHover]

Overheating to me says head gasket.

I did have a stuck valve once on a chevy truck that resulted in a misfire and rough idle. I poured every type of cleaner the auto parts store sold in just about every hole in that truck (so much that the truck started smoking) and drove it daily for about two weeks with no power and a rough idle. Was going to work one morning, came to a stop and thought the engine died as it was idling so smoothly. All was well after that. Must have been a carbon deposit or something on the lip of the valve that just finally broke loose.

[MHRX5]

I think I need to prepare to replace the Head Gasket but In the process I should find the problem, maybe carbon build-up on the valves or bent valve. I am concerned maybe a small piece of my original DISA valve may have broken off and been sucked into Cylinder #4 and maybe ... The photo's above show my original DISA valve with the corner cracked off. Just a thought. Guess I need to order a complete gasket set.

Any other ideas?

[HeliHover]

Looks like your moving in the right direction

[Cpenkwitz8351]

I have the exact same problem on my 2002 530i. Misfire cylinder 4. I have rebuilt the entire intake manifold before doing a confession test and #4 is at 100psi when all others are at 175psi. As soon as I am done with timing chains on my x5 I will hook a cylinder leak down tested on cylinder #4. Pressurize the cylinder and take the dipstick out, if there is a drastic change its rings. Open the coolant fill cap and look for bubbles, then it's a head gasket. Open the throttle body and the pressure changes or you can hear air leaking then it's an intake valve. Obviously if those all those check out them put you ear up to the exhaust and listen for leaking air that means exhaust valve. I wouldn't buy anything until you do this test. It may be rings and you just waisted money on gaskets.

Harbor freight has a leak down tester for like $50. It is worth just to figure our where you stand.

- - - Updated - - -

Have you had any loud "ticking" on start up in cold weather? I have had this all winter. Im going to do a leak down as stated above but if it is a valve I am going to figure out if its intake or exhaust and thake the problem cam out of the head and do another leak down test and see if the compression comes back. I have heard of lifters being stuck pumped up and only causing an issue at idle. Just a thought before you take the head off and figure out its in the valve train. As soon as the X5 is done I will let you know what i find.

[lanbrown]

What about putting a scope down the spark plug hole to see if there is any damage?

[RacerX5]

OTC makes a really nice leak down tester. Not too expensive.

- - - Updated - - -

With 250k on the motor, if it were my car, and saw that low compression in 1 cylinder, I'd put in a junkyard motor. It really doesn't matter what is the cause of the low compression; best case you still need a couple of hundred dollars of gaskets, a massive amount of work, and you still have a used up motor. Keep in mind pulling the head is not exactly a quick and easy job. To re-install the head you'll need the cam timing kit, and that's an easy thing to screw up. If you swap the motor, you easily could find one with 150k mile less, and at this point, (especially due to the low failure rate of the BMW I6 engines,) these motors are pretty cheap in junkyards.

[MHRX5]

Well, this is where I am now, I have confirmation that what I originally believed is true, I felt that a small plastic piece of my original DISA valve had broken off and got sucked into #4 Cylinder and while exiting it hit the exhaust valve and chipped it. I believe my #4 rings are good, all 6 cylinder walls are smooth as glass with no scratches or marks at all. I put a straight edge on my Cylinder and it doesn't appear to be warped at all. I bought the Double VANOS Complete Timing Tool Kit on eBay, made everything much simpler.

I includes some pictures:


I found a local cylinder head shop I will take mine to and get him to look at this and see if he can inspect all my valves, resurface and replace the problem valves.

Any thoughts or advise?

[HeliHover]

Wow!

Didn't think that was possible.

Are you sure the broken peice of plastic broke a steel valve?

[MHRX5]

I have no idea exactly what cracked the valve, but I have a small piece of my old DISA Valve missing (shown above) and a 250K mile engine that I would imagine the valves have become slightly brittle over time?

What would cause a valve to crack?

[MHRX5]

I went to the Machine Shop to check on the progress of my cylinder, they have cleaned the cylinder and removed the valves, they were pulling valve seals while I was there. I grabbed the problem valve and took some pictures. The Shop owner Dennis (20 years experience) tells me he sees this allot and thinks these exhaust valves get burned from ethanol in gas and water in gas or just bad leaded gas. He suggests always using a higher octane (premium) gas.

He is replacing all 12 exhaust valves and leaving the intake valves, he feels they are in excellent shape. Here's the photo's: