Pulled Codes After X5 Started Misfiring - Confusion Ensues...

[Bayerische E53]

As to the detective work - thanks. I feel like a bit of a fool as it should have been obvious the moment I removed the dan flap. Actually, I should have been obvious the first time I disassembled the valve; yet I only noticed the big hole in the side of the valve the second time I removed it from the intake manifold!

As to the filter - yes, that was a bit of a cock-up on my part. Whoops!

As to the G.A.S. kit - "WOW" is all I can say. What a piece of work. What I especially liked was the aerospace grade silicone gasket; very trick. All that aside, you can really tell that the engineering behind the part was very thoroughly thought out; I can really appreciate that. The only thing I would change would be to add a "bevel" to the little shaft that the DISA plunger slides over so that the clip-ring can fit in there at the appropriate depth (getting that thing in while allowing a little clearance was a bit tough). That said, I am overall VERY pleased.

As I said, I'll be ordering two more up in short order (the other two cars are in storage for the winter already so there's no rush).

[RedTRex]

I was going to tell you you have a vacumn leak but I see that you figured it out. I had an almost identical problem kick my butt for a weekend on my sons 97 328i, it ended up being the vac hose for the evap valve.
(BTW I joined here recently as I think I want an X5, just sold my 2008 135i, and have been reading a lot - I really want a 4.8is but the e70's are pretty sweet - Saw a black/brown that I would love to have on the bay.)

Originally Posted by Bayerische E53

I fixed the problem. It was none of the fears I mentioned above; it was the damn DISA valve.

I ordered the G.A.S. DISA repair kit and installed it - haven't thrown ANY CODES AT ALL. Well, here's what happened - my DISA flap LEVER broke in half. What I didn't realize was that the lever is hollow (has a hole running through it from outside the manifold to inside the flap. Well, this means that when you remove the DISA flap, the lever effectively becomes a hole on the side of the intake manifold (i.e. a vacuum leak). It was this that was throwing all the codes in my car; the DISA itself was the vacuum leak that I was trying to chase around.

Problem solved. So, the next time one of you have any sort of lean/rich, misfire, or 02 sensor codes and a rough idle, check your DISA valve first; especially because it's the quickest and easiest thing to check. If the DISA is broken, it's more than likely the reason your car is throwing those codes.

I am so impressed with the build quality and obvious durability of the G.A.S. kit that I'm ordering two more kits; one for each of my other M54 cars. Brilliant.

[Bayerische E53]

I looked at several 4.8s and 4.4s when I was shopping around. Honestly, they are too much of a headache and VERY expensive to maintain. I've got two 3.0s and I like it that way. The M54 is a little fortress. Sure, it may not sound as cool nor have as much power as the big block motors but its so much more reliable and easier/cheaper to maintain/fix when things under the hood need fixing.

If you're looking at E70s, same story. In an E70, I'd opt for a diesel 3L...at most. Let's be real - it's an SUV at the end of the day; how much power to you really need? Get a reliable car and upgrade the cosmetics if you want the "look."

my $0.02

[RedTRex]

I guess I should have mentioned I plan on towing with it too. I agree the M54 is a good engine (N54 better of course) ..... for that matter most any BMW engine. But it is overworked in a 5000 lb rig IMO. But what do you think? have you ever towed with either of your 3.0?s


I have owned at least 15 BMWs and just sold my 135i, outrageously fun car, bu not very practical. I have a 97 318is (on M3 suspension) for my DD, so the SUV....excuse me SAV, would be my fun car if you will. I do all my own work and I think the parts are pretty cheap all around - except for most of those dang electronics.

I have interest in the diesel, but they are still pretty expensive and don't seem to look as nice as the 4.8s, I haven't learned enough to figure out exactly why yet

[Bayerische E53]

Originally Posted by RedTRex

I guess I should have mentioned I plan on towing with it too. I agree the M54 is a good engine (N54 better of course) ..... for that matter most any BMW engine. But it is overworked in a 5000 lb rig IMO. But what do you think? have you ever towed with either of your 3.0?s


I have owned at least 15 BMWs and just sold my 135i, outrageously fun car, bu not very practical. I have a 97 318is (on M3 suspension) for my DD, so the SUV....excuse me SAV, would be my fun car if you will. I do all my own work and I think the parts are pretty cheap all around - except for most of those dang electronics.

I have interest in the diesel, but they are still pretty expensive and don't seem to look as nice as the 4.8s, I haven't learned enough to figure out exactly why yet

I disagree with your N54 statement - in my opinion, the M54 is superior to the N54; simpler, similar power, easier and cheaper to maintain, and more reliable. But I don't want to turn this into a pissing contest so I'll digress.

I've towed my racecar with my automatic X5 around 10,000 miles (90% of those miles were with the odometer reading over 100,000 miles; I most recently towed 1500 miles straight from the southeast to the midwest while the car had 145,000 on the clock. This was without any preventative maintenance. Everything under the hood was original parts). I've towed up and down the Pocono Mountains, the upstate NY mountains (Watkins Glen), and through the midwestern/southern (i.e. Tennessee) mountains without ever encountering a problem. Full loaded weight of the trailer was a little over 5,000lbs - towed a treat (and most of this was with suspension that needed quite a bit of work and the really tall profile 18" tires). The real trick, as with any lash-up, is to watch your tongue weight, balance your trailer weight, and manually select your gears.

All I have on the X5 is an OEM hitch, Tekonsha P3, SS brake lines, and Carbotech AX6 pads. I towed with stock brakes for about 6,000 miles without problems (although the AX6s and SS lines woke it a bit under braking when I installed them after having done those 6,000 miles). Honestly, the 3.0 has no problems towing a 5,000lbs load - even on stock equipment.

[upallnight]

Just fixed my P0171 and P0174 error codes (lean bank 1 and 2). Originally I took the DISA valve off the intake manifold but the valve wasn't rattling and the test for vacuum for the flap WAS O.K. SO I put it back on, but I was still getting the Service Engine Soon (SES) light. One cause for cause for the SES is a vacuum leak and since I didn't have a smoke machine I decided to use what I did when I use to race Triumph and Lotus in the 70's and 80's. I made a tool to listen for vacuum leak. The tool consisted of a funnel and a length of hose. I connected one end of the hose to the funnel and use the other end of the hose I use to probe around the engine compartment. I held the funnel to my ear and listen for vacuum leaks at all the known places. When I placed the hose by the intake manifold and disa valve I heard the vacuum leak.

Removed the DISA valve and noted that it came off fairly easily (another sign of a flattened seal). I removed the old seal (why BMW engineers didn't use a standard O-ring for this application I would never know) with a pick, jeweler screw drivers and a brass brush (don't use a steel brush), if you don't have a brass brush, use an old tooth brush. You need to remove all the old silicone gasket to insure that you will not have a vacuum leak.

Fitted an O-ring (62mm OD x 55 mm ID x 3.5mm Thickness) to the DISA valve and when I went to install the DISA valve it took a little more force to to push it into the intake manifold (smeared the o-ring with, a little bit of dish soap to help install). Started the engine and clear the previous SES. Went for a drive and a fill up and check for fault codes on my son's tablet with the Torque App. NO fault code found. Look at the Long Term Fuel trim and it was within the guideline. The idle was rock steady at 700 rpm.

I use to use Carsoft 6.5 when I drove an E34 Touring but since getting the E53 with the common OBD II connector, I have switch to an App on my android phone called Torque and use it in conjunction with a Bluetooth adapter called ELM.

I find the app so much more useful then carsoft. Torque is much more customizable and provide more info then carsoft ever did. I notice that there is still the old round connector for BMW proprietary OBD in the engine compartment. Has anyone ever use this connector? I'm too lazy to fire up my old laptop to see if carsoft still work with the later model BMW.

[Bayerische E53]

Great post!

Yup, that gasket is failure-prone. It's annoying that BMW designed it as an integrated piece. People who don't know that you can replace the gasket by scraping it out wind up shelling out hundreds for a new DISA.

The GAS kit is great. When I bought mine I also but the upgraded DISA housing gasket to the military-grade fluorosilicone piece. It's a nice piece indeed.:

BMW DISA O-Rings

[upallnight]

Originally Posted by Giznaz

Yes the operation changes. Why? i don't know.

When my X5 throws mis-fire codes, and I have the Peake connected while running, clearing the codes makes it run much better.

It will run much better if the ecu commanded the injectors not to inject any more fuel into the cylinder because the cylinder was miss firing, and by resetting or clearing the code the ecu is no longer turning the injector(s) off.

A cylinder may misfire, but not all the time. It is only after x amount of misfires have occurred that the ecu will shut off the injector(s) and turn on the SES light. Some scanners allows you to view pending codes. I use the app TORQUE and I can view pending code before a SES light is on.