Rough running 4.8is

[panchosouth]

Guess who changed their mind about selling- Sigh.

What can I say. I started surfing for parts-porn and found a pair of black comfort seats....And I'm off to the races. Now my current plan is to install the comfort seats in front, move the sport seats to the back, get rid of the bench seat, and install one of those nice shiny M3 paddle shift steering wheels. Oh and hard wire in some radar/laser stuff…Oh and get rid of the OEM GPS, remove the Dice media bridge (no likey) and install that thing on Ebay (Dinavin?). Oh and go with some new sporty bushings….And new sway bars….And possibly….Well I’m sure you know where I’m going with this…..

Rough running:

The Uber Donkey ran a wee bit rough when I first picked her up. It was really hard to get a good read because (using my ass-o-meter) the suspension was doing the low-rider bob and the DINAN tail pipes were giving me new-owner orgasmic sound woodies, so every time I went to sus out the rough running I would end up getting lost in the DINAN burble then forget what I was doing. That didn’t last very long because a week into owning it (this is amidst getting new tires, suspension etc sorted) I began to notice a stumble on throttle up. Once noticed, it seemed to jump from back ground irritation to CEL almost immediately.

A trip to the shop showed the usual culprits you see on here: multiple miss-fires, or cyl 2 or 5 or whatever misfiring.

First remedy:

All new plugs. Ran great for about 3KMs before the stumble was back onboard.

Back to codes- Same as last time.

Second remedy:

Replace indicated coils (in this case it was showing 2 and 5) Spent 200.00 on coils locally (lesson learned; ordered the next six from ECS Tuning for the price of two local ones). Ran great for about half an hour. Finally got a taste of how it was supposed to run and …..sigh.

Back to the shop. Same codes. So. Start from scratch. Check for vacuum leaks. Nope. Check for loose connections (more on this in a bit), discover that PO had some sort of sub-woofer set up in back, and check splice and tap in points. All good. Replace remaing six coils.

Third remedy.

Carbon build up is the suspect du jour. Run a cleaning agent through injection system. Lots of smoke from pipes. Lots of male grunting in shop as we all nod like spastic bobble heads, a collective agreement that this, this is the culprit. It is decided to run only 94 octane and take a couple of long trips (200kms or so) to blow out carbon.

CEL returns, however, it is usually a flashing engine light, and the rough running can be somewhat mitigated by pulling over and cycling the ignition. This done, light disappears, and if introduction of throttle is steady and limited, stumble is all but gone.

It should be noted at this point, that the issue seemed more prevalent when cold and damp (early morning), and under mild to medium throttle you could set your watch to the CEL coming on. Also, and this is why I said “more on this” when I mentioned connections….The airbag light in instrument pod and on sunroof/light control area started to come on….This was also the period when I was trying to get the suspension sorted out, so the pod looked like a Christmas tree on crack. Whenever the suspension inactive light came on, it was always simultaneously joined by the TPS light (tire pressure). Don’t ask me why, it just did, and the only way to get it off was when you re-set the codes. The airbag light would show itself, for maybe 5 or 10 minutes, then go off…..as in when the truck seemed to be producing enough heat….but that is again supposition on my part.

Back to shop.

Fourth remedy:

Check all vacuum lines again. Again with injection system flush, new fuel filter, also a Hot Oil Engine Flush (basically a blow-the-crap out of it scrub-a-dub-dub). Once more 94 octane and long drives. I can tell you that the head bobbing and grunting was far more pronounced this time, as the smoke was akin to the Hindenburg. Oh the Humidity! Thankfully the shop had just completed a compression test with flying colors so no sudden rectal convulsions were ensuing when I saw the great clouds of smoke billowing out of Uber Donkey.

So where am I at? Well, I still have the rough running and CEL. Last day I had it on the road (I work overseas so it was going into storage) it was rainy and somewhat cold aaaaannnnnd on comes the CEL and the airbag light. It also sounded like it was knocking, but I was on my way to the airport and couldn’t really hang around to get a handle on it. No luck with ignition cycling either. CEL stayed on. Air bag intermittent. Somewhere over the Atlantic I decided I wanted a turbo. Decided to sell the X5. Posted same. Contacted Otto’s BMW to go pick up the X5 and get it sorted. Was told I had to wait two weeks for someone to be able to pick up and then get it diagnosed. Accidentally looked at parts porn. Bought seats. Sigh.


Let’s hear your thoughts, and add any similar experiences to this post, and remedies! We should have a sticky on this so we can save some moolah to others who come up against this…..

Will let you know what I hear next week.

[upallnight]

You have injectors cutoff that is why when you cycle the on off switch it resets the computer so that it is no longer cutting out the injectors.

What are the DTCs that you or your mechanic have read from the truck? Cylinder misfire for many different reasons, you took care a couple of the easy one by replacing the plugs and coils. Have you taken a look at the short term and long term fuel trim? Have you done a compression check on the cylinders?

Unless you can provide us with additional info, all the suggestions that we have are just WAGs (Wild Ass Guesses).

[panchosouth]

Up All Night

Fourth Remedy: Compression check done.

DTC I assume is what codes? Multiple- Non that mentioned codes- There was a mention that the FP seemed to be less than is should be (this is a non-specific shop, so BMW kit testing limited….

[upallnight]

Originally Posted by panchosouth

Up All Night

It just one word.


DTC = Diagnostic Trouble Codes

Either buy yourself a scanner for the BMW or find a shop with the right equipment. The days of the shade tree mechanics is about dead.

[panchosouth]

UAN

As I said, I work overseas. Diagnostic tools are great if you have the time or inclination to use them. All mechanics work under some degree of shade.

[upallnight]

Originally Posted by panchosouth

UAN

As I said, I work overseas. Diagnostic tools are great if you have the time or inclination to use them. All mechanics work under some degree of shade.

As they would say on the TV Show Shark Tank

I'm OUT.

[bcredliner]

Originally Posted by upallnight

As they would say on the TV Show Shark Tank

I'm OUT.

You sure have a short fuse! Is it off to the movies or the beach this time?

[upallnight]

Originally Posted by bcredliner

You sure have a short fuse! Is it off to the movies or the beach this time?

Not a Short Fuse, just don't want to waste a lot of monitor ink on someone that don't want to learn how to fix a BMW and just looking to get an easy and cheap fix.

Since you are a very patient person why don't you help this poor chap out.

[bcredliner]

Originally Posted by panchosouth

UAN

As I said, I work overseas. Diagnostic tools are great if you have the time or inclination to use them. All mechanics work under some degree of shade.

Shade tree engineering will never go away.

The foundation of Shade tree engineering is troubleshooting. Computer based diagnostics can help finding the root cause but can also be mis-interpreted by even the best of computer dedicated techs. Without a common sense approach that has always been a critical part of shade tree engineering, it is not unusal that computer based diagnostics run up the cost by replacing parts that aren't bad. Troubleshooting is always a primary effort, to a fault, because most shade tree mechanics/engineers didn't have or don't want to spend the $$$ to keep throwing parts at the problem until one happens to hit the right spot. That is why they spent more time trying to be sure they have found the root cause.

That doesn't mean I don't see the benefits of diagnostic tools. It does mean, in almost all cases one can still git er' done without them. I can't remember the last time I replaced a perfectly good part unless it was preventative maintenance. A shade tree, common sense priority---pay a small price now to prevent a big price later because many can't afford to risk the big price and it does not pass the common sense test, not a strength of computer diagnostics.

[bcredliner]

Originally Posted by upallnight

Not a Short Fuse, just don't want to waste a lot of monitor ink on someone that don't want to learn how to fix a BMW and just looking to get an easy and cheap fix.

Since you are a very patient person why don't you help this poor chap out.

There is no indication OP doesn't want to learn, wants to take the easy way or is not willing to spend the money it might take to fix it right. That's out of line. None of us are always right. There is no need to lash out if an OP doesn't whole heartedly follow your direction. That is his judgment and his money. It sounds like you are saying there is only one way to do things logically and it is your way or the highway--not so. There is gratification withholding your expertise--suggest you reconsider.

I will certainly do my best to help.