Reduced Power Engine Malfunction - Diagnosis Thread

[mirob]

Originally Posted by m5james

So I finally received and got the chance to install the turbo water pump and silicone hoses...the pump is defective right out of the box and I'm still getting the damn reduced power warning. I'm at my wits end with this damn car. Tuner said he could code out the warning but not the computers ability to reduce the power for whatever in the hell it thinks is an issue.

How can such a simplistic warning come up, cause huge reductions in power, yet no CEL and surely no damn quick fix. Searches for this issue leads to a ton of different replies, so I'm thankful for this thread, but I'm just hoping for the day a CONCRETE answer is finally found for something that escapes us and the stealerships.

On a side note, which I'm thinking I shouldn't install yet, but my Aquamist HFS-4 kit is in the mail.

Well, you did everything except what I told you to look for...I think it's time you find your exhaust valve hoses and block them off...

[m5james]

Originally Posted by -c-

Yea I was talking to the Forman at the dealer and he told me they get tons of older x5's in with this issue and 9 times out of 10 it's a vacuum leak somewhere, so now they just replace all vacuum lines as part of a maintenance service. They said the rubber lines are very bad and deteriorate because of the heat and age and start to get hair line splits in them that could be anywhere, some you can't even see so they just do it all and it fixes the problem, now this is the non M versions he was talking about but it could be something similar.

In hindsight I should have ordered matching vacuum line as well, I'm just not certain what diameter and size(s) we need. I'd also like to delete the line running to the trunk where it feeds the exhaust valves since they're plugged.

[m5james]

Originally Posted by mirob

Well, you did everything except what I told you to look for...I think it's time you find your exhaust valve hoses and block them off...

I've verified they're in fact plugged. I'd mentioned it before, but maybe not on this thread. Either way it's under the RH storage bin in the trunk behind one of the panels.

[m5james]

Originally Posted by frankenm

Well thats great news

I am no closer to solving this on my end either and getting tired of this damn mystery machine.

I don't understand why this car throws a reduce power warning and doesn't give it a CEL to diagnose makes no sense whatsoever.

I have to replace my power steering pump and reservoir, solve an oil leak somewhere near the oil filter housing ( I think it is a pressure sensor leaking but not entirely sure need to remove the skid plate to investigate better ), replace the bank 1 air intake pipe and refresh my cooling system.

While I'm doing this I'm going to replace all vacuum lines and hopefully clear this up ... if not I'm going to start considering selling this money pit of problems.

Just an update...I'm still dealing with this, but seeing I work tons of OT at Boeing, I haven't tried fixing anything else either.

As for codes, ignore the 3EA9 for the turbo water pump as I'd replaced it, pumps working, but never cleared the codes.

I still get the 30FF code which is commonly found on the N54 boards as a potential wastegate not closing issue. I've got someone sending me real downpipes to replace my gutted ones to see on the wild chance that's my issue, but I'm going to vacuum check the wastegates while I'm at it.

I've also got a 310B, which is a sensor I plan on replacing once I figure out exactly which sensor it is.

As for the vacuum lines, I'd love if someone would go measure the ID and OD of it so I/we can know to order. Story of my life but I think about everything I should do outside of work while I'm already at work :-/ Did you ever attempt to replace ALL the vacuum lines, frankenm?

[frankenm]

Well thats not really good hopefully it is not a turbo issue ...

I haven't replaced any of the vacuum lines yet.

I have to do some work on the truck I've been putting off, PS pump + hoses + tank, oil pan gaskets and oil pressure sensor, turbo water pump, belts, thermostat and coolant flush and to get it ready for the winter before it starts getting too cold so I plan on replacing them then.

I'll likely be doing this all next weekend since it will probably take 2 good days to get it all done.

[frankenm]

Finally got around to doing the work I was putting off and while I didn't replace the vacuum lines I did get everything else finished.

And I still get the reduced power warning ... it only happens when pushing the truck up to 80+ in 4th gear.

I'm going to get some high-temp vacuum line, catch can and JB4 next to install.

My idea is that with the JB4 I just reset the warning when it happens so I don't need to cycle the truck off and on ...

Outside of a possible turbo issue I'm not sure what causes mine.

[MarioAlberto]

Having the same issues, between 1200-2000 rpm's the engine stutters. above that its all good. currently running the X5 in sport mode only to keep the rpm high.

[Revnato]

Originally Posted by frankenm

Finally got around to doing the work I was putting off and while I didn't replace the vacuum lines I did get everything else finished.

And I still get the reduced power warning ... it only happens when pushing the truck up to 80+ in 4th gear.

I'm going to get some high-temp vacuum line, catch can and JB4 next to install.

My idea is that with the JB4 I just reset the warning when it happens so I don't need to cycle the truck off and on ...

Outside of a possible turbo issue I'm not sure what causes mine.

How easy is it to reset the warning with the JB4? Are the controls mapped to the steering wheel or something?

[frankenm]

Originally Posted by TreyB

How easy is it to reset the warning with the JB4? Are the controls mapped to the steering wheel or something?

They are but I'm not 100% if it can be reset on the fly when the vehicle is on.

I'll find out more specifics once I move towards actual tuning and upgrading the truck more for now it's prepped for the winter and I don't plan on changing anything until the spring.

[F06msportmia]

Originally Posted by frankenm

Decided I'm going to start a thread on this to hopefully help myself and others with the dreaded limp mode/engine malfunction that randomly happens

I've been getting a Engine Malfunction/Reduced power message every once in a while for no apparent reason, seems to usually happen on the highway during soft acceleration ...

I've replaced the following so far in an attempt to remedy this problem,

Bank 2 Injectors
Bank 1 & 2 HPFP's
All Crankcase vent lines
Spark Plugs
Coils
Bank 2 Turbo Diverter valve
Bank 1 & 2 Air Intakes
Probably a few other things I can't remember right now ...

My truck does not throw any kind of check engine light when this happens, just goes into limp mode and turning the truck off and on again makes it go away.

It only happens on the highway, usually when I'm going to pass or getting on the on-ramp and slowly accelerating ... It could be that the truck doesn't like to be driving slowly like this so it goes into limp mode as a way to get back!!??!

I think this is a software issue with the car itself, I haven't hooked up my computer to the car yet when it goes into limp mode but I'm not even sure if it will register since it doesn't throw a CEL.

I know others have similar issues with this and hopefully we can come together and figure out what it is and help each other out here.

Just an FYI I have not had BMW diagnosis this and giving the only dealer in my area is a major crook and I DIY it is not worth it for me to waste my money on it for them to tell me everything is fine.

Thanks for the original post! It's exactly what I have experienced 3 times in the last 2 weeks. Again tonight...

I got on the highway and all of the sudden engine malfunction reduced power! When I got off at my exit I turned the car off for 30 seconds started back up and message was gone.

Changing the plugs this weekend.

Don't get why the message! :

A few days ago I got a coolant low message and I refilled it. Not sure if it stems from there.

Any insight or help is appreciated!

2011 LCI x5 e70 3.5i - 70k miles

Thanks.

[m5james]

Originally Posted by frankenm

My idea is that with the JB4 I just reset the warning when it happens so I don't need to cycle the truck off and on ...

Outside of a possible turbo issue I'm not sure what causes mine.

I don't believe it works like that. The JB4 reads and clears CEL codes, but seeing as the Reduced Power warning isn't kicking a CEL, I'm sure you're still going to have to cycle the engine. I've gotten to the point where I do it while driving if the conditions permit without being a safety issue.

Of the codes I get, I've gotten 30FF more than once. While searching here next see results, do that same search on some mass produced cars like the the 3 or 5 series powered N54's and you'll see theads, YouTube videos, etc in regards to wastegate issues. Long story short but I've gotten myself another set of downpipes, so I'm going to vacuum pump the wastegates and adjust the preload on the wastegate arms while I've hit the downpipes out. It's a very common practice on the N54 but I've never read about it being done here.

[Revnato]

Originally Posted by m5james

I don't believe it works like that. The JB4 reads and clears CEL codes, but seeing as the Reduced Power warning isn't kicking a CEL, I'm sure you're still going to have to cycle the engine. I've gotten to the point where I do it while driving if the conditions permit without being a safety issue.

Of the codes I get, I've gotten 30FF more than once. While searching here next see results, do that same search on some mass produced cars like the the 3 or 5 series powered N54's and you'll see theads, YouTube videos, etc in regards to wastegate issues. Long story short but I've gotten myself another set of downpipes, so I'm going to vacuum pump the wastegates and adjust the preload on the wastegate arms while I've hit the downpipes out. It's a very common practice on the N54 but I've never read about it being done here.

I just recently replaced the injectors, coils, & spark plugs, but I'm still getting the Reduced Power warning when I floor the car onto the freeway or any full acceleration like that.

Now that I've ruled out the ignition system, I'm bringing it back into European Auto Source (a pretty good reputable indy shop in SoCal) to see if they can figure out whats wrong. I'll be sure to mention what you said about the wastegate. I've also been told it could be the throttle bodies. Anything else that I should mention to have them look at/rule out?

At this point who knows what it is...

[Revnato]

Any updates from anyone?

[Maranello055]

Just posting this in here for the record - Check out my actual thread for updates

http://www.xbimmers.com/forums/showthread.php?t=1321492


I was on a trip to NC from Pittsburgh 2 weeks ago. On the way back from Charlotte roughly in Virginia, I received a Engine Malfunction - Reduced Power message on my dash. We were roughly 360ish miles from home on a Sunday with my wife and 10 month old son.

We stopped a few times in hopes that on a restart the light would go away. Of course it didn't. So we ended up limping home all the way.

We take the car to the dealership and at first they reprogrammed the ECU and all the modules in the car to the latest DME software. ( I personally didn't think this would solve this issue) But I went along with it. The dealership test drove the X5 and called me and said it was fixed!

I pick up the vehicle, pay the $255 for the program and start driving home. As soon as I get on the on-ramp to the highway... guess what - Engine Malfunction - Reduced Power. So i drive it right back to BMW and jump right back in the same loaner!

It takes a few days at BMW to run through their test plan and they notice that -

CLIENT STATES CHECK ENGINE LIGHT IS ON
FAULT FOR BOOST PRESSURE PLAUSIBILITY TOO LOW .
WORKED THROUGH TEST PLAN AND COMPLETED ALL CHECKS
INCLUDING MANUALLY APPLYING VACUUM TO WASTE GATE ACTUATOR
AND FOUND NO CAUSE FOR BOOST PRESSURE ISSUE. CONTINUED
TEST PLAN WITH RUNNING TURBO SELF TEST WHICH ABORTS.
FOUND WHEN ENGINE IS HOT PRESSURE CONVERTER IS
MALFUNCTIONING AND SUPPLYING CORRECT VACUUM TO WASTE GATE
ACTUATOR. ACTUATOR WORKED CORRECTLY WHEN TESTED EARLIER
IN TEST PLAN INDICATING A HEAT SOAK ISSUE WITH COMPONENT.
REPLACED PRESSURE CONVERTER FOR WASTE GATE. CLEARED FAULT
MEMORY AND ROAD TESTED 3 MILES OK. HAD DRIVEN EXTENSIVELY
TO VERIFY REPAIR , NO MALFUNCTION OCCURRED IN OVER 30
MILES.

11-74-7-626-351 PRESSURE CONVERTER (Pneumatic Wastegate Actuator)


So they road-tested the X5 for 30 miles and the light has not come back on.

I pick the car up later today! Lets hope that this fixes the issue!

I figured I'd write this up if anyone has this same issue and wants to replace the part themselves instead of the dealership.

[Revnato]

Little update for you guys on my mystery engine malfunction problem.

I replaced all 8 of the fuel injectors (the new updated index ones), ignition coils, and spark plugs as I posted earlier, but still had the reduced power warning coming up anytime I pushed the car hard.

I was fully expecting there to be something wrong with the wastegate in one of the turbos like James mentioned above. I new this would mean that I would have to buy a new turbo, so I was really upset at the thought of having to spend $$$$ on a new turbo.

Luckily for me it ended up being a bent vacuum line! It was literally as simple as that. Now the mystery engine malfunction is finally gone. Couldn't believe it when the mechanic told me I was beyond stoked

So to those of you with this same issue, I'd recommend checking/replacing your vacuum lines first.

[m5james]

http://www.xbimmers.com/forums/showt...4#post20830644

On a side note, can this thread be renamed to what it relates to, ie "Reduced Power" being in the title. I've contributed to this thread and even I had a hard time finding it when I wanted to add to it.

[m5james]

Might be too soon to tell after only 5hrs of combined driving, but I'm pretty confident I've fixed my reduced power warning. The usual driving patterns that would kick off the warning haven't caused anything:

- WOT in M and Sport mode just before it's about to shift
- 75% throttle in low speed and high gear situations while sitting in traffic
- pretty much anything above 50% throttle while on the highway

I wasn't able just yet to replace ALL the vacuum lines as the front 4 lines are the hardest to access. Those are the ones coming off the front of both vacuum canisters and both wastegates, which ultimately connect to two different sensors on the front of the engine, mounted to a bracket that requires removal of the passenger intercooler, all of which are mentioned on a thread linked above.

The lines I did replace connect from the vacuum module/pump on the backside of the engine, which feeds to the rear of the vacuum canister on the passenger side. I also did the line that goes from the rear of the vacuum canister on the drivers side, goes overtop the engine and connects to two T's behind the passenger canister. See top picture.

Here's where I'm not sure which was my issue:
- the vacuum line coming off the back of the drivers side canister was fairly short and didn't have a nice gradual curve, but instead was tight. I can't say it was crimped, but who knows what could happen under vacuum
- the vacuum line that fed into the muffler exhaust valves were removed and plugged when I bought the truck. I figured why have more vacuum lines running than necessary, so I figured out which line feeds to the trunk. Note also that this line is 99% hard plastic and only switches to rubber at the trunk sensor and at the T behind the passenger side vacuum canister. See the T I removed on the bottom right picture, which is located to the right of #7 on the bottom left picture.
- since deleting the vacuum line running to the trunk, I was able to delete one T from the lines. See bottom right picture.

My advice...double check for kinks (i don't know why it was kinked at all since it was stock vacuum line) and if you've already deleted your muffler valves, go a step further and simply remove one T, eliminating a possible leak from the entire length of the truck. If you haven't deleted your muffler valves, remove that one T for shits and giggles anyways, then leave the line dangling there as there's no need to plug it since vacuum won't be going through it any longer. Just note that the valves won't open in M mode due to lack of vacuum.

[xxdinoxx]

M5James,
what size are those vacuum lines ID/OD, I would like to replace mine and would like to use silicon lines instead of the original rubber lines.

Thank you!!!!!

[SerbX5]

m5James - what up buddy. Big game this weekend for the Hawks I'm in Bothell.. should receive my X5M today/tomorrow. This thread has me nervous.. well done on all your self diagnosis for the rig. You r truly a solid forum contributor., well done. Curious if your boost is back to what is expected after changing the lines.

[BzsBimmer]

Originally Posted by xxdinoxx

M5James,
what size are those vacuum lines ID/OD, I would like to replace mine and would like to use silicon lines instead of the original rubber lines.

Thank you!!!!!

Ditto on that one!

[m5james]

Sorry I haven't replied, I'm not getting notifications since having gone on ban for a bit :-D

http://www.ebay.com/itm/282198623991...%3AMEBIDX%3AIT

The ID is 5/32, OD I'm not sure of. I mostly just went for highest temps I could find and bit the bullet. It's been 100% error free since then. One thing I would suggest is to temporarily remove the T going to the exhaust valves as the line alone runs the entire length of the car. You can see where I removed it in my pics, find it on your car and follow the line to the passenger side fender. Remove the T, the exhaust line can simply hang freely since it won't be doing anything but for the time being you're eliminating 15' of potential leaking before having to replace a single vacuum line. If it does or doesn't work, then you've got two options...leave the line deleted and zip tie open your exhaust valves and/or start replacing vacuum lines like I did. I still haven't done the lines going from the wastegates to the sensors on the front of the engine because a lot more removal is required vs the easy to access stuff in my pics above. I'll be doing the rest when I swap out the downpipes.

[BzsBimmer]

Thanks for the reply M5James!
I've been reading a lot of your thread/posts since you've been a regular contributor regarding issues (maybe not a good thing lol). There's not a lot on this platform like there is for the E9X M3 which I also own.

Thanks for your contributions and lol on the ban. I've been there once.