[egregor]

Yesterday my car threw a "Engine Malfunction! Power Reduced" message. I brought it home and scanned for codes, and there were none.

Since then, I can't get the message to show up again, though my car feels like a 328i. When i hit it hard, it sounds a little different (a bit more throaty I guess) and just doesn't punch. When I drove around with the torque app, the highest boost it measured was 3.1, mostly around 1-2 psi under acceleration though.

Are there any common causes for this on N54 that would get me started? I'm kind of at a loss here how to start troubleshooting without any codes. Car is 102K miles, original turbos, hoses, O2 sensors. Fully stock.

[Jklad]

Sometimes to trigger a code or light you have to go wot in a high gear for at least a few seconds straight. Start with the basics. Check cp to tb connections. Since your stock you probobly don't have a leak at the IC, but you can inspect the opposite end of the cp. next, inspect vaccum lines starting at the brake booster, over to the canisters. Inspect canisters themselves. Then all the lines after canisters to the boost solenoids. Then to the wg's. Jump over to the intake side, inspect the lines coming off the dv's which join into the intake mani. At 102k, you should replace all of your vacuum lines and possibly the canisters too. I'll bet you have at least one that's cracked somewhere, and cracks can be very hard to spot. Theres a thread on here outlining where the lines go.

[Scrippy]

Originally Posted by egregor

Yesterday my car threw a "Engine Malfunction! Power Reduced" message. I brought it home and scanned for codes, and there were none.

Since then, I can't get the message to show up again, though my car feels like a 328i. When i hit it hard, it sounds a little different (a bit more throaty I guess) and just doesn't punch. When I drove around with the torque app, the highest boost it measured was 3.1, mostly around 1-2 psi under acceleration though.

Are there any common causes for this on N54 that would get me started? I'm kind of at a loss here how to start troubleshooting without any codes. Car is 102K miles, original turbos, hoses, O2 sensors. Fully stock.

+1

[Tiago@VRSF]

Probably blew the OEM CP, very common on these cars with your mileage.

[Javy]

Check your charge pipe. Mine cracked and gave me the same message you got.

[SLOWER]

N54 charge pipes are failing even on non tuned cars?

[DuDai]

Originally Posted by SLOWER

N54 charge pipes are failing even on non tuned cars?

You betcha

[egregor]

Jklad thanks! I checked the CP and DVs, looked fine. I found the forums posts about changing out the vac lines and replaced every one you mentioned (except the line the DVs join into, which goes somewhere I simply could't reach). The most likely culprit was one behind the oil filter which had a noticeable crack around the nipple.

Anyway before I was able to trigger the engine light going WOT in 4th, that's now gone! The car also pulls hard enough for DSC to kick in Night and day difference. My only remaining question is that the Torque app still reports a max PSI of 2.7. Is this an unreliable metric or something?

[Sgop335]

Good job with the vacuum lines, absolutely need it!

Yes i and many others see the same. The torque app on android maxes out at 2.7 psi. I still do not know how to measure my boost without actually sticking a gage.

And i did change the vacuum line to the manifold from the dvs. Hard but can be carefully done. Dont just try to pull on it.

[egregor]

Thanks sgop. Thats enough for me to think the problem is licked! But out of curiosity, if not pulling on that intake mani line, what did you do? I cant exactly fit a box cutter back there to score it.

[Sgop335]

Welcome! This is what i did. First put my hand in there and felt it on the barb. Took just the exacto blade (had a long blade) , put my hand in and gently scored it. Once there were some cuts, i pulled it out.

[Shadow007]

Originally Posted by egregor

Yesterday my car threw a "Engine Malfunction! Power Reduced" message. I brought it home and scanned for codes, and there were none.

Since then, I can't get the message to show up again, though my car feels like a 328i. When i hit it hard, it sounds a little different (a bit more throaty I guess) and just doesn't punch. When I drove around with the torque app, the highest boost it measured was 3.1, mostly around 1-2 psi under acceleration though.

Are there any common causes for this on N54 that would get me started? I'm kind of at a loss here how to start troubleshooting without any codes. Car is 102K miles, original turbos, hoses, O2 sensors. Fully stock.

DUDE THIS IS THE EXACT SAME SH** THATS HAPPENEING TO ME AS WELL! I recently got my car from overseas, Germany, and I've been driving around for about 2 weeks now. Before I left, I had a few issues but it wasn't anything boost related. So this past weekend I was out cruising around and every time I would push into my car it would feel likes it's struggling to gain boost, jb4 map 5, I would get around 3 psi, using the boost recall on the P3 gauge. After that, I switched to map 1 just to see if there was any difference and I got around 5 psi after going wot. My current setup is jb4 map 5 and Wedge 9 degrees pump flash using 91 octane. I recently bought the RB PCV valve which I'm hoping will eliminate the problem. As of now, my car feels like a Honda Civic running around. I'm trying to find a tuning place around El Paso, TX to see if they could do a boost leak test or something.

[Jklad]

Originally Posted by Shadow007

DUDE THIS IS THE EXACT SAME SH** THATS HAPPENEING TO ME AS WELL! I recently got my car from overseas, Germany, and I've been driving around for about 2 weeks now. Before I left, I had a few issues but it wasn't anything boost related. So this past weekend I was out cruising around and every time I would push into my car it would feel likes it's struggling to gain boost, jb4 map 5, I would get around 3 psi, using the boost recall on the P3 gauge. After that, I switched to map 1 just to see if there was any difference and I got around 5 psi after going wot. My current setup is jb4 map 5 and Wedge 9 degrees pump flash using 91 octane. I recently bought the RB PCV valve which I'm hoping will eliminate the problem. As of now, my car feels like a Honda Civic running around. I'm trying to find a tuning place around El Paso, TX to see if they could do a boost leak test or something.

Check (and if higher mileage 70k+ replace) all the vacuum lines as I noted above, then check your Cp/throttle body/dv connections. If you can't find anything, then take to a shop.

[Jklad]

Originally Posted by Sgop335

Welcome! This is what i did. First put my hand in there and felt it on the barb. Took just the exacto blade (had a long blade) , put my hand in and gently scored it. Once there were some cuts, i pulled it out.

+1 after cutting you could probobly just peel it off. Careful not to brake that plastic nipple, that would suck!!!