Limp mode power without Limp mode/SES light

1mang · 04-20-2016, 12:18 PM

Engine Type:
N54 with 3/2008 build

Car Mods:
oil bypass valve

Recent changes:
- replaced all vacuum lines with new silicon hoses except for rear turbo (too hard to get to)
- replaced diverter valve with new OEM (broke nipple from replacing vacuum lines)
- "upgraded" o-ring on diverter valves to be thicker/oil resistant
- replaced serpentine belt (shredded while driving)
- replaced tensioner

All these changes were done because I had limp mode and SES light for low boost. It was fixed after I done all that and it drove fine as it used to.

Problem:
Started car and drove home normally and noticed a really low power when shifting to 2nd, 3rd, 4th, 5th, and 6th gear. It feels like extreme turbo lag. Doesn't matter if it is upshift or downshift. If downshift, I need to press more on gas to compensate on the lag to rev match. I also noticed my radiator fan would not turn on at all. I tried a/c on full blast. Nothing. I did get a phantom SES for electric fan unit (shows up on ecu reader but not enough to trigger SES light). I also noticed oil temp was around 240F which seems normal. I thought my loss of power was maybe car's way of saying do not drive hard/fast because I cannot cool you down. 1st gear seems to be fine. It is the higher gears which gives me extremely low power. I checked radiator fan fuse and that is fine. I opted to replace radiator fan since it is relatively old and could have damage from shredded serpentine belt. Still problem exists. Anyone have any ideas?

Other engine history:
- walnut blasted 10k miles ago
- replaced spark plugs about 15k miles ago
- replaced ignition coils about 10k miles ago
- replaced oil filter housing gasket about 5k miles ago
- replaced oil filter cooling gasket about 5k miles ago
- blackstone lab oil analysis about 5k miles ago. Results were great everything was below averages. No fuel/coolant found in oil. Very small amount of silicon (maybe due to vacuum/diverter valve o-rings?) but not enough to worry.

1mang · 04-25-2016, 09:15 PM

Update:
Car shop found a 60 amp fuse blown but supposedly the slot is rated 40 amp. After checking various pictures, 60 amps (light blue should be the right fuse) and only found on location #92 which is cooling/temperature related which seems to be relevant to my issues (cooling fan).

My symptoms are close to this:
http://www.1addicts.com/forums/showt...light=fuse+box

However I am 6MT and not automatic.

1mang · 04-25-2016, 09:23 PM

Interestingly enough the fuse box in this youtube video is different from what is posted online. Could it be an early build issue?

1mang · 04-25-2016, 09:27 PM

Fuses boxes from 1M and 135i apparently differ too!

http://www.1addicts.com/forums/showp...&postcount=182

Judging by this post, that 60 amp fuse is on location #92

1mang · 04-25-2016, 10:03 PM

Quote:

Originally Posted by 1mang

Interestingly enough the fuse box in this youtube video is different from what is posted online. Could it be an early build issue?

Location #92 uses a 50 amp fuse which aligns correctly with the diagram. It posts 50/60 as the amperage.

1mang · 04-26-2016, 01:51 PM

Update:

After mulling over this last night, I decided to make a surprise visit to the shop to see what was going on. They were holding to their story that a 60 amp fuse was in a 40 amp slot and that was the cause of my problems. They kept on saying that the 60 amp fuse was in slot #89 which is for "secondary air intake." I do not believe it because I checked location #88 for a 40 amp radiator fan fuse earlier and I am VERY confident that I would not miss seeing another fuse there for #89 or #87. Strike #1. They also said that in location #92 there was NO fuse at all. You cat to be kitten me because I did a quick google search and have a member show me a picture, there is in fact a 60 amp fuse there. Strike #2. I then proceeded to see if they remove the location #89 fuse and put a 50 or 60 amp fuse (the diagram calls both could work) in #92, then use autologic program to activate the fan to see if it work. I wanted to see for myself because right now my trust in them is very low. Low and behold, it works! By now, they are "happy" for me because I fixed an issue they could not replicate (or did not want to in order to get more hours on the car...$150/hr ugh). I did not want them to further work on the car since this was my issue all along and I hoped that the low power would be resolved along with that. Even if the low power still existed, my confidence and trust in the shop is shattered. I rather have another professional opinion. My power was restored and all is well.

So there you have it. If you have similar situation as mine, I would recommend checking out fuses first before replacing items or going to the shop. For years I have relied on forums as a resource. After all, we are all enthusiasts and have no monetary gain from the advice. I am grateful for that and this is my way to give back.

04-20-2016, 12:18 PM	#1
1mang Private First Class 36 Rep 127 Posts Drives: 135i Join Date: Jun 2014 Location: Bay Area, CA iTrader: (0)	Limp mode power without Limp mode/SES light Engine Type: N54 with 3/2008 build Car Mods: oil bypass valve Recent changes: - replaced all vacuum lines with new silicon hoses except for rear turbo (too hard to get to) - replaced diverter valve with new OEM (broke nipple from replacing vacuum lines) - "upgraded" o-ring on diverter valves to be thicker/oil resistant - replaced serpentine belt (shredded while driving) - replaced tensioner All these changes were done because I had limp mode and SES light for low boost. It was fixed after I done all that and it drove fine as it used to. Problem: Started car and drove home normally and noticed a really low power when shifting to 2nd, 3rd, 4th, 5th, and 6th gear. It feels like extreme turbo lag. Doesn't matter if it is upshift or downshift. If downshift, I need to press more on gas to compensate on the lag to rev match. I also noticed my radiator fan would not turn on at all. I tried a/c on full blast. Nothing. I did get a phantom SES for electric fan unit (shows up on ecu reader but not enough to trigger SES light). I also noticed oil temp was around 240F which seems normal. I thought my loss of power was maybe car's way of saying do not drive hard/fast because I cannot cool you down. 1st gear seems to be fine. It is the higher gears which gives me extremely low power. I checked radiator fan fuse and that is fine. I opted to replace radiator fan since it is relatively old and could have damage from shredded serpentine belt. Still problem exists. Anyone have any ideas? Other engine history: - walnut blasted 10k miles ago - replaced spark plugs about 15k miles ago - replaced ignition coils about 10k miles ago - replaced oil filter housing gasket about 5k miles ago - replaced oil filter cooling gasket about 5k miles ago - blackstone lab oil analysis about 5k miles ago. Results were great everything was below averages. No fuel/coolant found in oil. Very small amount of silicon (maybe due to vacuum/diverter valve o-rings?) but not enough to worry.
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04-25-2016, 09:15 PM	#2
1mang Private First Class 36 Rep 127 Posts Drives: 135i Join Date: Jun 2014 Location: Bay Area, CA iTrader: (0)	Update: Car shop found a 60 amp fuse blown but supposedly the slot is rated 40 amp. After checking various pictures, 60 amps (light blue should be the right fuse) and only found on location #92 which is cooling/temperature related which seems to be relevant to my issues (cooling fan). My symptoms are close to this: http://www.1addicts.com/forums/showt...light=fuse+box However I am 6MT and not automatic. Last edited by 1mang; 04-25-2016 at 10:01 PM..
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04-25-2016, 09:23 PM	#3
1mang Private First Class 36 Rep 127 Posts Drives: 135i Join Date: Jun 2014 Location: Bay Area, CA iTrader: (0)	Interestingly enough the fuse box in this youtube video is different from what is posted online. Could it be an early build issue?
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04-25-2016, 09:27 PM	#4
1mang Private First Class 36 Rep 127 Posts Drives: 135i Join Date: Jun 2014 Location: Bay Area, CA iTrader: (0)	Fuses boxes from 1M and 135i apparently differ too! http://www.1addicts.com/forums/showp...&postcount=182 Judging by this post, that 60 amp fuse is on location #92
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04-26-2016, 01:51 PM	#6
1mang Private First Class 36 Rep 127 Posts Drives: 135i Join Date: Jun 2014 Location: Bay Area, CA iTrader: (0)	Update: After mulling over this last night, I decided to make a surprise visit to the shop to see what was going on. They were holding to their story that a 60 amp fuse was in a 40 amp slot and that was the cause of my problems. They kept on saying that the 60 amp fuse was in slot #89 which is for "secondary air intake." I do not believe it because I checked location #88 for a 40 amp radiator fan fuse earlier and I am VERY confident that I would not miss seeing another fuse there for #89 or #87. Strike #1. They also said that in location #92 there was NO fuse at all. You cat to be kitten me because I did a quick google search and have a member show me a picture, there is in fact a 60 amp fuse there. Strike #2. I then proceeded to see if they remove the location #89 fuse and put a 50 or 60 amp fuse (the diagram calls both could work) in #92, then use autologic program to activate the fan to see if it work. I wanted to see for myself because right now my trust in them is very low. Low and behold, it works! By now, they are "happy" for me because I fixed an issue they could not replicate (or did not want to in order to get more hours on the car...$150/hr ugh). I did not want them to further work on the car since this was my issue all along and I hoped that the low power would be resolved along with that. Even if the low power still existed, my confidence and trust in the shop is shattered. I rather have another professional opinion. My power was restored and all is well. So there you have it. If you have similar situation as mine, I would recommend checking out fuses first before replacing items or going to the shop. For years I have relied on forums as a resource. After all, we are all enthusiasts and have no monetary gain from the advice. I am grateful for that and this is my way to give back.
	Appreciate 0 Quote