Sudden loss of power

Knoxes · 02-10-2015, 02:39 PM

I've had this car since October and I'm generally pretty happy with it. 2007 E86 with ~56K. But I've had it lose power twice now and I'm looking for answers.

Both times, it happened around 40mph, in 4th gear with steady throttle. The loss was very quick - less than a second - but noticeable, like someone pulled the power plug. Interestingly, I didn't notice any loss in the electrical system - just in the engine.

Also, I've noticed it surging very lightly on the freeway - like a fuel flow or timing issue.

In any gear, it revs to ~3K well enough, but absolutely explodes after 3K. Is that normal?

RADRACR · 02-10-2015, 03:25 PM

Quote:

Originally Posted by Knoxes

Interestingly, I didn't notice any loss in the electrical system - just in the engine.

What do you mean and how do you know?

Sounds electrical (spark plugs, distributor) or fuel pump or filter.

Similar Story: Last year my engine went limp on the freeway. Felt like a few cylinders were dead. I pulled off, started the car again, and set off. Happened again 30 seconds later, so I drove cautiously the extra few miles to my house. Had it towed to the shop. They checked to make sure all electrical connections to the cylinders and distributor were tight. Never happened again.

Knoxes · 02-10-2015, 04:34 PM

I didn't notice anything with the dash or headlights when it happened.

So, you are right, it very well could have been an electrical issue in the engine.

gas-can · 02-10-2015, 04:43 PM

Another possible culprit for the n52 si could be the disa valves. These guys open and close at specific rpm ranges to control air flow. If one didn't open/close at the right time, you may feel some weird power fluctuations, since the air/fuel mix will be off from the expected.

That said, try to pull the codes if you can- there might be a misfire/cylinder code stuck in the brain that might indicate a problem.

Also fuel- fresh fuel, right? If the car was sitting for a while, you may have stale fuel which can also cause weird issues.

-gc

Knoxes · 02-11-2015, 09:40 AM

Can you pull the codes with a standard OBD2 reader?

Fuel should be fine - it sits for a week sometimes, but never more than that.

Steeler · 02-11-2015, 11:27 AM

Was it a stumble you felt or a complete cut of power?

Possibly MAF if it was a stumble

RADRACR · 02-11-2015, 11:30 AM

Quote:

Originally Posted by dbarton62

Possibly MAF if it was a stumble

+1 My VW GTI had this issue.

Knoxes · 02-11-2015, 11:57 AM

It was a complete loss, not a stumble. Like no electrical at all. I guess it could have been a misfire, but it felt like 2-3 cylinders in a row with one misfire each. Not like a steady misfire in one cylinder.

I think the surging could be a MAF issue. That makes sense. It only happens under steady throttle.

Since I'm new to this car I'm trying to get up to speed on the typical issues. Is the MAF a regular offender?

Steeler · 02-11-2015, 01:18 PM

Yes and it when it suddenly sorts itself out you really get a push in the backside.
Ask me how it feels on a supercharged car with a MAF going bad

Knoxes · 05-13-2015, 01:33 PM

Just bumping this to report that I finally cleaned out the VANOS solenoids and it seems to have cleared everything up. Installed new seals when I did it.

an3ony · 05-13-2015, 08:18 PM

Quote:

Originally Posted by Knoxes

Just bumping this to report that I finally cleaned out the VANOS solenoids and it seems to have cleared everything up. Installed new seals when I did it.

THANKS for the follow up. I've noticed something somewhat similar on my M, it feels like a power flutter, only for a split second and no predictable circumstances. I'm going to take it to my normal repair place and have the codes pulled.

Knoxes · 05-14-2015, 01:04 PM

Quote:

Originally Posted by an3ony

THANKS for the follow up. I've noticed something somewhat similar on my M, it feels like a power flutter, only for a split second and no predictable circumstances. I'm going to take it to my normal repair place and have the codes pulled.

I posted about what I think are two different issues above. The second one sounds like what you're experiencing. To be more explicit, it feels like a slight surging - or more accurately, that it's not quite able to accelerate. It only happened with light or no throttle pressure (cruising on the freeway, for example). If you really put your foot down, it took off just fine. And it idled fine, too. But under that neutral throttle - it just felt like it was being starved of something...

That's what the clean solenoids fixed.

The complete loss of power may have been related, but I'm not sure.

trevor · 05-19-2015, 04:30 PM

You will actually find your car has multiple issues, I would start with a standard oil change as bad oil is a rare contributor and it could be too thick for higher speeds, use 0W-XX and ask them to look out for the issue as part of the 27 point inspections (shouldn't cost extra since it is included as part of oil change).

I doubt it is the battery as the car uses the battery to start, not continue running.

02-10-2015, 02:39 PM	#1
Knoxes Private 5 Rep 54 Posts Drives: E86 Join Date: Oct 2014 Location: NC iTrader: (0)	Sudden loss of power I've had this car since October and I'm generally pretty happy with it. 2007 E86 with ~56K. But I've had it lose power twice now and I'm looking for answers. Both times, it happened around 40mph, in 4th gear with steady throttle. The loss was very quick - less than a second - but noticeable, like someone pulled the power plug. Interestingly, I didn't notice any loss in the electrical system - just in the engine. Also, I've noticed it surging very lightly on the freeway - like a fuel flow or timing issue. In any gear, it revs to ~3K well enough, but absolutely explodes after 3K. Is that normal?
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02-10-2015, 04:34 PM	#3
Knoxes Private 5 Rep 54 Posts Drives: E86 Join Date: Oct 2014 Location: NC iTrader: (0)	I didn't notice anything with the dash or headlights when it happened. So, you are right, it very well could have been an electrical issue in the engine.
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02-10-2015, 04:43 PM	#4
gas-can Second Lieutenant 25 Rep 204 Posts Drives: 2006 3.0i Roadster Join Date: Oct 2012 Location: USA iTrader: (0)	Another possible culprit for the n52 si could be the disa valves. These guys open and close at specific rpm ranges to control air flow. If one didn't open/close at the right time, you may feel some weird power fluctuations, since the air/fuel mix will be off from the expected. That said, try to pull the codes if you can- there might be a misfire/cylinder code stuck in the brain that might indicate a problem. Also fuel- fresh fuel, right? If the car was sitting for a while, you may have stale fuel which can also cause weird issues. -gc
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02-11-2015, 09:40 AM	#5
Knoxes Private 5 Rep 54 Posts Drives: E86 Join Date: Oct 2014 Location: NC iTrader: (0)	Can you pull the codes with a standard OBD2 reader? Fuel should be fine - it sits for a week sometimes, but never more than that.
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02-11-2015, 11:27 AM	#6
Steeler Colonel 2428 Rep 2,703 Posts Drives: Built not Bought 04 Z4 VF Join Date: Feb 2013 Location: Kitchener Ontario Canada iTrader: (2)	Was it a stumble you felt or a complete cut of power? Possibly MAF if it was a stumble __________________ W2A Intercooled Vortech V3Si, custom ducting, Alpha N, 60# Bosch,2.62 pulley, multi port WMI, Severn Tuning(pokeybritches), Tial, magnaflow,SS race muffler, 42 design,3.91LSD, H&R, Hotchkis,ST coils,Konis, Megan camber arms, AKG SS, Nylon mounts, Poly bushings, Carbon interior, CF Aero.APEX
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02-11-2015, 11:57 AM	#8
Knoxes Private 5 Rep 54 Posts Drives: E86 Join Date: Oct 2014 Location: NC iTrader: (0)	It was a complete loss, not a stumble. Like no electrical at all. I guess it could have been a misfire, but it felt like 2-3 cylinders in a row with one misfire each. Not like a steady misfire in one cylinder. I think the surging could be a MAF issue. That makes sense. It only happens under steady throttle. Since I'm new to this car I'm trying to get up to speed on the typical issues. Is the MAF a regular offender?
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02-11-2015, 01:18 PM	#9
Steeler Colonel 2428 Rep 2,703 Posts Drives: Built not Bought 04 Z4 VF Join Date: Feb 2013 Location: Kitchener Ontario Canada iTrader: (2)	Yes and it when it suddenly sorts itself out you really get a push in the backside. Ask me how it feels on a supercharged car with a MAF going bad __________________ W2A Intercooled Vortech V3Si, custom ducting, Alpha N, 60# Bosch,2.62 pulley, multi port WMI, Severn Tuning(pokeybritches), Tial, magnaflow,SS race muffler, 42 design,3.91LSD, H&R, Hotchkis,ST coils,Konis, Megan camber arms, AKG SS, Nylon mounts, Poly bushings, Carbon interior, CF Aero.APEX
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05-13-2015, 01:33 PM	#10
Knoxes Private 5 Rep 54 Posts Drives: E86 Join Date: Oct 2014 Location: NC iTrader: (0)	Just bumping this to report that I finally cleaned out the VANOS solenoids and it seems to have cleared everything up. Installed new seals when I did it.
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05-19-2015, 04:30 PM	#13
trevor New Member 2 Rep 28 Posts Drives: 2005 BMW Z4 and 2001 BMW 515i Join Date: May 2015 Location: Washington, D.C. iTrader: (0)	You will actually find your car has multiple issues, I would start with a standard oil change as bad oil is a rare contributor and it could be too thick for higher speeds, use 0W-XX and ask them to look out for the issue as part of the 27 point inspections (shouldn't cost extra since it is included as part of oil change). I doubt it is the battery as the car uses the battery to start, not continue running.
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