Limp Mode
 

Hey guys and gals,

I've got a 2009 535xiT with 53k miles, and if the car is even a little hot (example: hot day), it will go into limp mode if I rev it past 3k, or put a load on it down low in the RPM range. As soon as I shut it off, it goes back to normal.

My question is this: why is this happening? I have had the fuel pump replaced under warranty, and the water pump replaced by me. Can it be the turbos? The waste gates are definitely noisey on decel. I just want to get this figured out before heading to a dealer or indy shop.

Thanks for any possible input!

Dustin

Hard to give much input without any codes, which there must be some, if you're getting a check engine light. Could be a whole bunch of things from fuel injectors, spark plugs, coils, to possibly needing a walnut blast, I'd say, though at 50,000 miles, you're not too bad off (but get it done sometime soon).

For the turbos, look up the extended warranty on them, to see in case they might qualify, so you're educated on that front.

Ya, I already know about all that stuff regarding the turbo warranty etc. It just doesn't seem like that's the issue, I'm thinking the oil is getting too hot. I remember on my companies old 335i race car, it could only do 2 laps before going into limp mode...which is ridiculous. That was with an insane oil cooler the size of a radiator. And there are no codes, no check engine light, just limp mode "reduced power" sign.

I'm pretty frustrated with this car right now.

Really? I'm referring to the comment on the 335 overheating... They were known to do that before they introduced the oil cooler. I have a 335, stage 2+ with the OEM oil cooler, and race it a few times a year. Only once did it overheat on me, and I was running an E30 tune on it that time, And the track it happened on Is a very short track with not a lot of space for the car to cool down. I ran the car in mid July in 90+ degree temperatures all day at a different track and not once did I have a problem.

As far as your wagon, I don't understand how you can have a reduced engine power sign, and no codes in the car when you scan for it. If you do have a handheld scanner, without shutting the car off, I'd recommend you scan it for codes while the check engine light is visible. There are some codes that disappear once you cycle the car.

Good info for sure, thank you. I haven't been reading the codes while the car is still running. I usually do it after it has been turned off, then the code goes away. I'll give that a shot this evening. Thanks!

2008 535xi manual here, ~50,000 miles. FWIW, my limp mode was triggered not by revving above 3,000 RPM if I revved slowly, but similar to you limp mode was triggered by going WOT at a high gear / low load, say 4th gear at 1,800-2,000 RPM. We had already done the HPFP and walnut blast at ~35,000 miles.

Dealer couldn't replicate the issue, but under our extended warranty the dealer replaced the VANOS soldenoid valves (both intake and exhaust) and that eliminated the issue.

Good luck, limp mode is a bummer.

Ahhh, I'll look into the VANOS valves, that makes some sense. Limp mode is a total bummer, and it's so unpredictable.

Thanks for your input!

So did you scan it for codes when the limp mode was showing?

Have not! I've been out traveling for work so I haven't had the chance yet. Thanks!