128 hesitating after ~17min

[SkinnyVT]

Took the 128 to Lime Rock yesterday since my e30 doesn't have an engine in it at the moment, in 2 of the sessions after ~17 minutes or so it would hesitate/cut out in Big Bend and wouldn't clear up until half way down "No Name Straight". Neither time were any idiot lights on and the tank always was more than 1/2 full. I was running on all-seasons so I wasn't setting any records in the corners so I highly doubt fuel was the issue. Each time I proceeded to the pits to give the car a rest and the car would be fine the next time I went out. Anybody that is tracking a 128 experience it start to hesitate after 15-20 minutes on the track?

Also noticed a significant delay between the gas pedal and the actual engine throttle when getting back on the gas when tracking out.

[Dackelone]

First thing you should do is check for any fault codes. Or maybe go to the dealer and ask them to scan the DME. I wouldn't tell them about being a race track though. Just tell them you were driving thru some twisty roads.

[Bimmer-Bob]

Are you driving a slushbox?

I haven't noticed any significant throttle lag on my 128i, but I hear the auto trannys are worse about that, which is why I ask. Also, I'm thinking an auto tranny might overheat or something on the track, which could be a source of your issues. I've heard of auto-box 135i's/335i's having a harder time with going into limp mode at the track, so could be a similar issue.

But if you're driving a 6MT, I don't know. My 128i hasn't had that problem. Did four 20-30 minute runs a couple of weeks ago, and am on PSS's, so I was pushing as hard as I dared. Any chance the hesitation was the DTC cutting power due to loss of traction from the all-seasons? Just kind of brainstorming here...

[SkinnyVT]

Originally Posted by Bimmer-Bob

Are you driving a slushbox?

I haven't noticed any significant throttle lag on my 128i, but I hear the auto trannys are worse about that, which is why I ask. Also, I'm thinking an auto tranny might overheat or something on the track, which could be a source of your issues. I've heard of auto-box 135i's/335i's having a harder time with going into limp mode at the track, so could be a similar issue.

But if you're driving a 6MT, I don't know. My 128i hasn't had that problem. Did four 20-30 minute runs a couple of weeks ago, and am on PSS's, so I was pushing as hard as I dared. Any chance the hesitation was the DTC cutting power due to loss of traction from the all-seasons? Just kind of brainstorming here...

nope, manual tranny, traction control BS was off, only thing I can think of is when I put in new brake pads I didn't replace the sensors and I've got a warning light for that but I would figure that would effect the car all the time or at least more consistently.

Hopefully I'll get my ass moving on the e30 and I won't have to deal with all the computer controlled BS of this car.

[DriveHard]

Skinny... I was at limerock last week.. With EMRA next event is 6/17...

On to your issue.. I run a 128 for the last year and a half..Best time at Lime rock was a 1:06.9 and its an auto... but that is not the issue because i have had the same limp modes that you have experienced.. Usually i get it in the 3rd and 4th sessions ( 20 mi / 15 lap sessions ) I experience no throttle response but if i back off it allows me to continue.. i do 2 cool down laps and finish my session...

we have the same issue as 135... OIL TEMP LIMP MODE..

Ive been thinking of how to solve it, and there is a solution i think would work..

You would need to retrofit an oil filter housing from an early 128 / 328 that has the provisions for the small oil cooler that came on the early cars. you would need the filter housion, the cooler and the couple of hoses to route coolant to the cooler.. also as a secondary add on, you could not use the cooler and retrofit the plate from a 135 and install an external air to oil cooler like a 135.

In between session i am in the practice of using a water sprayer to spray the oil filter housing and the tranny cooler for the hell of it.

if you go to real oem and pick an early oil cooler pic you will see what i am talking about.

p.s i have scanned for faults befor and there are none. the car just goes into limp and protect itself.

regards..

[Bimmer-Bob]

RealOEM shows small oil coolers on cars built up until September 2010 - but it looks like they only came fitted to AT-equipped cars. Is that correct?

Interesting, because I never realized that there wear any year-to-year changes to the N52.

[GaryS]

Originally Posted by SkinnyVT

in 2 of the sessions after ~17 minutes or so it would hesitate/cut out in Big Bend and wouldn't clear up until half way down "No Name Straight".

Something like that happened to my 135i in two sessions one track day last year. It was like a 5000 rpm rev limit that happened on two of the four straights. My instructor thought it was fuel starvation. I think it was an ECU safety mode. Anyway, I've done 14 more track days since then, and it hasn't happened again.

The throttle delay tracking out sure sounds like DSC, but if it was turned off, I don't know.

[SkinnyVT]

Originally Posted by DriveHard

we have the same issue as 135... OIL TEMP LIMP MODE..

Ive been thinking of how to solve it, and there is a solution i think would work..

You would need to retrofit an oil filter housing from an early 128 / 328 that has the provisions for the small oil cooler that came on the early cars. you would need the filter housion, the cooler and the couple of hoses to route coolant to the cooler.. also as a secondary add on, you could not use the cooler and retrofit the plate from a 135 and install an external air to oil cooler like a 135.

This is pathetic if the car can't handle 20 minutes of track use in 75 deg weather. There must be more people running into this issue than just us.

The simplest solution may be to simply duct some air to the oil pan, e30 guys have found that is more effective than the stock small oil cooler. All that plastic under the car is good for aero but certainly doesn't help the cooling situation.

[DriveHard]

Originally Posted by SkinnyVT

This is pathetic if the car can't handle 20 minutes of track use in 75 deg weather. There must be more people running into this issue than just us.

The simplest solution may be to simply duct some air to the oil pan, e30 guys have found that is more effective than the stock small oil cooler. All that plastic under the car is good for aero but certainly doesn't help the cooling situation.

I havent done the retrofit myself, as the parts a re a little pricy and taking the housing out is a PITA..

I was thinking of that myself, even just cutting a slit in the plastic panels and screwing on a small scoop or something... who knows... just opening some holes may do it ??

[GaryS]

How do you guys know it's oil temp? I've never had oil or water temps anywhere near the thresholds, but I've had short-term limp modes and the lowered rev limit anyway. There are a lot of other causes besides oil and water temp. The stupid "brakes overheating" limp mode for example is pretty common.

[yandy]

<-- Crosses fingers

I've yet to have any Limp modes on the track, DSC/Brakes, Oil, Water.. well except for that one time my Wastegates stuck open.. but that's not really related.

[SkinnyVT]

Originally Posted by GaryS

How do you guys know it's oil temp? I've never had oil or water temps anywhere near the thresholds, but I've had short-term limp modes and the lowered rev limit anyway. There are a lot of other causes besides oil and water temp. The stupid "brakes overheating" limp mode for example is pretty common.

I don't know it is oil or water temp since BMW was so wise and neglected to put any damn temp gauge in the car.

By brakes overheating limp mode you are just referring to them fading and having to back off, not due to some mystery sensor?

[Focusedintntions]

Skinny there's been debate about if there's a sensor that will put it into limp mode b/c of temp of the brakes. Personally I think it's BS and there's no sensor b/c I've gotten my brakes uber hot on the track and never had a limp mode.

[SkinnyVT]

Originally Posted by Focusedintntions

Skinny there's been debate about if there's a sensor that will put it into limp mode b/c of temp of the brakes. Personally I think it's BS and there's no sensor b/c I've gotten my brakes uber hot on the track and never had a limp mode.

I would agree that it is BS, unless there is a magical wireless sensor built into the caliper.

To me the only things that currently make sense are engine temps (oil or water) or something to do with the traction control/e-diff not shutting off/working as they should.

Until it starts to happen when I am driving to work I'm not going to worry about it too much, just surprised that more people haven't run into an issue if it really was a temp issue, then again not many people are tracking a 1 series let alone a 128.

[DriveHard]

Originally Posted by Focusedintntions

Skinny there's been debate about if there's a sensor that will put it into limp mode b/c of temp of the brakes. Personally I think it's BS and there's no sensor b/c I've gotten my brakes uber hot on the track and never had a limp mode.

I answered this before.. There is no brake fluid/rotor/caliper/pad temp sensor anywhere in our cars..

There are pressure sensors in the dsc control unit, level sensors in master, wear sensors on the pads, rotational rate sensors on the hubs.. But there are no Temp sensors. can it see duty cycle and guess that brakes are warm / hot.. maybe ????

The guys with a 6 speed wont know what im talking about, but us ^AT guys may... on the track car is in DS and i paddle shift.. when this happens, i quickly put the car in D wait a moment and i get the throttle back although its limited... takes half a lap to cool off... but best to go 1 more lap and then your fine till the end.. Ill try to find the stuff on the oil temp..

[GaryS]

Originally Posted by SkinnyVT

I don't know it is oil or water temp since BMW was so wise and neglected to put any damn temp gauge in the car.

By brakes overheating limp mode you are just referring to them fading and having to back off, not due to some mystery sensor?

It's not a mystery sensor. It's something based on the wheel speed sensors and I don't know what else. Several 135i owners from all over have posted that their dealers showed them the codes. Someone posted just a few days ago after DriveHard said he didn't believe it that it's a published feature that was developed first for the X3 I think. That's all I know about it.

[GaryS]

Here, X5, not X3:

Originally Posted by Bmw135er

It's a calculation of brake temps based on a number of different variables. Such a road speed, brake on time, brake pressure etc. It first came out on the E53 X5 as a preventative measure due to brake application due to all wheel drive system intervention. It s feature that has progressed in its function, but at the track it can be a nuisance if you really push hard.

[SkinnyVT]

Originally Posted by GaryS

Here, X5, not X3:

that is ridiculous if it is the case, wonder how the car would like it if I unplugged all the wheel speed sensors

[Bimmer-Bob]

Originally Posted by GaryS

Here, X5, not X3:

Interesting. Actually pretty cool tech, but kind of a bummer on the track. I'm assuming it's non-defeatable?

OP, like I said, when I had my car on the track a few weeks ago I didn't have this problem, but I'm a novice and I wasn't getting into the brakes hard like my instructor was doing (in his car, a 135i, when I did a ridealong). I assumed that since he had a 135i, his brakes just bit better, but I think I also need to learn to brake more aggressively. I'm just thinking if this thing is brake-related, than that might explain why you experienced it and I didn't. I wonder if the system would allow more latitude if brakes were upgraded (I know the car gets recoded when installing the Performance brake kit)?

Anyway, so far I think we have a lot of conjecture more than anything else.

Incidentally, I'm doing a two-day track event this upcoming weekend. I'll let you know if I have any issues.

[SkinnyVT]

also Lime Rock is not a brake heavy track

[GaryS]

Originally Posted by SkinnyVT

that is ridiculous if it is the case, wonder how the car would like it if I unplugged all the wheel speed sensors

Afaik if you unplug just one wheel speed sensor, it disables the entire DCS and ABS. I'd like to know if we can do that for track, or if it would cause anything else to fail.

Here are two posts I found, but I still have no idea whether we can really do it.

http://www.e90post.com/forums/showth...02#post7066002

http://andysapp.com/2009/12/fully-di...dsc-in-an-e46/

[SkinnyVT]

Not sure the X5 statement applies to our car, seems as though it is a part of the Active Cruise Control, http://www.bmw.com.au/com/en/insight...-dynamism.html

In addition, the controlled downhill driving system incorporates a wheel-brake reduction through drive torque shifting and power reduction, which counteracts brake overheating particularly when towing a trailer.

However I did find in mentioned in reference to the 5 series, also states that there should be a log everytime it happens.
http://www.micro-tronik.com/main_functions_332.html

Engine torque reduction in response to overheating brakes
The brake temperature is calculated by the DSC control unit individually for all four discs. The input variables used are the wheel speed, the individual brake pressure for each wheel, time and ambient temperature.
At brake temperatures upwards of about 600 Deg C, the brakes are protected against overheating by
· limiting engine torque
· preventing action of differential locks on individual wheels
· Not allowing symmetrical braking torque on the relevant pair of wheels.
Once the brake temperature drops below approx. 500 Deg C, the engine torque is allowed to gradually increase again over time and intervention by the control systems is allowed again.
If the brake temperature has exceeded 600 Deg C, an entry is made in the fault memory. This is for the information of the service department - not that there has been a fault, but that a safety mechanism has been activated.