Cobb AP potential to promote failures in ignition/fuel systems?

[edoug]

Hi folks...

I'm an old guy from the e38 era over ten years ago... I just bought a 2010 335i cab a few months ago. 60k miles, automatic, decent history, great options... Couldn't help but check out the Cobb tune, and pulled the trigger... They warned me I could see issues with coils, plugs and injectors...

Well, installed the sw and filter and man o man is it crazy power... Blew the charge pipe within 20 minutes and replaced it myself with a metal one from Cobb. Drove the hell out of it again... Amazing.

2 days later, on a road trip, misfires code on cylinder 5, terrible time hobbling along mildly to my destination on cruise control, no power... I remove the tune and reset to stock.

I take it to the dealer because I have an aftermarket warranty, pretty comprehensive. Injectors shot, gotta replace all 6 to keep from mismatching newer/older injectors... Thrust arm bushings and also oil filter housing gasket replaced, all under warranty, about $3,600 dealer prices... Covered minus deductible... I feel fortunate.

I am replacing plugs and coils at my expense and walnut blasting intake manifold/valves. Should be good as new, I think, right?

So here's my question: should I NOW be concerned about installing the tune again? Of course it's a higher risk mod, but does anyone want to offer words of comfort or warning that I'm doing the right/wrong thing? I gotta say, that tune is addictive, and I don't mind paying to play. However, if anyone has DIRECT experience you wanna share on pitfalls, or happy stories, please do share with me. Speculators, please refrain, I'm not a complete idiot - looking for real life experiences.

Added edit: is this just "playing with fire?" Or is this just something that requires more frequent ignition and fuel system maintenance?

Thx
Doug

Note signature.... Circa 2005, haha... Cheers, good to be back.

[NFerber]

It is recommended to change plugs whenever you add a tune, and they will need to be changed more regularly due to the added stress of the tune. Walnut blasting is also something that is recommended, but this goes for non-tuned cars as well. As far as coils go, the tune will also misfire if you have weak coils. I would just replace them if they happen to start misfiring. A tune will put more stress on the car then stock, so weaker ignition and fuel parts will fail if they are old and wore out. But you already got new coils, and plugs/coils/walnut blasting is pretty cheap.

I've had my Cobb tune for a little over 3 months now. I did a plug change and walnut blast before I had the tune. I had one issue with a misfire about a month in, found that the cause was a bad coil so just replaced that one and have been good ever since.

I wouldn't be worried about installing the tune again, you ran into a common problem and got it all sorted out. Go have fun and enjoy your car, and enjoy modding.

[edoug]

I've had my Cobb tune for a little over 3 months now. I did a plug change and walnut blast before I had the tune. I had one issue with a misfire about a month in, found that the cause was a bad coil so just replaced that one and have been good ever since.

I wouldn't be worried about installing the tune again, you ran into a common problem and got it all sorted out. Go have fun and enjoy your car, and enjoy modding.

This is precisely what I was seeking. Thanks so much. I just needed a reality check.

As I mentioned, this is a 'pay to play' situation and I understand the tune that produces some crazy power is going to take a proportional heavier toll on the affected components. Since I think it's mainly limited to fuel pumps, injectors, plugs, coils, and intake carbon buildup... I think I can handle that. Also the extended warranty stepped right up for the injectors and labor, so I feel pretty comfortable for the next 5 years / 60k miles by which time I'm pretty sure I will move into something else.

So I should be back in action tomorrow but may wait a few days to drive it untuned to ensure all sorted before I reinstall the Cobb ap

Thanks again!

[NFerber]

No problem. I'm glad you got the ext warranty to cover the injectors, as those tend to get expensive when you are replacing all 6. But plugs and coils are cheap and a very easy DIY. Walnut blasting is also fairly inexpensive (i paid $330 at a BMW dealer) and only needs to be done every 40k miles or so. And HPFP will be covered under the extended warranty as well, so no need to worry about that.

As a side note about the HPFP, if you read codes on the Cobb AP you will sometimes get a code for "HPFP plausibility", this is a normal code that pops up frequently when tuned and does not mean that your HPFP is failing.

Other than that, these motors tend to be fairly bulletproof and have very strong internals. There are people pushing 700+ hp on stock internals and not having any major problems. Now go install the tune back on and have some fun.

I would also recommend upgrading your downpipes in the future, this will allow you to run the stage 2 tune, and provides a very nice exhaust note without having to upgrade your exhaust. Also look into custom tuning (let me know if you need more info on this), as the Off The Shelf Cobb tunes are just generic tunes, and custom tuning will provide a much more comprehensive and safer tune for your individual car.

Feel free to reach out to me with any questions, I have had my 335 for over 3 years and have started modding over the past 3 months (Cobb AP3, DCI, Downpipes, Intercooler, Chargepipe/BOV)

[edoug]

I would also recommend upgrading your downpipes in the future, this will allow you to run the stage 2 tune, and provides a very nice exhaust note without having to upgrade your exhaust. Also look into custom tuning (let me know if you need more info on this), as the Off The Shelf Cobb tunes are just generic tunes, and custom tuning will provide a much more comprehensive and safer tune for your individual car.

Feel free to reach out to me with any questions, I have had my 335 for over 3 years and have started modding over the past 3 months (Cobb AP3, DCI, Downpipes, Intercooler, Chargepipe/BOV)


Again - really helpful feedback - thanks so much. As the warranty covers for another 47k miles and 5 years (I don't drive too much), I plan to keep it simple. I installed the drop in Cobb filter, have the uprated charge pipe, and I plan to keep everything else stock for now. I will run the "Stage 1 Sport" tune because I think it offers about 85% of the bang and a small safety margin to boot. Honestly, with the tune - it's probably overpowered for the suspension, at least in a cab w/19s.

My "other car" is a reasonably tuned and modded 2002 Porsche 996 C2, 3.6L with coilovers, adjustable GT3 sways, track wheels / brakes, and Fabspeed dual cone carbon fiber Y-intake and exhaust... It got a new factory engine in 2008 and has about 30k on the new unit... That's my project car and it's silly fast AND handles like nothing I've ever driven. I love it - feels like wearing a perfect running shoe... so intuitive to drive on track and autocross but not so comfy with passengers...

The 335 seems more of a grand tourer - I'd consider moving down to 18" wheels - but I don't plan to make any additional mods, unless you might recommend a custom tune that's a bit less aggressive but still (almost) as fun.

Great to meet you - and thanks again!
Doug

Here's the current stable:
544969
544970

544971

And past....
544972
544973

[dallasfan824]

I run a Cobb in the twin of your car. No issues

[edoug]

I run a Cobb in the twin of your car. No issues

Thanks! Again, this is really helpful and I'm comfortable after hearing just a few inputs from you guys.

[edoug]

Well -

Picked up the car yesterday... Summary - all new injectors, walnut blast, all new coils, all new plugs. Car felt smoother than before - more stable in the power band. Assume that's just the walnut blast. Drove for 15-20 miles, put the Cobb Stage 0 in - ran fine, no different. Installed the Cobb Stage 1, Sport ST. Not so good - the power was ALL over the place coming on and dropping off in the middle of WOT acceleration. Figured I'd take it easy and then flog it again... same thing. Then I got it to actually reproduce the symptoms I had when the injector failed... Bogged down, noisy, no power - frankly a bit scary. Shut down - had dinner - went back out and it was much better, but still some symptoms when pushing hard. Went to Stage 1 DRIVE map, still happened, then Stage 0 - went away.

Woke up, ran it in Stage 1 Aggressive and took it easy before flogging (awaiting oil temps to get into range). Seemed to run MUCH better. Flogged it some more mid-day, and it threw a Cyl 6 misfire but I never heard or felt it. Reset it, and haven't thrown a code (besides the innocuous fuel pump (P2AAF?)

I have two theories - 1) Maybe they didn't code the new injectors after installing them at the dealer, or 2) The DME, with all those changes simply needed time and miles to readjust / adapt to all those new ignition and fuel components? Again, car has 60k miles, updated HPFP... drop in Cobb filter, rest is stock.

I'm not nearly so worried, but it is rather puzzling, isn't it??? Keep in mind, I'm a track guy usually - I was pushing the car HARD, getting about 8-9mpg - blew through 12 gallons of gas in my testing... Shell 93. Welcome any theories here - again, I think it's running okay now though. If it throws more codes or if power is uneven by next week - the Cobb equipment is going back to Austin - but I'd rather keep it!!!