[HighMile335i]

Hi all,

Loving my 200k-mile, $2300 335i6 more every day. New to F/I and I'm addicted! However, lately I'm having an issue under hard acceleration (with a Cobb AP stg1) where it feels like the car is going in and out of power--typically it pulls hard, then feels a bit rough and slower, then pulls hard again. I've replaced all coils/plugs. Is this the start of a failing HPFP? I put the AP on map 0 and didn't notice the problem. Car also feels more sluggish than before, and I've noticed a drastic increase in waste gate rattle on cold start (not present at all a month ago--a very recent change). Has two new boost control solenoids.

Side note: we've been having really hot weather recently (85°F +)--could this contribute to the car feeling noticeably more sluggish? I got 4.7 seconds 0-60 on my AP in June, but now can't beat 5.7s. Could this be due to temps alone? Obviously hot weather isn't the cause of the power inconsistency throughout each pull, though.

If there is a thread with this info already, please point me to it! Thanks!

Edit: Forgot to mention I'm still hitting 14.5-15psi

[Saif2018]

Originally Posted by HighMile335i

Hi all,

Loving my 200k-mile, $2300 335i6 more every day. New to F/I and I'm addicted! However, lately I'm having an issue under hard acceleration (with a Cobb AP stg1) where it feels like the car is going in and out of power--typically it pulls hard, then feels a bit rough and slower, then pulls hard again. I've replaced all coils/plugs. Is this the start of a failing HPFP? I put the AP on map 0 and didn't notice the problem. Car also feels more sluggish than before, and I've noticed a drastic increase in waste gate rattle on cold start (not present at all a month ago--a very recent change). Has two new boost control solenoids.

Side note: we've been having really hot weather recently (85°F +)--could this contribute to the car feeling noticeably more sluggish? I got 4.7 seconds 0-60 on my AP in June, but now can't beat 5.7s. Could this be due to temps alone? Obviously hot weather isn't the cause of the power inconsistency throughout each pull, though.

If there is a thread with this info already, please point me to it! Thanks!

Edit: Forgot to mention I'm still hitting 14.5-15psi

Can you post a log stock vs Cob AP Stage 1?

[HighMile335i]

Originally Posted by Saif2018

Can you post a log stock vs Cob AP Stage 1?

Will do. I've never logged before, though, so it might take me a few days to find the time to figure it out.

[Schmidty335i]

Originally Posted by HighMile335i

Will do. I've never logged before, though, so it might take me a few days to find the time to figure it out.

Since this is your first F/I car, put a ton of time into learning at least the basics of tuning and what the parameters mean. it seems almost impossible at first but spend enough time on it and you will laugh at the fact that non of it made any sense at one point to you.

Until you get it down just get a log and put it on here for us to check out. make sure to have your traction control completely disabled and do a 3rd gear pull from 2500 to 7000.

Good luck

[HighMile335i]

Originally Posted by Schmidty335i

Since this is your first F/I car, put a ton of time into learning at least the basics of tuning and what the parameters mean. it seems almost impossible at first but spend enough time on it and you will laugh at the fact that non of it made any sense at one point to you.

Until you get it down just get a log and put it on here for us to check out. make sure to have your traction control completely disabled and do a 3rd gear pull from 2500 to 7000.

Good luck

Thanks--definitely looking forward to learning this stuff.

I did end up doing two data logs yesterday evening (3rd gear, 69° outside), but forgot to turn off traction control. I'll attach them here anyway, but can do more if they're not useful because of it (I attached them as PDFs, but there's probably a better way to do it).

Looks like its pulling timing... I'm running 93 currently, and its the Stg1 Sport tune, which only requires 91. I had it on the 93 tune before, and the problems were slightly more noticeable.

Edit: data zap links posted further down

[stewbets]

You're going to want to create a free account at datazap.me and upload your logs there. It makes analyzing them so much easier.

[HighMile335i]

Originally Posted by stewbets

You're going to want to create a free account at datazap.me and upload your logs there. It makes analyzing them so much easier.

Done, thanks for the suggestion!

Links:

Stage 0: https://datazap.me/u/highmile335/200...og=0&data=1-20

Stage 1 Sport: https://datazap.me/u/highmile335/200...og=0&data=1-20

[stewbets]

That's a lot of timing corrections on not a lot of timing. What fuel are you running? Are you able to log IAT? Your intercooler could very well be getting heat-soaked and cause this inconsistency.

[HighMile335i]

Originally Posted by stewbets

That's a lot of timing corrections on not a lot of timing. What fuel are you running? Are you able to log IAT? Your intercooler could very well be getting heat-soaked and cause this inconsistency.

I'm running 93. From the logs it looks like, on stage 0, the charge air temp reaches 115°, but on Stg1 it reaches 145°, which sounds quite high to me. With the hot weather we've had recently (85-90°) the car feels noticeable worse, and considering it was only 69° ambient, am I right thinking that 145 could be the issue?

If so is there anything I can do to solve this, aside from getting a larger intercooler?

Never realized how much ambient temperature affects FI cars, but it does make sense.

[stewbets]

Ah, I see it now: charge air temp. Yeah, that could certainly be part of it. If you have access to e85, I'd try adding a couple gallons to your tank to see if that helps clean up the timing.

[HighMile335i]

Originally Posted by stewbets

Ah, I see it now: charge air temp. Yeah, that could certainly be part of it. If you have access to e85, I'd try adding a couple gallons to your tank to see if that helps clean up the timing.

Unfortunately no E85 stations in Maine to my knowledge/internet searches... I guess I'll try adding some octane booster and do another log.

[Bimmer_Bro]

Originally Posted by HighMile335i

Unfortunately no E85 stations in Maine to my knowledge/internet searches... I guess I'll try adding some octane booster and do another log.

Being such high miles, have you physically checked the condition of the stock intercooler? If the fins are all bent to sh*t, it may be getting heat soaked instantly and unable to cool the charged air. Shine a light in the lowest grill and take a look. There are some cheaper options like ARM that are reasonable and will still out perform the OEM core.

[HighMile335i]

Originally Posted by Bimmer_Bro

Being such high miles, have you physically checked the condition of the stock intercooler? If the fins are all bent to sh*t, it may be getting heat soaked instantly and unable to cool the charged air. Shine a light in the lowest grill and take a look. There are some cheaper options like ARM that are reasonable and will still out perform the OEM core.

Thanks for the suggestion. I'll take a look. May be full of bugs as well.

While I've read negative things about eBay ICs, I found one that seems to get good reviews, and I'm not looking for the best option out there--just something that will perform better than stock and will fit. Hot ambient temps are typically only a problem for a month or so around here! I also highly doubt I'll be pushing more boost anytime soon.

The ARM IC looks like a good option... with likely more backing than a random eBay IC.

[Bimmer_Bro]

Originally Posted by HighMile335i

Thanks for the suggestion. I'll take a look. May be full of bugs as well.

While I've read negative things about eBay ICs, I found one that seems to get good reviews, and I'm not looking for the best option out there--just something that will perform better than stock and will fit. Hot ambient temps are typically only a problem for a month or so around here! I also highly doubt I'll be pushing more boost anytime soon.

The ARM IC looks like a good option... with likely more backing than a random eBay IC.

Yes I would go with ARM if you're looking for a cheaper route. They are more proven and easy to get ahold of if any issues. Fitment is just as important as performance. You don't want to fit a intercooler that leaks at the connections... you will then be chasing a boost issue. ARM also uses the stock connections (depend on which size you choose).

[Bimmer_Engineer]

Originally Posted by HighMile335i

Thanks for the suggestion. I'll take a look. May be full of bugs as well.

While I've read negative things about eBay ICs, I found one that seems to get good reviews, and I'm not looking for the best option out there--just something that will perform better than stock and will fit. Hot ambient temps are typically only a problem for a month or so around here! I also highly doubt I'll be pushing more boost anytime soon.

The ARM IC looks like a good option... with likely more backing than a random eBay IC.

I have a stepped 5” eBay intercooler that I’m pretty pleased with. Was $200 shipped and uses stock connections. I’m running mhd stage 1+ in south Louisiana and it keeps up just fine...

[Saif2018]

Originally Posted by HighMile335i

Done, thanks for the suggestion!

Links:

Stage 0: https://datazap.me/u/highmile335/200...og=0&data=1-20

Stage 1 Sport: https://datazap.me/u/highmile335/200...og=0&data=1-20

Power loss issue is most likely due to your Intercooler heatsoaking, high IAT's

You have multiple timing corrections over several cylinders.

Need an Intercooler upgrade, but...

Even on stock tune posted above, you have multiple timing corrections accross cylinders.

When did you last change your Plugs and Coils ?

If you haven't done so recently, would highly suggest you get a set of stock oem Bosch plugs and Eldor or Delphi coils.

[HighMile335i]

Originally Posted by Bimmer_Engineer

I have a stepped 5” eBay intercooler that I’m pretty pleased with. Was $200 shipped and uses stock connections. I’m running mhd stage 1+ in south Louisiana and it keeps up just fine...

Good to hear there are budget options that at least are an improvement over the stock IC.

[HighMile335i]

Originally Posted by Saif2018

Power loss issue is most likely due to your Intercooler heatsoaking, high IAT's

You have multiple timing corrections over several cylinders.

Need an Intercooler upgrade, but...

Even on stock tune posted above, you have multiple timing corrections accross cylinders.

When did you last change your Plugs and Coils ?

If you haven't done so recently, would highly suggest you get a set of stock oem Bosch plugs and Eldor or Delphi coils.

Plugs were done ~9k miles ago, coils (Bosch) done ~1k miles ago. I got the car so cheaply because it was misfiring badly and cutting cylinders under boost, which turned out to be old plugs--lucky with that gamble. I plan to do plugs again in 5k miles.

Other than IATs, is fuel quality the last variable here? I also thought it strange to have timing corrections on the stock tune, so I'll try a different brand fuel next to see if it makes a difference.

Oh, and of course I'll be picking up an IC soon.

[Bimmer_Bro]

Originally Posted by HighMile335i

Plugs were done ~9k miles ago, coils (Bosch) done ~1k miles ago. I got the car so cheaply because it was misfiring badly and cutting cylinders under boost, which turned out to be old plugs--lucky with that gamble. I plan to do plugs again in 5k miles.

Other than IATs, is fuel quality the last variable here? I also thought it strange to have timing corrections on the stock tune, so I'll try a different brand fuel next to see if it makes a difference.

Oh, and of course I'll be picking up an IC soon.

As long as you are using common brands of fuel you are fine. Your timing is honestly most likely from your intake temps. Even new, the n54 oem intercooler is not very good... so one with 200 miles on it is going to be even worse (Bent fins, filled with rocks/bugs, oil build up inside). I would replace that first and then do some logs.

[HighMile335i]

Originally Posted by Bimmer_Bro

As long as you are using common brands of fuel you are fine. Your timing is honestly most likely from your intake temps. Even new, the n54 oem intercooler is not very good... so one with 200 miles on it is going to be even worse (Bent fins, filled with rocks/bugs, oil build up inside). I would replace that first and then do some logs.

Yes--just looked at mine and it's terrible--lots of bent fins. Going to try to straighten the fins/blast out debris with a hose for today, and will order a better one to install soon! Thanks for the help everyone!

I'll do another log once I've got the new intercooler.

[Saif2018]

Originally Posted by HighMile335i

Plugs were done ~9k miles ago, coils (Bosch) done ~1k miles ago. I got the car so cheaply because it was misfiring badly and cutting cylinders under boost, which turned out to be old plugs--lucky with that gamble. I plan to do plugs again in 5k miles.

Other than IATs, is fuel quality the last variable here? I also thought it strange to have timing corrections on the stock tune, so I'll try a different brand fuel next to see if it makes a difference.

Oh, and of course I'll be picking up an IC soon.

Id check the plugs, your due new Bosch plugs, wouldn't run tuned 9k miles to be honest.

I have Eldor Coils, would recommend Delphi or Eldor ones.

Bosch coils don't last very long tuned from what I heard.

Yes fuel has a big effect on timing corrections.

It's usually worn plugs/coils, low octane and/or Intercooler heatsoaking High IAT's that cause timing corrections.

[Schmidty335i]

Have you ever thought of doing methanol injection since your not near E85? it would help with your IAT's and your octane limits.