[br0wny]

Guys,

Particularly noticeable in higher gears, my car has developed a shudder/vibration/audible thing under WOT when going to overtake/WOT at motorway speeds...

First happened over xmas when in map5 on jb4 to which the car threw a drivetrain error on the idrive when i went to overtake in 4th gear, cutting engine power completely for a few seconds and then it cleared - quite scary when alongside someone

Switched back to my less potent map6 and all was fine and has been since

Up until last week when i thought id try map5 again... first few days were ok then slowly the vibration so i switched back to map6 before i got the drivetrain error but the shuddering then continued in map6 just not as bad and has done ever since

I switched to map 4 which is oem map with jb4 logging and all seemed ok just the car felt a tad rough in general (no noticeable shudder/vibration)

I have done a log on the jb4 today in map6 and nothing seems to be noticeably out of the ordinary

I have just spent the past hour reading MANY forum threads on this issue and havent really gotten anywhere... - some people cured by changing spark plugs, some people cured by clearing carbon build up, some people cured by changing coils/injectors, some people think its the dmfw and have changed to smfw, some have just put up with it, the list goes on...

Anybody have any thoughts on this? I know some of you are very knowledgeable and techy minded

 

[roshambo]

Car's knacked

Matt

 

[Octavius]

Take the JB4 off and see what happens ?

 

[sunshinewelly]

I did see a video review on YouTube of a guy with a 335 who had an identical issue which he curred with new spark plugs. It actually put me off getting a jb4

 

[marco_polo]

Put PS4's on, and are now getting lots of wheelspin / juddering traction control during peak boost / torque?

I'd pop a Drexler on, see if that fixes it.

 

[br0wny]

Put PS4's on, and are now getting lots of wheelspin / juddering traction control during peak boost / torque?

I'd pop a Drexler on, see if that fixes it.

PS4's so far are actually really impressive mate! hardly any slip even in wet

 

[br0wny]

I did see a video review on YouTube of a guy with a 335 who had an identical issue which he curred with new spark plugs. It actually put me off getting a jb4

could be a cheap fix if it works though eh?

 

[DaleB90]

I forgot to mention earlier Dan but your spark plug life span will be reduced because you are tuned. Our American friends have found an average life span of around 10/15k miles at similar or slightly higher levels of tune.

 

[br0wny]

I forgot to mention earlier Dan but your spark plug life span will be reduced because you are tuned. Our American friends have found an average life span of around 10/15k miles at similar or slightly higher levels of tune.

interesting, mines heading towards 13500 but has only been tuned since 11000ish

 

[marco_polo]

Definitely an engine issue?

If so, I guess starting with the plugs and coils is as good as anywhere. You'll probably need a special thin walled socket to get the plugs out.

 

[Shins]

So when tuned is there a better spark plug to use? Or just change them more often?

On my last tuned car we used Denso ITV24 on mildly tuned cars but around JB4 lvl we went to Denso ITV27's.

 

[br0wny]

Definitely an engine issue?

If so, I guess starting with the plugs and coils is as good as anywhere. You'll probably need a special thin walled socket to get them out.

it may not be and i hope it isnt just going on what ive read online

my bro inlaw is an ex bmw tech so hopefully will have the right tools and if not will just borrow from ferrari as im sure they will have specialist tools haha

its doing my nut in cos obv my warranty is as useful as a chocolate fire guard which i knew was the case but never really hear of many issues :?

 

[br0wny]

So when tuned is there a better spark plug to use? Or just change them more often?

On my last tuned car we used Denso ITV24 on mildly tuned cars but around JB4 lvl we went to Denso ITV27's.

i read that there is a lower temp :? one that can be used which i think dale said is from the m4 but summet needs doing which i didnt know what it meant (sorry dale)

 

[DaleB90]

I'm not sure at what mileage BMW change the oem plugs. I've been tuned for the majority of my miles and I'm still ok on the oem plugs. I'll most likely have to/will change them this year.

Ngk 5992 is tried and tested, 1 step colder than oem. I believe some are now using m3/4 plugs but I haven't read to much about them yet. Both need gapped to 0.56cm or 0.22"

 

[br0wny]

I'm not sure at what mileage BMW change the oem plugs. I've been tuned for the majority of my miles and I'm still ok on the oem plugs. I'll most likely have to/will change them this year.

Ngk 5992 is tried and tested, 1 step colder than oem. I believe some are now using m3/4 plugs but I haven't read to much about them yet. Both need gapped to 0.56cm or 0.22"

just looking at my log and the ign drops massively from 2500-3500rpm then levels out after

this is the same time as i get my vibration at its worse :? like we said i need to get some logs in map 2 and 4 to compare

 

[DaleB90]

Your ignition is just settling as you are transitioning from part throttle to WOT at 2.5k so that's ok.

It's around 5.4k to red line where you start to see ignition retarding. My ignition curve for example builds all the way to redline and normally peaks around 14 degrees.

 

[Penetrator]

Browny..........Kaput mate

Get back in a 125d lol

 

[mctga]

This is probably unrelated but I fixed a vibration in mine after reading the following thread. An air con hose was vibrating through the bulk head at about 2500rpm. An £8 dampening weight is the fix, so worth a try but your car may already have it fitted. And you would have prob already noticed it before now, so it's a long shot!

http://f30.bimmerpost.com/forums/showthread.php?t=949816

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[Blind Pugh]

Browny,

Any smell of fuel when the car is misfiring ? - if so hints at fuel pump problem.

Have you checked your JB4 connections and do a visual on wiring to check for damage ?

Coilpacks would usually throw a code.

Some of the Yanks, running tunes on 235i and 335i, are using OE M4 spark plugs with tweaked gaps. 6 off N55 or S55 plugs wont be cheap so perhaps check if there is a forum member near to you with an F series N55 that you could borrow plugs from to test your car with a different set.

EDIT - a bit of back ground on my last paragraph

OE fit N55 Plug: ZR5TPP33S. Single tip platinum electrode, mono binary nickle-yttrium with laser-alloyed platinum inlay ground electrode(referred to as double laser platinum). Comes with a gap of .8mm(.0314"). Heat rating of 5.

OE fit N54 Plug: ZGR6STE2. Multiple nickle-yttrium ground electrodes, single silver tip electrode. Comes with a gap of .7mm(.0275"). On Bosch's temperature scale, it is rated a 6.

OE fit S55 Plug: RB ZMR5TPP330. It's a double laser platinum variant. The M in the part number designates as a motor sports(racing) plug, .8mm(.0314") gap, and it has a heat rating of 5. Also spec'd for V8 TT m-cars.

Makes sense that N54 guys are using S55 plugs as they are colder rating and the coilpacks are the same across N54, N55 and S55. S55 plugs may well be priciest so not sure why they don't use N55 plugs TBH - same rating.....

BP

 

[marco_polo]

What fuel are you running? Has SWMBO put a tank of Asda 95 in it by mistake perhaps?