[nicktyler]

Hi

I got all my coils and sparks changed last week due to a big and sudden misfiring problem which caused limp mode and engine light and all seemed to be good.

I drove for 170 miles some motorway and some back roads with a bit of "spirited driving". Then left the car over night. The next day driving down the motorway and after 180 since the new bits (10 miles that day) a subtle missfire reappeared under slight load then after about 2 miles it just dissapeared and drove for the next 110 miles perfectly fine.

any advice on what to do or what is wrong?

[B005T3D-G]

Have you had the HPFP checked? Depending on the condition of the plugs that came out the technician (if paying attention) should have been able to determine whether the car was running lean or not. What's your oil temp at motorway speeds? Higher temps can indicate lean fueling in my experience running older cars. You may also want the injectors looked at too.

[nicktyler]

The temps seem pretty normal. It never gets to 120 and cruising on the motorway sits between 100 and 110.

The weird thing is that it went suddenly and restarting made no difference as soon as I pulled away the engine light and limp mode came on. Having the coils and plugs changed made it run perfect for 180 miles and seems to be running perfect now. If the problem was one of the other components changing the coils and plugs would not have "fixed it" instantly and for so long would it? Considering how badly and quickly the problem started. Also the code was for coils and nothing else.

Hopefully that makes sense

[B005T3D-G]

Makes sense mate, just thinking about the other components in the system that may induce the fault.

I would recommend taking it back and getting it checked over again if it's not 100%

[nicktyler]

Just one other thing is I have noticed that when the fault was very prominent the idle revs were at 700 and I'm pretty sure they are normally at just over 500. When I start the car from warm the revs seem to be just over 500 but then after a short while they are at 700.

Is this a symptom of the fault or is it a normal idle? Maybe the fan is coming on and raising the revs or something?

[B005T3D-G]

Sounds just like mine to be fair. When sitting at lights the RPM will sometimes drop and get a slightly lumpy idle, from what I've read on here it's just part of the engines character and nothing to worry about.

[nicktyler]

I suppose it is possible that one of the new coil packs or spark plugs is just dogey. It does have a warranty from the independant dealer that I bought it from but I have no idea how to claim. The dealer tells me to speak to the warranty company and they tell me to speak to the dealer.

[pjs]

Have you put decent fuel in it? the 335i engine is very sensitive to it. V power the way to go

[nicktyler]

I have only used V-power and more recently Tesco Momentum. Do you think it culd be the Momentum doing it? I thought that was regarded as being good?

[pjs]

Originally Posted by nicktyler

I have only used V-power and more recently Tesco Momentum. Do you think it culd be the Momentum doing it? I thought that was regarded as being good?

I've used Momentum occasionally, never had an issue with it.

[nicktyler]

It is also on an Evolve stage 1. I don't think it would be anything to do with that though as so many people have them.

[doughboy]

I've had time when the idle pops up to 700, then drops back by the next time you stop.

I'm not too fussed about it, its just the ECU doing something its programmed to do.

Also sometime you get the gentle shudders at idle, again, i'm not to fussed. Nice to feel the engine TBH.

[nicktyler]

With the idle on mine though it goes to 700 and it will stay there untill the car is restarted.

[nicktyler]

I have just spoken to the Garage about this and the bottom line is I should drive it untill the problem gets worse or logs a code so they can fault it. When it went in you couldn't pull away from start with out limp mode and engine light. I suppose 2 mins of slight misfiring in otherwise perfect 300 miles is quite intermittant but it is just very confusing as to what the problem is as all the plugs and coils were changed.

I can't see how something else could be at fault when changing the plugs and coils seemed to fix it instantly (apart from the 2 mins) from what was basically undrivable.

[335i E92]

I've had the same issue for early 2 years. Had all plugs, coils & injectors replaced & a de-carb. None of which have fixed!!

Same shakes on idle then the needle rises to 700 and sits thier until u restart the car. Have a look at the below thread, also do a quick search for 335i rough idle n you'll see your not alone. I've just learned to live with it as it only at idle.

http://www.e90post.com/forums/showthread.php?t=509274

H

[nicktyler]

Thanks for the link. I have seen that thread last week but it seems slightly different. I get no shakes or stumbles at idle, just when warm and after ca few mind running it will reach 700 and stay there but be very smooth and solid the whole time apart from the cruising missfire. I think the high idle is related to the miss fire, like the engine trying to make sure it doesnt stall or something.

[nicktyler]

So I'm back at the garage now waiting to see what codes the car has thrown from limp mode this time. Last time it was a miss fire in cylinder 2 and apparently all the plugs were warn out so makes sense. But I still don't understand how it can seem fixed and then go in exactly the same way with all new coils and plugs.

Basically it went into limp mode on start up and is doing the same now. If it is not the coils and plugs like the code and visual inspection suggested how did changing them fix it for a short while?

Sorry if I sound pissed off but I have only had the car 4 weeks, 1 of those in the garage and had to pay £500 for work that hasn't really helped. If it is going to cost me any more ill have to try and reject it but not sure how to do that.

[makkan00]

Nick Get the code from them.
If it was Cylinder 2, I would have change the plug and coil with a different cylinder to see, if the car gives new error for that cylinder (to reconfirm).

You have already spent the money and problem is still there.
Get the fault code from them, search thoroughly on internet and start from cheapeast to expensive solutions one by one.

If it was my car, I would start with
1- BG44K
2- Swapping the plug and coil to another cylinder and wait for the limp mode.
3- Act accordingly.

From where you bought this car, as previous owner may have sold it due to this problem.
Also where in Essex do you live, just wondering if I can help you with code reading.

[nicktyler]

Hi makkan

I live next to lakeside where the A13 meets the M25. If it is the same code then it must be something else. I will get down to kwick fit and see if I can get a pot of BG44K.

It could be that the last owner sold because of this problem but it ran fine for nearly 1500 miles and then came on very suddenly and dramatically.

[nicktyler]

Also the 700 idle is defiantly related to the misfire problem. Happens every time just before the misfire becomes noticeable.

Got the car back and apparently there were no fault codes. I diddn't think the engine light could come on without storing a code. I have driven it about for another 30-40 miles and it is absolutley fine. Apart from after about 10 mins from start if you let it idle for a while like at the lights the revs raise to 700 and idle stays there untill restart.

Pretty annoying as I can't really trust the car to work for journeys longer than a few miles which is pretty useless and I have no come back while they say there is nothing wrong with it.

I have put some BG44K in and hopefully that will help.

[makkan00]

Originally Posted by nicktyler

Also the 700 idle is defiantly related to the misfire problem. Happens every time just before the misfire becomes noticeable.

Got the car back and apparently there were no fault codes. I diddn't think the engine light could come on without storing a code. I have driven it about for another 30-40 miles and it is absolutley fine. Apart from after about 10 mins from start if you let it idle for a while like at the lights the revs raise to 700 and idle stays there untill restart.

Pretty annoying as I can't really trust the car to work for journeys longer than a few miles which is pretty useless and I have no come back while they say there is nothing wrong with it.

I have put some BG44K in and hopefully that will help.

That is bit strange, no code. Or did they reset it?
Where did you buy BG44K from then?
I hope it is already sorted.
See how it goes, and if it goes to limp mode again, send me pm, and I will read the code for you.
All the best.

[nicktyler]

It is a bit strange. I thought it would always store the code till it is cleared manually? They also had it far longer than it takes to read the codes.

I got the BG44K from kwick fit for £20. Done 70 miles driving around quite hard to see if the problem came back and nothing

Thanks for the code reading offer, I might have to take you up on it.