[Mboon]

Hi all,

I have a 2010 325d Auto N57 and when I start from cold I get a few minutes of rough running.

The car will splutter a little a few seconds after start and will idle a little rough, not too bad but certainly not as smooth as when warm.

When pulling away it will also hold back and stutter and then with enough throttle will pull away. This only happens on pulling away. Once driving the car is faultless and pulls as it should in all gears.

This goes once the car has been driven for 5 minutes or so.

I have read the codes and the air intake sensor is showing a fault.

Would this cause the rough running on cold start?

To me it seems to clear once it has some heat into her.

The car will run faultless for any kind of journey after this has cleared, be that driving her hard or sitting her on a motorway for three hours.

Do you guys have any thoughts?

Thanks

[Phil325i]

A few suggestions:

1. Could be glow plugs
2. Could be injectors leaking overnight
3. Suggest you find a good indy and get the car read for fault codes as a first step.

[Len_Beach]

I have a 330d with the N57 and the car had glow plug errors when I bought it and has suffered similar issues since the repair.

Glow plug faults were clearly indicated by the fault codes and the idle would be rough for a few seconds. This didn't carry over once I'd set off.

I've replaced all glow plugs and the controller.

I'd suspect you may have another issue. What was the specific air intake sensor issue fault you saw?

This "could" cause a rough idle if the MAF isn't reading the idle air correctly.

Cleaning the MAF and MAP sensors and resetting MAF adaptations showed a significant benefit in my car with smoother running and around 4mpg gained. This could help.

[Mboon]

Hi,

The codes have been read. The air intake sensor was showing a signal fault.

No other codes, I reset and took for a good drive and the only code was the air intake. Just wondered if this would cause this issue.

Would leaking injectors show any other faults?

Thanks

[E60525d]

Originally Posted by Len_Beach

Cleaning the MAF and MAP sensors and resetting MAF adaptations showed a significant benefit in my car with smoother running and around 4mpg gained. This could help.

I also did this and it did make a noticeable difference.

[Len_Beach]

Originally Posted by Mboon

Hi,

The codes have been read. The air intake sensor was showing a signal fault.

No other codes, I reset and took for a good drive and the only code was the air intake. Just wondered if this would cause this issue.

Would leaking injectors show any other faults?

Thanks

What's the specific code that's being shown?

[old grey steve]

Originally Posted by Phil325i

A few suggestions:

1. Could be glow plugs
2. Could be injectors leaking overnight
3. Suggest you find a good indy and get the car read for fault codes as a first step.

No1 not unheard off though more likely a controller failure
No2 Doubtful but again on diesels not heard of you would want to see/check smooth running results see some evidence and/or even carry out a leak off test
No3

My guess, if guess is the right word is you've got a inlet manifold issue usually swirl flap related seen loads and got 5 duff ones upstairs. Most if not all customers report lumpy rough running on start up a bit grumpy when pulling away and as the cars warms up things seem to get better, mileage wise the worst one I've seen is 41k EGR's worth checking out too but manifold would be my No1 choice

[AzRiz]

I had this (N57 330D), got worse over the course of 2 years, used to cut out at the first stop on a cold start etc. In the end it got REALLY bad and a code scan showed EGR valve errors.

Had the EGR valve swapped out for a new one, codes cleared, the issue went away completely.

The valve was coked up pretty bad, and was sticking. I had the glowplugs and controller changed out at the same time but code scans did not show any plug errors - I did them just as a preventative measure while it was at the garage.

[Len_Beach]

Originally Posted by old grey steve

No1 not unheard off though more likely a controller failure
No2 Doubtful but again on diesels not heard of you would want to see/check smooth running results see some evidence and/or even carry out a leak off test
No3

My guess, if guess is the right word is you've got a inlet manifold issue usually swirl flap related seen loads and got 5 duff ones upstairs. Most if not all customers report lumpy rough running on start up a bit grumpy when pulling away and as the cars warms up things seem to get better, mileage wise the worst one I've seen is 41k EGR's worth checking out oo but manifold would be my No1 choice

Have you ever removed the swirl flaps on an N57 Steve?

I removed mine as I was getting plausibility errors which indicates carbon build up. I fitted a cleaned, de-flapped manifold and the car runs great but I'm still getting plausibility errors.

I can't work out if it's due to no flaps which I suspect isn't the case as the car wouldn't know they're gone or it's due to a duff actuator.

Sorry OP; slightly off topic!

[Mboon]

00436A
004391

These are the two codes.

One is range

One is signal

No other codes other than line bus communication which I don't think is related.

The car is standard and covered 167,000 miles. It has done some big miles in the last 2 years over 30,000 each year.

I am happy to remove the swirl flaps as did this on an M57 engine. If the EGR is going to be an issue, would mapping the car and blanking the EGR be possible? I have had more dealings with the M57 rather than the N57.

Cheers all.

I will try all of the above. I want to pull the car a part and do the little bits on her and get her perfect again

[Len_Beach]

Originally Posted by Mboon

00436A
004391

These are the two codes.

One is range

One is signal

No other codes other than line bus communication which I don't think is related.

The car is standard and covered 167,000 miles. It has done some big miles in the last 2 years over 30,000 each year.

I am happy to remove the swirl flaps as did this on an M57 engine. If the EGR is going to be an issue, would mapping the car and blanking the EGR be possible? I have had more dealings with the M57 rather than the N57.

Cheers all.

I will try all of the above. I want to pull the car a part and do the little bits on her and get her perfect again

436a doesn't appear to be a valid code however 4391 suggests the boost temperature sensor is at fault.

http://www.e90post.com/forums/showthread.php?t=1191609

The EGR on the N57 doesn't coke up anything like as much as the M57 and it isn't usually an issue.

They can be coded out as part of a remap however they can't be blanked in the same way as the M57 can.

[Mboon]

I scaned it with Rheingold, which gave me the location of the sensor and a photo of what it looked like. I located the sensor which is the air intake temp sensor (checked on real oem as well) which is in the right hand side of the engine and is easily accessible. This is where the two fault codes point to according to rheingold...

Does this sound right or is this sending me up the wrong path?

The car boosts and pulls hard cold or hot and never had a power/boost issue with her

Thanks

[Len_Beach]

Originally Posted by Mboon

I scaned it with Rheingold, which gave me the location of the sensor and a photo of what it looked like. I located the sensor which is the air intake temp sensor (checked on real oem as well) which is in the right hand side of the engine and is easily accessible. This is where the two fault codes point to according to rheingold...

Does this sound right or is this sending me up the wrong path?

The car boosts and pulls hard cold or hot and never had a power/boost issue with her

Thanks

Is the sensor on top of the inlet to the front right held in by 1 bolt?

If so, that's the MAP sensor. Try cleaning it with contact cleaner as they often get filled with soot so read poorly.

Rheingold has a rest plan function which may allow you to test the sensor?

[old grey steve]

Originally Posted by Len_Beach

Have you ever removed the swirl flaps on an N57 Steve?

I removed mine as I was getting plausibility errors which indicates carbon build up. I fitted a cleaned, de-flapped manifold and the car runs great but I'm still getting plausibility errors.

I can't work out if it's due to no flaps which I suspect isn't the case as the car wouldn't know they're gone or it's due to a duff actuator.

I've had a look as have a couple of the guys this manifold is a different beast to the M57 to be fair when you look at the manifold you have to say it looks a little more complex inside and less straightforward to that fitted to the M57. IMO I smell trouble if you start tampering with it hence we haven't done anything other than repalce and when they are replaced we get no issues at all.