2.1l Diesel does not like idle for long periods

[BigJase88]

2018 2.1l diesel Mercedes engine

Noticeable in the last few weeks with the cold weather. I have never really needed to use the car for a winter commute until recently.

The other morning i had it on tickover in the works carpark to defrost it for approx 30mins. On setting off on the journey the car was hilarious. As if it was clogged up. Piles of black smoke out of the exhaust. Reduced power maybe 50% for 2 miles or so until it cleared itself. Once clear it runs no problem as it should.

I 1st noticed this issue when i collected the car from an airport parking facility and they had done the same. Let it run for 30mins or so to defrost. Has anybody else came across this before? Car is a 2018 CLA which i believe has a DPF.

I also notice this sometime happens when you have been nursing the car along and then plant the foot it kicks out black reek at a reduced power until it clears its lungs and takes off. Then behaves normally. As if it needs a good italian tune up now and again.

No warning lights on the dash / CEL

Thanks

 

[BigJase88]

Just to update this. Drove sedately home from work and hoofed it. Did the usual try to clear itself however instead of doing the usualy dump of soot and off it went this time for the 1st time it went into limp mode. No code thrown or CEL. Restarted and limp mode no more

It has done this ever since i got it 2 years and 20k miles ago i just thought it was clearing itself after a DPF regen or something. Now thinking maybe something is actually up with it.

 

[Smart320]

Leaving it idling for 30 minutes to warm it up is crazy , no wonder you’re having problems

 

[Bellow]

Two quid from Halfords.

 

[MrGreedy]

Leaving it idling for 30 minutes to warm it up is crazy , no wonder you’re having problems

And illegal.

Not criticising. Just for awareness!
I was sat in mine idling for a period this morning due to extreme cold temps today.

 

[ChipChop]

Pretty sure it is not illegal at all to run or idle your engine to defrost prior to driving.

 

[BigJase88]

Right come on defrosting police

It was in a works carpark [private and off the road] and it was minus 8. There is a gateman so no laws were broken. I work 12 hr shifts when the bell goes at 6am i want to get into my car and go. Not sit frozen and wait 10 mins

Anyways does anyone have help with the actual issue ?

I have read some things about swirl flaps / turbo actuator issues causing similar symptoms. Just wondered if anybody else had experienced the same poor running after defrosting of a cold morning? As surely even if piloted then there is still a period of sitting and waiting to defrost.

 

[Londonscottish]

Right come on defrosting police

It was in a works carpark [private and off the road] and it was minus 8. There is a gateman so no laws were broken. I work 12 hr shifts when the bell goes at 6am i want to get into my car and go. Not sit frozen and wait 10 mins

Anyways does anyone have help with the actual issue ?

If that's your fundamental problem you need to get out of a diesel and into a petrol. Petrols hit operating temp far quicker. My wife's Fiat 500 starts blowing warm air in 200yds, is at operating temp in under a mile. My E Class takes a bit longer but not much.

Diesels take for ever to get to operating temp - and in short journeys might never get there. So the rest of us get treated to all the soot and shit coming out the back - this is certainly a big problem in build up areas, hence ULEZ.

 

[BigJase88]

If that's your fundamental problem you need to get out of a diesel and into a petrol. Petrols hit operating temp far quicker. My wife's Fiat 500 starts blowing warm air in 200yds, is at operating temp in under a mile. My E Class takes a bit longer but not much.

Diesels take for ever to get to operating temp - and in short journeys might never get there. So the rest of us get treated to all the soot and shit coming out the back - this is certainly a big problem in build up areas, hence ULEZ.

It is Euro6 and i live quite rural. There are no ULEZ areas and even if there was the car can enter them. It has a DPF so the fact it is throwing black smoke out of the back indicates to me there is an issue.

Idling a diesel engine should not be an issue like what i am seeing. Boat engines diesel. Emergency firepump sets diesel. I do approx 12k a year which is diesel territory. Defrosting is not a daily event only in the depths of winter.

 

[JHS]

If that's your fundamental problem you need to get out of a diesel and into a petrol. Petrols hit operating temp far quicker. My wife's Fiat 500 starts blowing warm air in 200yds, is at operating temp in under a mile. My E Class takes a bit longer but not much.

Diesels take for ever to get to operating temp - and in short journeys might never get there. So the rest of us get treated to all the soot and shit coming out the back - this is certainly a big problem in build up areas, hence ULEZ.

There you go Jase, problem solved. Simple.
Don't know why you never thought of that.

 

[BigJase88]

There you go Jase, problem solved. Simple.
Don't know why you never thought of that.

Silly me.

Well it does need new tyres soon so i'm thinking thats the best bet. Buy an electric car

 

[MrGreedy]

Has it been remapped? Could this be an EGR or swirl flap issue? Could you try 'idling' at say 1200-1500 rpm to see if it makes any difference?

Just wondering if any of these could help locate the problem.

 

[BigJase88]

Has it been remapped? Could this be an EGR or swirl flap issue? Could you try 'idling' at say 1200-1500 rpm to see if it makes any difference?

Just wondering if any of these could help locate the problem.

It has been remapped however the problem was there before mapping.

Well i say problem i did ask previously and believed it just to be doing an DPF clean but looks more to it now

Car had 48k when i got it. Mapped around 55k and now on 68k. Before it was mapped the fault codes were read and the only one on it was a communications issue from the COMAND Unit

 

[ALFAitalia]

Illegal or not its a great way to accelerate engine wear.

Engine Idling: What it means, the law, and why is it harmful?

Engine Idling is a common error which results in unwanted situations. Read on to know more about the engine idling law, what engine idling means, and how to avoid it.

www.warrantydirect.co.uk

 

[BigJase88]

Illegal or not its a great way to accelerate engine wear.

Engine Idling: What it means, the law, and why is it harmful?

Engine Idling is a common error which results in unwanted situations. Read on to know more about the engine idling law, what engine idling means, and how to avoid it.

www.warrantydirect.co.uk

Who cares

Cars are replaceable. Is idling in a traffic jam for an hour or 2 also bad?

I would imagine idling from cold is much better than smacking it off the limiter. The engine wear from idling for 20-30mins 10 times a year is negligible.

Any actual advice on the actual problem?

I am looking at getting the EGR out giving it a clean and having a look / clean at the swirl flaps. Then see if anything improves. Any guides or help on either of those would be appreciated.

 

[TeddyRuxpin]

A car should be able to idle for a long time without causing issues like this. Time to get codes read.

 

[BigJase88]

A car should be able to idle for a long time without causing issues like this. Time to get codes read.

It's a pain Merc have it locked down as i do have a Carista but it is incompatible with Mercedes.

I will get them read on Monday hopefully at my stepdads garage

 

[ALFAitalia]

Who cares

Cars are replaceable. Is idling in a traffic jam for an hour or 2 also bad?

I would imagine idling from cold is much better than smacking it off the limiter. The engine wear from idling for 20-30mins 10 times a year is negligible.

Any actual advice on the actual problem?

I am looking at getting the EGR out giving it a clean and having a look / clean at the swirl flaps. Then see if anything improves. Any guides or help on either of those would be appreciated.

Lol...wrong side of bed?.....or wrong bed!?

Two hours idling in traffic would most likely be with a hot engine....not a stone cold one running rich and washing all the oil off the bores.....and in the case of a derv blocking the DPF. Start the car and gently drive is by far the best for your engine....of course no hard revving....90% of all engine wear happens from cold in the first couple of minutes....you are just extending that time......your car....your choice.


.....BOT no amount if idling, even from cold could cause the issues you are having. Does not sound like an EGR fault to me either....but without getting the codes read on a good scanner anything we say on here is pure guess work.....even if its educated guess work!!!

 

[PolishGeorge85]

But there is no codes...so you can't read it. Black smoke, so fuel/air ratio isn't right. Or fuel isn't delivered as it should.

I had my two E350 over few years, and not a single time I've seen smoke coming out while DPF was regenerating, engine ran faster and louder but still no smoke.

I think there is a problem elsewhere, xentry and good mechanic.

 

[ALFAitalia]

Missed that.....

....the only time my diesel EVER smoked was when there was a split in one of the intercooler hoses....It still ran fine with no codes but only about half way up the boost gauge....I could not even hear it leaking until I got under the car and got my son to rev it. Might be worth a look.