Engine idle rough, white smoke and vibration

[Darren Ritchie]

My ML320 2007 W164 CDI om642 has a very rough idle and produces a lot of white smoke. Car takes around 4 seconds of turning before it starts.

There does not seem to be any coolant being used

The idle clears up if you rev it above 2.5k rpm (still smoky though)

Computer reads a misfire in cylinder 3, tried swapping that injector over, made no difference.

If I pull the plug from Injector 3, would this stop the smoke and maybe prove its that injector.

Does a previously used injector need coded.

Any help appreciated

I can see a couple posts with almost exact same issue, bit no one ever come back to say the fix

Thanks again

Darren

 

[M80]

Yes, pretty sure the injector would want coding.
They aren't repairable either, apparently, being Piezo.

I would be cautious disabling a cylinder, especiallly any end cyclinder. The imbalance on the crank would put strain on the big end bearings.

Some years ago I took out a 4cyl engine within 12 miles running it a cylinder down to get home.

 

[Larkone]

White smoke:

White smoke is caused by raw, un-burnt fuel passing into the exhaust stream. Common causes include:
· Incorrect fuel injection timing
· Defective fuel injectors
· Low cylinder compression

Low cylinder compression may be caused by leaking valves, sticking piston rings, ring wear, cylinder wear, or cylinder glaze. When white smoke occurs at cold start and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing.
Continuous evidence of white smoke indicates a mechanical defect, or incorrect fuel timing.

 

[Darren Ritchie]

White smoke:

White smoke is caused by raw, un-burnt fuel passing into the exhaust stream. Common causes include:
· Incorrect fuel injection timing
· Defective fuel injectors
· Low cylinder compression

Low cylinder compression may be caused by leaking valves, sticking piston rings, ring wear, cylinder wear, or cylinder glaze. When white smoke occurs at cold start and then disappears as the engine warms up, the most common causes are fouling deposits around piston rings and/or cylinder glazing.
Continuous evidence of white smoke indicates a mechanical defect, or incorrect fuel timing.

Yeah I found that post already. I'm just hoping that someone somewhere has had the same thing happen to their car. I'm going to assume I will needs the injector coded now before moving onto any other possible cause.

Maybe do my own little compression test at the weekend just for peace of mind.

Any other ideas or anyone has similar, please let me know. Would love ther car on the road asap.

Thanks

 

[hamodi]

Hi, did you get anywhere with this? Experiencing the same problem after changing high pressure diesel pump.

 

[Darren Ritchie]

Hi, did you get anywhere with this? Experiencing the same problem after changing high pressure diesel pump.

I'm literally half way through stripping the head off. Might not be the issue but snapped a glow plug and also wanted to change the oil cooler seals and glow plug module. I'll keep you posted.

 

[Kev555]

As I was told by a few wise heads on here at the start of the year after having a similar problem start with the basics. Fuel pressures, low pressure tank pump if your vehicle has one then High pressure pump. After that compression test then start to look at injectors. If you have a icarsoft reader it should tell you the low and high pump pressures. Mine was an injector problem and they were Delphi. My problem does sound very similar to yours with cylinder three always showing up as the problem even when swapping injectors

 

[alexanderfoti]

Turn off the injector on no3 (via diag) and see if the smoke stops.

If it does, either injector spray pattern, or low compression on that cylinder. You can test the relative compression on that cylinder with diag, or use a traditional diesel comp tester.

 

[Darren Ritchie]

I snapped a glow plug so I'm all the way down and about to pull the head this weekend. (Off the car that is)

Doing the oil cooler seals etc while there.

U can clearly see all 5 inlet ports are carbon and cylinder 3 is very clean, so fuel has been around unburned that's for sure.

I'll keep you posted by Monday the 9th December what the issue was or may have been.

Not looking FWD to the rebuild. Not at all

 

[ajlsl600]

As I was told by a few wise heads on here at the start of the year after having a similar problem start with the basics. Fuel pressures, low pressure tank pump if your vehicle has one then High pressure pump. After that compression test then start to look at injectors. If you have a icarsoft reader it should tell you the low and high pump pressures. Mine was an injector problem and they were Delphi. My problem does sound very similar to yours with cylinder three always showing up as the problem even when swapping injectors

for me, after a quick look around for something simple the basics .would be a compression test FIRST if thats not right nothing is going to get better. then ,injector issues. as ,fuel press unlikely to effect 1 cly.

 

[ajlsl600]

I snapped a glow plug so I'm all the way down and about to pull the head this weekend. (Off the car that is)

Doing the oil cooler seals etc while there.

U can clearly see all 5 inlet ports are carbon and cylinder 3 is very clean, so fuel has been around unburned that's for sure.

I'll keep you posted by Monday the 9th December what the issue was or may have been.

Not looking FWD to the rebuild. Not at all

DONT be in a hurry and likely you will be fine , if yr not expeienced run thru the process 4 5 times in yr head before starting

 

[hamodi]

I snapped a glow plug so I'm all the way down and about to pull the head this weekend. (Off the car that is)

Doing the oil cooler seals etc while there.

U can clearly see all 5 inlet ports are carbon and cylinder 3 is very clean, so fuel has been around unburned that's for sure.

I'll keep you posted by Monday the 9th December what the issue was or may have been.

Not looking FWD to the rebuild. Not at all

Hey, sorry to ask again - do you have an update please? I hope you're back up and running.

 

[Gulbaz]

Anyone solved this problem waiting on reply’s