Cleaning EGR to hopefully fix LHM - anything else to inspect?

imsebastian

Member
Hey Folks-

I'm the second owner of a well used 2007 Freightliner Sprinter, 3.0 V6 OM642 ~184k miles. Since getting the van I've replaced the rear end with a remanufactured unit, replaced the turbo (horrible shaft play), replaced the intake manifolds (swirl valve problems), glow plugs, alternator, and several other o rings/seals/hoses. Prior to this work, I didn't drive the van much as I bed been focused on the RV buildout.

In November I took her on a ~1200 mile road trip and noticed what I think is LHM. About 500 miles in, with no other symptoms or CELs, the van was not responding to the throttle and it was difficult to climb hills. Downshifting didn't seem to make things any better, but turning the van off for a while and then back on seemed to fix the issue... sometimes for another few hours of highway driving and sometimes for much less. It probably went into this mode maybe 3 or 4 times on this trip.

I also noticed during idle I could smell diesel fuel from within the cab when the recirc was not on. There was one morning I idled for ~20 min to charge the batteries and warm up the van where the diesel smell was most noticeable. This was before I did a lot of reading about how bad it is to idle these vehicles...

Probably not related to LHM but definitely worth of more research was the dreaded rumble strip noise during acceleration under certain loads, which seemed to get worse / more sensitive with the longer drives.

I only recently bought an Autel AP200, so I don't have any live readings to reference. When I installed the AP200 I noticed a few codes but I have no idea when those posted since the KM readings were bogus.

The codes I saw on the Autel were:
2359 - 1 Charge pressure control - too low boost pressure (59026 mi)
2052 - 4 B28 (Intake manifold pressure sensor) - the signal voltage is too low (59080 mi)
2679 - 4 B76 (Fuel filter water level sensor) - the component is faulty (59738 mi)
(The WIF error was because connector wasn't pushed on fully)

The mechanic noted the codes were cleared after doing work, did Autel somehow retrieve codes he didn't clear? I noticed the WIF error when I picked up the van from storage (where the mechanic stored it after the work).... but storage is only 20 miles from the shop, so I don't see how the low boost code posted 700 miles prior. Each code has a milage number associated with the code, but the number are either extremely old, or just plain wrong. I only include this to say I think there were no newer codes posted to the ECM on my trip during the LHM. Anyway...

Now that I am home I have some time to dig in, so I decided to remove the EGR and clean it up. I also plan on removing the elbow near the EGR and cleaning/inspecting that Some questions:

1 - The EGR was stuck on there pretty good, and required a bit of persuasion from a hammer. Theres no damage on the housing, but should I do anything to ensure a good seal for the coolant? I see there is a seam between the top and bottom, held together with security torx, should I be worried the water seal might be compromised? The EGR didn't seem excessively sooty or clogged, below is a video of the spring return after some cleaning.

2 - Should I do anything to test or clean the EGT sensor? Or is that simple enough to swap later if needed?

3 - I've been reading about cleaning the EGR cooler, is this a worthwhile venture?

4 - I noticed a bit of dripped residue on my alternator, maybe from charge piping? I don't think I have the older defective charge pipes, but maybe it's worth removing these and inspecting for damage?

5 - Should I look elsewhere for the cause of this LHM?

Thanks in advance! Happy Holidays and New Year!

 

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sparkplug

Well-known member
I'm sure you did so already but....

You did replace the metal EGR gasket with a new one, didn't you?

Only time I've been able to smell diesel in the cab was when I had injector issues (black death) - again, you sound like you know your stuff so I'm sure you've already inspected those.
 

showkey

Well-known member
Diesel fuel smell or diesel exhaust smell ?

Diesel exhaust smell related to EGR at higher mileage cause by EGR pipe cracked at the flex connection by the cooler.
 

imsebastian

Member
Thanks for the replies -

@showkey - diesel fuel smell, but thanks for the heads up about the crack near the cooler I'll keep an eye on things. I know aging motor mounts can sometimes be blamed for cracks near that area... hopefully we don't get to that stage There is significant oil/crud on the vacuum pump cover (photo below) but from what I've read that is a trivial fix.

@sparkplug - I didn't reinstall things yet, but I will definitely use a new gasket. I don't see any early signs of black death yet... fingers crossed.
 

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hitchmss

New member
I bought my same year/model sprinter from a guy who bought it from the dealer new. He told me he had symptoms almost identical to what you're experiencing; lack/loss of power on grades, no CEL, pulled over-turned off-waited-turned on-issue resolved, but it would reappear regularly. Dealership said there was a "glich" in the ECU, and 20 minutes on their computer fixed the issue. I dont know what specifically they changed, but since Ive owned it, Ive never had this issue, and its been 150k+
 

imsebastian

Member
Diving back into things now and reassembling. Any tips for getting both of those gaskets on the EGR elbow (that feeds back into the intake)? Seems silly but it's driving me mad - I can line up the holes on the bottom gasket but when I try to install the second gasket, the elbow pinches the gasket and makes lining things up difficult.

Thanks !
 

cragg3r

New member
I have this same thing, though mine is throwing CEL. Thinking I'll replace the EGR tube first, or at least pull to inspect it. Did you get this fixed? Any sign of BD? When I take mine in for a seat belt recall I'll ask them about it. Good info, thanks for posting!
 

turbo911

Active member
overlooked is the throttle control where the cold side from intercooler meets back to the engine. there are sensors there and a o ring for sealing. if you have no joy with the egr cleaning and gasket replacement on the elbow(which hopefully isnt cracked or leaking)oil from above or the lower part of the vaccum pump weeps to the throttle control valve causing that seal to fail. removing it is a bitch, easier with alternator removed
 

imsebastian

Member
I'll chime in too - Here are the repairs I have done, all to no avail.

It seems like the problem is worse in the heat, I drove ~1000 miles to Boston in January without one instance of boost cuts, but just drove 600 miles with ~35-40C boost air temps and noticed the boost cuts frequently... often under load uphill at slower speeds.

Replaced EGR gaskets
Replaced the vac pump gaskets/seal, still seeps a little near one of the cover screws
Replaced intercooler (saw a TON of black residue near the end tanks)
Replaced tube from turbo inlet to airbox (saw cracks near clamp)
Replaced airbox filter
Replaced IAT sensor

Is this the sensor that is affected by the oil? This is the boost sensor, yea? I tried to remove this but couldn't figure out how to get that part of the manifold off...
 

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Dima74

Independent & Self Reliant - From Chattanooga TN
I'll chime in too - Here are the repairs I have done, all to no avail.

It seems like the problem is worse in the heat, I drove ~1000 miles to Boston in January without one instance of boost cuts, but just drove 600 miles with ~35-40C boost air temps and noticed the boost cuts frequently... often under load uphill at slower speeds.

Replaced EGR gaskets
Replaced the vac pump gaskets/seal, still seeps a little near one of the cover screws
Replaced intercooler (saw a TON of black residue near the end tanks)
Replaced tube from turbo inlet to airbox (saw cracks near clamp)
Replaced airbox filter
Replaced IAT sensor

Is this the sensor that is affected by the oil? This is the boost sensor, yea? I tried to remove this but couldn't figure out how to get that part of the manifold off...
With the ignition on, what are the values for:

Atmospheric pressure - ?
Intake manifold pressure -?
Boost pressure -?
Exhaust back pressure -?

What are the fault codes that are present?
 

turbo911

Active member
regarding boost pressure sensor. they put it where you have to take off the egr cooler or the front part of it. using a tune to get rid of egr, dpf and swirl flaps you can also remove the egr cooler and et al and never worry about the boost pressure sensor taking more than 5 minutes to change
 

imsebastian

Member
With the ignition on, what are the values for:

Atmospheric pressure - ?
Intake manifold pressure -?
Boost pressure -?
Exhaust back pressure -?

What are the fault codes that are present?
Hey Dima thanks for the reply - the fault is always 2359-1 Charge pressure control - too low boost pressure, and since it happens when I am driving I usually use my Autel AP200 to reset the code so I don't slow traffic too much :)

Do you want those readings only after the fault occurs? I've taken many screenshots during this troubleshooting, and I *think* this one is during a fault condition (I'm guessing the 5% charge pressure positioner is an indication of fault)

1589 Engine speed
681 rpm

1642 Intake air pressure
1000 hPa

1648 Boost pressure
982 hPa

8650 Exhaust back pressure
1023 hPa

420 Charge pressure positioner
5%

1651 Boost air temperature
36.8 °C

1644 Atmospheric pressure
999 hPa


Compared to this one, which I think is during an un-faulted condition:

1589 Engine speed
681 rpm

1642 Intake air pressure
985 hPa

1648 Boost pressure
991 hPa

8650 Exhaust back pressure
1046 hPa

420 Charge pressure positioner
93%

1651 Boost air temperature
42.1 °C

1644 Atmospheric Pressure
985 hPa
 

Dima74

Independent & Self Reliant - From Chattanooga TN
Hey Dima thanks for the reply - the fault is always 2359-1 Charge pressure control - too low boost pressure, and since it happens when I am driving I usually use my Autel AP200 to reset the code so I don't slow traffic too much :)

Do you want those readings only after the fault occurs? I've taken many screenshots during this troubleshooting, and I *think* this one is during a fault condition (I'm guessing the 5% charge pressure positioner is an indication of fault)

1589 Engine speed
681 rpm

1642 Intake air pressure
1000 hPa

1648 Boost pressure
982 hPa

8650 Exhaust back pressure
1023 hPa

420 Charge pressure positioner
5%

1651 Boost air temperature
36.8 °C

1644 Atmospheric pressure
999 hPa


Compared to this one, which I think is during an un-faulted condition:

1589 Engine speed
681 rpm

1642 Intake air pressure
985 hPa

1648 Boost pressure
991 hPa

8650 Exhaust back pressure
1046 hPa

420 Charge pressure positioner
93%

1651 Boost air temperature
42.1 °C

1644 Atmospheric Pressure
985 hPa
Post the values with the engine off, ignition on only
 

imsebastian

Member
Oh my bad -

Currently no errors present as I cleared them on the way back a few days ago, but KOEO:
Atmospheric pressure - 994 hPa
Intake manifold pressure - 994 hPa
Boost pressure - 990 hPa
Exhaust back pressure - 994 hPa
 

Dima74

Independent & Self Reliant - From Chattanooga TN
Oh my bad -

Currently no errors present as I cleared them on the way back a few days ago, but KOEO:
Atmospheric pressure - 994 hPa
Intake manifold pressure - 994 hPa
Boost pressure - 990 hPa
Exhaust back pressure - 994 hPa
The values are within the specs, no issues here... Make sure that you don't have any leaks in the charge system and that there is no oil in the swirl motor/actuator of the intake manifolds. Monitor and inspect the functioning of throttle valve and turbo actuator. Is your van stock or modified?
 

imsebastian

Member
Thanks for the reply. The turbo (including actuator and resonator), and swirl valves are all new with only ~3500 miles. I didn't do the work on the intake manifolds but my mechanic mentioned something about updated swirl valves with the work he did. Otherwise everything is OEM under the hood.

I've re-seated all the charge piping and dont see any obvious boost leaks.

I will mention that sometimes (usually uphill, slow speeds) the van will kind of stutter around 20-26psi boost pressure. I mean to say you'll hear/feel the turbo spool, then let off, then spool again, then let off, again a few more times... This usually happens right before the boost cut. I dunno if it's psychological or not, but I feel if I let off the accelerator it might avoid the boost cut.

I've also seen ~35psi of boost at highway speeds for hours at a time.

Could this be something with the atmospheric pressure? I kind of think this happens more in holly terrain?

Thanks for your help!
 

Dima74

Independent & Self Reliant - From Chattanooga TN
Thanks for the reply. The turbo (including actuator and resonator), and swirl valves are all new with only ~3500 miles. I didn't do the work on the intake manifolds but my mechanic mentioned something about updated swirl valves with the work he did. Otherwise everything is OEM under the hood.

I've re-seated all the charge piping and dont see any obvious boost leaks.

I will mention that sometimes (usually uphill, slow speeds) the van will kind of stutter around 20-26psi boost pressure. I mean to say you'll hear/feel the turbo spool, then let off, then spool again, then let off, again a few more times... This usually happens right before the boost cut. I dunno if it's psychological or not, but I feel if I let off the accelerator it might avoid the boost cut.

I've also seen ~35psi of boost at highway speeds for hours at a time.

Could this be something with the atmospheric pressure? I kind of think this happens more in holly terrain?

Thanks for your help!
Is the new turbo original or aftermarket?
 

cragg3r

New member
@imsebastian - how long of a job it is to remove the EGR tube and cooler to clean it out? 3 hours total? 6 hours total? Thinking that's the next item on my list. I already cleaned the valve, but with no change to the readout - still holding at 4.7% (Default).
 

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