Love to Hate my 2008 GL 320
Thread Starter
Junior Member
Joined: Sep 2012
Posts: 36
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From: Maryland
2008 GL 320 CDI
Love to Hate my 2008 GL 320
Ok All...Here I go... for the last 6 weeks or so my GL320 with 178,000 miles has been killing my bank account with pretty much the same issues. She would start then die. Replaced the fuel pump and she started-up with check engine light glowing. Error was mass airflow sensor - it too replaced. Cleared the code only to have it return with-in 10 minutes of driving away from mechanic. Mechanic then cleaned the filter in the catalytic convert. CE light still glowing. Drove her for less than a week and did the start then die thing...towed to mechanic shop and he said the new fuel pump died, replace it and a new battery. CE light still on, mechanic was researching what could be the underlining issue, drove home and two days later she did the start only to die again. Spoke to my mechanic and he said to have it towed to MB and they would have to try to resolve the issue. So now she is at the MB shop for about a week, they too replaced the NEW battery because it was dead and new fuel pump and crank position sensor.
Anyone out there have any ideas what could be causing this start only to die and killing the fuel pumps and batteries?Everyone is telling me to sell her...I dont want to but I don't want to keep spending thousands of dollars either. I bought the diesel for longevity and milage, Any advise?
Last edited by hmillham; Jun 27, 2014 at 11:10 AM.
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Someone need to spend some time diagnosing the issue instead of replacing parts.
EXACTL:Y what codes does it show?
Battery and Fuel Pump: Has anyone checked the voltage from the Alternator?
When it runs, is it normal in power?
Run and Die: Any one check for a clogged DPF?
How was it running right before the failure? (Normal, weak, etc?)
How does the fuel filter and Pump look? (Dirty fuel?)
EXACTL:Y what codes does it show?
Battery and Fuel Pump: Has anyone checked the voltage from the Alternator?
When it runs, is it normal in power?
Run and Die: Any one check for a clogged DPF?
How was it running right before the failure? (Normal, weak, etc?)
How does the fuel filter and Pump look? (Dirty fuel?)
Thread Starter
Junior Member
Joined: Sep 2012
Posts: 36
Likes: 0
From: Maryland
2008 GL 320 CDI
DPF was cleaned last month. After the DPF was cleaned the car was running normal. No slow acceleration issues.
Car was running normal. Parked it at night, wont start in the morning.
Fuel filter and fuel pump (x3 now) all new!!!
The dealership is running test on it now and has been for the last 3-4 days. I don't know if there are any new additional codes.
Car was running normal. Parked it at night, wont start in the morning.
Fuel filter and fuel pump (x3 now) all new!!!
The dealership is running test on it now and has been for the last 3-4 days. I don't know if there are any new additional codes.
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
DPF was cleaned last month. After the DPF was cleaned the car was running normal. No slow acceleration issues.
Car was running normal. Parked it at night, wont start in the morning.
Fuel filter and fuel pump (x3 now) all new!!!
The dealership is running test on it now and has been for the last 3-4 days. I don't know if there are any new additional codes.
Car was running normal. Parked it at night, wont start in the morning.
Fuel filter and fuel pump (x3 now) all new!!!
The dealership is running test on it now and has been for the last 3-4 days. I don't know if there are any new additional codes.
New fuel filter and pump does not tell the condition of the fuel in the tank.
Did they send the DPF out to be cleaned, or did they just back flush it with air or water?
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Member
Joined: Jun 2014
Posts: 90
Likes: 1
2008 GL320
I have worked on a lot of cars.... why would a DPF ruin a fuel pump? Were the fuel pumps bad (as in tested on a bench outside the car) or were they just replacing parts at random trying to fix the problem?
If it ruined your battery I would be trying to figure out where the current was going.... the old school way (might not work on an MB) would be to put your 20A current meter in between the battery (hopefully on a charger) and the car with everything off and read the current.... then pull one fuse at a time and see a drop in current.
PLEASE take great care in doing this and see if any one else has a better suggestion before trying it? The only other time I have seen batteries just die like that it was an Alternator that had a short in it. It would generate power when running but if you let it set overnight the battery was DEAD!
If it ruined your battery I would be trying to figure out where the current was going.... the old school way (might not work on an MB) would be to put your 20A current meter in between the battery (hopefully on a charger) and the car with everything off and read the current.... then pull one fuse at a time and see a drop in current.
PLEASE take great care in doing this and see if any one else has a better suggestion before trying it? The only other time I have seen batteries just die like that it was an Alternator that had a short in it. It would generate power when running but if you let it set overnight the battery was DEAD!
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97 S600 coupe/gf 16 C300 Lux. Former: 08 GL450, 83 300D, 97 C230, 08 c300 luxury, 92 500SL, 93 400E
Someone need to spend some time diagnosing the issue instead of replacing parts.
My MB tech famously stated to me when I was looking for a GL to buy the m273 version because "I'd rather have herpes than an OM642 diesel."
Maybe not helpful comments, but at 178,000 miles, things are going to fail, possibly for the 2nd time, especially in a complex, modern diesel.......having a competent indie shop work on your vehicle is essential.
Is this an MB-specific shop, or one of those good ol' "Euro" shops with a few vintage Audis and BMWs sitting out back?
Last edited by will_w204; Jun 30, 2014 at 07:52 AM.
Thread Starter
Junior Member
Joined: Sep 2012
Posts: 36
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From: Maryland
2008 GL 320 CDI
Update: As of right now car is running fine now for 36 hours. No CEL 
Car has been to my private mechanic 4 times (trained by MB with 12 years’ experience). He sent car to MB Dealership in B-Maryland and they replaced the fuel pump again. They stated that it wasn't properly installed 
- Now I question my mechanic of 3 years.
They also wanted to replace another sensor at $500+. My mechanic recommended NO because it was not related to any issues and they would not guarantee it would resolve any issues. This dealership held my MB for 2 weeks; they charged me 4 hours of diagnosis fees and could not find a definitive answer to why mass air flow sensors keeps sending errors. They also said they found fuel on the harness (I don't know what or where that is) and they would guarantee that job at about $9,000. I laughed but wanted to cry. Anyways I picked up the car and went car shopping. Wasn't too happy with what’s out there, so I decided to take car to N-VA-MB dealer (where I purchased her from new).
In short, what they believed to be my problem is…wait for it: I (yes, me) installed a K&N air filters, and they said it's the oil in those filters that have a history of causing mass air flow problems. So in short… DO NOT INSTALL K&N Air Filters in your MB. They installed OEM air filters.
So in the last 2 months, I have replaced the fuel pumps & fuel filter, Mass Air flow sensor, exhaust pressure sensors, battery, the rear shocks, air filters, cleaned the DPF and a total of 3 tows to mechanics. I could only hope I’m done with repairs for a while now my bank account can’t take it anymore.
Car has been to my private mechanic 4 times (trained by MB with 12 years’ experience). He sent car to MB Dealership in B-Maryland and they replaced the fuel pump again. They stated that it wasn't properly installed - Now I question my mechanic of 3 years. They also wanted to replace another sensor at $500+. My mechanic recommended NO because it was not related to any issues and they would not guarantee it would resolve any issues. This dealership held my MB for 2 weeks; they charged me 4 hours of diagnosis fees and could not find a definitive answer to why mass air flow sensors keeps sending errors. They also said they found fuel on the harness (I don't know what or where that is) and they would guarantee that job at about $9,000. I laughed but wanted to cry. Anyways I picked up the car and went car shopping. Wasn't too happy with what’s out there, so I decided to take car to N-VA-MB dealer (where I purchased her from new).
In short, what they believed to be my problem is…wait for it: I (yes, me) installed a K&N air filters, and they said it's the oil in those filters that have a history of causing mass air flow problems. So in short… DO NOT INSTALL K&N Air Filters in your MB. They installed OEM air filters.
So in the last 2 months, I have replaced the fuel pumps & fuel filter, Mass Air flow sensor, exhaust pressure sensors, battery, the rear shocks, air filters, cleaned the DPF and a total of 3 tows to mechanics. I could only hope I’m done with repairs for a while now my bank account can’t take it anymore.
Member
Joined: Jun 2014
Posts: 90
Likes: 1
2008 GL320
Update: As of right now car is running fine now for 36 hours. No CEL Car has been to my private mechanic 4 times (trained by MB with 12 years’ experience). He sent car to MB Dealership in B-Maryland and they replaced the fuel pump again. They stated that it wasn't properly installed - Now I question my mechanic of 3 years.
They also wanted to replace another sensor at $500+. My mechanic recommended NO because it was not related to any issues and they would not guarantee it would resolve any issues. This dealership held my MB for 2 weeks; they charged me 4 hours of diagnosis fees and could not find a definitive answer to why mass air flow sensors keeps sending errors. They also said they found fuel on the harness (I don't know what or where that is) and they would guarantee that job at about $9,000. I laughed but wanted to cry. Anyways I picked up the car and went car shopping. Wasn't too happy with what’s out there, so I decided to take car to N-VA-MB dealer (where I purchased her from new).
In short, what they believed to be my problem is…wait for it: I (yes, me) installed a K&N air filters, and they said it's the oil in those filters that have a history of causing mass air flow problems. So in short… DO NOT INSTALL K&N Air Filters in your MB. They installed OEM air filters.
So in the last 2 months, I have replaced the fuel pumps & fuel filter, Mass Air flow sensor, exhaust pressure sensors, battery, the rear shocks, air filters, cleaned the DPF and a total of 3 tows to mechanics. I could only hope I’m done with repairs for a while now my bank account can’t take it anymore.
Car has been to my private mechanic 4 times (trained by MB with 12 years’ experience). He sent car to MB Dealership in B-Maryland and they replaced the fuel pump again. They stated that it wasn't properly installed - Now I question my mechanic of 3 years. They also wanted to replace another sensor at $500+. My mechanic recommended NO because it was not related to any issues and they would not guarantee it would resolve any issues. This dealership held my MB for 2 weeks; they charged me 4 hours of diagnosis fees and could not find a definitive answer to why mass air flow sensors keeps sending errors. They also said they found fuel on the harness (I don't know what or where that is) and they would guarantee that job at about $9,000. I laughed but wanted to cry. Anyways I picked up the car and went car shopping. Wasn't too happy with what’s out there, so I decided to take car to N-VA-MB dealer (where I purchased her from new).
In short, what they believed to be my problem is…wait for it: I (yes, me) installed a K&N air filters, and they said it's the oil in those filters that have a history of causing mass air flow problems. So in short… DO NOT INSTALL K&N Air Filters in your MB. They installed OEM air filters.
So in the last 2 months, I have replaced the fuel pumps & fuel filter, Mass Air flow sensor, exhaust pressure sensors, battery, the rear shocks, air filters, cleaned the DPF and a total of 3 tows to mechanics. I could only hope I’m done with repairs for a while now my bank account can’t take it anymore.
I would think that a dealer would take one look at a non-MB approved filter and replace it.
I would think that their diagnostics would point them toward the air filter/intake system rather than the rest of it. Glad you got it working... From now on if I have something go wrong I am going to blame the air filter first
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E55, GLS450, GL63, GLE350
Ok, I believe the diesel engine uses a MAP sensor. If that is the case, a K&N will not affect a MAF because there is not one. You can't foul a MAP sensor due to the oil on the filter. This only applies to a car with a MAF sensor and even that is debatable.
Put it this way, I've been running K&N filters for over 150,000 miles on my MB's and have never had one ruin a MAF. I've had a MAF go out on stock paper filters but never K&N's. It wasn't a function of the filter; rather, Bosch had bad batches of MAF's.
Put it this way, I've been running K&N filters for over 150,000 miles on my MB's and have never had one ruin a MAF. I've had a MAF go out on stock paper filters but never K&N's. It wasn't a function of the filter; rather, Bosch had bad batches of MAF's.
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
If you take good care of your K&N they are OK on the road. They still let in more dirt then a paper filter.
Most people don't stay on top on them, and are FAR better off with paper filters.
Diesels may gain an marginal amount of power, gas engines even less.
Most people don't stay on top on them, and are FAR better off with paper filters.
Diesels may gain an marginal amount of power, gas engines even less.
Thread Starter
Junior Member
Joined: Sep 2012
Posts: 36
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From: Maryland
2008 GL 320 CDI
Thanks N_JAY & BlownV8, however my K&N filters were only 6 months old and I started having issues 2 months ago. Since they have been replaced with OEM parts, (knocking on wood), I have NO Mass Air Flow sensor issues. And I had the MAF replaced twice in one month.
I also have a 1996 Volvo 850 Turbo (325,000+) with the K&N Filter. I have over 200,000 miles with K&N filter. With all that said, I love to hate my K&N Filter. Good for one car, and not for another.
I also have a 1996 Volvo 850 Turbo (325,000+) with the K&N Filter. I have over 200,000 miles with K&N filter. With all that said, I love to hate my K&N Filter. Good for one car, and not for another.
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
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From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Have always used K&N on cars I race.
Have always used paper (or other factory fitment) on cars for the road.
Have always used paper (or other factory fitment) on cars for the road.
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From: Espoo, Finland
2012 GL 350
Same here...well, not always K&N, but oiled filters. Race engines get rebuilt often enough that longevity isn't the goal. And maintenance is much more frequent as well. Street cars I just don't see the point in trying to find 5 HP at 6,800 rpm. Diesels don't rev high enough that it would seem to be able to make a difference.
Out Of Control!!
Joined: Aug 2010
Posts: 12,516
Likes: 628
From: Charlotte NC area
2019 WS222 S450 4-Matic / 2007 W211 E350 4Matic (Sold) / 2008 X164 GL320 CDI
Same here...well, not always K&N, but oiled filters. Race engines get rebuilt often enough that longevity isn't the goal. And maintenance is much more frequent as well. Street cars I just don't see the point in trying to find 5 HP at 6,800 rpm. Diesels don't rev high enough that it would seem to be able to make a difference.
Actually, diesels are more sensitive to restricted airflow, so a low loss filter is a bigger advantage compared to a gas engine. (Remember they are running "unthrottled".
That said, with longevity as the goal, I still don't recommend an oil/fiber filter unless you are doing maintenance on a VERY regular schedule. (Both time and miles). I would guess 2 to 4 times as often as K&N recommends.
