Purchasing an older GL320 diesel, advice wanted
Thread Starter
Senior Member
Joined: Apr 2009
Posts: 261
Likes: 32
From: Where the Army sends me.
GL 350 Bluetec
Purchasing an older GL320 diesel, advice wanted
Been a while since I have posted in this forum. I am the previous owner of a few MBs and now I am looking at purchasing an older GL320 Diesel and will be attempting to find one circa 2008 before Bluetec. Most vehicles in this range will have at least 100k miles on them and will have had 2 or 3 owners. I would not expect to be able to find detailed maintenance history so I will have to look and listen for some of the common offenders myself at a secondhand car lot or private seller's driveway. I am reasonably good at working on cars myself but work and family commitments make some of the larger projects difficult.
Oil Cooler: This seems to be the big one, where exactly is it located and what are the symptoms of one that is starting to go bad? Photos would be helpful. Obviously a large oil leak would be fairly easy to spot but can someone point me to where it starts to seep before it fails completely? Are there any other early warning signs?
Timing Chain: Seems like the early symptom is that there is a rattling noise that owners notice during a cold start. How cold does the vehicle have to be (I live in Texas) and does someone have a recording or video of the noise it makes?
Steering rack leak: Not exactly related to the diesel engine but if someone has pictures or advice about how to spot these problems during an initial inspection that would be helpful.
Air suspension: Same as above.
Any other things to look for? There are not many of these around so hopefully I can find one worth buying.
Oil Cooler: This seems to be the big one, where exactly is it located and what are the symptoms of one that is starting to go bad? Photos would be helpful. Obviously a large oil leak would be fairly easy to spot but can someone point me to where it starts to seep before it fails completely? Are there any other early warning signs?
Timing Chain: Seems like the early symptom is that there is a rattling noise that owners notice during a cold start. How cold does the vehicle have to be (I live in Texas) and does someone have a recording or video of the noise it makes?
Steering rack leak: Not exactly related to the diesel engine but if someone has pictures or advice about how to spot these problems during an initial inspection that would be helpful.
Air suspension: Same as above.
Any other things to look for? There are not many of these around so hopefully I can find one worth buying.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
We do have several topics about 320 Bluetecs.
Sounds like you already did your homework. Very desirable engines, but even when you updated oil cooler, running above 100k miles at some point you will have to clean intake flaps and EGR. I took a look at 180k miles chain and it should last another 200k.
I post pictures of oil cooler somewhere in this section. The cooler itself is piece of cake, but it is buried at the bottom of engine valley, so all top stuff has to go and this engine has a lot of it.
Last edited by kajtek1; May 14, 2018 at 09:08 PM.
Thread Starter
Senior Member
Joined: Apr 2009
Posts: 261
Likes: 32
From: Where the Army sends me.
GL 350 Bluetec
Looks like an oil cooler leak will present itself at the back of the engine block underneath the turbo. Seems pretty difficult to get to if it does go bad.
MBWorld Fanatic!
Joined: Jan 2009
Posts: 9,224
Likes: 1,798
From: V E G A S
1922 Ford Model T / no OBD
The valley has drip hole on I remember driver side, so oil cooler leaks shows running down the block. Have seen youtube videos about it.
Bottom line, when you have oil dripping on this engine- 99% it is oil cooler. Suppose dealers charge $2000 labor for the job. New seals cost 20 some bucks. Or whole cooler is less than $200
Bottom line, when you have oil dripping on this engine- 99% it is oil cooler. Suppose dealers charge $2000 labor for the job. New seals cost 20 some bucks. Or whole cooler is less than $200
Newbie
Joined: Jul 2009
Posts: 3
Likes: 0
From: Montgomery, Texas
2008 ML 320 CDI
I don't have a GL but I do own an ML320 with air suspension. I had 145,000 miles and had to replace one strut front left. There was no warning, one day it worked fine and next day I received warning on dash that suspension had malfunctioned. Had it replaced at MB dealer with a remanufactured strut for $1800 (1 year warranty on parts). Yesterday, at 151,000, same message and am in shop now to see which corner is bad this time.
Thread Starter
Senior Member
Joined: Apr 2009
Posts: 261
Likes: 32
From: Where the Army sends me.
GL 350 Bluetec
I don't have a GL but I do own an ML320 with air suspension. I had 145,000 miles and had to replace one strut front left. There was no warning, one day it worked fine and next day I received warning on dash that suspension had malfunctioned. Had it replaced at MB dealer with a remanufactured strut for $1800 (1 year warranty on parts). Yesterday, at 151,000, same message and am in shop now to see which corner is bad this time.
Newbie
Joined: Jul 2009
Posts: 3
Likes: 0
From: Montgomery, Texas
2008 ML 320 CDI
Agree. Follow up to original post. Heard back from repair shop (non dealer) and both rear air bags leaking and compressor experience excessive heating resulting in recommended replacement. Looked at conversion options, but learned there were none so ok'd repair totaling $2500. Three down and one to go.
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Thread Starter
Senior Member
Joined: Apr 2009
Posts: 261
Likes: 32
From: Where the Army sends me.
GL 350 Bluetec
Might as well do that last one while you are spending the money I guess. Some people replace the air springs with regular springs I don't know if they make a kit like that for these vehicles. It may be worth looking for.
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