2008 GL 320 CDI - replacing oil cooler rings - what else can be replaced?
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2008 GL320 CDI
2008 GL 320 CDI - replacing oil cooler seals - what else can be replaced?
Hi,
I have a 2008 GL320 CDI and the oil cooler seals need replacing. Vehicle has 370,000 km / 229,000 miles.
I have already replaced the crank case vent and the PCV. This slowed consumption but there is still an annoying 2 quarts per 500 Kilometres / 310 Miles that requires topping up.
The previous owner never replaced the oil cooler seals.
Since I am getting in to this lengthy job, what else can be repaired replaced when getting into the oil cooler seals and appropriate gaskets / bits? I mean since it is a deep dive into the engine, what else can be easily accessed, or replaced while there?
I would rather replace / repair as much as possible than have to tear into the engine again.
It is like the old saying, measure twice, cut once.
As an example, would it be wise to get into the head gasket at this point? Fuel injector o-rings? Etc.?
Thank you kindly
I have a 2008 GL320 CDI and the oil cooler seals need replacing. Vehicle has 370,000 km / 229,000 miles.
I have already replaced the crank case vent and the PCV. This slowed consumption but there is still an annoying 2 quarts per 500 Kilometres / 310 Miles that requires topping up.
The previous owner never replaced the oil cooler seals.
Since I am getting in to this lengthy job, what else can be repaired replaced when getting into the oil cooler seals and appropriate gaskets / bits? I mean since it is a deep dive into the engine, what else can be easily accessed, or replaced while there?
I would rather replace / repair as much as possible than have to tear into the engine again.
It is like the old saying, measure twice, cut once.
As an example, would it be wise to get into the head gasket at this point? Fuel injector o-rings? Etc.?
Thank you kindly
Last edited by GL320_CDI; Mar 1, 2023 at 06:15 PM.
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Joined: May 2015
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From: Allentown, PA
'08 GL 320 CDI
You mentioned that the engine is "consuming" 2 quarts per 300 miles... which is ALOT. But that is different than a leak - which is what changing the oil cooler seals would take care of (a leak). Unless you're getting oil in the antifreeze... but then your AF level would be rising very quickly. So if it's consuming oil, we need to look elsewhere.
There's not a whole lot else that is "worthwhile" to change while you're in there, though. But the fuel injector seals would be a good idea. I'd also closely inspect your intake runners and swirl motors for being gunked up.
There's not a whole lot else that is "worthwhile" to change while you're in there, though. But the fuel injector seals would be a good idea. I'd also closely inspect your intake runners and swirl motors for being gunked up.
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Newbie
Joined: Feb 2023
Posts: 6
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2008 GL320 CDI
You mentioned that the engine is "consuming" 2 quarts per 300 miles... which is ALOT. But that is different than a leak - which is what changing the oil cooler seals would take care of (a leak). Unless you're getting oil in the antifreeze... but then your AF level would be rising very quickly. So if it's consuming oil, we need to look elsewhere.
There's not a whole lot else that is "worthwhile" to change while you're in there, though. But the fuel injector seals would be a good idea. I'd also closely inspect your intake runners and swirl motors for being gunked up.
There's not a whole lot else that is "worthwhile" to change while you're in there, though. But the fuel injector seals would be a good idea. I'd also closely inspect your intake runners and swirl motors for being gunked up.
Thank you for replying
Previously the GL320 was consuming about 5 quarts every couple of days. That was terrifying.
As mentioned previously, I replaced the crank case vent and PCV (valve and tubing). The original Crank Case seal was worn and open and definitely allowing oil to get past into the PCV and turbo.
Following that, there was no more black exhaust smoke and oil consumption dropped considerably to the mentioned 2 quarts every 300 miles.
It is a real head scratcher in terms of where that oil is going.
I was thinking of also adding a catch can and re-routing the PCV hoses to vent back into the system through one of the air filter boxes for the engine.
That turbo is so powerful it seems to still be sucking oil in my mind out of the crank case vent.
Just sharing some of my thoughts out loud and appreciate your time and help
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Joined: Apr 2017
Posts: 106
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From: Northern Kentucky
2012 GL350
Ah, that's quite a bit of oil to be losing. If you aren't leaving a puddle everywhere you go, for that kind of oil consumption I'd be looking at rings and/or valve seals. I'm not aware of valve seals being a normal weak point on these, though, but I believe that they are known to need to be re-ringed.
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Joined: Jun 2012
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2008 GL320CDI (310k) & 2017 GLS450 (160k)
Since I am getting in to this lengthy job, what else can be repaired replaced when getting into the oil cooler seals and appropriate gaskets / bits? I mean since it is a deep dive into the engine, what else can be easily accessed, or replaced while there?
I would rather replace / repair as much as possible than have to tear into the engine again.
It is like the old saying, measure twice, cut once.
As an example, would it be wise to get into the head gasket at this point? Fuel injector o-rings? Etc.?
Thank you kindly
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