Any engine issues with GL450 or GL550?
Our ML suffered the dreaded balance shaft issue, I was hoping if anyone could tell me if the 450/550 had any major issues like balance shafts etc? I know it effected some Mercedes V8's and my searches have come up blank
Anyone have any personal experience with the 450 vs 550? Power vs. Weight?
I know what to expect overall from the car valve body, cam plugs and airmatic struts as maintenance items.
Just want to ensure the engine selections are both south and reliable.




The idler gear is an issue in some but it seems to be very rare with only one issue posted, that I can recall, on this forum since I've been a member. However, there was a lawsuit and MB extended the warranty to cover the issue for 10 years or 125k miles so it must be an issue in some engines. It is a very labor intensive and expensive repair but, again, seems very rare.
and ECU (thank God all still under warranty). I was then told that the wiring harness has to be remade in Germany and would take 3 MONTHS to come in. After 3 months I got the truck back but am concerned that this is a problem (around 5k to fix) that could reoccur (and reportedly has for many) again once out of warranty. There was no mention of "new" parts to alleviate this problem in the future l. AND I have the dealer installed Renntech upgrade! Any others had this or know of this? Any recalls on this??
Last edited by Sean Daveiga; Jan 8, 2019 at 01:51 PM.




Sean, you have a completely different engine and chassis. This is the X164 GL section and you have a X166. I also have an GL63 and I love, love, love it. Just too fun!
Sean, you have a completely different engine and chassis. This is the X164 GL section and you have a X166. I also have an GL63 and I love, love, love it. Just too fun!
I posted on a few areas here as several have experienced this in several different models concerning cam magnets. Considering the cost of repair (5-8k), you'd think this would be addressed and fixed by now. I'll seriously reconsider keeping outside a warranty.


