hey everyone,

I recently took my 2015 GL450 (55k miles, I drive about 5k miles a year) in and they highlighted the following maintenance/repair recommendations:

Question 1: Should I do the transmission service (I have read in other places where those might not be as helpful as they make them out to be but I will admit to not being a 'car guy').

Question 2: rear bushings starting to crack? Is this a big deal? It sounds like it is.

Question 3: crusted coolant? This seems consistent with a 7 year old car?

Question 4: oil pan seeping? This seems bad?

 

The advice I received years ago is regular automatic transmission fluid/filter service is recommended. With 55K miles on the car having the 60K mile transmission fluid service done now is I think a good idea. I plan on having my cargo van's automatic transmission treated to a fluid/filter service at 20K miles. A bit early but a few dollars (relatively speaking) for an early fluid service is better than spending thousands of dollars to address a bad automatic transmission.

Generally speaking I'm a fan of adhering to the automaker's service schedules for engine oil/filter, plugs, air filters (engine/cabin), fuel filters, transmission fluid (unless the automaker claims the fluid is *lifetime* then I pick a reasonable service interval for this). And while some automakers don't call for this service I'm a firm believer in a 2 year brake fluid flush/bleed.

(As an aside I often shorten the engine oil/filter service schedule from what the automaker calls for. For instance with my M-B van I have the oil/filter changed every 5K miles rather than every 10K miles. And I have been known to shorten the time between transmission fluid services.)

Also, I prefer to stay "on top" of things by having any issues dealt with. So I'd have the bushings replaced. And the engine oil pan leak addressed. And even that crusted coolant issue of the connection pipe to the water pump addressed.

That intake valve cleaning service I have encountered with other vehicles. So far I have not had to have it done. However, I make some effort to drive the vehicle service the vehicle to avoid the need to have the intake valve cleaning service done. This involves running a good oil -- the oil the factory recommends using -- and changing it at least on schedule but as I mentioned above I shorten the oil/filter service schedule. I try to avoid super low RPM driving. A bit higher RPMs tends to keep the intake cleaner so nothing accumulates.

With another brand of car with a diesel engine the engine intake was notorious for coking up. This happened over time until at some point the engine would not rev very high the build up affecting air flow through the intake. I drove my vehicle to just over 150K miles. I never had any problem. In fact just before I decided to sell it I inspected the intake. While the intake walls were coated with a black oily film there was no build up.

Last but not least every so often I'll fill up with Chevron Supreme with Techron. This stuff really works to remove deposits from the intake valves, injectors, combustion chamber, piston crown, and so on. I have never had reason to look into this but Chevron might offer a Techron suitable for use in diesel engines.

If Chevron gasoline is not available where you are you can buy Techron concentrate at an auto parts store. Use the Techron according to directions. Ideally if you use the additive from a bottle you should change the oil/filter after. So what I do is if I use Techron concentrate I arrange to do so close to when the oil/filter service is due so pretty much when the bulk of the gasoline treated with Techron is used up the vehicle is in for an oil/filter service.

The Techron is not burned up but is heated to a vapor from the heat generated by combustion then when this vapor contacts cooler surfaces it reverts to liquid form. This is in part how Techron cleans. But the downside is this Techron back in liquid from can increase oil contamination. An oil/filter service after shortly after using Techron is advisable.

 

really good advice thank you!

 

Transmission service on all MBs is a must. They are borderline designs and fluid change avoids major problems. Most of the time.

 

Transmission service usually around 70k miles. A necessity. The rest - if you have money - go for it.