I bought a 2007 ML320 CDI about a month ago and am finding that it has a few problems. It has 121000 miles on it and needs the oil cooler seals replaced. Dealer quoted $4900.00.

Is this worth putting that kind of money in to? If we do, what is the next most common issue we may be looking forward to?

We just did the 120000 mile service and replaced the front cv axles.

Thanks for any input you can offer.

 

I've been driving one for 1 year, 10k miles & have been overall impressed. All fluids & filters have been swapped out for new on time. There were coolant, oil & fuel leaks all over engine that PO had let go unchecked so once I replaced all leaky seals & cleaned engine with brake cleaner, I just left all plastic soundproofing off so more easily inspect for any leaks after long drives . I had to replace turbo as PO had allowed turbo air intake seal to get pinched & partially ingested. Impeller blades were all chewed up & turbo codes kept showing up on Quick Test that would put car in limp mode. The oil leakiness of engine is biggest issue imho. Oil cooler seals had been replaced prior to me buying it. Oil leaks around turbo air intake seal from CCV valve is what should be monitored closely. This oil will cascade across swirl flap motor, turbo pedestal, & then into engine valley where it will channel around oil cooler & eventually find it's way to driver's side weep hole of engine. It will make all components suspect for leaks. I installed a oil catch can circuit with stainless steel scrubbing pads to my CCV return in front of turbo to mitigate blow-by oil. Another common leak is around oil filter housing which will drip into serpentine belt & sling it all over engine. Power steering leaks on mine around where steering linkage connects to rack & pinion but leak is so slow that I just monitor dipstick & add a little as needed (rarely). If you seriously want to own this vehicle for any length of time, it is MANDATORY to own a Mercedes capable scan tool so that you can monitor actual values of diesel particulate filter, fuel rail & injector pressures, & turbo performance as examples + much more. These systems can leave you broke-down roadside on long trips but be very happy that you don't have diesel exhaust fluid fun like bluetecs get to.

 

Its worth it if you do it yourself.

 

Its a big job. I've done it myself... (now they're leaking again )

Overall, it's been a pretty good vehicle but I would know what you're getting into. If it's just the oil cooler seals and the leak isn't bad, there's really no rush in fixing it. If the flap motor has died, that's a different story. If you do end up doing the seals, replace the flap motor while youre in there.

 

I was able to locate a German shop about an hour away. They are replacing the seals, flap, oil cooler, air and fuel filter as well as cleaning the intakes and carbon build up. Total cost out the door is $2490.53

much better that the dealer for just the seals. They have definitely earned my future business.

thanks for the reply’s everyone.

 

That's actually not a bad price. You might want to ask them to replace the flap motor while they're in there. It's another $100-$200 or so, and if it fails, you'll have to spend $2500 again to replace the motor. Just a thought.