Looking at it would be all you could do since it would be too slow to safely drive it.

A GL weighs 5,550lbs+

I am glad I went with the OM651 as my modern diesel ownership experiment. Engine has been flawless, a few emission system issues (exhaust) but overall good experience so far 2 years/21k miles into it. And double the MPG my 420SEL used to get, can't compain!

When you think of how many OM642s are out there roaring around all day these failures amount to a fraction of a percent of total engines in operation....you never hear about all the ones running just fine.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)