Name the bad stuff about the M104 I6 motor
 

I know the gaskets leak, but are there any other bad things to really say about the M104 lineup??? I'm new to the Benz game & that is the motor that gets me to work & school. I dont like bummin rides!

Hmm... the only across the board issue I can think of is the wiring harness. The ones through about 1995 had bad insulation, and would often fail prematurely creating a huge variety of symptoms. Many of these were changed under warranty. I've seen some reports of leaking from the head gasket, but that was really more of an M103 problem. That's what I recall FWIW - 'course I don't have one, so maybe someone w/ personal experience will help.

Engine wiring harness, Upper timing cover leaks, front crank seal leaks, Every now and then main oil pan leaks. Overall, damn near bulletproof mill. :D




Joe

I agree...engine is nearly bulletproof...it's the ancillary components that give you headaches! :rolleyes:

The radiator will crack at the inlet neck at around 100K.

You already know about the head gasket problem. It's a problem for BOTH the M103 & M104, just the failure symptoms are different. Oil leaking at the front is the timing cover seal, at the rear, it's the head gasket.

Water pump, alternator, and other parts depend on usage and conditions, but they will go belly up eventually.

Loud clanking sound at idle? Connecting rod? No. More like a worn bushing on the belt tensioner shock.

Loud grinding sound at startup? Bearings going bad on the air pump. The bearings are (of course) not a readily-available size, so total replacement is necessary. :rolleyes:

The OVP relay is the source of all sorts of weird idle and starting problems. If yours is original, be prepared.

Fan bearing about 200,000 miles goes bad also.

Bulletproof my butt.

My M104 AMG engine had to have it's heads resurfaced at 90,000 Kilometers.

I don't drive aggressively either.

the wiring harness isuue only affects late 1992 -1995 m104's from what I know.

Other than that, head gasket is the only other issue I know about.

Haven't heard of any leaking elsewhere.

Mines at 103k no leaks, no harness problems. My car was made aug 1991 though, but is a 92 model year.

Alon

The wiring harnesses are bad from '93 to '95.

The original head gaskets were poorly designed, and the new head gaskets have steel inserts and don't leak.

Other than that, there are really no major complaints.

My 92 400SE has been fairly good up to now, 128000 k miles, I had all the wiring harness replaced a couple of years ago when it got fried, but since then I have the ac/heater blower going slow, the window motor dead, window regulator dead, power antenna dead, a couple of door vacuum? don't work, besides that it is a pretty nice car.
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John