1995 C280 Issues - Help Please

[Yujin]

Hi Club202,

So I have a 1995 C280, with 145K miles on it. Thing is a beast, but I feel that it needs lots of love, so parts haha.

But anyways, when I drive the car, everytime it upshifts/switches gears, i feel a massive push, as if someone just kicked my car, like a loud jerk, and yes, I can hear it in the rear. No idea what it is. Some people claim its a 'tranny mount?' or the transmission itself? No idea. I really like the car and plan on fixing it up. Any information will be appreciated.

I also washed the engine bay and now has a rough idle. No idea what I did or accidentally screwed up. MAF? Engine is stuttering. Maybe the spark plugs are f****?

Hope you guys can help me!

[rick1]

sounds like the transmition mounts..put the car in neutral..can you feel a slight shake?..
either that or the prop shaft flex disc..does the car snatch into gear from neutral?..

my bet would be the gearbox mounts..

as for the rough idle..you probably just got the plugs wet...it should dry out in shortly.

[Yujin]

sounds like the transmition mounts..put the car in neutral..can you feel a slight shake?..
either that or the prop shaft flex disc..does the car snatch into gear from neutral?..

my bet would be the gearbox mounts..

as for the rough idle..you probably just got the plugs wet...it should dry out in shortly.

Thanks a lot rick, very helpful. I didnt think of the gearbox mounts. Im gonna get them checked out soon, and see whatsup. Guess the old motto "A clean engine bay is a happy engine bay" isnt the case after the wash hahah

[rick1]

Thanks a lot rick, very helpful. I didnt think of the gearbox mounts. Im gonna get them checked out soon, and see whatsup. Guess the old motto "A clean engine bay is a happy engine bay" isnt the case after the wash hahah

if the car has a plastic under tray.you could also take that off (4 x 8mm bolts if i remeber correctly) and look for remains of the gearbox mounts in the tray..
you can sometimes find bits of the dead rubber mount laying in there..

[SD202]

Could be the flex disc's. I had bad ones when my 96 C280 started to drop into gear how you are describing. It was real violent when i dropped it into Reverse. it would clunk into gear real hard. The flex disc on these cars are noticeable if bad. also. You cant miss it.

[horgantrevor]

hi

did you change the oil and filter in auto box and if so when

has any one moved the gear-stick from drive into neutral while driving or into reverse quickly with out full
stopping and back into D then as this will damage torque converter ,

as for the plugs check water in head near leads for plugs best thing is not wash an w202 engine as several things take in water in their like the BAS unit will take in water and you can get a bas asr fault

i would remove plugs and and replace or clean and it can only help

[Sulaco]

I hate to be unhelpful, but I wish I had a dime for everytime on this forum someone washed their engine and then reported back here with engine electronics issues.

Could have ruined the MAF, OVP, gotten water in vac lines, plugs, coils, plug ends. And if your's still has factory original wiring harness, then you definitely pushed it over the edge and shredded some wiring insulation which can only be repaired by getting a new, pricey wiring harness. If that be the case, I have one I can sell you at a huge discount. I think they run $1100 at the dealer and $750 online.

If you're going to change plugs, use OEM only--and not what autozone says is OEM. Bosch copper plugs only, F8DC4 I think is the specific model. The m104 engine only likes 2 different plugs on this earth, and they only still make 1 of them (the bosch).

[SD202]

What sulaco said. Man is right Sounds like hes speaking from a stand point of experience and knowledge and not a stand point of guessing and those values are what make a man. Ive learned what hes saying the hard way with my old M104. DO NOT run any other plugs than the F8DC4. Unless your car needs a new valve cover.... No CEL thrown because of the rough idle ?

[Yujin]

Apologies for the super late reply!

But my brother has been driving the car and it runs good now, except for the misfires. Blown spark plugs maybe? Is there any damage that can be done with misfires?

Thanks

Yujin

[horgantrevor]

unburned fuel can reck cats

[mbsickness]

unburned fuel can reck cats

Exactly. I have seen cats melted down in one day of driving due to misfires.