[Jura117]

Hey guys, I'm new to the forum so first of all hello to everyone. I have a problem with my 1993 500SEL. Recently I've changed the spark plugs and since then the car started to idle rough, not all the time but noticeable. While changing the plugs I've realized that the wiring harness had deteriorated so I went and had it rebuilt. Today I've mounted the harness and started the car and it idles rough all the time and has really poor acceleration. I'm wondering what the problem could be. Also I had transmission issues when I bought the car so I changed the tranny. The one I installed looked to be in perfect shape and the oil inside it was perfectly red. Since I put it on I've done about 3000 kilometers and the transmission started to slip, there's a few second delay when putting it in D/R. When the car is in 2nd gear and I floor it, it starts to rev all the way to redline but doesn't change gear and changes only when I release the gas pedal. Any help would be much appreciated.

 

[Drbobme1]

I WOULD SUSPECT THE NEW WIRING HARNESS. Either wires misplaced by builder or you installed two on the wrong plugs.

 

[Jura117]

Thanks for your input, do you have any ideas regarding the transmission issues? This was happening even before the harness was replaced.

 

[Drbobme1]

Is the slip only when going into D/R or all the time. Why would you redline a 27 year old car?

 

[Jura117]

I'm not redlining it, it revs up to redline when I try to kickdown as in it doesn't downshift, but it slips and revs up the engine as if it were in neutral. When I start the car and it's in park and I select drive or reverse it doesn't engage Right away as it should, if I give it throttle it just revs without moving, and it only catches the gear after approximately 5-6 seconds. And once it catches the gear it's slipping and revving as if it were in neutral from time to time. Sometimes it won't even go it just revs. The transmission, filter and fluid have been changed 3000 kms ago.

 

[Drbobme1]

Sounds like your used trans is bad.