perplexing & frightening experience - PeachParts Mercedes-Benz Forum

poorstylishman · #1 08-14-2002, 02:35 PM

Hello everyone. After reading countless threads over the past year, and subsequently finding answers to my queries, i've got to ask a question regarding a frightening experience:

The other day I was driving my 87 190 2.3 8v to the beach on a two lane road in the cottage country of ontario. As i started to make a pass in a designated passing zone, i manually shifted my autobox from D to 3rd (to avoid appling full throttle and encountering a violent kickdown). As i accelerated past 80km/h i hit full throttle. Just then the car came out of gear as if trying to shift down into 2nd, and instantly bounced off the rev limiter. I quickly backed off the throttle, and pulled over. No idiot lights came on, and the engine still runs fine. What could have caused this? My car has an 86 8v engine in it with ALOT of KM on it, bouncing off the rev limiter is not something that I like, nor can afford to do. Any suggestions to avoid this would be greatly appreciated.

BTW, great site... it's nice to see a dedicated enthusiasts site that's about great cars and owners.

pentoman · #2 08-14-2002, 07:35 PM

Hi,

Glad you came out from the woodwork to ask a question!
I commonly do what you do with my autobox - changing down the gears on the stick ready for instant acceleration, and for fast cornering (although a high engine speed can = less stable car). I have heard these cars can be driven 'on the stick' forever with no problems (and I have done for a year or so).

Sorry to bear possible bad news, but this is the exact symptom I had when my autobox went bad 15 months ago. It never happened because of being under full acceleration, usually while simply cruising along, the drive would be lost in 3rd and 4th gears (can't remember which one at first, but after a while, both) and I could freely rev the engine despite being in '3' or 'D'. The gearbox at this point will actually be trying to engine 2nd gear.

The only solution I found was to slow to a speed applicable for 2nd gear, and bring the engine revs up to the required revs for that speed, then 2nd would engage fine. It would later change up to 3rd or 4th gear as usual, only to do it all over again a few seconds later.

Eventually it was found to be water in the transmission oil (radiator broke) and of course, big UK £££ or in fact Can $$$ for you and a reconditioned autobox.

BUT! This is a worse case scenario. There may be a more simple fix, but generally the cheap & simple fixes in MB automatics seem to be reserved for harsh shifting/not shifting etc. not 'loss of drive while in gear'

Recommend, if the problem persists, taking it to an automatics specialist with as much Mercedes experience as possible, or a good independant garage. The dealers may be a bit too keen to assume & say 'yeah it must be broken - you need a new one. Please sign us a blank cheque'
Otherwise, keep on driving it. The engines are very solid and can stand running on the limiter. I believe 'Sisco' who sometimes lurks here, drove his 170,000++ miles 4-cylinder 190E on the rev limiter for a whole 15 minute drive to try and break the engine (he failed, it continued to run like clockwork) before removing it to fit a 2.4 supercharged beast.

hope you get good news!

later

Russ

P.S. There's not too many idiot lights on a '87 190E, only low engine oil, alternator, ABS, water level that's about it. Certainly no warnings about gearbox or engine problems.

poorstylishman · #3 08-15-2002, 12:31 PM

thanks for the tip... my girlfriend's got the car now (cringe) i just hope that she at least holds it in 3rd while accelerating. Usually she'll take off in drive, allow the car to bog severly because of 'economy mode', then she stomps on the gas and encounters that violent kickdown i mentioned. sheeesh! why don't women understand the concept of gear ratios?! but now i'm just venting.

thanks again.

pentoman · #4 08-15-2002, 07:04 PM

Heh.. I know what you mean by the bog when in Economy mode - you could run it in 'Standard' mode?

But sometimes I like to cruise in Economy mode in '3', letting the torquey engine do the work. In fact the 4-cylinder is a rather good engine when you get past it's lack of pace - it pulls quite hard at very low revs, yet is willing and revs to the 6000rpm limiter again and again without sounding stressed or blowing up. Max torque at 3500 rpm is an impressive figure, especially compared to the six-cylinders' 4400 rpm peak.

Makes me wonder why I'm swapping mine out and fitting in a 2.6 or 3.0 Mercedes Six-cylinder... but I've already made up my mind to do it!!

later

Russ