c220 problem with starting...

[anyweb]

hi again all,

i've had the same problem twice in one week so something must be up, i just drove to the shop about 14k away and needed to get some cash from the cash machine, so i pulled up, turned off the car, got my money, back in the car, started it and as i pulled away noticed the engine was reving itself and the revs were all by itself, as if i had my foot stuck down hard on the accelorator, a quick few flicks with my foot on the accelorator pedal did not convince it to stop this behaviour so i struggled to get the car to the shop which was very close. I then parked the car and turned it off. Let it rest for a few seconds and tried to start it, no go engine turning over, starter motor turning but no life. This happened for the next five minutes or so, repeatadly trying to start but no life. I did check that the GREEN led was on on my rear view mirror, still the same .

I had a very similar incident in the same week, where i picked up my son from a friends,. and we went to get pizza. The pizza shop was literally 20 metres away so i pulled up to that shop and the car cut out on me, stone dead with the car half way on/off the road, repeated efforts to try and start it failed.

the car battery is new, less than two months old so i doubt it's that, once i got the car started (after trying time and time again, i then left it ON while i went in to pick up the pizza, my son sat in the car.) When i came out of the pizza shop i could have sworn i heard the car accelerating itself and asked my son was it, and he said it was.

So there you have it, a very odd problem which i'd like your advice too,

why is my car REVVING up by itself (up to 20/30 on the rev clock), and why does it then (when shutdown imediatly after this behaviour) refuse point blank to start.

It's a very strange problem which i'd normally ignore, but twice in one week is too much of a coincedence,

all advice appreciated i hope you can give me an idea of what is causing this issue

it's a merc c220 from 1995, petrol, 170k on the clock.

cheers
anyweb

 

[anyweb]

*bump*

any thoughts guys ?

 

[Myros]

sounds a bit like an easy answer

have you checked the OVP. I hear they can do all sorts of funny things to the car. Mine never stopped it cranking though.

 

[television]

Three things come to mind, stop withdrawing money, stop eating pizza or check your Over voltage relay, Pin 30 (input) should have 12 volts. Pins 87 (output) should have 12volt, this device sufferes from dry joints, in its worst state the output drops to 7.5 volt and this shuts down the engine management ECU.as a safety measure the engine is speeded up.
As you know with your computers if the power supply goes down, so does everything else, its a matter of basics, and you must start there. Tapping the unit with the engine running would instergate the fault.
talk to you later

malcolm
this fault often comes to light on changing Batt

 

[anyweb]

Three things come to mind, stop withdrawing money, stop eating pizza or check your Over voltage relay, Pin 30 (input) should have 12 volts. Pins 87 (output) should have 12volt, this device sufferes from dry joints, in its worst state the output drops to 7.5 volt and this shuts down the engine management ECU.as a safety measure the engine is speeded up.
As you know with your computers if the power supply goes down, so does everything else, its a matter of basics, and you must start there. Tapping the unit with the engine running would instergate the fault.
talk to you later

malcolm
this fault often comes to light on changing Batt

hmm you are so technical ! thanks a lot Malcolm

where can i locate this unit/relay ? do you have a photo of where in my engine i should be looking for this relay ? i'm not as technical as you ya see

thanks again for the advice

cheers
anyweb

 

[television]

hmm you are so technical ! thanks a lot Malcolm

where can i locate this unit/relay ? do you have a photo of where in my engine i should be looking for this relay ? i'm not as technical as you ya see

thanks again for the advice

cheers
anyweb

Its next to the battery,i think under bonnet on yours. its got a fuse on top.

Its not a case of being technical, I get through faults much quicker by saying well its not this and its not that,so the fault must be ------can still be arkward or hard. I only ask the above so that one can move forwards and not backwards, Make the most of life, in a few years time when the car is all data and CAN buss, there will be nothing we can do to sort it out. The 123 was a DIY car, the 124 was the start of not being able to do that much.and it gets harder and harder, even MB cant fix that many, I mean if you change everything you stand a chance of fixing it

Malcolm

 

[anyweb]

my battery is in the boot, so should the over voltage relay look conspicuous ?

cheers
anyweb

 

[television]

my battery is in the boot, so should the over voltage relay look conspicuous ?

cheers
anyweb

yes it normally sits just behind the battery or just in front (Iwill check this evening) just a small 30x 30mm kind of size with a red or orange fuse on top.
if you cant find it as I say I will look it up,afew cars have it in the bulk head.
It will be dark where you are by now or do you have a garage (warm)

Malcolm

 

[anyweb]

dark, but i have a torch, i'll take a look later this evening if i get a chance

thanks malcolm i appreciate your help

 

[Myros]

on the C280

it's up in front, passenger side on an LHD, near the ECU. Tall, about 6cm, square section,about 2.5cm, silvery, with a transparent top and a blade fuse located in it. Probably made by Siemens, who also made the cr*p computers I have at work.

 

[anyweb]

hmm ok im confused should i look in the front or the back, i havent had a chance yet, but i have noticed another failure (related ???)

while driving today on second start the lights near the sunroof (reading light etc) stayed ON full the whole drive no matter what position the switchs were in

also, they didnt want to go off when i turned off the car, eventually i have no idea how they decided to turn off normally with the 10 second or so delay

later this evening i popped in the car to get something (still no time to check the fuse/relay) and upone closing the car the reading lights were full on again for 15 minutes no matter if i pressed the key fob on or off

so what is going on here ??? and what do i need to fix, can i fix it myself (i'm ok with a soldering iron) or do i need to purchase spare parts, and will it be costly if so ?

cheers

anyweb

 

[television]

hmm ok im confused should i look in the front or the back, i havent had a chance yet, but i have noticed another failure (related ???)

while driving today on second start the lights near the sunroof (reading light etc) stayed ON full the whole drive no matter what position the switchs were in

also, they didnt want to go off when i turned off the car, eventually i have no idea how they decided to turn off normally with the 10 second or so delay

later this evening i popped in the car to get something (still no time to check the fuse/relay) and upone closing the car the reading lights were full on again for 15 minutes no matter if i pressed the key fob on or off

so what is going on here ??? and what do i need to fix, can i fix it myself (i'm ok with a soldering iron) or do i need to purchase spare parts, and will it be costly if so ?

cheers

anyweb

Myros is right, I had some doubt but hard to remember it is in the bonnet by the ECU, this still needs checking first

malcolm

 

[anyweb]

ok managed to get a moment to look under the bonnet and in the boot, i do see a silver colored RELAY with a fuse in it (at the top of the relay) under the bonnet, standing about 2 inches tall beside two black cables which i assume are plugged into the ECU, this is on the right hand side of my LHD car.

is that the part i need to fix ? do i need to completely replace it, do i just pop it out and put in a new one or do i need special removal instructions

drove to the shop again this evening and the accelration was acting weird again (noticeable when you push in the cluth, the revometre goes way up to 30 by itself and the engine sounds hard at work

hmm, cant wait to get this problem fixed it's really annoying

cheers
anyweb

 

[anyweb]

thanks again to both myros and television,

i'll see if i can dabble with the ovp relay tomorrow (all depends on time) !

any idea of cost of replacement, or can i just solder it back together ?

cheers
anyweb

 

[television]

You must have a voltmeter (multi meter) you must have 12v on pin 30 and 12 volt on any pins 87( could have 2) I only ask this basic check. the unit does respond well to resoldering make sure that all joints have flowed and are bright and shiny, do all of them even if they look perfect.
this could well not be the fault but it has to be isolated from the list.

Malcolm

 

[anyweb]

i have a multimetre but i'm no electrician,

do i remove the relay and test it with the multimetre out of the car or what ? sorry for being so clueless but i'm just trying to learn

cheers
anyweb

 

[television]

No test on the car, the pins are clearly numbered.

You remind me of my youngest son he has 15 servers in his garage all running the noise is unbearable and the heat!! If I ask him something about computers its all done so fast I don't take in one thing, outside of computers he is lost too

Malcolm

 

[anyweb]

is this the OVP relay ?

hi again, just to be sure, is this the part you are referring to ? if so i cannot see ow i can resolder it (its sealed) and not only that the pins are numbered 1 to 9 and in order to test any pin would be difficult as when i attach the cable to the relay, the whole device is out of reach


so assuming i cannot re-solder this part (if its the correct one) then i should pop down to the stealers and buy a new one....

pls advise

cheers
anyweb

 

[anyweb]

guys how can i resolder it, do i have to manhandle the white plastic cover off ? i'm afraid of breaking it...

pls advise

from googling ive discovered that the part number on mine 000 540 67 45 is the good OVP

see here

http://groups.google.com/group/alt.auto.mercedes/msg/e27ba7d63ed045d9?hl=en&

so if mine is the 'replacement' model from mercedes, then is it indeed broken or ?

anyweb

 

[anyweb]

i took the unit out, cleaned the pins and sprayed some oil on them then wiped the excess off

since then i have not had the car 'accelerate on me' by itself, however i still have my intermittent and very annoying interior lights coming on by themselves after about 10 minutes or so of driving

i guess that'll be another post....

cheers
anyweb