R129 help please...desperate now!
R129 help please...desperate now!
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Jibber Jabber

Original Poster:

1,034 posts

235 months

Thursday 22nd November 2012
quotequote all
Hi All,

I've had my 93 500SL for 3 years now and she's been great until she sat for a couple of months whilst life took over. This was about a year ago.

I now have this issue that nobody (including a merc specialist) can seem to solve.

The car fires up first time, no problems at all. If I drive it the 5 miles to the petrol station and switch off it will not start again until it's cooled off. I have to leave it 2-3 hours before trying again. Recently it's started to cough, splutter and cut out before it reaches the garage. Only once it warms up though?

It will turn over fine, although after a while it will pop as though it's overfuelling.

I don't use the car at all now and I need it off the drive but I really don't want to sell with an issue (not that I wouldn't mention it, I'd just rather the car be in good working order).

I'm started to be tempted to get a ticket and sell as is but not knowing what the problem is will mean losing a fair amount of £££. I just don't have the time nor finances at the moment with a new business starting to take off and the thoughts of spending £100s if not £1000s does not appeal as the business needs the cash.

Anyone have any advice, seen the problem before?

Thanks.

S-Express

66 posts

269 months

Thursday 22nd November 2012
quotequote all
Worn out/cracked distributor caps perhaps? Has the bio-degradable top engine loom been replaced?

Jibber Jabber

Original Poster:

1,034 posts

235 months

Thursday 22nd November 2012
quotequote all
S-Express said:
Worn out/cracked distributor caps perhaps? Has the bio-degradable top engine loom been replaced?
The merc specialist did mention the caps and rotar arms but asking about no one could think why this would affect it only when warm and not when cold?

Top engine loom not been replaced as fas as I am aware?

chazola

459 posts

186 months

Thursday 22nd November 2012
quotequote all
Sounds like vapor lock that some of the older Mercs used to get, maybe dodgy coil pack? Fuel pump? Distributor cap/arm like previous poster said?

Jibber Jabber

Original Poster:

1,034 posts

235 months

Thursday 22nd November 2012
quotequote all
chazola said:
Sounds like vapor lock that some of the older Mercs used to get, maybe dodgy coil pack? Fuel pump? Distributor cap/arm like previous poster said?
This is my issue. I could spend a fortune on things that aren't the cause.

Does anyone know what the availablity of seconds are like for these? Can't imagine that many have been broken up recently.

r129sl

9,518 posts

232 months

Thursday 22nd November 2012
quotequote all
There are two possibilities, neither will cost the earth.

1. Crankshaft position sensor. Classic symptom: car will not start when hot.

2. Distributor caps. Condensation forms. Car comes up to temperature. Condensation turns to water vapour. Vapour causes arcing. Car runs rough or cuts out and refuses to restart.

I would go with dizzy caps first. You should do the rotor while you're at it.

Jibber Jabber

Original Poster:

1,034 posts

235 months

Thursday 22nd November 2012
quotequote all
r129sl said:
There are two possibilities, neither will cost the earth.

1. Crankshaft position sensor. Classic symptom: car will not start when hot.

2. Distributor caps. Condensation forms. Car comes up to temperature. Condensation turns to water vapour. Vapour causes arcing. Car runs rough or cuts out and refuses to restart.

I would go with dizzy caps first. You should do the rotor while you're at it.
Great, think I'll bite the bullet on the caps and arms and sensor If still no joy then it'll be an ebay as is job.

Merc guy told me to get Bosch only for the caps. Any suggestions on where to get them as I'm guessing Mercedes will not be the cheapest!

GregE240

10,857 posts

296 months

Thursday 22nd November 2012
quotequote all
Just read this, sorry.

Yep, sounds like caps. Had a similar issue with mine.

Get Bosch, the OEM Merc ones are made by Bosch, except with a Merc part number they are twice as expensive.

The first set I had weren't Bosch. They lasted 6 months. Don't make the same mistake!

r129sl

9,518 posts

232 months

Thursday 22nd November 2012
quotequote all
Any motor factor. Try Andrew Page, there's bound to be a branch near you.

Highway Star

3,615 posts

260 months

Saturday 24th November 2012
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Sounds similar to the problem my wife's SLK had which turned out to be the crankshaft sensor.

slk 32

1,529 posts

222 months

Saturday 24th November 2012
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Does sound like crankshaft sensor.same symptoms as my 11 yr old 32. The mobilo life guy had one on the van which makes be believe part was interchangeable across several models. Cost £100 (not inc fitting)

Yuxi

650 posts

218 months

Sunday 25th November 2012
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Not sure how good your specialist is!

I have a 93 500SL - one of the first 067 cars, it started doing the same thing, it would be fine when cold then start missing and running on less than 8 cylinders after a few miles and was sometimes very difficult to start once this started happening. I removed and cleaned both rotor arms and caps, they were dirty, wet and corroded and covered in tracking marks, the wet in them tasted very strongly of acid. I thoroughly cleaned and dried them and the problem went away for a few months, the moment the issue started to return I repalced all four items with new parts from GSF, about £140, no issues since.

I suggest you remove and clean caps and rotor arms and see what happens, if they are in bad condition replace them anyway.


355spiderguy

1,476 posts

200 months

Sunday 25th November 2012
quotequote all
r129sl said:
There are two possibilities, neither will cost the earth.

1. Crankshaft position sensor. Classic symptom: car will not start when hot.

2. Distributor caps. Condensation forms. Car comes up to temperature. Condensation turns to water vapour. Vapour causes arcing. Car runs rough or cuts out and refuses to restart.

I would go with dizzy caps first. You should do the rotor while you're at it.
+1

had both of these issues before ( albeit years ago! )

first with a 300 te auto estate.... would travel 18 miles ( bang on! ) then die...had to wait untill is was cold. in this case it was crankshaft sensor.

second with SL500 of '94 vintage.... would cut out infrequently when stationary; it was about to go in to MB anyways for a service and we replaced (if i reacall correctly) 2 distributor caps and rotors. this may of been how your SL started out before developing into cutting out and not restarting.

i would defo try both of these relatively inexpensive ideas before offloading 'with a problem' at a huge discount.

hope this helps, and do post what, if anything you discover.

Gouki

352 posts

213 months

Sunday 25th November 2012
quotequote all
I experienced a similar issue when driving my dads w140 s500. Condensation in distributor caps, make sure you by the MB ones though. I was able to remove and dry them out myself and I am no mechanic!

sim16v

2,177 posts

230 months

Monday 26th November 2012
quotequote all
I'd normally suggest Eurowrongparts for the bits, but they have another company that is normally cheaper than even their 30% discount prices.

Might be worth trying www.cartparts4less.co.uk to see how the prices compare.

Jibber Jabber

Original Poster:

1,034 posts

235 months

Tuesday 27th November 2012
quotequote all
Thanks for all the replies.

The 'specialist' did give the caps a damn good clean. The car ran fine sat on the drive but took it for a spin and it died. Think I'll go with the crank shaft sensor to start with.

Am I right in presuming I am looking for one of these?? http://www.gsfcarparts.com/929me0181

Major ball ache of a job or could a novice have a go?

slk 32

1,529 posts

222 months

Tuesday 27th November 2012
quotequote all
Depends where it is on the car. When mine was done by the mobiloservice fellow took only a matter of 30 mins (that also included clearing the STAR machine and resetting to make sure all was working)

The part itself seemed to be buried in the very bowels of the engine so access was awkward. Needed a long handled tool of some kind but should be reasonably easy to do for someone who is not completely inept (unfortunately this ruled me out)


Dog Star

17,540 posts

197 months

Wednesday 28th November 2012
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I'd be looking at plug/coil breakdown due to heat.

Also (had this on a V6 Pug 406 Coupe) - started and ran fine when cold, popped and spluttered and wouldn't start when hot, symptoms of overfuelling. It was the thermistor that controlled the auto choke; car thought it was cold all the time so, effectively, was keeping the fuel mix rich.

AC43

13,593 posts

237 months

Wednesday 28th November 2012
quotequote all
I had crank sensors let go on both of my C43's and on my current W211 (another V8).

On one of the C43's I once had a slight but hard to trace misfire. The indie tested all 16 HT leads and all 8 coil packs individually and found two faulty leads and one dodgy coil pack.

anonymous-user

83 months

Wednesday 28th November 2012
quotequote all
Stick a cap and rotor arm on it, seen it so many times (Mercedes tech).