How's this for coincidence??

[Alex Argent]

Yesterday, whilst in Romford, Essex I decided to venture into the local stealership to get the parts required to change the ATF fluid this weekend (e.g. dipstick, gasket, filter, etc), only to be told "sorry mate, wrong place. You need the parts department on Eastern Avenue". As time was pushing on, I hastily said my thanks, and returned to the car park.

On opening the car, and turning the key (DAS type) the engine would simply not fire. Not even a cough or splutter! Engine turning fine, battery definitely okay, car opening and closing on remote key fob, but no start. So out of car, locked it again, left it about 2-3 minutes and tried again. Nothing. Went through this procedure twice more to no avail - engine turning good but did not even try to fire. Oh dear, well at least I had broken down in the MB car park, so it was not all doom and gloom. After summoning a member of the sales team to establish if their knowledge was greater than mine, or if I was missing something obvious here, one helpful fella came out stating "it's probably the batteries in the remote", and proceeded over to the car to 'try' to start it and........you've guessed, started first time!!

On the assumption this was yet another MB foible, I departed the car park with engine running as well as ever. However, on parking about 30 minutes later, locking the car, returning to car after 10 minutes (yep, guessed again.....parts not in stock), same problem again. Plenty of turning, plenty of battery power, zero firing. After locking and unlocking the car several times, the car started perfectly after about half a turn of the starter motor (as it has always done), drove home, and it's been okay ever since.

Something makes me assume this has something to do with either the immobiliser system or possibly the DAS. The remote fob batteries seem okay as they are locking and unlocking the car okay, albeit not from the distance it used to when they were last replaced (about 2 years ago).

The other thing I noticed which may or may not be normal (because previously it's always started 'on the button'), is when the starter motor was simply turning, the ignition key was not returning to its 'normal' position from its 'start' position for about 6 -7 seconds, i.e. the starter motor was still turning although I had let go of the key.

Anyone any ideas what may have been going on?

All comments gratefully received.

Alex

 

[MangoMan]

This is probably of no real help, but my 300ce does this sometimes, exactly as you describe, plenty of engine turn but absolutely no 'fire', as if someones removed the rotor arm as a joke.

Then minutes later, it's as if it's never happened. It's happened to me twice in a year.

Very strange......

 

[stats007]

Do you have a transponder ignition switch? I know these can be problematic on R129s.

 

[kbhogalW126]

Maybe the Stealers have a special remote control that makes cars breakdown in their car parks?

Could be an embedded module that is only activated when in the car park?

Good little earner, isn't it?

Seriously though, sorry I cant help but after being in a meeting for 10 hours I needed to have a little chuckle to myself.

I'll just crawl back into my hole shall I? . . . . . . . . . . . .

 

[Alex Argent]

Maybe the Stealers have a special remote control that makes cars breakdown in their car parks?

Could be an embedded module that is only activated when in the car park?

Good little earner, isn't it?

Seriously though, sorry I cant help but after being in a meeting for 10 hours I needed to have a little chuckle to myself.

I'll just crawl back into my hole shall I? . . . . . . . . . . . .

I'd stay well away from that hole 'cos that's the first thing I thought about too!

Do you have a transponder ignition switch? I know these can be problematic on R129s.

It has a 'Driver Authorisation System' (DAS) which one assumes is MB speak for a transponder type ignition link. The key transmits an infra red signal to a corresponding receiver fitted within the ignition switch. I think this must be interfaced with the immobiliser system for it too work as it's designed to (i.e. the car can only be started with a correctly programmed key).

It would be helpful to know if the immobiliser (factory fit MB type) will still allow the engine to turn once it has been activated. If the answer is definitely not, then I can forget the connection with the immobiliser.

Keep 'em coming guys!

 

[Fandango]

The other thing I noticed which may or may not be normal (because previously it's always started 'on the button'), is when the starter motor was simply turning, the ignition key was not returning to its 'normal' position from its 'start' position for about 6 -7 seconds, i.e. the starter motor was still turning although I had let go of the key.

Anyone any ideas what may have been going on?

All comments gratefully received.

Alex

This is a feature, not a fault. You only have to momentarily turn the key to the start position, and the starter motor will turn until the engine fires.
Or not, as in your case

For your starting problem:
I know it sounds unlikely, but I would definitely try a new battery in your fob, or try your spare key for a while. It's the cheapest possibility eliminated anyway...

Regards
Karl

 

[Glenn Smith]

Our C class did this once, even rang the breakdown, then it started, been fine since, alsohad a puegeot that did it occasionly, I put it down to the transponder not being "read" by the vehicle electronics, this part of the system requires no power from the ignition key, the later type uses radio signal for locking & alarm and infared for opening or closing doors (point at door handle and hold button) perhaps a reset on your vehicle would help i.e. disconnect battery for a while.

 

[Dieselman]

If your car has DAS3 with the electronic key then no batteries are required for the immobiliser as it uses the power from the vehicle to exite the key and pass an IR beam back to the ignition barrel.
The batteries are there for the central locking only.

My bet goes on the crank sensor being faulty.

 

[stats007]

Crank and cam sensors are a bit dodgy it seems - especially on M112s. It's a possibility though wouldn't it cause a fault code?

 

[jaymanek]

I had this EXACT problem last week. Customer picked up car and when I went to deliver him some bits leftover he said this had happened on his trip to preston.

We tried it there and same thing, plenty of turning no firing. then two minutes later it started fine..

I had washed all the carpets and seats, some were still damp.

We left the car running, removed all mats and put heating on max to dry it all out...

He said if it continued he would take it to local specialist... havent heard from him but not looking forward to the bill if it still is playing up!

EDIT: PS this was an E240 Estate, 2000 X reg...

 

[Alex Argent]

Help!!!!

Guys,

Thanks for all of the very useful replies.

Today has been an absolute nightmare. Car started perfectly this morning and ok all the way into London via fast roads and M11. Got to the Highway (Tower Bridge) and sitting in outside lane at lights..........it just died. Rang AA, explained problem, they said they'd send someone within an hour (max) to investigate. AA man rang back after 15 minutes, explained problem again, he said "you'll probably need a star diagnostic test (obviously knew his game!). However, by this time, I had managed to restart the car, and it was as if nothing had happened, so advised Mr AA (not me!) not to bother as I was no longer causing an obstruction and would get it into an MB dealer prompto.

4 hours later following another 7 x 20 minute approx breakdowns, I finally managed to get to MB Dartford. Throughout this period I had been thinking a fuel starvation problem all along as a result of the symptoms, i.e. it would run for about 15 minutes, die, wouldn't start again for another 20 minutes. Explained to service guy at Dartford with my thoughts (good idea??), who agreed and thought it was probably fuel pump relay. Also stated too busy to do this afternoon, so I just bought it and said I'd change myself. On asking where it was, I got all three options, "it's in the boot", "it's under the bonnet", "it's above the drivers footwell under the dash". Looked under boot carpet, nothing there but fuses, removed fuse cover and then relay housing cover from under bonnet and found only one of the same pattern relay in there, so just changed that one. Car started on the button, and seemed to be okay.

10 minutes later, broke down again in Dartford Tunnel! Thank God it's a free tow out of there. Managed to get to my partners house in Romford which is exactly where I am now. Phoned MB Romford....nothing doing until next Wednesday, phoned MB Bury St Edmunds (my usual closest)....nothing doing until next Thursday.

The relay I was given (or rather, bought.. for £23!!) is a 4-pin type which I can only assume is the correct one as packaging was marked fuel pump relay. The main question is.....have I changed the correct relay? Can anyone advise where this relay is on a W202 facelift please? I used to get rather a loud click on switching ignition on and a 'whirring' noise for a few seconds afterwards (relay activating/fuel pump purging?). Now I am only getting a faint click. Beginning to suspect fuel pump itself. Any more ideas before I give up and sell it as scrap

Extremely fed up, pi**ed off and not looking forward to B/H weekend with no car

Thanks in anticipation of the usual excellent contributions.

Alex

 

[DansSlk]

On a W202 the fuel pump relay appears to be in the trunk of the car.

Cheers
Dan

 

[Asif Kazani]

Alex,
This maybe just a wild guess but I had suffered the same problem on a Volvo a few years ago. I had bought the car preowned and during the initial ownerhsip period, I discovered that the fuel filter was so packed up that it had been putting a lot of strain on the fuel pump causing the "slight faint sound" instead of the loud noise that these pumps produce ad the car to give me the same kind of problems that you are experiencing. Replaced the fuel filter and the pump and it was fine. However, on my 1981 280SE, the fuel pump relay did cause intermittent problems like these, so good luck.

Regards,

Asif.

 

[MangoMan]

On a W202 the fuel pump relay appears to be in the trunk of the car.

Cheers
Dan

Like in this Illustration, P/N 11.

Ciao.

 

[DansSlk]

That looks like it has come from the EPC, i used the SDS at work to find the relay on the WIS and then checked the EPC and got the very same diagram so yeah its P/N 11

 

[Alex Argent]

Update

Guys,

I really appreciate all of your replies. Very helpful thus far .

I've now changed the 4-pin relay in the boot well (the only one there I could find!) as well as the one under the bonnet. I thought that must be it now. Sadly not. Everything looked good yesterday afternoon after doing about 20 miles of local driving, then exactly the same problem - conked out again at traffic lights. Same remedy......waited for about 15-20 minutes, then started again perfectly. I'm now becoming a tad frustrated .

After changing relay(s) and on switching on ignition I can now definitely hear the 'whirring noise' - assumed to be fuel pump priming. However, it is not doing this every time and for the life of me, I cannot remember if it made this noise each time I switched on before, although 'gut feeling' tells me it did. I'm now 90% sure it's the fuel pump that's given up the ghost, but it seems I'm now beginning to embark on a 'suck-it-and-see' trial, which as we all know can be very exbenzive and time consuming. TBH, I really suppose it could be any of the other faults mentioned in some of the previous posts above, but I would have thought that a dodgy crankshaft sensor would have made the car feel a bit lumpy, which it clearly isn't - once it's started, it's running as smooth as anything!

I don't think it's the fuel filter blocked, although I can probably get hold of a new unit on Tuesday morning and fit it myself, albeit I'm a bit restricted on availability of tools at my present location in Romford.

Therefore, a couple of further questions to those of you that may have an answer:-

1) On a W202, can you hear the fuel pump running each time the ignition is switched on (or does it appear to be random - as mine is at the moment)?,

2) Following on from the outcome of a definitive answer to the Q1 (i.e if the answer is NO), how easy/difficult is it to change the fuel filter? IIRC, this is underneath the car on rear o/s. FYI, I have nearly a full tank of fuel - is this an issue?

I fully appreciate that a 'Star Diagnostic' will probably show up some sort of fault code and that is the obvious way to go, however as mentioned in the original post above, MB Romford cannot book it in until Wednesday at the earliest (more than likely Thursday now), and I am very loathe trying to get it either back home or to MB Bury St Edmunds, bearing in mind the 70 odd or so miles of motorway in between!

Anyway, I'm having a good weekend in the south of Essex, albeit without a car and it being totally unplanned .

As always, any help will be gratefully received,

Alex

 

[Alex Argent]

Update 2

After an hour of telephoning MB Romford service earlier this morning, trying to see if I can get the car booked in today, finally told cannot do anything until Thursday earliest - "we've had a lot of breakdowns in this morning after the bank holiday weekend". Instils a great deal of confidence doesn't it!!

I then thought to myself it's only a fuel filter so I can get a local indie to do it. Back on the phone to MB parts dept and an hour later finally someone decided to answer it. Do you have a fuel filter in stock for a W202, C240............ etc. Yes, in stock sir - £85.00 + VAT . Then located an indie about 5 minutes away from here. Can you change a fuel filter for me urgently if I get the part from MB? "Why don't you try the Bosch dealer next door for the filter?" I did just that - in stock - £37+VAT! . Back to indie with filter and they have promised to have it all done by 2.00pm.

For those still interested, I'll let you have a further update later. Obviously if the filter resolves the problem, then there's really no need for the diagnostic check anyway.

Ciao,

 

[Alex Argent]

update 3

How about that - took car in at 11.15, phone call from indie at 12.15 to say it's ready. Not only that, without any prompting they produced the old fuel filter, got one of the mechanics to stick an air line on the inlet, and then proceeded to show me the junk that came out. The mechanic that actually done the job said once he'd emptied whatever fuel there was in the old one, it still weighed about twice as much as the new one (exactly the same type of filter I would add).

Excellent service all round, which is a tad more than I can say for the assistance (or lack of) from MB.

Hopefully that is what the problem was, but I'm still inclined to get a star diagnosis done as and when to see if any fault codes are being retained in the OBC.

 

[GazCaff]

I had a similar problem on a Vauxhall Omega a few years ago. It turned out to be a faulty crank angle sensor (Hall sensor) preventing the ignition/fuel system knowing when to spark/inject fuel.

 

[jaymanek]

As Dieselman predicted, mine seems to have been a faulty crank sensor... Think the enthusiastic Jet Washing may have done some damage!

I had this EXACT problem last week. Customer picked up car and when I went to deliver him some bits leftover he said this had happened on his trip to preston.

We tried it there and same thing, plenty of turning no firing. then two minutes later it started fine..

I had washed all the carpets and seats, some were still damp.

We left the car running, removed all mats and put heating on max to dry it all out...

He said if it continued he would take it to local specialist... havent heard from him but not looking forward to the bill if it still is playing up!

EDIT: PS this was an E240 Estate, 2000 X reg...