engine management light

[mheadbee]

to cut a long story short. I have an 2003 c00k and a third party warranty which means I pay for the diagnosis. A year or so ago I took to a dealership when the light came on and they charged me £300 diagnosis, 1.5 hours at 125 plus vat and they also kindly replaced my perfect spark plugs for £40 plus vat. The warranty work which was a faulty coil cost around £100 to replace and that was covered.

When my light came on just before xmas 07 I decided to try a recommended Merc specialist (osbournes in maidenhead) to avoid being ripped of again. They charged me £30 for diagnosis and said the starter cable had gone, it was not urgent so leave it for a few months. About 1 month ago the air con packed up. I took it into this garage and they did a re diagnosis, told me their were 3 faults, the air mass sensor and the alternator were gone (and under warranty) but some valve on the aircon needed to be replaced and it was an 8 hour job (dash had to come off) and would cost me around 1K. I questioned the starter cable and they said it was perfectly Ok. I booked the car in a week later and a friend looked at the air con in the meantime and used a tin of gas that cost £20 and fixed it. OK OK, the alarm bells should have been ringing.

To cut to the chase, I picked the car up ad on the way home the light came on again. I took it back and they reset it. On the way home the light came back on again. I took it back and they reset it and said there was no fault. I had to take it in another 3 times and eventually they told me the lambda probe needed replacing and did this under warranty as well. You guessed it, the light came on again after 79 miles. I took it in again and they reset it and then ...well, you know what happened next. This time they kept it for 3 days etc etc and they said the air mass thing was loose, its been repaired and is now 100% fixed. I picked it up last saturday and after 79 miles the light came back on again.

I have taken the car to the garage at least 12 times now and I just can not face it again. I want to sell the car but can not whilst this damn light is on and also it is not fair to the buyer to reset it and let them drive off. I just do no know what to do anymore. I have no faith in the garafe as you would expect but the last thing I want to do is get a huge bill of merc when I want to sell it.

Anybody got any bright ideas?

 

[star]

sorry need to read it 1st as there are lots of reasons for engine lights coming on. Do they have the right level of equipement to read it??

 

[BlackC55]

Have you any fault codes?

They suffer with water ingress on number 1 cylinder which can cause missfires and bring the light on.

Some of the 271 engines (your car has one) suffer with poor sealing valve seats which bring on the light.

Also, the rough running can be de-sensitised (bad spelling) so it is less likely to pick up minor missfires.

Ask the garags for the fault codes and report back.

 

[mheadbee]

thanks, i will get the codes, but after the last few visits i would guesse they probabaly do not know.

 

[BlackC55]

New garage then......

 

[mheadbee]

New garage then......

Well, yeah, the only thing is you have to pay all over again for the diagnosis. Merc will want £200 and I do not know of any other garages.

 

[colechelle]

gotta agree with black, seen so many with valves leaking, we just put heads on but thats big bucks, and the only cure, very very rare its a coil or plug!!

 

[darrenb1707]

Well, yeah, the only thing is you have to pay all over again for the diagnosis. Merc will want £200 and I do not know of any other garages.

Might be cheaper in the long run to invest in a OBD II scanner (which can read fault codes). You can pick them up on Ebay for about £50-60. Check out http://search.ebay.co.uk/_W0QQsassZ*sand66p*

I've bought one from this seller and its been invaluable. It also allows you to clear fault codes like your garage has been doing so should save you trips back and forth until you get the underlying problem resolved. Make sure you buy the 38pin adapter lead though as the standard obd connector wont fit on the Mercedes ECU plug.

 

[mheadbee]

Might be cheaper in the long run to invest in a OBD II scanner (which can read fault codes). You can pick them up on Ebay for about £50-60. Check out http://search.ebay.co.uk/_W0QQsassZ*sand66p*

I've bought one from this seller and its been invaluable. It also allows you to clear fault codes like your garage has been doing so should save you trips back and forth until you get the underlying problem resolved. Make sure you buy the 38pin adapter lead though as the standard obd connector wont fit on the Mercedes ECU plug.

its a great idea, but... and please don't laugh...... but the last time i opened the engine about a year ago I tried to put oil in the break fluid.

I have taken it to the garage again and this time they told me their is no fault code but the message is "up sensor lambda probe" or something like that (I forgeot exact wording). They replaced this last time.

 

[mheadbee]

After 3 days of diagnosis apparantly the wiring loom between the cam shaft sensor and the computer is failing, the sensor is leaking oil onto the wiring loom and this is causing the lambda to fail. About £700 apparantly.

The lambda may need replacing too. If they had diagnosed this first time round then we would not need a second lambda so I will not be paying for that.

Does anyone know if any of this should be covered by the warranty, its a standard third party warranty that covers all mechanical and electrical parts?
The garage seem to think it will not be covered because the parts are not faulty, they are being made to fail by the oil.

 

[colechelle]

this is a common fault belive it or not! hoping for your sake its covered as you need new loom and bits, even had to replace engine ecu because of this fault!!!