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Mercedes Benz C-Class W203 (2000 - 2007) - 03 2.0 Engine misfire after 20 seconds at tickover  
03 2.0 Engine misfire after 20 seconds at tickover - Johnny G
Hi I would just like to add some info on the guy who has the same problem as I do, NOVEMBERS FORUM, my total milage from new is 36000, car runs as new, EXCEPT if I am stopped at the lights or a traffic jam, the engine gives symptoms as if its running out of petrol after about 20 seconds, the engine warning light comes on, and stays on, and the engine then runs on about 2 cylinders! IF I SWITH OFF AT ONCE AND RESTART, the engine is back to its normal self, PERFECT, until the next set of lights, then the same thing starts again.

I took the car to my local M/Benz main agents, who said its a common fault on this type of Mercedes multi valve engines, in the past we have changed the head, valves and springs, "as the engine valves gum up! total cost about £2500!! but Mercedes Benz now do whats called an "engine burn" where the engines computer is programmed to heat the valves "red hot" and burn off the gum, so I booked it in for this engine burn today, cost me £103, the engine now runs like a road rocket, masses of power, but after a short road test, THE PROBLEM IS BACK AGAIN! I telephoned the garage, who said "thats the cheapest thing we can do, rebook the car in and we will now look for another fault" They have inspected the plugs, injector jets, fuel pump, filters etc, any ideas please? Thanks

slt

Edited by Pugugly on 02/01/2009 at 21:27

Tags: technical issues warning lights ABS electrical faults

03 2.0 Engine misfire after 20 seconds at tickover - Pugugly
www.honestjohn.co.uk/forum/post/index.htm?f=4&t=68...0

Was that the posting you referred to ?
03 2.0 Engine misfire after 20 seconds at tickover - Johnny G
Hi yes the same problem as far as the tickover is concerned, car drives perfectly all day, but starts to miss fire after standing in traffic, or the lights, I have been told that the EMS cuts fuel to all the cylinders due to gum on the valve seats, thus the engine is running on a near nil mixture to save damage? I still dont think the gum problem is the fault with my car, as I said it has just received the full "burn off " treatment? i have also been told that once the valves gum up, nothing but a full top end, strip and rebuild will cure this problem cost about £2500 Plus VAT, £2937.00 !!!!?????

03 2.0 Engine misfire after 20 seconds at tickover - Johnny G
Hi Guys, car went back to main agent today for more tests, its down on compression on 1 cylinder, so it needs a new head, valves and springs, about £3000 parts labour and VAT, its not going in for a few weeks, so if you have any thoughts on this please let me know, by the way, they said that they will try and reclaim most of my money back, as the cars an ex M/b demo from Lancasters bought at 18000, miles, I have done only 18000 miles in 5 years, total since 2003, 36000!!! good cars Mercs, arnt they, or is it just the world today!
03 2.0 Engine misfire after 20 seconds at tickover - Johnny G
Hi Guys, I guess this has got you lot stumped, so if you want to know what the problem, more than lightly is go to, MBClubUK plenty of comments there!
03 2.0 Engine misfire after 20 seconds at tickover - Sgt Kelly

Hi appreciate that no conclusive answer was confirmed but did anyone ever get to the bottom of this issue. I have exactly the same issue started on my 2003 Merc C Class. Car runs perfectly but when you pull up at lights after a run it starts to misfire on 1&4. If I turn off engine and pull out key then restart it clears issue which kind of says to me the issue is electrical rather than burnt valves etc but what do I know. In the time that has past has the knowledge evolved to what issue was or could be. I have had coils replaced, problem still exists ? Further thoughts appreciated. Did the gent who had the problem ever get to bottom of ? what was it ? Thanks for any guidance.

03 2.0 Engine misfire after 20 seconds at tickover - unthrottled

I took the car to my local M/Benz main agents, who said its a common fault on this type of Mercedes multi valve engines, in the past we have changed the head, valves and springs, "as the engine valves gum up!

Sorry, but that's nonsense. All engines are multivalve these days-and they don't suffer from gummed up valves!

An 03 car shouldn't be using semi-sequential ignition/injection which is what normally causes a misfire in cylinders 1 and 4.

03 2.0 Engine misfire after 20 seconds at tickover - Sgt Kelly

Sadly it is not nonsense. Granted a lot of engines are multivalve variable timing engines but sadly Mercedes is not the company it once was where it made cars of quality to last. These engines do have a design defect recognised by Mercedes but kept quite about. They fixed it on later engines. I think it affected a couple of years 02/03 but I may be wrong on exact date. Symptoms are misfire evident at tick over. Engine ECU throws up no codes except misfire normally 1 and / or 4. My experience and advice is as follows if this does happen to you then do the basics first , check the obvious things as it could be these:-

1) Check change plugs, coil packs - Mo a could pack and see if fault moves if it does your lucky one as these are relatively cheap to change

2) Check Cam sensor for oil ingress into wiring. If you have this then can cause electrical issues

3) Check breather pipe for hole. Not easy to access it is under airbox but normally if this has a hole in you also get codes thrown up indicating a fuel mixture issue. These dow go over time.

4) Undertake a compression test. If # 1 most likely or any cyclinder is down then standby for an expensive shock as you will be having head changed.

If having completed the above and 4) is indicating a compression difference and you can find no other cause then don't waste any time and money fitting parts you don't need. Solution:

1) You may be lucky. MB recognising the problem upgraded the ECU software to provide an engine burn feature. essentially running the engine to a very hot temperature to try to burn off any deposits. It may work and worth a try but may not if exhaust valves knackered. Cost is about £100 ish

2) Invest time finding someone competent and reasonable to change cylinder head. Ouch ! I looked into doing this myself but this engine is complicated and there are a number of critical alignments. You need some specialist tools. Find a good mechanic familiar with mercs and raid the piggy bank.

Lesson I learned is that it confirmed my belief that now having had BMW, Porsche and now Mercs that the believe that German engineering is reliable is a total myth. These cars are no more reliable than a Ford in some cases significantly less. Give me Japanese car any day if you want reliability. I have had a number of japanese cars and the reilability is significantly better. Not as stylist but if you want to get from A to B a better choice.

Hope this helps anyone with this problem. If Mercedes was truly quality focused then they would put this right FOC on all cars up to 100k but there not and they earn good money from people having to pay £3k having a head changed. There are independents who will do repair for £1.5k-2k

That said appart from this expensive issue the car has been good but this has certainly made me think twice.

My car has now a new head and is running smoothly with no misfire problem

Good luck. Hope this helps anyone with this issue it took me time and a lot of money to work out was was the enderlying cause. I hope this can help someone.

03 2.0 Engine misfire after 20 seconds at tickover - Sgt Kelly

Update on my issue. Sadly it appears it is not nonsense. Granted a lot of engines are multivalve variable timing engines but sadly Mercedes is not the company it once was where it made cars of quality to last. These engines do have a design defect recognised by Mercedes but kept quite about. They fixed it on later engines. I think it affected a couple of years 02/03 but I may be wrong on exact date. Symptoms are misfire evident at tick over. Engine ECU throws up no codes except misfire normally 1 and / or 4. This is a good indicator to what issue maybe. My experience and advice is as follows if this does happen to you then do the basics first , check the obvious things as it could be these:-

1) Check change plugs, coil packs - Mo a could pack and see if fault moves if it does your lucky one as these are relatively cheap to change

2) Check Cam sensor for oil ingress into wiring. If you have this then can cause electrical issues

3) Check breather pipe for hole. Not easy to access it is under airbox but normally if this has a hole in you also get codes thrown up indicating a fuel mixture issue. These do go over time.

4) Undertake a compression test. If # 1 most likely or any cyclinder is down then standby for an expensive shock as you will be having head changed. Second big indicator of valve issue

If having completed the above and 4) is indicating a compression difference and you can find no other cause then don't waste any time and money fitting parts you don't need. Solution:

1) You may be lucky. MB recognising the problem upgraded the ECU software to provide an engine burn feature. essentially running the engine to a very hot temperature to try to burn off any deposits. It may work and worth a try but may not if exhaust valves knackered. Cost is about £100 ish Did not work for me although some modest improvement in general running but misfire still evident

2) Invest time finding someone competent and reasonable to change cylinder head. Ouch ! I looked into doing this myself but this engine is complicated and there are a number of critical alignments. You need some specialist tools. Find a good mechanic familiar with mercs and raid the piggy bank.

Lesson I learned is that it confirmed my belief that now having had BMW, Porsche and now Mercs that the belief that German engineering is reliable is a total myth. These cars are no more reliable than a Ford in most cases significantly less. Give me Japanese car any day if you want reliability. I have had a number of japanese cars and the reilability is significantly better. Not as stylish but if you want to get from A to B on low running costs a much better choice.

Hope this helps anyone with this problem. If Mercedes was truly quality focused then they would put these issues right FOC on all cars up to 100k but, there not and they earn good money from people having to pay £3k having a head changed. There are independents who will do repair for £1.5k-2k

That said apart from this expensive issue the car has been otherwise good but this has certainly made me think twice.

My car has now a new head and is running smoothly with no misfire problem

Good luck. Hope this helps anyone with this issue it took me time and a lot of money to work out was was the enderlying cause. I hope this can help someone.

03 2.0 Engine misfire after 20 seconds at tickover - jay4u2006
Also had this problem with my Mercedes c class 200 k 2001.when I drove it .it had lack of power and a misfire when u pulled up at traffic lights. After time the light came up on dash . Got friend round with his computer and he said it was tell him that there was a misfire on two cylinders. Then tried looking for air leaks in any pipes and could not find any.I then changed air mass sensor and did not make a difference also check sensor throttle pedal that was ok. Then I checked throttle body to find that was working but not the way I should . I purchased a new and fitted it yesterday and I have got all power back and the misfire seem to be gone. Have driven the car for 50 miles and still been fine. So I'm keeping my fingers crossed that's what the probl was. On the tests it said that there was a weak fuel mix on two cylinders so I don't know if that could damage engine if you keep driving it? Hope this is a help or may mine a different problem to yours

Edited by jay4u2006 on 16/09/2011 at 15:16

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