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ok guys... my buddy was driving his 02 c240 and all of the sudden it lost power and semmed to be riding on half the amount of cylinders and the check engine light came on and started flashing. we checked the codes and it threw 8 codes initially. it was P0300, P0301, P0302, P0303 and it repeated for tha last four codes. i had changed the wires and all 12 plugs (i also swapped all coils from cyls 1-3 to 4-6) and cleared the codes. There was no change except the codes went from 8 to 4 codes (still the same). The problem did not move and the car still sounds and feels like its running on 3 cyls and if i press the accelerator, it will go close to 3k rpm and begin to drop as if its dying (this is with my foot stillon the pedal). i then cleared the code and disconnected the MAF, put the key in and started the car... it still sounded and felt like sh.. but when i accelerate it will go beyond 3k rpm. any ideas? i could really use them.
Codes like that are rarely sparkplugs/wires/coils, epecially on the v6 that has 2 spark plugs per cylinder. If it were, it wouldn't be on every cylinder. More than likely it's fuel related, check fuel pressure at the rail, should be about 40-50 psi or about 3 1/2 bar.
how do i check out fuel pressure from the rail. Also... other forums mention the O2 sensors or bad catalytic. What are some of the best ways to test these? Would it be better to take it to the Stealership and have them diagnose, then i'll do the labor myself? The last time this has been to the Stealership was to replace alternator which cost $2500 and the oil dip stick came up missing (its still missing).
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Right - let's try again - my DSL line went down.
You check the pressure by attaching a pressure gauge to the fuel rail. The only flaw in this argument is that the rail is common so why a problem on one bank only - anyway this will tell you if you have a pump or clogged filter problem
As I said on the other forum you need to check you don't have a collapsed Cat on one side or faulty O2 sensor. (& watch for fuel trim codes). I also asked of the codes changed to 304,305 & 306 when you swapped coilpacks.
You must check for a vacuum leak in the pipework on one bank.
ok fuel seems to be good and vacuum lines all seem to be in place. I pulled off the MAF and cleaned it w/ CRC MAF cleaner. i will install and see what happens.
i installed the MAF and cleared the codes, still the same problem (P0300 P0301 P0302 P0303). it idles ok under 2k rpm, but when i try to accelerate past 2k rpm, it begins to shudder like it going to die. when i swapped coils 1,2,3 to 4,5,6, nothing happened. the codes stayed the same. what should i do next. i really need help on this guys!!
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
If you unplug the MAF & force the ECU onto a default map what happens? try this
If it is not HT electrical (wires,coils) then we have to look at bank 1 in isolation. You've checked the pipework which leaves the exhaust on that side (clogged cat, O2 sensor etc) or something causing all the injectors on bank 1 to shut down (O2 sensor, cam timing jumped - unlikely)
Standing back from the problem it could be a defective MAF or CPS (crankshaft position sensor) What mileage has the car done? What confounds me is that the problem is isolated to 1 bank of cylinders.
We are heading for getting this car onto a STAR diagnostic machine. There are limits to what can be achieved on the internet. You don't have the pleasure of trying things from other vehicles or the spares dept that the dealer can.
How did you check the fuel rail pressure & what pressure did you get? Are you absolutely sure that this car does not have a clogged fuel filter? When last was it replaced?
Same thing happened to me but 3 cylinders were misfiring on the computer. The problem turned out to be the catalytic converter. The honeycomb ball inside the cat came lose and was clogging which made the 3 cylinders misfire.
Are you hearing rattling coming from your catalytic converter? If so, you might want to look into that.
i havent gotten a chance to look at fuel filter, o2 sensors, or catalytic just yet. im trying to avoid having to buy parts that i dont need. i'll be taking off the fuel filter later today when i get a chance. i really appreciate all the input guys.
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Originally Posted by roland w203
Same thing happened to me but 3 cylinders were misfiring on the computer. The problem turned out to be the catalytic converter. The honeycomb ball inside the cat came lose and was clogging which made the 3 cylinders misfire.
Are you hearing rattling coming from your catalytic converter? If so, you might want to look into that.
Yes - I'm suspicious of this too. It does not even have to rattle although it usually does. A friend of mine went over a speed bump too fast & broke off a big chunk of cat honeycomb & it jammed up solid in the pipe causing misfires & wheezing.
Speed bumps are big cat killers. If you hit a bump hard while the cat honeycomb is incandescent it will break.
i yeah i forgot to mention... my buddy got it @ 30k miles and now it's running on 153,000+ miles. only the alternator and some fuses(couple months back), spark plugs and wires have been replaced other than your regular oil changes and brakes service... plugs and wires were changed just last friday.
late 2009 CLK 350 Coupe Elegance, '65 Jaguar S Type wires
Please answer some questions here:
What fuel pressure did you read at the end of the rail - are we sure that the fuel pump is up to snuff?
You say you replaced the wires & coils. Did you replace all sparkplug wires or only the ones on bank 1? What wires did you use? Benz is wire fussy - some don't work.
Have you managed to check the exhaust/cat/O2sensor output 0 to 5volts?
Have you unplugged the MAF and run on a default MAP? - if so what happened?
Are you absolutely sure that you don't have an air leak in the vacuum & other pipework?
The problem here is that if you have done all of the above which are the normal failures then we have to keep throwing parts at the thing like the dealer will until they find the problem if the STAR does not pick it up. This can get expensive & you might be better off going to the dealer or indy with STAR or Snap On Solus diagnostic machine. You can't return items to the spares dept like the dealer can. I'm not worried about wires & filters - they probably needed changing anyway.
As mentioned the CPS is a common failure on this engine - however I would expect it to give you random misfires on all cylinders not just one bank. It's a cheap if contortion requiring replacement and at your mileage is probably tired if never replaced. It tells the ECU when the engine is at TDC.
If all the above have failed to produce a result then I'm worried that the electronics are shutting down fuel to the bank one injectors. This can be caused by many things. The most common thing being loose or corroded pins on the ECU plugs/connectors.
Good luck!
Last edited by Glyn M Ruck; Sep 19, 2009 at 08:59 AM.
OK. My buddy is taking it to a dealer alternative. I want to thank you all for all your input. As soon as we find out what it is... i will keep you all posted. This way, if someone else runs into it... we may have some answers. Thanks again.
Ok guys. Id have to say Roland... you and Glyn got it right with the Catalytic causing the problem... along with the "air fuel sensor" (is that the MAF?). Now my question is... since its on bank1, should i just replace the passenger side Cat or both? The mechanic said that both needed to be changed. I did remeber some rattling when reving the engine past 3k rpm. I have to thank Glyn and the rest of you for all your input.
Ok guys. Id have to say Roland... you and Glyn got it right with the Catalytic causing the problem... along with the "air fuel sensor" (is that the MAF?). Now my question is... since its on bank1, should i just replace the passenger side Cat or both? The mechanic said that both needed to be changed. I did remeber some rattling when reving the engine past 3k rpm. I have to thank Glyn and the rest of you for all your input.
Which part of the cat did you replace? Was It the whole thing or the upper portion?
Which part of the cat did you replace? Was It the whole thing or the upper portion?
Just had the same problem. Misfires were all on bank 1 so I removed the right side exhaust pipe which includes 2 cats. The picture is what came out of the first cat nearest to manifold. Nothing but dust and chunks that were almost totally blocking it. After removing all remnants I decided to leave the rear cat alone and go with an empty front cat. The now runs phenomenal with no CEL which baffles me a little but I’ll take it.
Just had the same problem. Misfires were all on bank 1 so I removed the right side exhaust pipe which includes 2 cats. The picture is what came out of the first cat nearest to manifold. Nothing but dust and chunks that were almost totally blocking it. After removing all remnants I decided to leave the rear cat alone and go with an empty front cat. The now runs phenomenal with no CEL which baffles me a little but I’ll take it.
So even going our cels were identical I’ve recently replaced my cat with avail. I’ve done multiple tests and have replace quite a few parts with no resolve. I’ll be unfortunately taking my baby to dealer to get a definite answer and update everyone who weren’t as lucky just to have to replace a cat.
So even going our cels were identical I’ve recently replaced my cat with avail. I’ve done multiple tests and have replace quite a few parts with no resolve. I’ll be unfortunately taking my baby to dealer to get a definite answer and update everyone who weren’t as lucky just to have to replace a cat.
Just so you know I had already replaced plugs, wires, coils, MAF sensor, fuel filter, crank position sensor, replaced valve cover gaskets, and replaced intake manifold gaskets along with just about all vacuum lines. Compression was good as well as fuel pressure. The cats were the last thing it could have been.
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