SL320 cylinders 5+6 B misfire

[rajinder_1]

Hi guys,
Have just been out in car and noticed the engine management light come on and it was real lumpy and poor respose to accelaration.....
I had a friend who ran diagnostics on the car and found that Cylinders 5+6 were misfiring on B. He changed the leads over and swapped the coil pack for a new one both with no joy.
We (well he) ran a test on the MAF and that was showing ok i think it read 16 which is ok on the M112 engine ( needs to be between 12-20 i think ).
He reccomended changing the plugs as this was the only thing left, now im not to sure as i would need to replace all of the plugs and according to the servoce these were only change around 1-2 yrs ago (from what i recall).
Has anyone had any problems like this with a similar fault does anyone know what could cause this?????

Regards,

Raj

 

[rajinder_1]

Anyone????

no body had any similar problems???? and suggestions????

Raj

 

[rajinder_1]

Right not good news, been to my mechaninc, redone the diagnostics and now cylinder 4 is out so that 4,5 and 6 and 3 is on its last legs, this leads them to think its the cat breaking up!!!!!! not going to be cheap fix then !!!!

Any ideas or suggestions on replacement cats? do you go with dealer parts of aftermarket..... i have bought aftermarket for the c class but did notice a bit more noise and is raspy..... if anyone has replaced cats on SL could you please advise me on which ones you used

Regards

Raj

 

[Blobcat]

It depends upon how long you are keeping the car for. If a decent length of time, put on a genuine MB cat as you say the cheaper aftermarket ones are louder and in an SL you would notice it.
Cats breaking up can rattle, can you hear anything? If it has been misfiring the cat could be blocked causing some of your woes. When a cat starts to block lack of power and an unwillingness to rev are the signs.

 

[rajinder_1]

blobcat,
thats exactly what has happened, it is so bad now taht my mechaninc said it even stalled at one point!!!! i will need to see what the costs will be as i cant justify paying double the cost which it usually is with MB. Im not sure how long i will keep at least another year or so i would have thought

Raj

 

[rajinder_1]

mmmm now after a long discuaaion with my mechanic and a friend they are doubting the cats..... and will be checking again.... i feel the same scenario coming along with what happened when i first got car and went into limp mode..... a long long story...

 

[ALAN@ECUCLINIC]

couldve aworn i posted here, anyway merc pms and hfm suffer with misfire on 2 or more cylinders IF it turns out to be ecu related please call me
i can help

 

[rajinder_1]

right guys been on a cat hunt!!!!! found that there is very few places taht will get you a decent german cat, i searched all over and found that 2 places that will get you german cats KMS and GSF. GSF offer a make called BM which is german and KMS offer Eberspacer. BUT the price is alot different. Now having read a load of forums eiberspecher are supposed to be the oem for mercs, im not 100% but i think they are and they are coming in at just under 1K which is £200-300 cheaper that mercs so i may be opting for a pair of these..... will keep u all posted, i think i will get both the cats replaced as if one has gone the other cant have much longer left ....

Raj

 

[Blobcat]

Pls ensure that whatever the problem wsa that caused the cats to fail is fixed before you put the new cats on.

 

[psmart]

Rajinder, are you sure the prices your getting quoted are right, 1K for a cat?

A fortnight ago, I bought the Pre-cat from Merc in Germany and it worked out at approx 303 quid. The 2nd cat is similar, so is the back exhaust box.

Eberspächer are a Rolls Royce type company, not a fly by night, (albeit I have issue with there latest designed diesel air heater :evil: ), there supposed to be spot on for cats! I've replaced mine, even though the old one hasnt gone, as a routine maintenance exercise whilst replacing theTurbo, (which also hasnt gone ie. no play on the bearing). My current cat is over 5 years old, still looks in great shape internally (so Im keeping as a backup), thus go for Eberspächer, and if possible, go for Merc. I did post the details of the German dealership where I buy last week, but can repost if you want to give them a buzz.

 

[rajinder_1]

thanks mate, i have ordered the eber cats, were £300 more than the uk made ones but as you said they are supposed to be quiet good

raj

 

[rajinder_1]

guys quick update, got the cats and guess what, there are NOT Eberspecher as described to me on the phone, now i will have to return them and order some from another place......
Why would you tell someone that they are one brand when the cats are labeled with another (BM)....

Psmart where did you get your cats from???

Raj

 

[psmart]

Psmart where did you get your cats from???

From the Mercedes Werkstatt in Düsseldorf, Germany. There was a post last week about a dealership offering 10%+ discount to forum members, perhaps it would be easier and cheaper to give them a buzz?

 

[rajinder_1]

Thanks Psamrt,
I ended up using GSF who needed 2-3 days delivery time, Germany would have taken the same maybe longer to get here.... the only thing with using germany would be a problem returning things for whatever reason?

Cant believe KMS though such a large company and trying to blag me into forking out nearly £1000 on cats which i had been quoted £700 for..... then trying to make me think taht eberspecher make the cats for BM????? mmmmmm i dont think they will be getting my custom in the future, cheeky ****s even made me drive to the b'ham office to return the cats which they mis sold to me.....
Why why why would you mess somebody around who is about to give you business.....and a grands worth aswell..... go figure???

Raj

 

[Parrot of Doom]

What year is the car? If its before 93 (IIRC) then you don't need cats.

Personally I'd just rip them out anyway and worry about it when the next MOT is due.

 

[rajinder_1]

its 2001 parrot, i did think taht at one point, but wasnt reccomended by my mechanic and also advised that its alot of work. I think on the year and value of the car its best to replace.

Raj

 

[rajinder_1]

cats look smaller

hi got the cats from GSF and they look really small compared to the ones on the car????

what should i do? fit them or not?

Raj

 

[rajinder_1]

any suggestions?

 

[jberks]

I'd query through GSF/the manufacturers - I would have thought they should at least be the same size, else the flow, sound etc would be different.

 

[psmart]

The Cat I bought from Mercedes, albeit different part number, is absolutely identical to the unit I took out of the car, same welds, everything, just a different part number stamped.

Your 2001 car is probably worth more than mine, so its probably a good idea to keep standard. Glass's guide puts mine at 13,950 Private sale in Good condition, so putting on cheap parts seems false economy at this stage ion the cars life.