Replacing Catalytic Converter - W124

[eyelight]

Posted this yesterday in the middle of someone elses thread about a cat, but everyone seems to be replying to the original question and not my addition so hope it's ok to repost here.

We had very slight rattle on our 1994 E220 Coupe when accelerating, which I've heard on other similar cars, but in the past 2 weeks has got much louder. Looked underneath and gave the cat a bit of kick last weekend and confirmed that it was rattling internally. Got it looked over yesterday at the local tyre and exhaust place and yes we need a new cat. It's breaking down internally.

So the Mercedes dealer just quoted me £802.01+VAT, (got to love that extra penny)but GSF have one on their catalogue for £198+VAT so obviously that's the one to go for.

Searching through the forum here I found the link to these guys
http://www.carsandcats.co.uk/cataly..._Recordset1=185
who have one for £223.87 not sure if that includes VAT or not.

interestingly, Cars and Cats have 2 different parts numbers listed for the E200 and the E220, whereas GSF just have the one part number for both cars. Hmmm....

Our car has the twin downpipe so got to make sure we match that.

Also looking through the forum, it seems the non Mercedes Cats and downpipes could be more difficult to fit. Can anyone give me advice on that end of things ? Is it an easy enough job for average DIY mechanic, or should I pay local exhaust guys to do it ?

One final question. This is my girlfriend's car and lately she's been saying that she's not getting the mileage she used to. Could this rattling cat be increasing the fuel consumption by partially blocking the pipe ?

Thanks,

Larry

 

[Tony]

Eyelight, read my post on the other thread.

On the subject of fitting, the aftermarket cat I bought fitted OK. But ...

On the subject of mpg, yes, the cat can dramatically affect your mpg and the way your engine runs. These 3-way closed loop systems are exceedingly sophisticated. See link below.

https://mbwholesaleparts.com/StarTu...atConvMar05.pdf

Sorry link no longer works. Basically (very simplistically) these 3-way cats attempt to turn CO into C02 and NO/NO2 into nitrogen. This simple and can be done by passing over various precious metals. The other thing they have to do is convert hydrocarbons into CO2 and water. This is difficult because it needs extra oxygen (obviously). The only place it can get the O2 from is from the engine. So the engine needs to run lean to provide the O2 which is then stored (adsorbed) in another part of the cat. But if you run the engine lean it can't turn the CO and NO/NO2 into CO2 and water. SO your engine is performing a full-time balancing act running rich and then lean depending on the gases coming out of your cat (looking for O2 in particular). That's why the cat can destroy your mpg - and your engine.

BTW, I took my lemon down to George Fraser and he said that the cats they fit are made on the same line as Mercedes, but they're cheaper (of course). I asked what they were called and he didn't seem to know - something like "Abischwecker" but he couldn't spell it, or didn't want to tell me. I've googled it and got no match.

 

[eyelight]

Thanks Tony,

Just been looking at the Cars and Cats site and firstly, what I wrote about different part numbers for the E200 and E220 is wrong. i'd just been reading it wrong.

However, looking at their picture of the cat they sell for the E220
http://www.carsandcats.co.uk/catalytic-converters/two-year.php?recordID=860
it has two smaller cats instead of one large one as is on the car now, (the original Mercedes one). Anyone got experience buying from this company ? Will this work out in terms of fitting ?

Also, Tony's post suggests engine damage from running with a noisy cat. is this the case. Hoped we could delay replacing it till next month. Lot of bills just came in. Usual story. Should I move this to the top of pile.

Thanks,

Larry

 

[Tony]

The cat part on that web-site is exactly the same as the one I bought (although from buypartsby.co.uk) 90974, only it costs a bit more. There are various different sites but they're all selling stuff from the same manufacturer I would guess. Mine fit fine and looked OK, but if it doesn't keep the various sensors happy it's not of much use IMO.

A bad cat can damage an engine in two ways. The fragments can be sucked into the bores - don't ask me how because I would have thought that they would be blown out the back, but all the dealers (and George Fraser) say that can happen, so I guess they know what they're talking about. The other thing is that it can star sending wrong messages to the engine management unit and the mixture will be wrong. However, if this were happening the CEL would almost certainly be on. If the cat breaks up entirely it can block the exhaust which is bad for the engine also.

Having said that I've had two blown cats and on each occasion I've driven the car for many months before repair and haven't had any problems.

 

[dougtsc]

Tony,

Is this the link that you were trying to post?

https://www.mbwholesaleparts.com/StarTuned/pdfs/CatConvMar05.pdf

Particularly liked the piece on page 7:
Replacement Considerations.....Remember that the original converter was designed and engineered to last for the lifetime of the car.

Also on page 8 it says: the cat is covered for 8 years or 80,000 miles and the dealer is responsible for all costs associated with a replacement

Sadly, only in the USA.


Interesting site. Thanks for the link.

Doug

 

[clive williams]

Greetings!

I've got a Merc 500E with 347,000Kms on the clock (~217K mls)! on the original cats. I've looked after them by keeping them warm and they are still performing wonderfully at MOT time, so I'm VERY impressed with mercs original quality. the aftermarket cats i've fitted to other cars always looked cheap compared to the merc's and as and when the original die I will fit OEM (subject of course to how long I will keep the car).
I also had a '91 Audi 80 2.8E in which the cats broke up and clogged the exhaust. Gradually they blew the stuff out of the rear over a few days and you could tell they were nice and loose inside! I kept that car for another 4 years adding 50K to the mileage and there was a wonderful and significant improvement in power, flexibility and fuel consumption over that period. I came to the conclusion that despite what Audi said, the cats were strangling the engine even when new.
Re the comment about the cat litter getting into the engine HOW???? The gas flow is in the wrong direction, it would have to climb uphill and besides there is no static vacuum to suck it back! Sound like st(D)ealer BS to me.

 

[Tony]

Doug, top man! I couldn't get it to work. Thanks. It's an interesting article, but it's thinly disguised sales material as you point out.

On the post about Merc cats being top quality and lasting 300k if you take care of them, I'd be interested to know what "taking care of a cat" involves.

 

[davidsl500]

BTW, I took my lemon down to George Fraser and he said that the cats they fit are made on the same line as Mercedes, but they're cheaper (of course). I asked what they were called and he didn't seem to know - something like "Abischwecker" but he couldn't spell it, or didn't want to tell me. I've googled it and got no match.

lol, I think you will find it is EBERSBACHER. Bit of a mouthful so no wonder George had problems saying it - let alone trying to spell it !! They are a German Exhaust Manufacturer - OEM on some VW/Audi, BMW - not sure about Merc but a good chance they will have some OE

 

[davidsl500]

A bad cat can damage an engine in two ways. The fragments can be sucked into the bores - don't ask me how because I would have thought that they would be blown out the back, but all the dealers (and George Fraser) say that can happen, so I guess they know what they're talking about.
QUOTE]

Tis true ! Modern Exhaust systems are suprisingly complex for a bit of pipe. To get maximum benefit the exhaust length/bore is critical and designers use "pulse tuning" to drag out the gasses. If you have a constriction in the pipe then the exhaust gasses will flow over the blockage and as a result will be travelling at a higher velocity which would cause a partial vacuum to be formed upwind of the blockage - the debris can thus be dragged back up the exhaust into the engine.

 

[eyelight]

Does anyone know if these Ebersbacher cats are available retail in the UK then ? Can't seem to find anything on them on Google. Just a German candle factory.
Just checking all my options before ordering one.

 

[liverpool mercedes]

had a new exhaust and cat for my e200 w210 cost me £550 ish
at a.t.s it,s a well known make but does sound a bit snarly if you know what i mean. my old one had been rattling for weeks when suddenly a power loss on the way home at 0600 on the motorway so don,t leave too long to replace .

 

[Oxmerc]

my cat

My 1995 W124 coupe was fitted with an aftermarket CAT costing around £200 when I bought it. It was always very noisy, and the car failed its MOT because of the CAT, only 18 months after it had been fitted. I didn't want to risk another aftermarket CAT, so bought the OEM one for £800.

At least I didn't get it from a stealership, but from a decent independent, Star Motors in Caversham, Reading.

 

[television]

Cats with a short life

Doug, top man! I couldn't get it to work. Thanks. It's an interesting article, but it's thinly disguised sales material as you point out.

On the post about Merc cats being top quality and lasting 300k if you take care of them, I'd be interested to know what "taking care of a cat" involves.

If the cat is low down as it is on my SL, and you park on long grass this cools the outer casing down before the ceramic cat has cooled and crushes it. cars that are not used much often have cat problems.
I replaced mine with a wire mesh cat so I hope no more problems

 

[Bolide]

I'd be interested to know what "taking care of a cat" involves.

Well, for one thing it means not putting leaded petrol in as the lead poisons the cat. The cars we're talking about are around 10 years old so plenty of opportunities for a few tanks of leaded or contaminated unleaded. Or diesel...


Nick Froome
www.w124.co.uk

 

[Tony]

Ebersbacher! Thanks very much David. I would never have found that.

On the subject of what can destroy a cat, I can think of the following:

- Rapid changes of temperature which can crack ceramic cats (like driving through water)
- Badly adjusted engine, particularly running rich. This causes the cat to verheat and melt.
- Duff lambda sensors
- Physical damage

Well I'm on my third cat in 25k miles and none of the above has been the case. The lifetime of a cat is going to be shorter if you do a lot of stop-start journeys, particularly if the cat never warms up. It's better to do long journeys. In my case I very rarely do short trips in the car - I walk. It's mainly used on relatively long trips, 10 miles or more. It's low mileage because it's a second car. So again, I don't see how that can be the cause of the short life. Basically Merc have flogged me 2 defective parts, full stop.

BTW, the after-market cat I bought is a metal (rather than ceramic) one. These are meant to be resistant to breakup. Although my CEL is on all the time the car runs OK, the mpg is unchanged and the emissions as measured by the MOT station are fine. The car does go quicker, however - less back-pressure?

 

[big x]

To your list I would add cats on MB 4-cylinder engines don't last as long as smoother running 6's and 8's.
The Ebbersbacher fitted to my C-180 lasted 8 years 90k before breaking up.The cat had the name and date stamp on it clearly visible if you crawl under the car.I'm still on the original cat on a 1992 BMW 735i 180k.

adam

Ebersbacher! Thanks very much David. I would never have found that.

On the subject of what can destroy a cat, I can think of the following:

- Rapid changes of temperature which can crack ceramic cats (like driving through water)
- Badly adjusted engine, particularly running rich. This causes the cat to verheat and melt.
- Duff lambda sensors
- Physical damage

Well I'm on my third cat in 25k miles and none of the above has been the case. The lifetime of a cat is going to be shorter if you do a lot of stop-start journeys, particularly if the cat never warms up. It's better to do long journeys. In my case I very rarely do short trips in the car - I walk. It's mainly used on relatively long trips, 10 miles or more. It's low mileage because it's a second car. So again, I don't see how that can be the cause of the short life. Basically Merc have flogged me 2 defective parts, full stop.

BTW, the after-market cat I bought is a metal (rather than ceramic) one. These are meant to be resistant to breakup. Although my CEL is on all the time the car runs OK, the mpg is unchanged and the emissions as measured by the MOT station are fine. The car does go quicker, however - less back-pressure?

 

[Tomkinsm]

Hi

Take a look at:

http://www.eberspaecher.com/en/abgas/abgas.htm

Not sure if they supply direct to public, but there might be a distributor somewhere. Perhaps its worth an email...

Mark

 

[eyelight]

Thanks to all for their info on cat problems. I e-mailed Eberspächer looking for more information on their cats, and specifically on for a W124 E220, and got the following reply from Gert Hoffmann today. Might be useful for anyone with similar problems.

Please note that we do not sell to the public but to several
clients.
''Global players '' like EURO CAR PARTS or GERMAN-SWEDISH-FRENCH
or specialist importers in London (for example MIKU)and in
Birmingham (for example KMS).- I dont know where you are living
but your garage might know (one of) them!?
The mentioned catalytic converter should be the
OE# 124 490 4120 replaced by Eberspächer # 23.294.60

Euro Car Parts don't seem to stock a cat for this car and GSF have a pattern part which I might end up buying. Quick Google search doesn't bring up anything on the other two companies mentioned.

Another alternative for anyone looking for a cat is a company called Exhaust Shack, http://www.exhaustshack.co.uk, who sell Bosel exhausts and cats. A little more expensive than most of the pattern ones but they look more like the OEM ones.

 

[flyingtech55]

Before a certain date, the car doesn't need to have a cat even if one was originally fitted. I think it's pre August '94. The cat. on my 190E (W201)started rattling so I had it removed and replaced with a small silencer instead. The car still passes its MOT OK on emmisions. The price of cats for W124s and W201 is high because it includes the front pipe as well and its all stainless steel. You can also have the original cat. box removed and a new cat welded into the original pipe instead. Cheaper option. However, before you have the new cat. fitted, ensure that the engine is not running too rich as this will cause the cat. to over heat and fail prematurely. If its rattling, mine was, this is often a sign of overheating. Renew the lamda sensor (use a genuine one (£50)) and new injectors (£25.00 each)). The lamda sensors degrade over time and the injectors wear.

 

[soj]

However, before you have the new cat. fitted, ensure that the engine is not running too rich as this will cause the cat. to over heat and fail prematurely. If its rattling, mine was, this is often a sign of overheating. Renew the lamda sensor (use a genuine one (£50)) and new injectors (£25.00 each)). The lamda sensors degrade over time and the injectors wear.

This is exactly what happened to me!
I noticed the rattle and thought it to be a heat shield, so i didn`t worry too much about it.
I took my 1995 C class (1.8 ) for an mot and was told that "the car failed the emmisions test sir, on the cat ....it`s broken up and it has distributed itself all through the exhaust, you need a new exhaust and cat"
I took the car for a second test and they confirmed that is wasn`t working they offered to fit a complete new system for £320 inc. vat.
I needed the car so i authourised the work. Then all was well for 11 months until i took the car for an mot again.....it failed again because the engine was running slightly too hot and too rich, all it needed was basically a regualr tune up and servicing *before* i bought it, yes it had service history ...mainly from a "specialist", who it seems wasn`t much of a specialist at all because if they had given it a tune up e.t.c. it would not have needed a first cat, let alone a second.
I sold the car after that and bought an alfa..... which i sold after 9 months because it was a complete nightmare!
Now i really am short of cash!