W204 6 cylinder diesel vs petrol

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philnewmerc

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Dec 11, 2008
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894
Location
Gateshead, Tyne and Wear
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CLS55
Hello MB forum. I haven't been on here for a few years now. I've owned a w202 which was lovely but rusted away like a 1970s Alfa and the gearbox went wonky, a w203 which was smooth, but felt a bit cheap inside and, unbelievably, also started to rust badly too. So, I've had two Italian Alfas, a Fiat and a Volvo since then and none of them had a spot of rust. There's a Renault 5 near us parked outside for 30 years and even that hasn't rusted nearly as bad as a 8 year old Mercedes. Anyway, this put me off them at the time but i did very much enjoy driving them. So, I've been perusing Auto trader and w204s seem to look nice and affordable and I want to avoid two things: rust, premature automatic gearbox failure (i don't want a manual tho) and the high uk road tax bracket, ok 3 things! ☺️ I'm thinking c350 diesel vc c280 petrol. Have you guys any tips on these choices or other options please? Budget is 6k. Cheers ! I👍
 
Depends on what you want to do with it. Long distances , lots of miles ? Get the Diesel , short runs low mileage = petrol version all day long. Not sure what you mean by 'premature automatic gearbox failure" The gearboxes are pretty robust and simple to service . You might want to research rusting rear subframe , there have been a few.
 
Thanks gir the info. I only do 10k and i know from experience diesels only do a tiny bit more mpg but do have nice mid range punch. And they tend to be more expensive to keep going at high mileage... assume same for merc?
By premature failure i mean the sealed for life gearboxes end up running on syrup and the damage may be done before i buy it and do a fluid change. My w202 gearbox (car bought at about 100k, then servicd by me) was slipping badly by 130k... Love Merc driving but my experience is they're potentially very unreliable and rusty so just wondered if w204 was similar
 
Thanks gir the info. I only do 10k and i know from experience diesels only do a tiny bit more mpg but do have nice mid range punch. And they tend to be more expensive to keep going at high mileage... assume same for merc?
By premature failure i mean the sealed for life gearboxes end up running on syrup and the damage may be done before i buy it and do a fluid change. My w202 gearbox (car bought at about 100k, then servicd by me) was slipping badly by 130k... Love Merc driving but my experience is they're potentially very unreliable and rusty so just wondered if w204 was similar

I previously owned the w204 3.5 diesel and moved away to petrol for two reasons:

1) The issue regarding diesels being outlawed - I live in London so this was becoming a major costly issue, and as a result I was losing loads of money in depreciation even though the car was immaculate.

2) It was coming up to that mileage where oil leaks occur on the oil cooler oil seals (common problem) and I didn't want to land up with having a costly repair on my hands. (Oil cooler sits in the V and needs a major stripdown to repair it. Note when this repair is done it is best to address the swirl flap motor, and the swirl flaps and save yourself future expense if you are keeping the car, as the all reside in the same area in the engine. Also if I would have had the job done, I would have probably reconditioned the turbo at the same time as it was out of the engine......so all in all, expensive.

I never had issues with rusting on the subframe but my car was garaged so I guess that helped. However they do suffer from brake line rust, and this can become an MOT advisory.

The W204 ignition switch can become an issue as the motor inside the unit fails. (Again a common issue). If it fails, it can lock the steering wheel. I changed mine as a precautionary measure before I suffered from this issue.

On the plus side the W204 is refined, comfortable, and the v6 diesel has bags of torque and is a pleasure to drive. Also very good fuel economy if you don't continually boot it around.

The V6 diesel far as performance is concerend is brilliant, however they are depreciaing a LOT and are also complex beasts, and expensive to repair.

Re the gearbox, having the transmission fluid and filter changed at regular intervals keeps it healthy. The gearbox is not sealed for life.

Hope this helps.
 
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BlueTEC engines are generally great unless you happen to be unlucky and something goes wrong... then they can be a money fit. Not all, obviously, but the risk is there.
 
Based on the above I think I'll look for petrol, but has to be c280 as the c350 is well over 500 quid road tax, which seems very wasteful. I definitely agree sealed for life is nonsense, the trouble is when buying second hand for most original owners a fluid change wouldn't have crossed their minds. Cheers
 
The 09 211 I've bought has an ATF fluid & filter change detailed in the service schedule at 37.5k miles.
It seems MB had learned their 'sealed for life' was bs by then.

It also follows that MB would suggest this to owners asking them to do a service at that mileage.
 
My view would be that if it's well over due the transmission service mileage (mileage requirement depends on box) and it's either not listed in the Merc service sheet or there isn't an invoice, walk away. Some owners DO get their oil changed on time or even early, and keep the invoice.

May be if you're keeping the car for a year or so you might be prepared to risk it. Longer term, I wouldn't.
 
I bought an 06 Vito, the owner (2nd in its history) had no idea what an ATF service was. So at 115,006 miles no ATF service, I gave it a service the box was spot on.

The Viano outside had no ATF service in its 162,412 miles, confirmed by the date on the filter that came out, again no issues with the box.

I totally agree these should get their 1st service at around 40k miles. Following services being a bit longer wouldn't be an issue in my mind..
I agree the risk of these having an abused box is high risk due to the expense of replacement, but I wouldn't consider a box not serviced means a knackered box.

Just looked, the 2014 Viano service book details an ATf service at 75k miles. Strange as it's the same box as the 211 and would likely suffer heavier use, anyway it didn't get one.
 
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Well changing the ATF in mercedes boxes is not hard and well cheap at indys,you might need to do it twice in 10 years of ownership doing the mileage you do say £500 for the two services,as already mentioned the sealed for life idea for automatic boxes is a crazy one,take the Aisin japenese box fitted to many makes but not mercedes,again there seems to be a sealed for life idea floating around with these,they make a 6 speed and 8 speed box,and they are popular because they are built with size as the most important point and so they can fit into BMW,Volvo Peugeot and Citroen cars and others ,anybody running that box and does not change the ATF at around 50,000 miles is asking for serious trouble,I watched a Citroen with 52,000 on the clock have its atf changed and what came out did look like black engine oil.
 
Thanks all. Yes I supposed cars used in town probably need a atf service and ones going up and down the motorway perhaps much less often. My old w201 only had a weasy 2 litre so not hammered with high torque but no aft change and was geriatric by 130k. Anyway, i will keep my eyes open.
 

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