C220CDI vs C250CDI W204 long term reliability

[Geg1992]

Hi all,

I’m looking at buying a w204 Mercedes.

I understand that the C220 CDi is very reliable, almost bullet proof with very little going wrong. Is this the same story with the C250 CDI with the twin turbos? Both I am looking at are the Blue Efficiency.

The basic details of the 2 cars im looking at are:

C220CDI
2012
58,000 miles
Less spec but black which is preferred

C250 CDI
2011
65,000 miles.
More spec but dark blue.

I’d like to keep the car for atleast 4 years so reliability is a big consideration. I’ve had a lot of lemons in the past but from what I’ve seen, there aren’t many people changing turbos or having issues with the auto box etc.

Any help is appreciated.

 

[merc85]

Water pumps are quite common on the 250 engine from what I’ve heard of. If your not worried about performance I’d stick with a c220.

 

[Geg1992]

Water pumps are quite common on the 250 engine from what I’ve heard of. If your not worried about performance I’d stick with a c220.

Performance is important to me to be honest! But C220 remapped would probably be adequate!

 

[CowleyStJames]

Engines are identical, even water pumps.
Difference is down to mapping and injectors. 250 has larger capacity injectors.
Both have identical turbos, they're both two stage, so if you like two turbos in one.
My E250 has been remapped to 254bhp and 600nm of torque.
Believe me when I say it pulls like a train but still gives 55mpg on a long run.

 

[Geg1992]

Engines are identical, even water pumps.
Difference is down to mapping and injectors. 250 has larger capacity injectors.
Both have identical turbos, they're both two stage, so if you like two turbos in one.
My E250 has been remapped to 254bhp and 600nm of torque.
Believe me when I say it pulls like a train but still gives 55mpg on a long run.

Thanks for clarifying! From the bit of research I done people said “the C250CDI is much more of a refined engine” so I assumed they were different. Any idea on long term / high mileage reliability?

I haven’t seen much on consumables like alternators, control arms etc either!

 

[merc85]

Om651 pump is completely different to the om646 and is very common to leak. Plenty of threads about it on here. The sump is also plastic and leaks on the om651.

 

[CowleyStJames]

Om651 pump is completely different to the om646 and is very common to leak. Plenty of threads about it on here. The sump is also plastic and leaks on the om651.

Both cars he's interested in would be OM651 engines

 

[merc85]

That’s cleared that up then lol

 

[Gazwould]

C250 CDI all the way !

Same engine , same issues .

Sheds more torque -500Nm and potential , identical , exept map , fueling capability and a larger 2nd turbo I believe .

Just a few mpg worse off .

 

[Geg1992]

What issues are there? I just done a search on the engine and there appears to be timing chain issues?

 

[CowleyStJames]

What issues are there? I just done a search on the engine and there appears to be timing chain issues?

Some do most don't. We have a fleet of Sprinters with that engine, various mileage from 32,000 up to a stellar 390,000. We've never changed one timing chain.
Regular service with approved oil and they seem bullet proof.
Couple of our cars have had problems with dpf sensor but not the actual dpf itself.
But they don't like short commute mileage, get a petrol as the DPF will complain

 

[CowleyStJames]

C250 CDI all the way !

Same engine , same issues .

Sheds more torque -500Nm and potential , identical , exept map , fueling capability and a larger 2nd turbo I believe .

Just a few mpg worse off .

Turbo is the same whichever model, two stage.

 

[Geg1992]

Any idea how common the timing chain issue is and how much it costs to repair?

Makes me think c350cdi might be a better option - are there any issues with the 3 litre?

 

[Gazwould]

Seriously it's rare and easily heard from a cold start up or after an oil change .

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I assume you are buying retail from a garage ?

 

[Ted]

Also don’t forget that maximum torque is put out between 1600 and 1800 rpm on the 250. They really do pull like a train.
On my slc with 9 speed box, you are pushing towards an indicated 80 at 1500 rpm in top.

 

[Monkeylegend]

The 4 pot diesel is very reliable with very few timing chain issues in comparision to the millions being run as taxis all over the world. That's why they are by far the most popular choice as taxis and chauffeur cars.

I have had 3, and all have done over 300k with no issues, my current one is the twin turbo on 305k and still running well.

I had the water pump replaced at 220k ish, that cost £374 at a Mercedes franchise, thankfully paid for by them, but hardly wallet breaking.

 

[grober]

What may be confusing you was the early W204 cars C220 C250 diesels came with the single turbo OM 646 engines which were reckoned to be more reliable. The early twin turbo OM 651 engined cars had timing chain and piezo injector problems and were thus deemed "problematic" compared to the older single turbo cars. Its possible those reliability reviews you have read are not comparing like with like engines.
* the early OM651 piezo cars should have had their injectors changed by now- later cars reverted to the older solenoid type injectors. The way to tell is that the more reliable solenoid injectors have fuel return lines the piezos do not.
Blue Efficiency injector recall?

 

[Geg1992]

What may be confusing you was the early W204 cars C220 C250 diesels came with the single turbo OM 646 engines which were reckoned to be more reliable. The early twin turbo OM 651 engined cars had timing chain and piezo injector problems and were thus deemed "problematic" compared to the older single turbo cars. Its possible those reliability reviews you have read are not comparing like with like engines.
* the early OM651 piezo cars should have had their injectors changed by now- later cars reverted to the older solenoid type injectors. The way to tell is that the more reliable solenoid injectors have fuel return lines the piezos do not.
Blue Efficiency injector recall?

Thanks for clarifying. I was loooking at later models because of a nicer dash and sat nav. Maybe the earlier ones would be a better choice.

I wouldn’t have money to spend to fix any timing chain issues really. What is the cost of fixing the issue worst case?

I assume the 320 / 350 don’t have these issues?

 

[Gazwould]

Also don’t forget that maximum torque is put out between 1600 and 1800 rpm on the 250. They really do pull like a train.
On my slc with 9 speed box, you are pushing towards an indicated 80 at 1500 rpm in top.

Incredible low rpm torque that unfortunately drops off at just 2K , hence in E it wants to pull you around at even lower revs 1.1-1.3K that's especially enhanced with a remap .

 

[Peter103]

My E350 will do 30 mph in 6th at 900/1000 rpm. 60 mph in 9th at 900/1,000 rpm. And 85 mph in 9th at just about 1500rpm and it's not remapped. Love it!