C350cdi sport.

[smudge11]

Hi guys,

Just bought my first MB.. A late 2010 Tenorite Grey C350cdi Sport.

Lovely car and I'm very pleased with it.

However, i do have a couple of questions.. The car seems to idle around 550rpm which causes a slight vibration. Every now and again it decides to idle around 800 rpm and the vibration seems to go away.

What sort of idle speeds are you other c350cdi owners getting cold/hot?

Also I've only done 200 miles in it since collecting and it has been in slow moving start/stop traffic but from a full tank I've used 3/4 tank in 200 miles. The trip is telling me I've been getting 22.8mpg which is seriously bad in my book for a modern diesel. It's a blue efficiency one too (without start stop).

Any ideas guys?

Thanks and much appreciated.

I'll post some better pics when I get chance.

 

[smudge11]

Bumpety bump?

 

[gunning]

Errm I think I've heard of this happening to a few 3.0 diesels? I heard its a big job on them as it could be a balance shaft? Are you getting a lot of black staining around the exhaust and bumper?

I'm not 100% on this but your car is certainly burning way too much fuel and sounds similar to previous symptoms I've read about. Another sign to look for is burning rubber smell.

What ever it is get it back to the dealer asap

 

[MancMike]

I thought the C350 was a 3.5L V6?

My C280 is a V6 3.0L Petrol and for what it's worth in slow stop start traffic, I get mid to high teens. I'd be happy with 16mpg on my busy creeping commute. It often goes into low teens when particularly slow.

I know you'd expect more from a diesel, but it is a big one, and you are getting more...

 

[gunning]

He's got a CDI with a 3.0 derv

 

[smudge11]

Errm I think I've heard of this happening to a few 3.0 diesels? I heard its a big job on them as it could be a balance shaft? Are you getting a lot of black staining around the exhaust and bumper?

I'm not 100% on this but your car is certainly burning way too much fuel and sounds similar to previous symptoms I've read about. Another sign to look for is burning rubber smell.

What ever it is get it back to the dealer asap

Cheers fella. There's absolutely no smoke at all even when I give it a foot full.

It's not a bad vibration, just like the vibration you get on full lock, you know, when the revs drop with the PAS pump on max.

Oh and it's a 3.0 V6 diesel.

Cheers gents.

 

[gunning]

It's not so much the smoke you are under acceleration it's just one sign of it is black soot around the exhaust outlet.

Either way your engine isn't running right, have you got MB warranty or anything like that?

 

[hammerrr7]

I have a 2010 c350 CDI and I have to admit, in slow moving traffic it isn't great. I get mid 20's at best.

On longer runs I get high 30's maybe even low 40's when cruising along.

I would take it for a long run and see what the range returns. Also I find my car runs better and get much more range from using premium diesel than normal. Worth a go?

 

[hammerrr7]

Errm I think I've heard of this happening to a few 3.0 diesels? I heard its a big job on them as it could be a balance shaft? Are you getting a lot of black staining around the exhaust and bumper? I'm not 100% on this but your car is certainly burning way too much fuel and sounds similar to previous symptoms I've read about. Another sign to look for is burning rubber smell. What ever it is get it back to the dealer asap

You mention burning rubber smell? I get this occasionally after a long run but smells more like tyres to me than anything? Am I wrong and could be a common problem on these?

 

[smudge11]

It's not so much the smoke you are under acceleration it's just one sign of it is black soot around the exhaust outlet.

Either way your engine isn't running right, have you got MB warranty or anything like that?

I do have a 12month approved MB warranty. It's been in for the vibration already and they've allegedly fixed it. (They havent)

I did actually view the car pre prep and the drivers side tailpipe was very black, passenger side was ok tho.

I'm worried now.

 

[kianok]

I'm now expert but it sounds like your DPF might be performing an active regeneration.

Never really noticed the RPM rising on idle but then again most of my journeys are motorway.

With regards to the comment above about a burning rubber smell, that can be caused by the the heat from the exhaust heating up the rubber mounts during a regen.

I also have a small amount of vibration when the engine is cold but i've identified the plastic engine cover as being the culprit.

 

[smudge11]

Cheers chaps. It's getting a bit of a run on Sat - ill see what sort of MPG I get on that run.

I am pushing the vibe with the dealers tho. I've got 12 months to get it tip top.

 

[GAV105N]

I have had two c350 cdi's , first one was a 2010 and the second 2013 , I averaged 31 mpg in the 2010 and 34 mpg in the 2013 model , average speed was around 22mph on the trip over a period of 12 months and around 6000 miles , you wont see more than mid twentys on the trip if your in stop start traffic , on a steady run 40 mpg is easily achievable , hope this helps
Get the dealer to check your engine / gearbox mounts regarding the vibration

 

[johns E350]

I have an E 350 CDI and get between 28-30 around town 50 mile run gives me low forties and a long run being careful gives me the magic 50 miles to a gallon I get no black soot in my tail pipes you could eat your dinner in my tail pipes tick over is 600 and constant.
Higher when first started cold It is a clean mean diesel machine

 

[st13phil]

At this time of year fuel consumption for a big Diesel engine goes down the pan for two reasons:

1. Winter blend diesel has lower energy content per unit volume
2. At near zero ambient temperature it takes a long while for the engine and transmission to get up to operating temperature

When I had my E350CDI I used to experience a good 10% increase in consumption on my daily commute at this time of year compared to the summer months, and that's on a 23-mile run on fast A- and B-roads.

How long are your stop/start journeys? My guess is that the drive train isn't getting properly up to temperature and that if you give the car a good run you'll find that fuel economy is massively better.

 

[smudge11]

Thanks guys.

My commute is only 7 miles each way (just started a new job after lost my old one of 16 years and 30 mile round trip commute)

The engine only just gets up to temp as I arrive at work and home.

My tailpipes seem clean so far, I just noticed it when I saw the car in its untouched pre prep state.

I will be using my motorbike more in the summer (and I can park it outside work for free)

 

[Mbstarz]

I think your mpg for this time of year is probably about right for driving in stop start. I get between 24-27mpg around town in my 220cdi and on a long steady run will achieve high 40's. I think warmer weather will help with mpg figure for diesel drivers..

 

[st13phil]

My commute is only 7 miles each way (just started a new job after lost my old one of 16 years and 30 mile round trip commute)

The engine only just gets up to temp as I arrive at work and home.

The water temperature may just hit the normal mark in that distance, but the oil is still relatively cold. My E63 has an oil temperature display and in the current conditions it takes around 12 miles and 18 minutes to hit 80c, which is the bottom end of the "normal" range. I know that it's a bigger engine, but a petrol warms up quicker than a diesel, so I'd guess that there would be little difference in the time to get the oil up to temp.

Now I understand more about your usage pattern, I'd say 22mpg is pretty good frankly. You'll do much better on a longer uninterrupted run.

 

[Bjm34new]

I have a 2010 c350 CDI and I have to admit, in slow moving traffic it isn't great. I get mid 20's at best.

On longer runs I get high 30's maybe even low 40's when cruising along.

I would take it for a long run and see what the range returns. Also I find my car runs better and get much more range from using premium diesel than normal. Worth a go?

same here around 27 on my 6 mile commute, and pushing 40 on the longer runs as long as the right foot behaves

 

[Rungles]

Very nice car mate. I hope you get your issues sorted.