CLK230 Kompressor - High Fuel Consumption

[Will]

Hi Gang,

A friend of mine has just bought (literally a couple of weeks ago) a 2001 facelifted CLK 230K Auto.

It's an Avantgarde with factory AMG wheels (245 rears).

I went with him on a journey over the weekend - up to Coventry and back. Very light traffic and managed to cruise most of the way close to the limit on the motorway. Same again on the return - couple of bursts of speed but mainly driving in top at normal motorway speeds.

Anyway, was quite surprised at how poor the fuel consumption was for a journey like this - around 25MPG!

Car isn't due a service for another 5k miles. Tyres are all inflated to manufacturer's spec. It's running and driving lovely, currently on 60K miles with history. I've since replaced the air filter for him and will do the plugs at some point soon - not that I suspect these items, but it seemed prudent due to the age/mileage of the car.

I'm guessing MAF or maybe the lambda sensor could be out of spec? Anyone else agree with me that 25MPG is a poor figure for this type of journey?

As a guide, my auto 2.5-16 (which is nearly twenty years old!) will give over 30MPG driven at an even higher crusing speed.

I'd have expected low to mid 30s for this car (the CLK 230K)?

Will

 

[jaymanek]

Quoted combined is 27.4 but at an average of 57 it should be more like 30...
I would get it plugged into see if any codes are coming up..

 

[vijilants]

Hi Will,

My C230K which has the same engine, and also 60,000 miles gives approx 30 - 33 on the long run.

 

[Adam230K]

Same here, i get 35 on mine on a motorway slightly more if i'm not aggressive on the pedal, Manual tho.

 

[Kompressor_Dude]

I put a tenner in and managed 57 miles of 100% motorway driving at the weekend. Works out at around 29mpg :bannana:

Probably could've got better but it's chipped.... and it was very late at night

 

[Adam230K]

hey where did u get it chipped and what kind've differences has it made? u got a higher engine redline limit? any speed/consumption differences? I'm thinking of doing mine... (sorry to high jack the thread here!)

 

[stevend]

My 230k give 29 mpg regular as clockwork...
I see the sprintbooster link ended a few months ago. Anyone know if the discount still applies.
Steve

 

[clktel1]

must admit i get mid 30s on the motorway, and 25-28 round town its a 99 clk 230komp auto

 

[ukcodger]

Maybe do a double check on the dash display by brimming the tank over a couple of fills and getting an exact figure.
Could be there's a different rolling radius on the wheels now to when it left the factory. I know you said factory AMG's but are you sure they're the wheels the dash was calibrated for?

 

[Will]

Following on from this thread:

My friend hasn't done anything about this yet. A couple of days ago he noticed a light on the dash - it's the engine warning light.

Anyway, I have since replaced the plugs and oil/filter for him (he has these already), but I suspect it might be related to this:

http://www.mbclub.co.uk/forums/showthread.php?t=63484

Looking around on the forum, it seems as though the oil leak around the cam can cause problems with the lambda/o2 sensor. Sounds plausable - ie high fuel consumption/engine management light on and the oil leak around the inlet cam.

Obviously needs plugging in to read the codes, but does this sound likely?

Will

 

[flango]

My CLK 230 32 - 34 mpg always but it is manual

 

[W210 Fan]

echoing UK codger I would check the consumption the manual way, I assume thats pretty much the same fuel computer I had in the S class which told me I used to get 12ish MPG on the way home which was not true as I used to check it every fill up and it was nearer mid to late 20`s

 

[ChrisPSR]

Hi,
I have a straight forward CLK320 2dr Elegance Automatic of 2003 vintage now at 90,000 miles and recently serviced by way at least of engine oil and all filtres (checkable and self checked) I bought the car at the end of May this year with 89,230 recorded miles, the body is rust free, services apart from the last one which was by the vendors, is all by Mercedes main dealer and the car is of cream upholstery, Ise-Blue exterior paint and immaculate inside and out (may all help with diagnosis).

I consider my fuel consumption to be very disappointing;
Visit Tesco 1.5 miles distant and then return 13-14 mpg
Visit my engineering club 8 miles distant and then return 20-21 mpg
Overall recorded mpg calculated by way of billing and recorded mileage which includes many other trips from 1.5 miles to a maximum of 15 miles in any one direction 17.9mpg

Is it thought that I do have a problem or is my BMW M5 owning son correct in stating that I am just not getting the engine warm enough (given summertime) to provide reasonable fuel figures or is there something more sinister or arrie.
Chris Spreckley

 

[clk208]

Could see mid 30s easily on a run in my old 320 and late 20s / early 30s no bother around town.

Saw an increase in fuel consumption for a while and it was a duff lambda sensor. No warning on the dash - the car has to be plugged into a STAR or similar diagnosis machine to show up the fault codes.

A plug/air filter change might be wise too - may have not been done for a while.

 

[John Jones Jr]

Following on from this thread:

My friend hasn't done anything about this yet. A couple of days ago he noticed a light on the dash - it's the engine warning light.

Anyway, I have since replaced the plugs and oil/filter for him (he has these already), but I suspect it might be related to this:

Oil leak around inlet cam on 2001 230 Kompressor engine (M111) - MBClub UK - Bringing together Mercedes Enthusiasts

Looking around on the forum, it seems as though the oil leak around the cam can cause problems with the lambda/o2 sensor. Sounds plausable - ie high fuel consumption/engine management light on and the oil leak around the inlet cam.

Obviously needs plugging in to read the codes, but does this sound likely?

Will

The oil leak on it's own won't throw a code, well it didn't on mine or another M111K that I'm aware of. Prime candidates are MAF & Cam Sensor I reckon. Then again it could be the o2 Sensor too.

As you said, read the codes first and go from there. Worth opening the loom up at the Cam Magnet Solenoid and see if there's any 'wicking' but, I think this was more of an issue on the later M111 with Eaton M45 S/c's (don't quote me on that).

Anyway, once the loom is open right down to the wiring itself, just flatten a small section and add solder all the way around, tape up and this will prevent a 'wicking' problem occurring in future.

Edit: Worth while looking at the original date of the thread first, Sorry ChrisPSR.

 

[flango]

The oil leak on it's own won't throw a code, well it didn't on mine or another M111K that I'm aware of. Prime candidates are MAF & Cam Sensor I reckon. Then again it could be the o2 Sensor too.

As you said, read the codes first and go from there. Worth opening the loom up at the Cam Magnet Solenoid and see if there's any 'wicking' but, I think this was more of an issue on the later M111 with Eaton M45 S/c's (don't quote me on that).

Anyway, once the loom is open right down to the wiring itself, just flatten a small section and add solder all the way around, tape up and this will prevent a 'wicking' problem occurring in future.

Yep I agree classic symptoms, Cam magnet issue is present on the earlier cars too. Also quite often diagnostics throws up false codes, mine originally came back as cam sensor changed that and cleared codes then flagged O2 sensor so changed that no trouble since. Are you definitely sure the supercharger is working as if not it can also be down to these items and that really kills fuel consumption.

 

[John Jones Jr]

Here's thing f1. The Cam Magnet & the Cam Sensor can both be faulty and in my case they were and the S/c still engaged as it should.

If the S/c is not working or the bypass valve is inop, I think the driver would feel that straight off. I doubt the problem is lack of boost.

 

[flango]

Here's thing f1. The Cam Magnet & the Cam Sensor can both be faulty and in my case they were and the S/c still engaged as it should.

If the S/c is not working or the bypass valve is inop, I think the driver would feel that straight off. I doubt the problem is lack of boost.

I agree but you would not believe the number of 230k's and 200k's that came into our place with inoperative superchargers and the driver had never noticed, all they had noticed was an increase in fuel consumption