C220CDi 2001/W203 loss of power

[djg555]

My 2001/W203 C Coupe 220CDi has developed a fault where part way through a journey it loses power.

Happens after 30mins/30 miles, car will accelerate up to 70mph on flat - on hills it slows to 55mph. Only first 30% of accelerator travel has any effect, the next 30-100% makes no difference.
Fuel consumption is also worse, c. 37mpg instead of usual 44mpg.

On journey home (8 hours later), all is fine for the about 30mins/30miles and the fault reappears. This repeats every day.
There are no fault lights/malfunctions reported on the dash.

Spoke with an inde MB who through it was the MAF. They said stop the car, remove the key, wait a mintue and any fault code would be cleared and the car would be OK.
Tried this, but the fault was still there immediately I drove off again.

Any thoughts ?

 

[Steve@Avantgarde]

If its a MAF fault it wont necessarily reset with the ignition. It does sound like a MAF fault you need a star test to be sure though.

 

[djg555]

Steve

Thanks for the reply and clarification of ignition reset.

I suppose the question is how likely is it to be the MAF - I've been quoted £35 for the STAR test and £75 for the MAF, so is it worth the gamble of justing buying a new MAF?
(If so, any advice on where to buy - some say any autofactors part, others say it should be genuine MB/Bosch as voltages outputs vary)

I've seen posts where people say they disconnect the MAF completely and the car runs fine - so could I do this to see if the MAF is at fault?
Once removed is there an electrical test that can be done on them (thought this may be hard with an intermittent fault that only occurs after 30mins)?

I've also seen posts about removing and cleaning a MAF - is this true.

Once again, thanks for your time and advice.

 

[oigle]

Maybe you should also consider a sticking egr valve. Can also cause similar issues.

 

[MB TECH WARRINGTON]

Disconnecting maf will not tell if the maf was the cause.

We had a customer who disconnected the maf and it ran better, he wanted us to fit a maf, we duly obliged, erased faults. Car ran terrible with brand new maf.

We investigated, found the fault,

The fault was a completely bolcked EGR and intake manifold, the air was entering through a hole the size of a 5p coin, such was the build up.

Thoroughly cleaned out, job done.

Moral of the story just because disconnecting maf makes the car run "fine" (which it wont with maf disconnected, it may run ok), does not mean maf was the cause. It could be £50 misspent.

Just my educated/experienced input to consider.


We charge £20 to put on star and quick diagnosis, im sure other specialists charge similar.
"Our" customers dont get charged a penny to hook up on star.

 

[television]

Many a MAF has been fixed or solved by unplugging to try on here, more petrol than diesel sadly many indies and all dealers charge so much more,, I will remember what you charge and recommend accordingly

 

[MB TECH WARRINGTON]

Many a MAF has been fixed or solved by unplugging to try on here, more petrol than diesel sadly many indies and all dealers charge so much more,, I will remember what you charge and recommend accordingly

As stated Malcolm we feel £20 is a fair price for a diagnostic run, thanks for the thought.
And just to reiterate, as I have seen a few posts over the past few months saying we are expensive, Our hourly rate is £45 per hour, always has been and will remain so for forseeable future.

We will be having another GTG in the new yr, I trust you will attend.

We will put up an official post when a solid date is planned. But we plan for late January, let everybody get settled in after Christmas.

 

[television]

As stated Malcolm we feel £20 is a fair price for a diagnostic run, thanks for the thought.
And just to reiterate, as I have seen a few posts over the past few months saying we are expensive, Our hourly rate is £45 per hour, always has been and will remain so for forseeable future.

We will be having another GTG in the new yr, I trust you will attend.

We will put up an official post when a solid date is planned. But we plan for late January, let everybody get settled in after Christmas.

Thank you for pointing that out and it will get passed on when you are too busy to post Nice to know as well.

My life has changed a little and I have limited time but I would do everything possible to attend a meet with you again, the last one was great and that was a wonderful spread that you so kindly laid on for us

 

[MB TECH WARRINGTON]

Thank you for pointing that out and it will get passed on when you are too busy to post Nice to know as well.

My life has changed a little and I have limited time but I would do everything possible to attend a meet with you again, the last one was great and that was a wonderful spread that you so kindly laid on for us

Yeh I try to post, but no chance in work time, I then leave work, race home to spend some time with little baby, then feed myself, then bed and start over again. Besides you beat everyone to the posts

And although we dont post much on here, there is alot of traffic diverted to our email in the form of questions which we will always respond to, so if you need to contact ourselves for any matter, likewise anybody needs contact us, click our site and send email from our contact page. We reply to every email recieved.

It will be pretty much the same again, nice spread, some interesting cars, star machine available for free diagnostic runs as well this time to all attendees if needed and if we can fit everyone in.

Ill keep everyone updated nearer the time too.

 

[ELGRINGO]

Hi think £20 is more than a fair price look forward to meeting you at next get to gether, in same boat as you. gazx.

 

[kolobos]

Hi Guys,

My w203 C220 CDI 2004 is having a few issues with power, as such it feels like the turbo isnt even working. If i fully press the accelerator it doesnt change gear nor does it speed up a great deal either. However after being sat in traffic for 5 to 10 minutes it suddenly appeared fine once again. Also prior to a run I could smell burning and a bad gas type fume, although this only happened once.

Reading the above I believe I may have an EGR fault as STAR Diagnostics indicated a few errors when my glow plug relay was changed and the faults cleared. Perhaps the EGR valve is now the problem, thanks.

Steve.

 

[Steve@Avantgarde]

I would check the fault codes again with STAR, any codes there can be verified with actual values.