1999 180c upshift & power probs

[rswaffie]

Hi
I have a 1999 180c Elegance, 94k on the clock, serviced at correct intervals by main dealer.

It is experiencing an intermittant problem, that manifests itself as follows :

The autobox seems to 'delay' the upshift from 2-3 and 3-4, holding the car at high revs. It then upshifts but with a 'clunk'. This is normally followed by a general loss of power, making acceleration sluggish and very lumpy at idle (almost as if it is not firing on all cylinders or about to stall). This can only be rectified by switching off the engine and restarting. The problem then disappears for days or even a week. I did a round trip of 300 miles - no probs. Two days later, travelled for 10 miles and problem started again. Then went for a week with no problem before it happened again.

I thought this may be a fuel delivery prob at first, but with the upshift problem, I'm not so sure.

Any idears ?

Regards
Richard.

 

[television]

I think that it is the MAF filter that is past its sell by date

If the power of the engine is down the box does not know what to do


Unplug it and try the car

 

[rswaffie]

Thank you Malcolm.

 

[rswaffie]

Hi,

Took the MAF apart at the weekend to check for dirt,oil etc. It looked clean as a whistle but I sprayed some isopryl on just in case.

As this is intermittant at the moment, I won't know if this has made any difference for a while. If the problem persists, I will try the unplugging of the MAF whilst the car is having the problem. I assume this will mean a replacement of the the MAF if this proves to be the problem ?

If it doesn't sort it out - is there anything else I can look into ?

regards

richard.

 

[MotardMan]

Sounds exactly like the issues I have on my C240 ATM. It pulls through the box fine until you want it to go fast, you press the pedal to the floor and the motor slowly builds revs, then hangs on to them for too long, (sometimes on the limiter!) until it lurches into the next gear. It is horrible as overtaking is not a possibility currently....

Let me know how it goes with your car? I'll try driving the C240 with the MAF disconnected and see what happens. SWMBO has it today though so I cannot update the thread until tomorrow earliest.

 

[jimsinessex]

Could be a rear wheel speed sensor on it's way out. Having the codes checked would confirm this and indentify the faulty sensor.

Jim

 

[jibcl500]

Sounds too much like MAF to be anything else, sometimes cleaning them on a diesel can work wonders but petrol engines dont seem to clean with success, biggest problem is fine particles getting through the filter and blasting past the sensor.
If the sensor wire breaks then all you can do is replace the air flow meter.

jib

 

[rswaffie]

Hi,

Thank you all for the replies so far. I can report that there have been no recurrances of the problem since cleaning the MAF at the weekend - but as this was intermittent I won't count my chickens for another couple of weeks or so !

When I rang up the local stealership in Peterborough to enquire about the cost of a new MAF (£240 +vat ouch), the parts guy mentioned that it may also be a problem with the 'idle speed valve' (or something like that). This is a brass valve that is connected to a pipe at the back of the engine. He suggested disconnecting it and blowing down it to check for blockages.

Any comments ?

 

[television]

Buy the MAF from a Bosch service center for ½ the MB price

 

[MotardMan]

Buy the MAF from a Bosch service center for ½ the MB price

Any idea if there is such a place in the Gloucestershire area Malcolm?

 

[rswaffie]

1999 180c upshift & power probs - UPDATE

Well, after a couple of weeks of non-recurrance, the problem resurfaced on Friday. Took the car out for a short (2 mile) run with no probs. Left it for 40 mins, then drove another mile with no probs. Parked up for 10 mins and drove home and within 2 mins the gearbox wasn't shifting up until revs were high, loss of power and very lumpy at idle. This time, I managed to pull over and pop the bonnet. I disconnected the MAF power lead, but it made no difference (apart from the cooling fan kicking in). Reseated the connection but still no change. Switched the engine off & back on again and problem gone. USed it several times for both short and longish (10 mile) runs over the weekend and still ok. I have also noticed that there appears to be oil around some hoses that are connected into the air intake ducting between the MAF & the throttle body. Also, I removed the large hose at the throttle body and noticed some oil arond what looks like a butterly valve of some sort inside the throttle body itself. Any ideas ?
Regards
Richard.

 

[jimsinessex]

Here we go again

Sounds like the dreaded "oil in air intake system" problem which up to now has mainly been associated with the Kompressor engines but the non-komp engines have a crankcase breather system of similar design but with slight differences.

Check out the DIY thread "How to stop MAF oil contamination" by JamesMc, also search for and read the long thread "oil in air intake". Then access the russian parts diagram for your model, look under "engine housing" and check the parts listed for the first six numbers of your VIN (after W202).

I am guessing the non komp engine has a plain tee-piece without the valve but stress that is just a guess.

The mileage of 94K you quote also makes the crankcase breather system under the intake manifold a prime suspect!

Then come back here if you need more info, this is a well known problem on the kompressor 111 engines.

Jim