c250td chugging at idle

[Uberderv]

Hi all,
When the car is at idle and I put my foot on the brakes the engine really seems to struggle, would this indicate a vacuum problem?
Thanks in advance, Pete.

 

[JonathanC250]

If this is happening in gear, I'd have a guess at something in the gearbox or torque converter.

If is just vibrating and shaking the car, then i'd check your engine and gearbox mounts.

 

[gtvlusso]

Chugging is usually a n injector seal that has gone - this would affect the fuelling map in the ECU.
Take the engine covers off and check the head for black carbon build up.

 

[SilverSaloon]

its probably the common air in the fuel pipes issue.... hard to tell with vague description of the problem.

check your clear fuel pipes - do you see any bubbles when the car is idling?

 

[Uberderv]

I did have a problem with air in the pipes but after changing the orings its much better.
I happens when the engine idles in neutral, runs nice and smooth until you put your foot on the brake and it starts to chug like it wants to stall.

 

[Dieselman]

That sounds like a torque converter fault.

 

[SilverSaloon]

hmmm i've had this with cars in the past, where you come to a stop and the revs drop really low and then rise back up..... could it be alternator/voltage related????

 

[Uberderv]

At idle in neutral the revs drop by 1-200rpm when I press the brakes which makes the engine chug, could it be a pump fault as I seem to get problem after problem with this bloody car.

Thanks Pete.

 

[Dieselman]

Check the engine earth strap and the alternator +ve connections. It could be the voltage is dropping when the brakes are applied, so causing poor running somehow.

 

[pingping]

hmmm i've had this with cars in the past, where you come to a stop and the revs drop really low and then rise back up..... could it be alternator/voltage related????

that was my immediate thoughts also

 

[Uberderv]

Thanks for the ideas chaps.