mattuk
Senior Member
Hi
Due to mud in "fluctuate revs again" thread here is fresh one
My car c320 petrol 2001, 95k miles
Car runs faultless apart hunting/fluctuate revs on idle and sometimes vibrations
I checked all vacuum hoses few times - good condition
Also cleaned throttle body, maf, sealed breather cover leak, checked everything! Car pass MOT without problems, car feels powerful and accelerate without problem, no codes on diagnostic tool , i/m readiness shows that everything works correctly, o2 sensors work in correct values, no oil leaks
Today I was checking EGR valve.
- disconnecting does not indicate check engine light However was pending code. All clear now
- with correct engine temp vaccum supply was disconnected, no difference on idle, still fluctuation, no vaccum in hose.
- engine revs at 2000- 2500 rpm, disconnecting vacuum supply does not make any difference to engine, there is vaccum in hose.
- with engine off vaccum was applied directly to the valve. Valve holds the pressure.
- engine on, idle - valve is hot but it's tube which goes to manifold is cold.
- engine on, revs at 2000-2500rpm - valve is hot but tube(pipe) only slightly warm.
- also I hit valve by screwdriver few times on idle but no changes.
Egr pipe(tube) - how hot it has to be ?
I would be very thankful for help
Due to mud in "fluctuate revs again" thread here is fresh one
My car c320 petrol 2001, 95k miles
Car runs faultless apart hunting/fluctuate revs on idle and sometimes vibrations
I checked all vacuum hoses few times - good condition
Also cleaned throttle body, maf, sealed breather cover leak, checked everything! Car pass MOT without problems, car feels powerful and accelerate without problem, no codes on diagnostic tool , i/m readiness shows that everything works correctly, o2 sensors work in correct values, no oil leaks
Today I was checking EGR valve.
- disconnecting does not indicate check engine light However was pending code. All clear now
- with correct engine temp vaccum supply was disconnected, no difference on idle, still fluctuation, no vaccum in hose.
- engine revs at 2000- 2500 rpm, disconnecting vacuum supply does not make any difference to engine, there is vaccum in hose.
- with engine off vaccum was applied directly to the valve. Valve holds the pressure.
- engine on, idle - valve is hot but it's tube which goes to manifold is cold.
- engine on, revs at 2000-2500rpm - valve is hot but tube(pipe) only slightly warm.
- also I hit valve by screwdriver few times on idle but no changes.
Egr pipe(tube) - how hot it has to be ?
I would be very thankful for help