Technical Vibration around 1700 - 2000 RPM

[EvilJaxx]

Hey

Currently when driving my Dad's 1.9 Diesel there is a vibration through the entire car between 1700 - 2000 RPM which goes away when declutched the car is also smoking alot which started within the past few months.
My friend owns a very respecatable garage who is doing the work on the car for my Dad but cant seem to find what the problem is although they can feel it and believe the smocking is releated.
What they did say was that it is not the Turbo as all seals are fine etc however that on some diesels there are flaps or something in the manifold (not sure if they mean inlet or exhaust) and they have tendancy of going on higher milage cars (car is currently 70k) thus causes the vibrating and smoking.

Any ideas would be most welcome!

Cheers

 

[MadMan0]

does it have an inter-cooler by any chance?

 

[DaveMcT]

At the mileage on the engine its unlikely to be a compression issue.

Smoke usually means not enough air - black smoke from a faulty turbo, blocked air filter or air system leak
Grey smoke means the injectors are faulty & not atomising the fuel.
Blue smoke can be the turbo shaft seals blowing oil down the exhaust.

Most diesels have an exhaust gas recirculation system. This can cause carbon build-up in the inlet manifold especially if it been driven very slowly for a long time. This will also cause black smoke - no air getting through.

 

[Ffoxy]

Dual Mass Flywheel heading for hell maybe?

 

[MadMan0]

my thoughts where that the air pipe from the intercooler to the engine may have a leak.

or a dirty/blocked air filter - both the cheep fix

 

[RB2009]

Smoke and Viabration likely to be 2 separate issues.

unless its the engine running rough causing the viabration.

assuming its not, only 1 thing which usually causes engine viabration on diesels and its the dual mass flywheel.

flywheel is not 1 piece, its 2.. inner and outer flywheel, with the 2 parts suspended together using a similar method to the inner and outer part of a clutch plate with springs/rubber dampers

problem is the DMF wear and the outer part becomes loose from the inner part.. this is what causes the viabration because its making the flywheel unbalanced.

have no idea if it works on other cars, because ive never tried it, but found this.



if it yeilds no results lol dont take it as ok because its a different car and no idea if it works.

what a DMF is, explained better here,

http://moodle.student.cnwl.ac.uk/moodledata_shared/cdx%20etextbook/dswmedia/trans/clutchMan/clutches/dualmassflywheels.html

Smoke problem, check the EGR valve first, they tend to get clogged up with carbon buildup which causes the valve to stick or clog up blocking exhuast gasses, or causing too much exhuast gas to flow into the inlet manifold.

once thats clean, if its still smoking likely to be injectors not atomising properly, diesel produces smoke when its not burning efficiently/cleanly.

if your burning oil.. usually valve stem seals, but dont rule out turbo failure.. the bearings can go in turbos as they use a floating bearing.. it floats on a bed of oil, and that oil can leak past the bearing through the shaft, into a hot exhuast... normally accompanied though by a distinct oil burning smell

but I dont think its the turbo on your engine, as you would soon know about it.. not only would the engine be down on power, but you would have plumes of smoke and dripping oil

white smoke, normally head gasket failure.

not an impossible cause, the intercooler hoses... so check them anyway its free to check.
but split intercooler hoses are normally accompanies by a whistle, or failing that..lack of power.