Club 80-90 Forums

Folks

I+On my recent trip to Cornwall I noticed that the engine was running rough (in a kangarooing style) around 2000rpm, but smoothed off above 2500rpm. Bugger i thought - will post a query on 80-90 when I get home.

Then I noticed that there was a speed related vibe - which I (correctly) put down to unbalanced tyres. Later I checked the tyres and found bald spots on both rears, so rather than risk the family I had all 4 tyres replaced before the run home to Manchester.

And behold, the engine kangarooing disappeared!

I'm putting the coincidence down to 'the vibe from the tyres affecting whatever engine speed regulator there is on the diesel engine' - I'm assuming there's some sort of centrifugal jobbie that hated the tyre vibes.

So a statement and a question...

Statement - if your TD runs rough- check your rear tyre balance/wear

Question - can anyone techical here throw some light on what was going on.


Simon

This sounds familier.

I too want help.

I got a 1.6td as well and I have simular problem at low revs when acelerating hard. New tyres recently, no change. New clutch, no change. New gearbox mounting, no change. Could it be engine mounts? Fuel pump problem? Seems to only happen at low revs like its in wrong gear. Dont think its clutch related as it dont happen when clutch is let off.

Sorry 'sorebums' for latching on like this. I didnt help much, only added to the great mistery of the kangaroo symptoms.

Any one out there who can help us???

Earlier type diesel engines (not neccesarily VW ones, I`ve seen it on Peugeot/Citroen units) can suffer from the "kangaroo" syndrome, later diesels (certainly Peugeot/Citroen) had a damper fitted to the fuel pump throttle connection to try and stop this. I think because the throttle cable/linkage is so long you get the kangaroo more pronounced, as when it starts to do it, the "kangaroo" motion makes you slightly press/depress the throttle pedal and this makes it worse. My 1.6TD does it slightly I`ve noticed, usually when trying to pull too high a gear after setting off or having slowed down then hoofed the pedal! I found that it stops if you let off the gas, then slowly bring it on again or just change down a gear and accelerate again.

Soft or damaged/broken engine mounting rubbers won`t help the situation, one of them on my `van is looking a bit dodgy I noticed when I was sorting the cambelt last week, another job to do! I think they get soft due to contamination, and the rubber block "de-bonds" itself from the steel mounting plate.

ive yet to see any data stating that worn tyres make an engine run rough ?? next time i run out of diesel, i`ll check my tyres. its probably theyre fault.

If you have bald spots on your tryes chances are your rear shockers are knackered.
Plus I cannot see any reason for a out of balance tyre can make an engine run rough.
Fair enough, you may get a vibration which you may think is the engine but it won't.
Dodgey tyres give symtoms that are road speed related rather than engine speed related.

My problem is definatly engine / drive related when power layed down.
Without a doubt it aint tyre.

bilbo sounds to me like you may like to check your drive shaft CV joints, worn or stiff joints can cause a right viberation ect