I have a golf TDI 110, 2000.
Car starts fine and idles well for 3 or 4 minutes and then starts to judder pretty badly, like its about to konk out - but it doesn't. If I switch of and try to start after 2/3 seconds it turns over but doesn't fire, if I leave for 5/6 seconds starts and the uneven idling has gone away. When accelerating, even at around 1600 revs it judders badly, but if I accelertae slowly no problem at all. The problem is not always there.
Volkswagon say its the flywheel, but not that sure becuase they also said it was a solenoid and fuel control valve and it wasn't. Also when idling bad, if I push the butterfly valve on the EGR (in line with the intercooler) it idles fine, when I take the pressure of the problem comes back.
Can anyone help - the flywheel has been quoted at £970 so don't want to change unless sure its the problem. If its the flywheel, why does pushing the EGR valve seem to alleviate the problem?
Your suggestions would be appreciated!!
|
have a look at this post.
www.honestjohn.co.uk/forum/post/index.htm?t=25826
may be barking up the wrong tree, but you never know
|
|
If you have identified the EGR valve as having an effect on the problem how about replacing that first...got to be cheaper than the flywheel...and you could possibly do it yourself. Have you tried checking Fred's TDI forum for any possibly causes?.
|
|
I can't see how the flywheel could cause this problem. EGR fault is much more likely.
|
How long have cars had flywheels? I'm assuming the flywheel is there to conserve energy when the car is stopping and starting - but there was a question about it on my A-Level physics exam 3 years ago. :)
Can't see how a flywheel would cause this sort of problem though - wouldn't it be constant?
|
Jesse,
Cars have had flywheels for about as long as they have had engines! As you correctly say, it is an energy storage device, but its purpose is to smooth the running of the engine.
Unlike a gas turbine, piston engines produce torque in a discontinuous way. In a four stroke engine, for example, only one stroke in four produces torque, the other three absorb it to varying degrees #.
So, on the firing stroke, the inertia of the flywheel restricts the increase of the engine's angular velocity. During the idle strokes, the flywheel restricts the decrease in the engines angular velocity in a similar way.
Two stroke engines with large numbers of cylinders need the flywheels with the least inertia while engines like the three cylinder 1.0 Corsa engine have the largest.
As soon as you engage a gear, the mass of the car, via the rolling radius of the wheels, and the gear ratio between wheel and crank becomes the equivalent to added inertia which can further smooth engine running.
number_cruncher
# Excepting turbocharged engines, which may also deliver a small toque during the inlet cycle - but it is negligible.
|
|
After much asking around the generl consensus is that the problem is indeed the flywheel, have managed to pick up a second hand one (with warranty) with clutch for £120+vat - new is £550 to £700. Apparently manually closing the intercooler/EGR valve will trick the engine and alleviate the problem. Hope to get it fitted next week and will let you know if it solves the problem for future reference!
|
|
And how was it decided that the flywheel was causing the problem?, and, umm, what exactly is this flywheel problem?...we still don't know it. How did the EGR "trick" the engine?. Its too late now, but I would have put the £120 towards a new EGR valve.
|
The only failure I can easily imagine is in the case of it being a two mass flywheel, the springing medium between the two parts of the flywheel has failed.
number_cruncher
|
|
|
