Crank pulley failure !

[mgoode180566]

Is this a first ?????

Lifted the broken engine out of the sunflower this evening. Suspect headgasket as lack of compression across cylinders.

As i lifted it out i noticed the aux belt not sitting correctly and pinched under the cambelt cover. Immediately i was thinking that it had jammed the cambelt and jumped the timing.

Always one for a mystery i cut off the aux belt and the ribbed part of the crankshaft wheel fell out on the driveway !!! It would seem that the crankshaft pulley is a pressed part and the outer had separated from the centre. Now this points back to an odd noise that had started some weeks ago when the car was on full lock. My guess is that under load the outer part was spinning but would track correctly at normal driving speed.

Anyone heard of this failure before ???

 

[rampantreaper]

Seen a few diesels do that. Pugs used too

 

[Jonny1*2]

You mean the cambelt one or the largers one that the aux belt goes on? The larger one has rubber bits to it, so potentially could perish. The cambelt one looks like a single piece to me, but could be wrong.

 

[Jay Payne]

Yep, see it a lot on all sorts of cars. Last one I saw was an espace a few days ago

 

[bennno2005]

Seen a few diesels do that. Pugs used too

Especially on the HDI's. They normally make a racket before they go but if they do go they can take out the cambelt too.

 

[Alastair.]

Changed one on a Laguna 2.2dci for this problem today

 

[mgoode180566]

Not a tensioner but the main crankshaft pulley. Just fell in half...

 

[Dan519]

changed the pulley on a VW LT46 van a few weeks back

 

[scotty2hotty81]

Mercedes v6/v8 do this and then start to mill a cut into the front cover and pi$$ oil out everywhere
Also had a bmw with intermittent battery warning and loss of power steering due to it slipping

 

[MicKPM]

dampened pulleys are supposed to be replaced with aux belts and timing belts but they never get done due to price. Another great money maker that came about in the late 90's

 

[mgoode180566]

are they damped to stop resonance destroying the crank \ bearings ?

i have never heard of this before.

dampened pulleys are supposed to be replaced with aux belts and timing belts but they never get done due to price. Another great money maker that came about in the late 90's

 

[mgoode180566]

i dont have my other engine to check but is there a rubber between the inner and the out parts of the pulley ?

 

[Gray]

i dont have my other engine to check but is there a rubber between the inner and the out parts of the pulley ?

See below, dampened crank pulley:

 

[mgoode180566]

So i am now guessing that the timing has jumped a tooth. What are the chances of having it simply timed up again ? Would i be looking at valve damage ?

 

[Bren Rogers]

Is this a first ?????

Lifted the broken engine out of the sunflower this evening. Suspect headgasket as lack of compression across cylinders.

As i lifted it out i noticed the aux belt not sitting correctly and pinched under the cambelt cover. Immediately i was thinking that it had jammed the cambelt and jumped the timing.

Always one for a mystery i cut off the aux belt and the ribbed part of the crankshaft wheel fell out on the driveway !!! It would seem that the crankshaft pulley is a pressed part and the outer had separated from the centre. Now this points back to an odd noise that had started some weeks ago when the car was on full lock. My guess is that under load the outer part was spinning but would track correctly at normal driving speed.

Anyone heard of this failure before ???

Another Sunflower with engine trouble! - bottom end went on mine the other day, think it was down to an oil pump failure or a blockage somewhere.

 

[Dan519]

are they damped to stop resonance destroying the crank \ bearings ?

i have never heard of this before.

exactly that. Some engines are more sensitive to it than others, but generally replacing a damped pulley with a non damped one isn't a good idea (very popular thing to do on the jap scene)

 

[Toastfrenzy]

If you replace the crank pulley with a light weight one, can you still fit the rubber damper?
Pure motorsport one

 

[Andyman]

If you replace the crank pulley with a light weight one, can you still fit the rubber damper?
Pure motorsport one

No mate because the damper on the Renault crank auxiliary pulley is built in to the actual pulley.

Guessing Pure just do without a dampener altogether ?

 

[Dan519]

I've not got a lot of time for lightened crank pulleys. From anaylising balancing data, you can see that the flywheel end, even when balanced, shows a greater degree of error. Lightening the other end only serves to make the end to end difference worse