pug 306 - 1800 rpm rattle?

[Ben Lessani]

hi all,

i've got a pug 306 and it makes this strange noise when i rev it to 1800 and balance it there. it does it cold or hot, idle or moving, its very odd. ive had comments saying it could be the big end bearings, cat convertor and crank pulley shaft. what ways can i check this out myself- i know a small amount about cars, but i would not be willing to strip complex parts down.

any simple ways i can check this prob, or has anyone experienced it before.

i appreiciate all responses,

ben

 

[R.N. Robinson]

"Ben Lessani" wrote:

hi all,

i've got a pug 306 and it makes this strange noise when i rev it to 1800 and balance it there. it does it cold or hot, idle or moving, its very odd. ive had comments saying it could be the big end bearings, cat convertor and crank pulley shaft. what ways can i check this out myself- i know a small amount about cars, but i would not be willing to strip complex parts down.

any simple ways i can check this prob, or has anyone experienced it before.

...

Try thumping the exhaust system in various places to see if it rattles. With our 306 XT the heat shield over the cat used to rattle until I bent it a bit. That was over two years ago and it has been OK since. On the other hand, when my 806 did something very similar it was the cat itself. Rather more expensive. If it isn't the exhaust, you could try getting a bit of wood like a short broom handle and use it as a stethoscope to try to locate the noise on the engine, but keep it away from drive belts and anything that goes round. You don't really want to drive it in one ear and out the other, so if possible put your ear to the side of it not the end. If you have a spanner the right size you could check the tightness of whatever it is that holds the front pulley on. I don't know what sort of pulley you have, but if it is fabricated rather than carved from the solid it is possible that it might be breaking up. Big end bearing noise tends to vary with engine load.

HTH

Ron Robinson

 

[Ben Lessani]

Try thumping the exhaust system in various places to see if it rattles. With our 306 XT the heat shield over the cat used to rattle until I bent it a bit. That was over two years ago and it has been OK since. On the other hand, when my 806 did something very similar it was the cat itself. Rather more expensive. If it isn't the exhaust, you could try getting a bit of wood like a short broom handle and use it as a stethoscope to try to locate the noise on the engine, but keep it away from drive belts and anything that goes round. You don't really want to drive it in one ear and out the other, so if possible put your ear to the side of it not the end. If you have a spanner the right size you could check the tightness of whatever it is that holds the front pulley on. I don't know what sort of pulley you have, but if it is ...

I've checked the heat shield, but thats not the problem, if only it was . I have a grave fear that the problem may be the CAT, as I 'think' I am experiencing bad fuel economy (29 mpg in town) and thats for a 1.4 Petrol. Only problem is, short of removing the exaust system, I cannot check the CAT. It has just recently had an MOT and its emmissions passed with flying colours - wouldnt they usually indicate a CAT problem ?

Thanks for the reply.

Ben