Leading on from a previous thread in which Mapmaker did advise that he was able to tell that his cambelt was about to give up, I'd just like to know what this sound is exactly? Specifically on GM engines if there is a difference
I've been thinking that it may take the form of a rattle at high revs, or a screeching noise potentially, or even a regular ticking noise. But not having heard it before I wouldn't know what to look out for.
|
Its a wheel and bearing basically, so push it and pull it and check for roughness, run the engine with the cover off and aux belts removed and listen for dry bearing noises a bit like white noise on a radio
|
|
Not your car I know, but on our old Punto the tensioner pully had failed and was screeching like a loose fanbelt ... it ran like that for a couple of weeks before I got round to diagnosing it ...
|
you can sometimes see if its the tensioner by squirting a bit of wd40 into the bearing , if the noise goes away for a few seconds its that
can be squealing ,sqeaking , grumbly rattlely noise.....worth fixing before the cam belt leaps off
|
Sometimes if you look at it or near it, you will see a fine dust of rust/copper/ other metallic fragments!
|
Had an cam belt idler go on mine and it took quite a while to fail, I was convinced it was the alternator free end bearing failing.
It whined, varying in pitch with engine speed, though not at all evident at idle.
Luckily when it did go the plastic cambelt cover held the outer race/belt roller in place enough to keep sufficient tension on the belt prevent it slipping!
|
Thanks for the replies. Does sound like it's one of the two bearing noises -- either a screech or a rumble.
I'll tell you why I posted this up. This morning I took the car out, and I noticed a slight clicky/tappy noise which increased in frequency with the car engine -- could be heard from inside but was not particularly noticeable from the outside.
It was like a very feint version of one of the tappets tapping. Went away when the clutch was depressed.
Came to the conclusion that it was a noise from the release bearing. Gone away now. Engine sounds the same as it ever did. Odd.
Shows what paranoia can do for you though ;)
Edited by jase1 on 04/10/2008 at 17:26
|
>>Came to the conclusion that it was a noise from the release bearing.
Did the noise go away as soon as you put any pressure on the pedal, or, just as soon as you were below the biting point?
|
|
Not sure NC -- probably the latter.
|
If it was the latter, the noise was coming from the gearbox input shaft, not the release bearing.
|
|
Forgive my ignorance in these matters, but is that anything to be concerned about?
|
Beyond checking the oil level in the gearbox, I wouldn't do anything - let it develop!
|
Sounds like I possibly shouldn't bother with that belt after all if the box is potentially on its way out!
Ah well -- twas a free car -- as long as it lasts to the next MOT I'll be happy enough with it.
Edited by jase1 on 04/10/2008 at 22:29
|
If there's plenty of oil in the gearbox, I've known gearboxes rattle like this for years.
|
It sounded like a (quiet) old-fashioned football rattle - a rapid clicking sound. click-click-clic-click, obviously at a faster rate than you would rattle a rattle. I initially thought it was a bearing on the alternator-belt setup, but investigation showed it was coming from elsewhere. Mechanic put his ear to the cylinder head cover, and said "cambelt tensioner".
|
Cheers, right well that's certainly not the sound I heard. I didn't think it was the cambelt tensioner but it got me thinking the other day.
As far as the noise on this car is concerned, it went away, it's been driven about 50 miles over the weekend and it hasn't returned. If it is a box noise, it's very intermittent. Hopefully nothing to worry about.
Had a good listen to the engine yesterday -- nothing untoward. Will forget about it for now. Thanks for all the replies esp NC.
|
|
Fzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzzplnkplnkplnkjggajgga
jggawhoooosh...oh
shi
|
|
|
