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Rattle from alternator drive belt at low revs

10K views 27 replies 11 participants last post by  T-Cut 
#1 ·
My 99 Club 2.0 diesel has started making a horrible rattling type noise from the alternator drive belt area. The noise is only there up to about 1250 revs then seems to settle down, any load on the electrics, A/C, lights on etc. makes the noise worse. Just had a look and either the drive belt or one of the pulleys seems to move across when the engine is revved and the noise stops when this movement has occured. Hope that makes sense, all seems ok, charging, running ok just sounds scary at tick over/ low revs.

Thanks for any help in pin pointing the problem, Rich.
 
#7 ·
Thanks guys, what sort of further damage are we talking, major probs or just stuck in the middle of nowhere with a broken belt?

Really busy at work next week, 60 mile return trip and covering for my workmates, both on their hols, means little time for a trip to the garage. I know it's a piece of string question but could it make it through the week?
 
#10 ·
Crank Puller/Tensioner

Yes, the pulley is expensive from Xpart. A member yesterday got his from Euro Car Parts, about half the price, I think.
Not an easy job & I think needs to be done from under car. Biggest problem, evidently, is loosening the pulley bolt. Need right size STRONG socket (one member said 1st socket broke, had to use an impact socket (as in air gun & some say this is easy way to loosen).......... with a '15 foot lever' ! !
I assume if left, pulley can disintigrate.
Far as I know it is advisable to also fit new tensioner.
 
#11 ·
Thanks again everyone, does seem quite a bit of money for a couple of pulleys. Any decent independant mechanics known in the Portsmouth area, thinking of using Sewards at Havant but they are certainly not the cheapest. Thanks again for all the help and suggestions, will update on progress/costs etc. Cheers, Rich
 
#12 ·
If it was me I wouldn't bother replacing the tensioner unless it is faulty. You don't hear of many going and I know one that has done well over 300k, and felt as good as new the last time the belt was off and it was spun. ;)

Worth checking all the pulleys with the belt off including any play in the water pump pulley. How many miles has your car done?

Mike
 
#15 ·
I'd just do the pulley, that's what the noise will be. My tensioner is original on nearly 200k and is perfectly smooth.

Aftermarket pulleys have been known to fail - go for OEM if you can afford it.

The reason they're expensive is because it's a lot more than just a pulley, it's also a damper system to kill any resonation in the crankshaft which could cause a crankshaft failure. If you have a look at one when you have it in your hand, it's a pretty clever bit of kit really. :)
 
#17 ·
Quick update, drove to work and back, all ok, took car to Sewards at Havant, ex Rover dealer and Xpart stockist, they have confirmed it is the crank pulley, have ordered one and going to fit it on Thursday.

They have quoted me £400 based on a 3 hour job, they reckon there is no book time for the job and have based this estimated time from previous, albeit limited, experience, so could be more or maybe less.

Thanks again for your input so far and preparing me for the worst, would never have guessed £200 for a pulley!!
 
#24 ·
Metric/AF



Sorry Terry, no such thing as a 22mm A/F
A/F Has always been, to me, American Fine (as opposed to BSF-British Standard Fine / BA / Whitworh / Metric) I remember nuts on a distributor were BA !
A/F used to be the standard on all American cars (& if I remember correctly all British American - Ford, GMC etc) While I think they now use metric bolt sizes, they are slow to change to metric measurement eg:- US quart, gallon etc.
A/F, open end spanner sizes:- 5/16 - 8.15mm, 3/8 - 9.7mm, 7/16 - 11.5mm, 1/2 inch - 13mm, 9/16 - 14.5mm, 5/8 - 16mm, 11/16 - 17.8mm, 3/4 inch - 19.25mm. Funny enough a 3/4 AF socket measures 22mm across but a 22mm socket measures 1.005 inches.
My old engineer neighbour says he has always known A/F as 'Across the Flats' !
 
#21 ·
Crank Pulley



They do say you can damage the crankshaft using an impact wrench. Seems improbable but who knows
Have you seen the tightening proceedure in Haynes ? Tighten to 100Nm (74 ft/lbs) Then angle tighten 60 degrees. Then another 60 degrees then another 30 degrees. Wonder how many garages do that, and if they don't does it result in failures ! Maybe is the case with aftermarket pulleys.
Anyway, with the locking tool, correct socket (impact/stronger) and appropriate breaker bar it should not be difficult I would think.
As per post above, do A/F come in mm now ? None of my A/F spanners or sockets are but then I've had them for years !
 
#25 ·
Well all done, final cost £365 inc. genuine Rover pulley and belt. Probably, well almost certainly, could have got it for less but working in the middle of nowhere, starting at 5.40 a.m. meant a quick and efficient job was needed and have paod a premium for that.

Thanks again for all your great help and advice, much appreciated, Rich.
 
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