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Discussion Starter · #1 ·
Have an intermittent rattling noise coming from low down on the cambelt side of the engine, can be heard at its loudest through the drivers side wheel arch.

If the aircon is off, no noise, if the aircon is on, can be heard when the engine has warmed up. Wrongly diagnosed by myself and a local indie, who I trust, as a worn clutch or input shaft bearing on the a/c compressor which was replaced yesterday. The old compressor did have excessive play in the shaft bearing, so needed replacing anyway BUT the rattling noise persists.

I am thinking may be the noise is being caused by the extra load being put on the v belt when a/c is on so thought of the v belt tensioner but no noise coming from there and as said previously, it's coming from low down. Is it possible that the vibration damper could be going? Don't know how this is constructed internally so haven't got the knowledge to think this one through.

Any help would be greatly appreciated as it's not the time of year to be running without a/c!
 

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Could it be the hydraulic tensioner for the cam belt?...ive heard that these rattle when failing??
 

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Discussion Starter · #4 ·
ades tt 180 said:
Could it be the hydraulic tensioner for the cam belt?...ive heard that these rattle when failing??
I had thought of this but couldn't make the connection between extra load on the v belt being transferred to the cambelt. There may well be a connection of course, it's just my lack of understanding of the relationship between the 2.
 

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ades tt 180 said:
Could it be the hydraulic tensioner for the cam belt?...ive heard that these rattle when failing??
+1, which would scare the c--p out of anyone. I would be tempted not to use until
I was certain that it was not the above. Dont know the mileage on your motor but
if it's close to 80-90k then it's possible. [smiley=bomb.gif] Hope were wrong.

Mark.
 

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Discussion Starter · #7 ·
TTMBTT said:
ades tt 180 said:
Could it be the hydraulic tensioner for the cam belt?...ive heard that these rattle when failing??
+1, which would scare the c--p out of anyone. I would be tempted not to use until
I was certain that it was not the above. Dont know the mileage on your motor but
if it's close to 80-90k then it's possible. [smiley=bomb.gif] Hope were wrong.

Mark.
Car's done 56k and cambelt was changed 21/2 years ago at 34k but don't think tensioner was changed as no mention of it on invoice.
 

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steveupton said:
TTMBTT said:
ades tt 180 said:
Could it be the hydraulic tensioner for the cam belt?...ive heard that these rattle when failing??
+1, which would scare the c--p out of anyone. I would be tempted not to use until
I was certain that it was not the above. Dont know the mileage on your motor but
if it's close to 80-90k then it's possible. [smiley=bomb.gif] Hope were wrong.

Mark.
Car's done 56k and cambelt was changed 21/2 years ago at 34k but don't think tensioner was changed as no mention of it on invoice.
I'm in the same boat, cam belt done at 47k tensioner not replaced now covered 82k. Next job me thinks along with
new belt, pump etc.
 

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steveupton said:
ades tt 180 said:
Could it be the hydraulic tensioner for the cam belt?...ive heard that these rattle when failing??
I had thought of this but couldn't make the connection between extra load on the v belt being transferred to the cambelt. There may well be a connection of course, it's just my lack of understanding of the relationship between the 2.
Could you take the cam belt cover off to see if the rattle is coming from in there?
 

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Interesting.

So the noise is deffo coming from the belts, / tensioners and not the block it's self? Hows the oil look? It could also be the engine mount it's self. however if it's just a noise and not vibration on the engine i doubt it to be this. with the engine off, peel the cambelt cover off and just check the condition... mine was cracked and frayed after 35'000 miles, (was on 45K changes) so it's 9'000 miles off the life i expected...

I changed all the pulleys for the lightweight neuspeed ones,
 

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The best thing to do if i were you is to change the entire cambelt kit before something happens.

Werner
 

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Discussion Starter · #12 ·
Thanks to everyone for their advice, looks like I might have to change the cambelt and hydraulic tensioner just to be on the safe side. Still don't understand however why the noise goes away if I turn the A/C off.
 

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Is the rattle from the ac pump?....makes sense to find the faulty part...lots of dosh to replace the belts and still have the rattle.
 

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I've had noise like this twice now in the same sort of location. You might consider the possibility of it being the air conditioning clutch. Mine went at about 90,000 miles. Shortly after that the pulley went. Pulley was cheap but the clutch wasn't. However, if you don't get it done it'll wreck the engine as it will seize and I believe it is linked to the cambelt. I stopped driving as soon as I heard the rattling on both occassions.

Hope it's all OK.
 

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Discussion Starter · #18 ·
kazinak said:
Remove cambelf cover and check hydraulic tensioner ,

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Thanks Kazinak, along with other members posts, this seems the most important thing to check first. Without the the engine running and pumping oil into it, how will I know if it needs replacement? Also is this an easy job or do you have to get half way through a cambelt replacement strip down? If no parts are needed such as engine mount bolts will do this Sunday as heavily committed to work until then.

Fortunately, can use the wifes car in the meantime as I'm not keen on using the TT until I've found the cause.

Thanks again to all who have posted but still no nearer knowing why turning the a/c off stops the noise.
 

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Its not a hydraulic tensioner, its a damper.

I would run the engine with the aux. Belt removed to rule everything out that's connected with this belt.

If it is the hydraulic damper that is causing the belt to flap about then there will probably be oil leaking from the seal of it. A visual inspection will confirm this.

It might be worth running the engine with the can belt covers off and looking before you rush into replacing things

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also check the alternator bearings if you get the belt off and check the pulley (I know some cars use a one way drive pulley that sometimes wears and makes a noise but don't know if the TT had them)

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