goody

Could a defective cambelt tensioner have an impact on the alternator?

I recently had a cambelt change @ 61000 miles on an octavia 1.9tdi. After 13000 and 12months a bearing type rotational noise appeared and within a few days the alternator failed.

I had a new alternator put in however the noise was still there

After quite a bit of money and numerous visits to the garage it was found to be a cambelt tensioner was making the noise.

My issues are:

A. Surely the tensioner is changed as part of the cambelt replacement and should last longer than 13000 miles
B. Could this defective/incorrectly renewed tensioner be a cause of my alternator failure?

With many thanks in advance to all that can help

mathepac

When I had my cambelt done on my Fabia @ 58k miles (4 years), the main dealer sold me a kit which included the belt, tensioner, idler and water-pump.

My non-franchised VAG specialist who was fitting the kit asked me to get an auxiliary drive belt and replaced the gear on the alternator drive-shaft that the belt contacts, as he said its a known weakness.

I don't know how many of the parts are common (my engine-code is ASZ) to the Fabia and Octavia, but both the dealer and the technician were adamant that all the parts and work were needed.

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SKN Stage 1 Remap, 175-ish Ponies to Feed, 325-ish torques, KW V1 Coil-overs, Audi TT Comps with Toyo Proxes, JabbaSport RARB, Cage Mod, Pikey Arch Vent Mod, PD160, K&N Panel Filter, Milltek cat-back exhaust, 312 mm brakes, Mintex X1's, Osram Night Breakers, Seat Surgeons Leather, Bosch Aero Wipers, brisky sticker & number plate surrounds, 'Ring sticker. @ 58k miles: SRE Organic Clutch, release bearing, Sachs Flywheel, cam-belt, tensioner & idler, water-pump, G12+, aux belt & tensioner, engine mount bolts. @ 63k miles: EPEHCCVM-M1 @ 63.7k miles: SI-EPEHCCVM-M. Planned for 64k miles: BIG!

KenONeill

The cambelt tensioner should have been changed with the cambelt.

The only way I can see the alternator issue being connected is if whoever did the cambelt change way overtensioned the alternator belt, and that ran the alternator bearings.

goody

Cheers for answers.

I shall now go back to customer service and try and get some money back. Somehting has been done wrong as i should get more than the 13k miles/12 months out of the tensioner...Or it wasn't cahnged...or shagged when installing.

Lummox

Lets sort some facts out.

No1 the aux/alternator belt is self adjusting, so no one could have over tightened the belt.

No2 Not all cambelts require the replacement of the tensioner by the book. Some people advise them much the same as water pumps. It very much depends on engine code and number.

But surely if there was a noise and the alternator was replaced and the noise was still there that would indicate the alternator wasnt faulty so why pay for a new one? If the tensioner had been changed then I think it carries a 12 month warranty on the part, if it was over 12 months ago it was changed and it failed then you dont have any come back on it.

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KenONeill

No1 - I knew the alternator belt tension is supposed to be self-adjusting, but the last time I looked at a belt tensioner (not a VAG alternator belt tensioner), it would have been possible to over-tension the preset, because it was effectively a slack adjuster and not a full tensioner. Don't take this as an argument; just an expn of why I believed it to be possible to overtension a belt fitted with an auto-tensioner.

Lummox

If you were to force the auto tensioner past the tension of the spring it would come back again to the correct level unless it was seized.

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