Damn it! The car sounded a bit more noisy than normal last night (ref: my thread on aux drive belt). Anyway in Salisbury this morning, there it went *clonk*, and the battery/alternator light came on and I had intermittent PAS (more assisted than not assisted).

I had a look at the car in the rain/dark when I got to work, and the belt is still there, as I expected because the power steering was working, but is is really rather flappy and loose - which is why I guess I get intermittent PAS.

Does this sound like a classic case of alternator freewheel thing? I need to work out if get the car towed to a garage (not sure I fancy a drive home in the dark/rain tonight), or if I have it towed to my parents and try and dispatch my father to collect the parts I need.....

Yhe clonk sounds a bit like the sprague clutch, but the floppy and loose sounds more like the aux belt tensioner.

The clonk was a bit like running over something and it hitting the underneath of the car. Initially I had assumed it was the belt falling off, as the PAS failed at that point too. Then the PAS started to work again...... Day light is now here, so I might pop out and have another look at things rather than shining a torch at it.

Without sounding too stupid, which is the sprague clutch? Is that something relating to the aircon pump, or this freewheel thing on the alternator?

Edited 10 February, 201115 yr by mbames

Just phoned my local Skoda dealer and spoke to a mechanic, he suggests that as the belt is on, but slack it is more likely to be the tensioner, but obviously would not commit himself.

I have asked for prices for both alternator pulley and the aux tensioner, so will wait to see what they come up with....

Just phoned my local Skoda dealer and spoke to a mechanic, he suggests that as the belt is on, but slack it is more likely to be the tensioner, but obviously would not commit himself.

I have asked for prices for both alternator pulley and the aux tensioner, so will wait to see what they come up with....

My understanding (an certainly in my case) when the tensioner went, there was a clonk, the belt remained taught however.

If you look at the power steering pulley (think that's the top one on ours, right behind it you can see the top of the tensioner, a black piston. This should be bolted to a lug just behind the power steering pump, not flapping around. If it's flapping, then your tensioner has gone and the break is caused by most likely the alternator clutch failing.

If you have a slack belt, then I guess it could either be the tensioner spring has gone, I don't think you can see enough of the tensioner to move it around unless you're underneath with all the panels off. Or could it be the aircon pulley has failed, apparently they are prone to fracturing across the front and eventually dropping clean off, that would give you plenty of slack, the tensioner would try to take it up and might explain intermittent power steering and alternator?

Tom

Edited 10 February, 201115 yr by tomsimmons

Right, got some prices:

Aux tensioner: £106.03 inc VAT (supply)

Aux tensioner: £162.31 inc VAT (supply & fit)

Alt Pulley: £59.41 inc VAT (supply)

Alt Pulley: £99.61 inc VAT (supply & fit)

My local garage say they would not even attempt to change the alternator pulley, so that rules them out. As my local Skoda dealer will get the parts from TPS, that seems to take then a few days so I will be without a car for a few days, and potentially a bill of £250 if they decide both have failed..... :-(

I'll pop out and have a look at the car now there is daylight outside.

Right, got some prices:

Aux tensioner: £106.03 inc VAT (supply)

Aux tensioner: £162.31 inc VAT (supply & fit)

Alt Pulley: £59.41 inc VAT (supply)

Alt Pulley: £99.61 inc VAT (supply & fit)

My local garage say they would not even attempt to change the alternator pulley, so that rules them out. As my local Skoda dealer will get the parts from TPS, that seems to take then a few days so I will be without a car for a few days, and potentially a bill of £260 if they decide both have failed..... :-(

I'll pop out and have a look at the car now there is daylight outside.

Sprague clutch is inside the pulley on the alternator.

Basically what it does is prevent the angular momentum of the small alternator pulley damaging the crank pulley. It achieves this by freewheeling in one direction, so when the engine stops, the kick back as it actually comes to a stop is not transferred round the aux belt to the crank, but disappears as the clutch allows the freewheel to happen.

Well at least that was my take on the big doc that someone on here kindly sent me, if you want the link to it I'll dig it out.

So when the sprague fails, the free wheel doesn't happen and the tensioner absorbs the kick instead, over time that results in the tensioner breaking it's mount at the top of the damper. The damper and sheered piece of metal then sit there bouncing around on your aux belt - well they did on mine, so I wrapped it in a pair of socks and tucked it under the top turbo pipe until I had a replacement and time to swap it. Not a fun job. Because it was the damper mount that went on mine, the tensioner was still there, so no slack.

However, I was told by the same chap who explained all this to me and sent me explanation that occasionally the air cons pulley fractures across the pulley where the rivets are, it then falls off. I'm wondering if this might have happened on yours, freeing up a load of belt, the tensioner has taken this up, but can't absorb it all so if the belt is under heavier load then it slips giving you intermitent power steering.

Tom

That make sense to me. I was just on the approach to a roundabout when I knocked the car out of gear (as the lights were red).

I have found VeeW spares (think that is their name) in Bristol have the parts at a much better price. I'll go back to my parents, and try and take the thing apart. They have a workshop in Bedminster and say they can change the pulley for me, if the garage local to my parents have said they will do it for a few quid.

As I am Haynes-less, I can't quite remember what to do.

From underneath:

- under tray off.

- Undo the cables on the alternator.

- Undo the aircon pump

- Move aircon pump to one side

- undo alternator bolts and drop out

From above:

- Engine cover off

- Top turbo pipe off

- Undo bolts on tensioner (from above) and remove

Maybe remove the offside headlight+indicator to make access to turbo pipework and clips / tensioner / etc easier.

Check to see what is broke, replace and refit.

That make sense to me. I was just on the approach to a roundabout when I knocked the car out of gear (as the lights were red).

I have found VeeW spares (think that is their name) in Bristol have the parts at a much better price. I'll go back to my parents, and try and take the thing apart. They have a workshop in Bedminster and say they can change the pulley for me, if the garage local to my parents have said they will do it for a few quid.

As I am Haynes-less, I can't quite remember what to do.

From underneath:

- under tray off.

- Undo the cables on the alternator.

- Undo the aircon pump

- Move aircon pump to one side

- undo alternator bolts and drop out

From above:

- Engine cover off

- Top turbo pipe off

- Undo bolts on tensioner (from above) and remove

Maybe remove the offside headlight+indicator to make access to turbo pipework and clips / tensioner / etc easier.

Check to see what is broke, replace and refit.

When I took my tensioner off I only had a normal socket set to hand and found that that as the bolt come out the wrench was hitting the washer bottle, which prevented them coming all the way. This turns it into a very slow job using a normal spanner and getting about a quarter turn. you really need ratchet spanners I guess.

I can't recall the size, but from underneath you can get a spanner on the outside edge of the tensioner pulley and pull it back to take the tension of the belt, the belt then comes off easily. Once the belt is off you should be able to tell without removing the tensioner whether it's still working and the damper is unbroken.

As to how to remove the alternator, I'm afraid I've not tried yet. I've read two posts, one says you can get it out the top, but be carefully and you'll get wrapped knuckles, the other says out the bottom is easy, but yes you need to shift the AC pump.

Tom

I have some ratchet spanners - could be their second outing!

I shall review both options, and the pick what ever looks to be the easier of the two, only to regret it!

i'd replace the tensioner first and try it, much easier job and worth the few minutes putting the belt back on rather than having to take alternator/aircon pump off.

I figure that once the belt is off, I can easily see/feel if the alternator pulley is knackered, and then I'll take it off. Only want to make one trip the parts supplier as I have only booked the morning off work to do this!

You probably won't be able to feel if the alternator pulley is freewheeling without jamming the alternator. I looked at a brand new pulley in the dealers expecting to be able to mve it in one direction and not the other, but on its own it felt solid in both directions.

You probably won't be able to feel if the alternator pulley is freewheeling without jamming the alternator. I looked at a brand new pulley in the dealers expecting to be able to mve it in one direction and not the other, but on its own it felt solid in both directions.

I assume I should be able to stick a nice big screwdriver into it and jam it against the fan inside (someone else suggested I do that) and then I should be able to check if it knackered or not.

Not sure if you can do that without taking the alternator out first?

I have a feeling that there isn't much space.

The clonk sound was probably the tensioner being yanked as the alternator pulley froze. This often happens when you change gear.

The tensioner is easier to check than the pulley, so do that first. From underneath the car, put a spanner (16mm?) on the tensioner pulley with the handle pointed downward. Push the spanner to the rear of the car and then release. The tensioner pulley should return and take up any slack in the v-belt.

You can check the freewheel pulley as you described, but often the problem can be intermittant.

If you have to do the pulley and take out the alternator, remember to disconnect the battery first and be very gentle with the 4 small wires (2 alternator, 2 a/c) that run in the same sleeve as the main alternator cable. They can be brittle.

Quick update: definitely the pulley on the alternator as when I took the under engine tray off I found half of it laying there. I will try and stick a picture up tomorrow.

Just need to figure out how to the get the alternator out. Up seems to the look like a light with the PAS pipework, and down looks like the Air Con pipework.....

I have disconnected one plug from the alternator and seen the nut for I guess the main +ve feed from it. Not taken that off, as it was about 2215 and I was tired - been a long day, started at 0530

I have however removed the tensioner, and the pulley wheel from the PAS pump. I noticed the wheel on the tensioner while it feels lovely and smooth makes a clicky/ticky noise, so I am thinking that just to be safe I should change that too. Also got the offside headlight out, and various bits of turbo air pipework, and a few bits of plastic undertrays, etc.

had forgotten how little room there was in there after I did my cambelt.

Thanks to everyone so far!

Yes, Skoda were a little mean with the space weren't they, why they couldn't have put some of the stuff, over on the right I don't know.

Hopefully someone else will reply, but I have a vague memory of the pulley on both my old and new(er) tensioner being smooth but having that slight ticky noise when spun. I have to confess I assumed it was a ball race bearing or similar.

I know it's the last thing on your mind, but any photos/details on how you achieve this job with the alternator would be very helpful.

Tom

I'll try and take a few pictures.... will certainly do one of the knackered alternator pulley.

Some more space would be handy. Guess I had better head back down the garage and start battling with it again.

Dare I ask how it went?

Tom

All sorted :-)

Drove back home last night, 60 miles and an average of 59.9mpg, with a couple of black cloud generation moments too boot, and no limps

Full pics here: http://www.matthewames.co.uk/briskoda/index.php?loc=./20110211_alternator

However a couple of good ones:

The pulley from the alternator - with a hole in the metal cap.... I found this sitting on my undertray:

A few down to what was left sticking out of the alternator (still in situ):

Eventually I got the alternator out:

New one on - thanks to Vee W Spares in Bristol kindly fitted it for me

Fitting was much quicker than removal. I pushed the bushes back in and that made a world of difference. Also removing the smaller radiator gave easier access, along with the PAS pump - I removed the alternator from above.

I did have to consult my Skoda workshop manuals to work out the route for the aux belt (as my Haynes manual was stuck at home, 60 miles away)

I fitted a new aux tensioner too along with a new aux belt, as I thought I might as well.... Might have been slightly overkill, but never mind. I also bought a new cambelt kit and metal water pump to fit when I have a bit more time (and it is warmer), so the total cost was £289.00.

I also tried to make a better bodge on my split vacuum brake servo pipe with some heat shrink rather than the previous insulation tape and jubilee clips!

Edited 13 February, 201115 yr by mbames