A/C & Alternator belt idler

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saintjamesy89
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A/C & Alternator belt idler

Post by saintjamesy89 »

Hello folks, I'm trying to source an idler/pulley/tensioner for the Alternator and a/c compressor belt. I can't find much online except for an aussiefrogs post and the part is obviously no longer available.

"Compressor tensioner roller 6453 E0 (NFP) Diameter 85 Lar 23"

The parts catalogue suggests this bolts to the 16v cylinder head and is not used in 8v XU's, but with the free length of the belt, it would be helpful. Does anyone know if the 8v head has a threaded hole for it? Any 16v owners with a picture? TIA
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Jaba
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Re: A/C & Alternator belt idler

Post by Jaba »

My AC 8v does not have a tensioner pulley at all and has never had one fitted.
But there is provision for an adjustable pulley to be mounted on the sump. It takes up slack between the crank and compressor pulleys. Spares might be available in UK but they are definitely listed on French websites like Oscaro and Autodoc which is where I tend to buy BX spares from when I am in France.
There is also a pulley used on some models and ages of BX that fits onto the head of the alternator mounting bolt. I have got an old and worn one in my box of aircon spares.
Easiest thing to do is get a belt which fits on without the extra pulley and do without it - as long as the belt does not slip and squeal when the AC is working that is.
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Vanny
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Re: A/C & Alternator belt idler

Post by Vanny »

If it's the big round one with offset hole, they where only used on the 16v for a few years (because they were shit) before using the the lugs on the sump. There was a TSB that I eventually found, but in a nut shell, use the pug 405 method.
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saintjamesy89
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Re: A/C & Alternator belt idler

Post by saintjamesy89 »

Thanks for the replies chaps, I only really wanted to put an additional roller on to reduce what feels like the very long length of belt between the alternator and compressor, I don't yet have a functioning a/c system but I did have the compressor and correct belt on - at least until I ruined the sump back along! If the 8v's don't need or benefit from one, then that is great and I won't worry!

I'll look up the 405 method anyway, just for interest :D
I'm not a Saint, or a James, but a Tom Saint-James!

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Vanny
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Re: A/C & Alternator belt idler

Post by Vanny »

16V pulley looks like this, with that stupid M6 one side and M8 the other side bolt. And its the M6 side that goes into the block, so guess which bit get snapped off!
IMAG0100.jpg
Then the 405 instructions look like this
Mi16AuxBelt.jpg
And at this point my car should look like this.
IMG_0246.jpg
It's the lap angle over the AC pulley that is critical. Especially when the compressor clutch kicks in and out.
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saintjamesy89
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Re: A/C & Alternator belt idler

Post by saintjamesy89 »

Lol! I wonder which 🤣

Thanks Vanny, that's fab. I wonder why the 8v's didn't have them? Especially as the alternator is so much higher up, it's level with the top of the engine. Perhaps it's at a different enough angle that there isn't any issue with pulley belt coverage etc.

Good to know the reason too, I was ignorant of lap angles 👍
I'm not a Saint, or a James, but a Tom Saint-James!

Mes voitures:
1985 Citroen BX19 GT
1988 Volvo 740 2.0 GL Hearse
2006 Lexus RX 400h SE hybrid