What does the variator do? - Alfa Romeo Forum
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What does the variator do?

Can someone tell me what does the variator do and if it's a bit noiser than normal what that means?

I've been told mine's a bit noisy.
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Re: What does the variator do?

Being an ex Turbo fan, variators are a bit of a mystery to me: Reckon they alter the induction phase, valve timing, to give better aspiration of the engine. I'm sure the guys will give you more technical theoried details, but seem to remember that being noisy is not that detrimental, just B-----! annoying. The guys that know will check it out I'm sure.:
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Re: What does the variator do?

Alters the Cam shaft geometry.

It's effectively a Variable Valve system.

A noisy Variator doesn't mean it's going to fail, it'll just rattle a bit on cold start up.
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Re: What does the variator do?

like mine does...
 
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Re: What does the variator do?

It rotates the inlet camshaft to alter the timing.

Early Alfa 8 Valve (1986 ish) TS engines had a hydraulic oil/revs two position variator that had a switch on the end that altered the ECU map between two settings as well as rotating the inlet cam. At that time Alfa didn't have enough cash to develop a 16 valve head for this engine and this was their very neat alternative. The idea was to give you an engine with good low rev torque characteristics, and then a second cam setting allowing better high rpm breathing. It was very basic compared with the Honda VVT system which was fully electronic, but in practice it worked extremely well and was pretty well 100% reliable..except where oil changes were ignored and they sometimes clogged up...owner error. Also on these engines the two identical spark plugs fired at fractionally different times.

On the Fiat based 16Valve TS engine the setup is a bit more sophisticated with more of a view to emissions limitation than out and out power.So the mapping is more adaptable and the variator is more variable, but has proved to be of indifferent quality and fails with depressing regularity. A few years back it was mooted that Alfa had hard words with the supplier of the variators to improve the quality, but I don't know if it made any difference. On the 16 Valve the twin plugs are different sizes but fire simultaneously. Variator failure is recognised by the diesel rattle at low revs and loss of bottom end go. Its not harmful to the engine, but not desirable either.

Thus a fundamentally good idea has become a pain in the arse

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Re: What does the variator do?

Nice one AlfaLincs, here's some more:-

http://en.wikipedia.org/wiki/Variator
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Re: What does the variator do?

I will add that regardless of what anyone says, when it goes, you will lose low down torque. The difference it made replacing the one on my punto HGT was huge.
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Re: What does the variator do?

Agree with your last sentence Alfalincs, most emphatically so! Extra 'B' nuisance!:
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Re: What does the variator do?

maybe check the oil, my understanding was that if the oil was kept topped up the variator would start rattling and the car would end up sounding like a diesel. a friend's 147 sounded like a diesel, all because the oil was low. if you search for posts on diesel sounding noises emitting from under the bonnet you might get some more info.
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Re: What does the variator do?

So biascally a variator is VVT and it controls emissons and power?

So if it's a bit noisy and I have regular 12k oil changes should I get it replaced? The car has done 60k. If I have the cambelt etc changed do I need the variator replaced as well?
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Re: What does the variator do?

Quote:
Originally Posted by mojo_jojo View Post
If I have the cambelt etc changed do I need the variator replaced as well?
No, you don't NEED to get it done. But if you're getting the belt done, it's a good idea to have the variator changed at the same time, as the belt has to be removed to get at it. Saving you labour, in the long run.
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Re: What does the variator do?

If you feel it performs well enough, and the noise is not too unbearable, the choice is a difficult one. Probably on balance, you would have peace of mind, for the extra cost?:
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Re: What does the variator do?

Before I changed the Variator on my car it really sounded like a diesel when first started it was actually really embarrasing.... As well as making the car slower and worse on fuel.

The Variator will initially only rattle on startup, this is due to the seals failing inside which allows the oil to drain out. After a while it will not be able to hold enough oil pressure to operate at any time. It will then rattle all the time and will not operate.

I personally would change the variator whenever the belt is done. It adds about an hour to the cambelt change plus around £80 for the part. It has to be worth it for peace of mind IMO.

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Re: What does the variator do?

Quote:
Originally Posted by mojo_jojo View Post
So biascally a variator is VVT and it controls emissons and power?

So if it's a bit noisy and I have regular 12k oil changes should I get it replaced? The car has done 60k. If I have the cambelt etc changed do I need the variator replaced as well?
I'd get it changed if it is noisy, eventually it will affect power at the top-end of the rev-range. An oil flush may help but at 60k i'd say it's worth replacing.

Interesting fact: the variator on Fiat/Alfas was designed and built in Japan, hence it's failure!

Yes it is essentially a VVT unit, it advances (I think) the cam-timing above about 4400 rpm, if you are very perceptible you can feel it in the car.
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