Variator?

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hybrid565
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Location: Manila, Philippines

Variator?

Post by hybrid565 » January 19th, 2011, 11:30 am

Hi everyone. I recently purchased a 1996 Fiat Barchetta with 57,000 kms on the odometer. I knew that the car had a problem that's why I was able to purchase it for a cheap price.

On idle the motor has a mechanical clatter pretty much like the sound of an old diesel engine. I believe it's the variator.

I included a link on this post which I found on youtube. My motor sounds exactly like it.

Am I right by diagnosing it as the variator being the culprit?

Any advice would be much appreciated. Many thanks in advance.

This is the link: http://www.youtube.com/watch?v=XMsWGfH0KS8

kpsig
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Location: Greece

Re: Variator?

Post by kpsig » January 19th, 2011, 2:23 pm

hybrid565 wrote:Hi everyone. I recently purchased a 1996 Fiat Barchetta with 57,000 kms on the odometer. I knew that the car had a problem that's why I was able to purchase it for a cheap price.

On idle the motor has a mechanical clatter pretty much like the sound of an old diesel engine. I believe it's the variator.

I included a link on this post which I found on youtube. My motor sounds exactly like it.

Am I right by diagnosing it as the variator being the culprit?

Any advice would be much appreciated. Many thanks in advance.

This is the link: http://www.youtube.com/watch?v=XMsWGfH0KS8
Most probably yes. It could also be the hydraulic lifters of the valves (less chance).

robert kenney
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Re: Variator?

Post by robert kenney » January 19th, 2011, 3:01 pm

My ears say valve noise. Maybe the variator/cam timing mechanism failing causes a loss of lifter gallery oil pressure allowing them to become flat. hence the valve noise. The oil pressure idea is a guess but the noise is valve clearance related.

Robert

Nobby
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Re: Variator?

Post by Nobby » January 19th, 2011, 4:45 pm

Normally the cam variator noise gets worse with time, firstly just coming on at startup and disappearing after 5 seconds or so. Eventually it gets to the point where its permanently 'diesel like'.

When was the cambelt last changed (if ever)? If it hasn't been changed it might be an idea - the variator change shouldn't add much more to the overall cost either. Ithink new variators are about £100.

TomLouwrier
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Re: Variator?

Post by TomLouwrier » January 20th, 2011, 9:14 am

hi,

Yes, that does sound like the dreaded variator.
When I bought my Coupe in 99 (same engine) the service interval for the cam belt was listed as every 100.000km, but very soon after Fiat changed it to every 60.000km. So you're going to replace it pretty soon, anyway.
I'm now nearing 300.000km and on my 4th variator, which is also starting to make some noises. So next service it will be replaced together with the belt. Nobby is right, they cost about €100-125 over here too.

You can drive the car, but it will not have as much torque as it should. I have noticed that when the variator is on its way out, the oil pressure at hot tick-over drops by about 1/2 bar and then goes up and down by about the same. New variator and fresh oil fix this. Selenia Racing 10W60 synth helps to get a longer variator life. Remember that oil may sound expensive, an engine rebuild actually is a lot more expensive.
Be aware that you need a jig to replace the variator on the camshaft and the cam wheel on the variator; it is not keyed but plain screwed on. Maybe let your local Fiat/Alfa dealer take care of this.

Good luck, enjoy the Barchetta.


regards
Tom

hybrid565
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Joined: January 5th, 2011, 9:46 am
Location: Manila, Philippines

Re: Variator?

Post by hybrid565 » January 20th, 2011, 11:29 am

Hi Mr. Kpsig, Mr. Kenney, Mr. Nobby, Mr. Louwrier,

Many thanks for the quick replies. The first thing I did was to check if there was current on the connector of the variator. It was dead. No current whatsoever. I then proceeded to power the variator through the battery and the noise instantly got quieter. Although there was still a lifter ticking sound but it was substantially less.

I suppose the variator is controlled by the ECU. Is it safe to wire the power to the variator off the ignition switch or do I have to route it through the ECU?

I will most definitely do a valve lash adjustment and replace the timing belt. Also after reading your posts I will purchase a new variator, but is it safe to run the car in the meantime?

Regarding engine oil I'll go with your suggestion on a synthetic 10W60.

Again many thanks. I really appreciate it.

kpsig
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Joined: May 10th, 2008, 7:41 pm
Location: Greece

Re: Variator?

Post by kpsig » January 20th, 2011, 8:15 pm

A question on the oil.
Why would 10w60 prolong variator's life?
Wouldn't a 10w50 (thinner oil) be better for (cold) starts during low temperatures?

hybrid565
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Location: Manila, Philippines

Re: Variator?

Post by hybrid565 » January 21st, 2011, 8:14 am

Hi Mr. Kpsig,

As per the post of Mr. Louwrier on his choice of motor oil being 10W-60 as opposed to your choice of a 10W-50, the 10 weight is the viscosity of your motor oil upon initial start up. The only difference is the 60 weight being thicker when the oil is already heated up. I do believe that both motor oils will offer superior cold start-up protection but the 10W-60 may offer slightly better protection during hard / spirited driving.

Although there are motor oils that have a rating of 0W-30, I would like your opinions on this particular type of motor oil. Is this oil applicable to older cars or is it detrimental due to older cars having much looser clearances?

TomLouwrier
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Re: Variator?

Post by TomLouwrier » January 21st, 2011, 11:17 pm

hi guys,

Yes, that solenoid must be driven by the ECU, switching in and out between about 2000 and 5000 rpm. Otherwise there would be no real reason for the whole setup being there, right?
To be honest I don't have a firm reasoning behind that choice of oil, but it was suggested by my garage (there are some decent Fiat dealerships, though you have to try and find out). My current variator lasted more than 120.000km, a lot longer than the earlier ones. Second and third one were both of the later, modified type.

As mentioned I do see a distinct relationship between low and fluctuating oil pressure at hot idle and a defective variator. Either the thicker oil gives a bit more pressure at idle which makes the variator behave, or the variator works better with the thicker oil so doesn't go rattling which makes the oil pressure irregular.
I don't think the oil will reduce wear in the variator as such, but you may have longer use of it.
Having taken apart some of these, it's still not clear to me why they fail. They seem simple enough inside and no obvious clues like wear or sludge.


regards
Tom

hybrid565
Posts: 27
Joined: January 5th, 2011, 9:46 am
Location: Manila, Philippines

Re: Variator?

Post by hybrid565 » January 22nd, 2011, 3:51 am

Hi Tom,

As per your most recent post on this subject, my understanding of the variator then is somewhat akin to Honda's variable valve timing. So since it's connected to the intake camshaft it thus only alters the cam profile by advancing the cam from 2k to 5k rpm, thus enhancing mid range torque then the ECU shuts off the power to the variator to retard the cam for more top end power. Ie., I should return the powering duties of the variator back to the ECU. It thus leads me to believe that the dieseling sound itself emanates from the camshaft itself. Lash adjustment is in order.

Manuel

TomLouwrier
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Re: Variator?

Post by TomLouwrier » January 22nd, 2011, 10:38 am

hi Manuel,

That is correct: the solenoid should be controlled by the ECU.
The valves on your engine have hydraulic tappets, so no adjustment needed nor possible.

The variator should only be in one of two positions: fully advanced or fully retarded. There are no positions in between like e.g, BMW's Vanos systyem. It's on or off, driven by the solenoid and the hydraulic pressure it governs, as you mentioned earlier.
If the variator fails, it does not stay firmly in the 'on' or 'off' position, which means the direct connection between the distribution (cam belt and wheel) and the camshaft is lost. The cam shaft will start jumping forward when one of the cams is on the closing ramp of a valve set, then to be overtaken by the drive of the wheel and pushed up the next opening ramp. Turn a camshaft in a head (on the workbench!) by hand and you will feel what I mean. It is no smooth motion.

Of course if the engine starts up the oil pressure is not up yet and the tappets must build up as well, so that gives a moment of noise as well. Nothing abnormal about that. If the failing variator does cause pressure loss in the head, that can lead to extra tappet noise, as suggested by Robert.

Since you are going to tackle this yourself, I suggest you get a good workshop manual for your engine.
Good luck, let us know what you find.

hasta luego
Tom

WhizzMan
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Re: Variator?

Post by WhizzMan » January 25th, 2011, 8:07 am

The camshaft variator on the barchetta engine is exactly the same as on the Alfa Romeo 16V twin spark. The price recently went up, unfortunately, they do cost a bit more than the 100 GBP mentioned. The variator is indeed an on/off type of affair and is powered by oil pressure. Once they wear, oil leaks through them and this is why they don't fully advance the cam anymore. This will give your ECU a misaligned cam to deal with, costing you fuel economy and engine power. 10W60 helps slightly, since that is a bit thicker with warmed up engine, hence less leakage and better pressure to keep the variator tight.

To replace the cam belt and variator, you will need a few special tools. First of all, since the verniers aren't marked, you will need cam calibers to lock the cams into position. Second of all, you will need a micrometer with an adapter to fit in your #1 or #4 spark plug hole to determine TDC to the degree. Yes, it makes a difference and you won't be able to feel the final 1-3 degrees or so with a screwdriver down that hole. The same applies to the verniers, you need to do the cams by the degree and you just have to undo them. Marking the pulleys and just swapping the belt will most likely give you a few degrees off on your cam timing and these engines really like the timing to be precise. It does help to have a tool to take the variator off your inlet cam shaft. It's basically a wrench with 2 holes in it so you can bolt it in the place of the pulley. You have to remove the cam shaft from the engine and wrap the cam shaft in a cloth, then put it in a vise so you can take the variator off. Clean the thread for the variator, degrease it and put the new variator in using thread lock. Remember to tighten this to the recommended torque. Just "doing it up" will most likely make it shift position after you put it on, giving you a mis-aligned inlet cam shaft once you rev the engine the first time. Take care to replace all moving parts in the distribution and don't skimp on it by just replacing the belt. Both the small roller and the tensioner are known to not last 2 cam belts and in the past, often not even one. Also, do not use the bolts you got out of the bearing cap you had to take off for the calibers to bolt the calibers down. The calibers are higher and you are likely to strip the threads in your head if you use the too short bolts.

hybrid565
Posts: 27
Joined: January 5th, 2011, 9:46 am
Location: Manila, Philippines

Re: Variator?

Post by hybrid565 » January 26th, 2011, 2:16 am

TomLouwrier wrote:hi Manuel,

That is correct: the solenoid should be controlled by the ECU.
The valves on your engine have hydraulic tappets, so no adjustment needed nor possible.

The variator should only be in one of two positions: fully advanced or fully retarded. There are no positions in between like e.g, BMW's Vanos systyem. It's on or off, driven by the solenoid and the hydraulic pressure it governs, as you mentioned earlier.
If the variator fails, it does not stay firmly in the 'on' or 'off' position, which means the direct connection between the distribution (cam belt and wheel) and the camshaft is lost. The cam shaft will start jumping forward when one of the cams is on the closing ramp of a valve set, then to be overtaken by the drive of the wheel and pushed up the next opening ramp. Turn a camshaft in a head (on the workbench!) by hand and you will feel what I mean. It is no smooth motion.

Of course if the engine starts up the oil pressure is not up yet and the tappets must build up as well, so that gives a moment of noise as well. Nothing abnormal about that. If the failing variator does cause pressure loss in the head, that can lead to extra tappet noise, as suggested by Robert.

Since you are going to tackle this yourself, I suggest you get a good workshop manual for your engine.
Good luck, let us know what you find.

hasta luego
Tom
Hi Tom,

Thanks so much on your inputs on this matter. I got a bit side tracked on this car cause my attention shifted to my integrale. Now that the problem on the integrale got solved it's time to get back to working on the barchetta. First things first, as you suggested, I will look around for a workshop manual to guide me on this.

Thanks again and I'll keep you posted on my findings and developments.

Manuel

hybrid565
Posts: 27
Joined: January 5th, 2011, 9:46 am
Location: Manila, Philippines

Re: Variator?

Post by hybrid565 » January 26th, 2011, 2:25 am

WhizzMan wrote:The camshaft variator on the barchetta engine is exactly the same as on the Alfa Romeo 16V twin spark. The price recently went up, unfortunately, they do cost a bit more than the 100 GBP mentioned. The variator is indeed an on/off type of affair and is powered by oil pressure. Once they wear, oil leaks through them and this is why they don't fully advance the cam anymore. This will give your ECU a misaligned cam to deal with, costing you fuel economy and engine power. 10W60 helps slightly, since that is a bit thicker with warmed up engine, hence less leakage and better pressure to keep the variator tight.

To replace the cam belt and variator, you will need a few special tools. First of all, since the verniers aren't marked, you will need cam calibers to lock the cams into position. Second of all, you will need a micrometer with an adapter to fit in your #1 or #4 spark plug hole to determine TDC to the degree. Yes, it makes a difference and you won't be able to feel the final 1-3 degrees or so with a screwdriver down that hole. The same applies to the verniers, you need to do the cams by the degree and you just have to undo them. Marking the pulleys and just swapping the belt will most likely give you a few degrees off on your cam timing and these engines really like the timing to be precise. It does help to have a tool to take the variator off your inlet cam shaft. It's basically a wrench with 2 holes in it so you can bolt it in the place of the pulley. You have to remove the cam shaft from the engine and wrap the cam shaft in a cloth, then put it in a vise so you can take the variator off. Clean the thread for the variator, degrease it and put the new variator in using thread lock. Remember to tighten this to the recommended torque. Just "doing it up" will most likely make it shift position after you put it on, giving you a mis-aligned inlet cam shaft once you rev the engine the first time. Take care to replace all moving parts in the distribution and don't skimp on it by just replacing the belt. Both the small roller and the tensioner are known to not last 2 cam belts and in the past, often not even one. Also, do not use the bolts you got out of the bearing cap you had to take off for the calibers to bolt the calibers down. The calibers are higher and you are likely to strip the threads in your head if you use the too short bolts.
Hi Mr. Whizzman,

Thanks so much on your inputs and advice. Aside from needing a good workshop manual, as per Mr. Louwrier's suggestion, I'll need to put in an order for the special tools that you mentioned on top of the parts that I'll also be needing, ie., variator, timing belt, gaskets, etc,. Seems that the relatively cheap purchase price on the barchetta isn't going to be cheap after all the work has been done to get it running properly.

Thanks again and as per my previous post to Mr. Louwrier, I'll keep you posted on the developments. I only wish there were a cheaper way to work on this car. Wishful thinking.

Manuel

WhizzMan
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Re: Variator?

Post by WhizzMan » January 26th, 2011, 6:51 pm

For Alfa Romeo I know that totallyalfa.co.uk can supply you with all the special tools required for a very reasonable price. I have no idea if the calibers for the Barchetta are the same as those for the Alfa 1.8, but it could very well be the case.

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