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Hi All

I've just bought my first Alfa, a 2005 156 JTS Sportswagon with 89000 miles on it, and think I might have bought badly.

Having read the service record more carefully there's a gap between 59000 miles and 87000 miles and I fear there really was not even an oil change during that time. I opened up the rocker cover today to take a look and the main body of the cams look corroded and have a rough surface (see photos), although the lobes are smooth and are not pitted.

156 cams 1.jpg 156 cams 2.jpg

The engine noise at idle is quite loud and I had assumed that this was the diesel noise caused by a bad variator, but now I'm concerned it's caused by more general engine wear due to the old oil. If the cams look like they do should they be changed and is it it likely that there is going to be further damage elsewhere in the engine?

I'm planning to have the variator and cam belt changed in a few weeks as it's not had one since 48000 miles, but if there is other stuff that might need doing presumably it would be worth getting it all done at once.

Any advice gratefully received.

Many thanks,
Colin
 

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Discussion Starter #4
That is just an un-machined part of the cam.

Nothing wrong there (apart from needing an oil change!).

Thanks for the replies. Sorry I think I got my terminology wrong in the original post the rough area I was talking about was the main body of the lobe not the un-machined part of the cam. The tips of the lobes are nice and shiny and smooth but the rest is rough and corroded. Is that something to worry about?

On the oil change this is the colour the oil has gone in the 2000 miles since the last service which again worries me a bit, and I am going to do an oil and filter change ASAP.

Colin
 

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From those small pics it just looks like dirty oil on the cam lobes.

But if they are pitted and worn, then it may be an issue.
 

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the thing that matters on the cam is the lobes, esp on the JTS where some can be worn almost totally away (esp cyl 1) - if you do not have this problem, thank your lucky stars...

u might like to try running engine oil for diesels and dumping that out early... or using engine oil flush...
 

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Remember, the cam lobe contacts a cam follower, bucket, shim, rocker arm, or whatever (depending on the design of the engine) when the valve is opening and closing. When the valve is fully closed, there isn't any pressure from the cam on the valve. Consequently, the tips of the cam lobes get polished while the rest of the cam lobe will have an entirely different wear pattern. That's a good thing because it indicates that there has been the existence of valve lash over time. i.e. the valve hasn't been held open because of the absence of valve clearance (lash). A valve held open won't cool properly and will soon "burn". So what you're seeing is normal and good, assuming the corrosion you mention isn't somehow WAY out of hand. Is it simply a surface which is less polished then the tip of the cam lobe? Or is it all rusty?

Modern oils and filters are pretty good. Changing them on a regular basis is highly recommended, but going significantly beyond the change date is not, in itself, a reason to start shopping for a replacement vehicle. Operating with insufficient oil is indeed a bad thing, but running with old oil isn't a death warrant for your engine.

As far as the oil color goes, don't worry. An older diesel engine will turn beautiful new oil completely black in a very short time; nothing to worry about. Chances are a second oil change in the immediate future won't do any good, but it won't do any harm either and if it brings you piece of mind, go for it.

Changing the cam belt is a good idea. Driving with one past it's prime makes a knowledgeable owner uncomfortable and (for me at least) takes some of the fun out of driving. A brand new cam belt, puts a smile on your face. Breaking a cam belt will definitely make you and your bank account unhappy.
 

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There have been some issues with cam wear in quite a few modern cars (not just Alfas)

The reason being that to meet the latest API specifications oils have to have less Zinc dithiophosphate, which is an extreme pressure lubricant.

Basically the oil gets wiped off the surface of the cam by the tappet as it rotates, but if Zinc dithiophosphate is present it will provide a last "Boundary" layer of protection before metal to metal contact occurs.

Zinc dithiophosphate can cause damage to catalytic converters in the long term, and this is why later oils have less of it included.
 

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Am i missing something, but the lobe on the right of the right picture is well worn, the main trouble with worn lobes isnt just the noise or the loss in preformance it's what the swarf turns you oil into. It can turn you oil into a cutting paste, i would be running a flushing oil through with a new filter (i dont normally use flushing oil but in these cases) replacing the oil with 10-40 again with a new filter and replace the oil once more after 250 - 500 miles, doing this once i hade changed the CAM shaft and the lifter that are affected. Alf recommend 10-60 for the JTS but you have suffered the the draw back of using 10-60 and that is top end wear, although still better than bottom end failure...
 

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I hadn't noticed the right lobe in the 2nd pic.
Yes that does look a little worn!!

Surprised the OP hadn't seen that.
 
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Hi All

I've just bought my first Alfa, a 2005 156 JTS Sportswagon with 89000 miles on it, and think I might have bought badly.

Having read the service record more carefully there's a gap between 59000 miles and 87000 miles and I fear there really was not even an oil change during that time. I opened up the rocker cover today to take a look and the main body of the cams look corroded and have a rough surface (see photos), although the lobes are smooth and are not pitted.

View attachment 130302 View attachment 130303

The engine noise at idle is quite loud and I had assumed that this was the diesel noise caused by a bad variator, but now I'm concerned it's caused by more general engine wear due to the old oil. If the cams look like they do should they be changed and is it it likely that there is going to be further damage elsewhere in the engine?

I'm planning to have the variator and cam belt changed in a few weeks as it's not had one since 48000 miles, but if there is other stuff that might need doing presumably it would be worth getting it all done at once.

Any advice gratefully received.

Many thanks,
Colin
Looks normal to me... See if the noise goes away with Variator change.
That is just an un-machined part of the cam.

Nothing wrong there (apart from needing an oil change!).
in the rhs picture the lobe most to the RIGHT is worn flat .... you need a replacement inlet cam.
 

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Discussion Starter #15
Thanks for all the replies. I've been away with work for the last few days so not been able to look at them properly until now.

So it seems like I do have a problem with my camshafts, only not the type of problem I first thought. I've done quite a bit of work on my previous cars, but never had to delve inside the engine before so this is new ground for me.

On closer inspection of the other photos which I took with the valve cover off there looks to be one lobe on the exhaust camshaft that is also very worn, so they might both need replacing. I only had time for a quick look then, but I'll open it up again tomorrow for a proper inspection.

I've had a look for camshafts online and the only one I could find was a used exhaust one on Autolusso's eBay shop. Does anyone know where I could get hold of them (new or used), or is it a main dealer only type of part? I've put out a request on a few used part finder websites too, but there seem to be so many of them out there does anyone know which are the best to use?

Also is this likely to have damaged any other engine parts, big end bearings etc and if so is there any straightforward way of telling?

Colin
 

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Pics were too small!! ;)
 

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Calm down! Calm down! :D

The lobe in the photo does seem to have some wear .. but before you rush off to hand over £400 or more of your moolah, measure the height of the lobe and see whether it's within the wear limits. If you can shim the offending valve(s) up so that they open the right amount, the cam is still good.

There's no need to change it just yet... (or at all, arguably).

Don't worry about the oil history. The modern semi-synthetics last 12,000 miles according to the manufacturer so the long interval isn't too shocking as far as the oil is concerned. It's actually more likely that the oil change happened and just wasn't recorded.

The black oil is just carbon, gum and varnish being picked up inside the new oil. You want your oil to go black because that means it's absorbing the contaminants inside the engine. If I was you, I'd change it again since it'll put your mind at rest a bit.

Use 300ml of kerosene (or "engine oil flush" if you want a fancy label) in the hot engine oil... Let it idle at 2000rpm for 10 or 15 minutes and then let it cool and drain it. Don't drive the car with kerosene in the oil.

That will loosen up a load more black stuff.

Put a new filter on it too... let it drain for a very long time... refill with synthetic oil (0W60 for your JTS donkey...? ) as this has more detergents than semi-synthetics. I think AR do state the JTS needs synthetic anyway... but look in the book.

The clattery engine could be the variator but also check the valve gaps etc. They could just need the tappets adjusting.

Put that all together with a new cam-belt and tensionerator and see if the beast is much better or not... :)

If he's still feeling a bit weedy next year, then start saving up for some good cams and stick them in at the next service (12,000 miles?)



Ralf S.
 
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