It's the same but they only wear if the chain guide snaps, I'm on 142,000 miles my brother is on 165,000 no chain problems, however my previous snapped on 90,000 diagnosis guide for chain broke. The thing is I noticed a slightly different noise from day one just like the chain was catching somewhere and it proved to be a problem. So basically if you have an incling something is wrong it will be, only thing is it's not much difference in price for snapped or replacing the chain.

varesecrazy said:

now it's a popular subject on FF again..,:doh:
I decided to Google "cam chain snapped"

apart from a pointless US V8 thread..they are SAFE engines..

the next hit was a BBC Watchdog thread about BMW UK engine failures due to snapped chains,
typical fix was @£4500,
and BMW UK would only entertain a contribution if all work was done in their dealernetwork - so they "earnt" their money back..

Click to expand...

Are they- I would imagine no diesels are safe (non interference) engines due to their high compression ratios. Not even sure (m)any modern petrols are.

They are safe as in valves and pistons, designed to do the rockers 16 needed.

zanes said:

Are they- I would imagine no diesels are safe (non interference) engines due to their high compression ratios. Not even sure (m)any modern petrols are.

Click to expand...

Sorry - the US thread was talking 351 PETROL / Gasoline motors

VERY lightly stressed..

No Diesel is SAFE , but SOME have better designs than others,

the BBC argument was that BMW had put the chain at the REAR of the engine..so it appeared a "fit'n forget" item


not quite the case as one @26K mile failure showed..

There's quite a lot on the Honest John website about failures on chain cam VAG and BMW engines. Not noticed anything about Fiats.
Apparently VAG squeezed their chain supplier for a lower price, so they continued using pressing tools beyond their optimum life. This, combined with 18,000 mile service intervals, has caused many failures. VAG engines have recently gone back to being belt cam.
The BMW problem seems to be failing tensioners, and yes, the chain is very inaccessible.
I'll continue with frequent oil changes, with the correct oil, for my chain cam twinair engine and I'm sure all will be fine. No idea how accessible it is though.

TrevC said:

I'll continue with frequent oil changes, with the correct oil, for my chain cam twinair engine and I'm sure all will be fine. No idea how accessible it is though.

Click to expand...

same here with mine,

the Scottish owner has @95K in theirs..no mention of chain issues

it's a twin,
so plenty of room in my Punto..LESS so with the 500

Hi, out of curiosity, how does changing oil often help the timing chain?

ahmett said:

Hi, out of curiosity, how does changing oil often help the timing chain?

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Reduces the amount of particulate contamination that can jam things, like the tensioner, up and cause wear.

Robert G8RPI.

varesecrazy said:

now it's a popular subject on FF again..,:doh:
I decided to Google "cam chain snapped"

apart from a pointless US V8 thread..they are SAFE engines..

the next hit was a BBC Watchdog thread about BMW UK engine failures due to snapped chains,
typical fix was @£4500,
and BMW UK would only entertain a contribution if all work was done in their dealernetwork - so they "earnt" their money back..

Click to expand...

A next door neighbour of mine, the timing chain on his BMW 118d snapped at just 75,000 miles. Because he hadn't bought it from a BMW dealer, it was out of warranty and it hadn't been serviced by BMW for over 3 years, he was told to go away, they weren't interested. A complete brand new engine cost him 5.5k sourced and fitted through an independent garage.

ahmett said:

Hi, out of curiosity, how does changing oil often help the timing chain?

Click to expand...

in a word = "grindingpaste":yuck:

unlike a cam belt,
the chain is INSIDE the casings and so gets a fair bit of engine oil around it..

great for something like a camper.. or show car , that could spend 9 months of the year motionless

for most other applications I'd prefer a belt,

Charlie

TrevC said:

I'll continue with frequent oil changes

Click to expand...

As far as I know, neither BMW nor VAG changed the oil change interval to fix the chain problems. Therefore more frequent oil changes might not be very effective at all. Although it sounds like horse sense.

jazz452 said:

They are safe as in valves and pistons, designed to do the rockers 16 needed.

Click to expand...

Are you saying that the rockers break when the valves hit the pistons? The valves survive these collisions?

Yes valves survive usually

Why would VAG or BMW want their engines to last forever?
Since the chain and tensioners are lubricated by the engine oil, it makes sense to replace the latter before it gets too corrupted with tiny engine particles, products of combustion, excess fuel etc.
Many manufacturers make money by selling service packages up front when the car is new. If the official service interval is 18,000 miles, they have less to do for the money already paid.

varesecrazy said:

........ for most other applications I'd prefer a belt,

Click to expand...

Little story here.

Next door neighbour of ours some years ago had an Austin Maestro. It had a timing belt. BL S-Series petrol engine.
https://en.wikipedia.org/wiki/BL_S-Series_engine

One day, his car wouldn't start. Battery was ok, but it refused to start, so he rolled it down the hill, dipped the clutch, ignition on, put it in gear and lifted the clutch.

Off he sailed, engine turning over like a good 'un, but it still refused to fire up. He carried on until he ran out of hill!

He managed to get a tow to the local garage and they found his timing belt had broken. They replaced it and started the engine easily.

The good thing about those engines, is that there was clearance between piston at TDC and the open valves.

Happy New Year!
Mick.

the FIRE engines do that, fit a new belt, and continue your journey - Progress eh..

TrevC said:

Why would VAG or BMW want their engines to last forever?
Since the chain and tensioners are lubricated by the engine oil, it makes sense to replace the latter before it gets too corrupted with tiny engine particles, products of combustion, excess fuel etc.
Many manufacturers make money by selling service packages up front when the car is new. If the official service interval is 18,000 miles, they have less to do for the money already paid.

Click to expand...

Why would any company want their engines to last forever?? Reputation has a big part to play in that one.

The service intervals on my 2.0 litre diesel golf is 10,000 miles or once a year......

I'm fairly certain however that fiat are now pushing longer and longer service intervals on new cars.

There is an option if wanted to extend servicing to 18,000 miles on volkswagens if you're cheap and don't want to regularly service the vehicle, they then use a different oil and charge slightly more for it.

Whoever makes the car, petrol or diesel, there is always the potential for a chain or a belt to go prematurely. My 1.3 Diesel punto had gone 119000 miles when I sold it and no problems with the chain and gave me no reason to get it replaced. However our 1.9 Diesel punto decided at 78000 miles to throw its belt off into the plastic cambelt cover when the tensioner gave out just 10,000 miles after being replaced. Fortunately the plastic cover melted from the friction and produced smoke, alerting us to the problem as otherwise there were no signs of any problems.

Clearly a chain should last a great deal longer than a cambelt. My old Nissan Primera went to the scrapyard with 200k miles on the clock on the original timing chain.

Ultimately though, be it cambelt or chain, 99 percent of the reason why owners won't replace it at the correct service interval, if at all, is because they won't fork out the cost of the job. Odd that, let your car engine self destruct for the sake of £350 to £500 and then leave yourself in the position where you have to either spend £1k plus for engine repairs or a whole lot more money buying a replacement vehicle.

Andy, I guess I was being a bit flippant in my remark about VAG and BMW!
You are right, any system has the potential for failure, all we can do is improve the odds, be it by frequent oil changes or changing the timing belt and waterpump at least as frequently as recommended.
Another failure mode can be the auxiliary belt failing and the bits tangling in the timing belt if it is partially exposed. It makes sense to have this replaced with the timing belt, as it normally has to be removed to get to the cambelt anyway.

Just got a price from my local fiat dealer for a timing chain replacement plus all other ancillaries (gaskets, tensioners etc) for my 1.3 mjet. The total was £728 Inc vat.