Screwloose, it's interesting that this engine uses the Hi-Vo chain system. Every single application of this chain I have ever encountered has given trouble and the range is diverse. Here's a selection:
SAAB 99/900 automatic (manual version used Renold triple staggered drive with no trouble)
Landrover transfer drive
RR CV12 Auxiliary drive (not often seen on the road - it's a 26 litre V12 diesel)
I think the perceived advantage of this arrangement was the omission of the tensioner. It didn't work and still doesn't work. I'm sorry to say I have encountered other examples of dubious engineering from its originator. If a chain drive system is required for some application Renold (UK) will produce one which works.
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The only thing I've ever driven [only briefly] with a CVT12 was a Scammel Constructor. Like most RR truck engines - awful!
I too am coming to the conclusion that there's something fundamentally wrong with Hi-Vo. There was nothing visually amiss with the old drive chains; but when compared with the new ones [£500 each!] they've stretched about 3/4 of an inch.
As the eccentric on the 3rd sprocket only has a 7mm offset; that's it. I did consider installing a back-runner block, but opted for new chains as the easier option - except that they're a smidgeon too short and I can't get the box back together without using unacceptable force.
If I could get it together, they'd soon run in and adjust; Catch 22! I've run out of legs, so it'll have to sit there for a while.
The new design for the joining links is a joke! The originals have the longer rocker blade of each pair peened into the external guide plate. The new joiners push both blades through a big hole in that plate and the longer one sticks right out each side with a short 1mm rollpin pushed through to "secure" it!! I knocked two out in the struggle to get them on to the sprockets. I'm seriously considering taking the new chains out again and welding a washer on instead.
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Try the military version of the CV12 if you want an interesting ride... When I was involved in the development of this unit I witnessed a Morse chain failure - not very dramatic as it's only an aux drive although I was able to detect the fuelling change as the alternator load suddenly disappeared. My friends at RR were a bit less pleased - the Hi-Vo sprocket is machined directly on the crank. I'll leave you to speculate as to the cost of a CV12 crankshaft.
As I see it the problem with the Hi-Vo is that although the involute tooth form to some extent obviates the need for rollers there is, as you point out no compensation for link elongation. As soon as this occurs the geometry becomes completely wrong for rolling contact and failure follows very quickly. I just don't see eye to eye with the engineering philosophies of the originating company.
Screwloose, if your chain is a bit short, put it in oil heated to 150 deg for about half an hour. I've seen this done and it's surprisingly effective. You need good oven gloves.
A back block tensioner won't work on a chain without rollers. The system used on Renold chains is a lot more sophisticated than it looks. Once the side plates have ploughed their furrows, nearly all of the contact is rolling. The nice (and clever) man from Renold told me that they aim to have the rollers pre-rotating as they leave the sprocket before the tensioner on the applications they detail. The staggered drive they designed for SAAB is a bit like a 3 phase motor in philosophy and contributes greatly to the smoothness of the drive. You can't do that with a Hi-Vo.
The drive in my SAAB never gave any trouble after a huge mileage including lots of towing. I did peep in there during a clutch change - the twin hydraulic tensioners had plenty of reserve travel.
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Thanks for the tip about heating the chain in oil; all I have to do now is to work out a way to keep it warm on the drive back from the chippy!
Seriously; it's so difficult to engage the heavy sprockets into the double chains, they would be stone cold before I got even the first one in. [Maybe I could freeze the alloy casing?]
The triangular 3-shaft box has three holes that are just big enough to take the sprockets - cue much blind levering with long screwdriver to lift the awkward, external guide, chains into position. [You see how the tiny rollpins got dislodged. I had to use a dentist's mirror to even check them and tapped them back in with a 5mm Allen key. Yes; they're that tight!]
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Allo screwloose ... Well, as you know - there are loads of Almera's with the ole timing chain problem, in fact many people have contacted Watchdog about it.
It seems to mainly affect the 1.5 lump but can (and does) affect the 1.8 which I own and as you say - the Micra and even the Primera 1.8
Ideally, the chain, tensioner, guides and sprockets should be replaced and there is a company in London that I believe can source the Jap chains rather than fit another Frog one ... The company is called Board Brothers which is in Battersea SW London and their tel no. is 02072286846
The first symptom is usually a slight, stuttery random misfire, both at idle and under load. This gets progressively more pronounced until the MIL light comes on. Scanning it will show a discrepancy between the cam and crank position sensor readings. To ensure it is a stretched chain and not a dodgy sensor the chain tensioner protrusion should be checked - 10mm or more and the chain is knackered.
P.S. I'm not a mechanic, I was a mobile tune up merchant from 78 - 92 ... I got this info from another forum.
Praps I should shoe-horn the 2.2 lump into my Almera ... now there's a thought !
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I have a 1.8 '52' reg Primera - starting to get a bit worried now. I usually research purchases pretty thoroughly and don't remember it coming up in connection with the Primera before.
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I wouldn't worry. Unlike a belt, the chain will give you plenty of warning if there's problem - as others say misfires and the like.
Until then, sleep easy. No point in worrying about something that might never happen.
(and any Nissan more than about 4 years old will have a Japanese engine anyway).
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On the K11 Micra I did, I found it didn't appear to be the chain that had worn, as much as the centre sprocket. In particular the rear teeth IIRC were particularly 'hooked'. Because I'd already bought new chains, I replaced them. Comparing new and old chains by measuring the amount of 'arc' sideways showed no noticeable difference.
In retrospect, I think I should have only replaced the centre sprocket, top tensioner and sold it on. ;>)
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The CG engined K11 had conventional roller chains, which lasted far longer than the internal tooth Morse chains on the later CR engines.
The sprocket on a Morse chain looks exactly like a straight-cut gearwheel. They deleted the centre sprocket completely.
Edited by Screwloose on 20/06/2008 at 23:00
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I also have a 1.8 Primera and yes I've heard that the timing chains on these are more prone to failing than to the timing chains on previous Primeras. But am I worried ?
No.
I'll just keep changing the oil every 9k and if it lets go then it lets go.
the car is only worth a grand anyway so it would be pointless spending a grand on it, I might as well sell it for spares and buy another.
relax, just keep changing the oil & filter.
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You may well be correct on your assumption Herr Bathtub as this piece explains ~
Most of my work is in research and development for the aerospace industry. I'm no expert in the issues involved here but my job does give me easy access to people who are experts in this sort of thing. The timing chain from my daughter's car was looked at by both a metallurgist and a tribologist (a specialist in such things as lubrication and wear). Both were very strongly of the opinion that the issue was one of lack of effective lubrication probably due to oil degradation. To be absolutely sure would require a stripdown of a complete failed engine, including analysis of the oil, under forensic conditions. That's simply not practical on cost grounds - it would cost many times the value of the car! That said I know who's advice I'm going to follow and it's not Nissan's.
The main injun's involved seem 2 b the QG18 & QG15 lumps.
Chain kits are available on eBay (where else !) for a tad over £160
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how do i check the protushion on the tensioner?almera 1.5 petrol n16 2001 model
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My first car, a K11 Micra, ran very nicely for 10 years (and 55-60k miles) as far as the engine (oil changes every service at 9k miles) was concerned. I wonder whether the problems listed above refer to engines jointly developed with Renault after the tie-up in the late 1990s.
Hopefully Japanese makes have learned their lesson in 'collaborating' with European ones - all the problems on my current car, mk1 Mazda3 (not mine personally - none of the components listed as having faults are on my model, thankfully [and luckily]!), relate to components 'shared' with related cars (e.g. the PSA/Ford 1.6 diesel) and the TEVES (or whatever the acronymn was) stability/traction control/ABS thingy.
Hopefully they can get their reliability credibility back (or improve it) as that's always been the hallmark of Japanse marques.
Edited by Engineer Andy on 28/11/2013 at 14:29
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Just goes to show how little you seem to know about the sources of engines.
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Fairly sure I've read that 10mm is the maximum it should protroud.
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Collos, what is the point of a post like that? If you disagree with Engineer Andy, who is always polite and knowledgeable on here, (a) do so politely, (b) explain to the rest of us what you think the correct position is on the issue.
People are being discouraged from posting by your continuing rudeness and arrogance.
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I wonder what chains are used in VAG engines. I know that up to 2010 the 3 pot engines used conventional roller chains, early examples having problems with the tensioners. In 2010 VAG redesigned the 3 pot engine, slimming down the crankshaft etc and fitted a new type chain, from what I remember of the photos/drawings, they look like this new Hivo type. So far I'm unaware of any problems with these but VAG have a habit of not acknowledging problems and repairing on a case by case basis or doing a "silent recall" where remedial work is done on the QT during regular servicing.
The new generation of VAG petrol and diesel engines have all gone back to cambelt, supposedly for efficiency reasons, but I do suspect they've had enough of expensive camchain failures...
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Here is a good video on Nissan 1.6L Timing Chain Rattle
www.youtube.com/watch?v=oS7kTQ6wG-8
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Collos, what is the point of a post like that? If you disagree with Engineer Andy, who is always polite and knowledgeable on here, (a) do so politely, (b) explain to the rest of us what you think the correct position is on the issue.
People are being discouraged from posting by your continuing rudeness and arrogance.
Its quite obvious to me that the subcriber is writing rubbish and expects people to believe his thoughts he has niether thought about the matter or done any homework.If you were to look at were the Japanese source their engines and gearboxes you will find a large proportion are sourced in Europe.The new Infiniti is nothing more than a Mercedes who in there wisdom are using Renault engines ,example you find Nissan,Mazda, Suzuki sourcing their diesel engines from PSA or Fiat no doubt Japan makes engines but not as many as you think.
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Suzuki use fiat 1.6 in the s cross or a Renault 1.9 in the Gv im not sure anout the swift but all there petrol engines are there own design witch seem to be on the whole trouble free.
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"Its quite obvious to me that the subcriber is writing rubbish and expects people to believe his thoughts he has niether thought about the matter or done any homework."
You avoid Avant's point, which was about rudeness and arrogance, and just trot out your point of view. Some people think that "speaking the truth" about something (which nearly always means just their version of the truth) justifies anything they put.
As Avant is a moderator here I suggest you pay attention.
Edited by FP on 29/11/2013 at 11:06
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Collos, what is the point of a post like that? If you disagree with Engineer Andy, who is always polite and knowledgeable on here, (a) do so politely, (b) explain to the rest of us what you think the correct position is on the issue.
People are being discouraged from posting by your continuing rudeness and arrogance.
Its quite obvious to me that the subcriber is writing rubbish and expects people to believe his thoughts he has niether thought about the matter or done any homework.If you were to look at were the Japanese source their engines and gearboxes you will find a large proportion are sourced in Europe.The new Infiniti is nothing more than a Mercedes who in there wisdom are using Renault engines ,example you find Nissan,Mazda, Suzuki sourcing their diesel engines from PSA or Fiat no doubt Japan makes engines but not as many as you think.
Collos - I was making the point that when Japanese makes had full tie-ups with European makes, they shared much more parts (until then most Japanese manufacturers had few diesel-engined cars available) - yes, parts may have been sourced from european companies, but, like the known problems with european suspension springs (from HJ), those used in Japanese cars were higher quality from an engineering perspective and didn't fail anywhere near as quickly, if at all (before the cars were scarpped).
There's a whole world of difference between changing the shell and dash but keeping the underpinnings the same and sourcing higher-quality components from the same continent than other EU manufacturers. Quite a lot of cars or major components (such as engines) ARE jointly developed between EU and Japanese makes, much more than there were before the early-mid 90s. My belief is that this is why the Japanese makes have suffered to a degree from higher instances of unreliability, and mostly from Diesel engines bought from EU car manufacturers.
Just because you disagree, it doesn't mean you have to be rude and disrespectful - if you want that, I would advise you stick to the tabloid newspapers and websites catering for the angry person.
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