Japan not too happy with GF-4 Oils ?

[Al]

quote:

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Originally posted by JMG:
Are chains more realible than belts? Do they, the chains, have to be replaced at certain intervals?

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Chains eliminate a replacable wear item (belt. I think you could expect a timing chain to go 150K miles+.

Timing chain wear may be a concern that proves to be unsubstianted. And don't forget that many of the GF-4 oils have lots of extra moly. If there is a problem..testing will discover it before it gets to be an issue for most of us.

 

[Alan]

This is just "concern",nothing concrete.I don't think there will be any problems with GF-4 stuff in the long run.

I personally think the attempts by these auto makers to make their vehicles more "maintanince free" by extending oil change intervals has caused more problems with timing chains then just oil the "quality".

 

[Schmoe]

When is the theoritecal date on Honda's going to chains for timing? Wanting to get a new Accord, but may wait until this new "design" emerges. Anybody know?

 

[Ken4]

quote:

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Originally posted by ex_MGB:
Unfortunately, some timing chain tensioners over time fail to provide sufficient tension at start-up (the tensioner plunger is pressured by the oil system) and one gets a pronounced rattle until the vehicle is warmed as in the Nissan VQ30. Replacing the tensioner, with its minuscule access cover on the timing chain cover is akin to neurosurgery

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You are right. The Timing Chain may be durable, but the tensioner is not. My Suzuki GV started having cold start timing chain rattle at 60,000km. There is even a TSB for replacing this little tensioner. Not a simple task. Basically Suzuki says to live with this problem and advises that rattle for the first 5 secs of operation is normal.

 

[Jimbo]

quote:

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Originally posted by n8wvi:
I have 6 Subaru's in the family 'fleet'. All but 2 have belts. $55 every 100k miles doesn't seem like much to me

...

Dave

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How many labor hours and cost if it is done at the dealer? Subs also have a longitudinal engine which has to make it simpler. I changed a timing belt on a Corrola once and it was a lot more difficult and time consuming than I thought possible. The part was only $20. Toyota specified 60,000 mile intervals on belts and dealers typically charge $400 on a V-6 Camry. Chains do make a little noise, but last the life of the engine, up to 300,000 miles on BMW and Mercedes. Hydraulic plunger and sproket, rather than spring loaded shoe, tensioners also last longer. GM first came up with the timing belt on the short-lived Pontiac OHC I-6 of the 1960's.

 

[satterfi]

quote:

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Originally posted by Schmoe:
When is the theoritecal date on Honda's going to chains for timing? Wanting to get a new Accord, but may wait until this new "design" emerges. Anybody know?

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Honda's cam chain tensioners on their motorcylces are prone to failure. When they fail, the pistons and valves try to occupy the same space.

You better hope they come up with something more reliable than that crappy design.

 

[gerhardb]

Time Chain Discussion:

I have a Honda H22A series motor that uses a timing belt.

The belt is primarily used as a means to eliminate (reduce actually) engine noise.

To get longevity out of the belt, I use an aftermarket kevlar belt... doesn't need to be changed...

 

[Cyprs]

Anthony, I had your engine in a 01 Altima, at time I was told by dealership and manual to drive it for 320,000 kms or 210K miles and forget about it, the manual says nothing about tightening it, I believe it has an auto tensioner. In my new 05 QR25DE I cant hear the steel chain as I did in the 01 Altima. Do not go past the 320K or 210K, if you do I know of first hand accounts of serious engine problems resulting. The 1980 Datsun did have a sprocket adjustment, these new Nissans dont as far as I know.

Steel time chains do have to be changed, the intervals are up to five times less with a good quality chain. As I said, it seemed I was changing belts on my Accord like socks, now I drive my Nissan and one less worry with this chain.

Cyprs

 

[dustyjoe1]

quote:

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Chains eliminate a replacable wear item (belt. I think you could expect a timing chain to go 150K miles+.

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True, and that is good, you can re-use it when you replace the broken plastic guides (re: toyota 22 series engines)

I'm pretty indifferent either way (chain or belt), I will say though that its considerably easier (early maxima excluded) to replace an external belt than an internal chain.

my .02

 

[Schmoe]

My '90 Cutlass V6 has a chain, still running like a scalded dog at 195K.

 

[darryld13]

quote:

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Originally posted by Schmoe:
When is the theoritecal date on Honda's going to chains for timing? Wanting to get a new Accord, but may wait until this new "design" emerges. Anybody know?

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The 4 cylinder Accords use a chain, the V6s currently use belts that have 105,000 mile change intervals.

 

[Anthony]

Cyprs, this one guy i know has a 95 hardbody which has the single cam ka24e with 241k with no internal engine work at all and it really runs good and he beats the crap out of this truck constantly pulling loads well over the max rated tow capacity and probably the gcwr.
The chain has never been touched and his 241k engine sounded as good as my 97 hardbody with 150k before it was totaled!!
My 97 hardbody lived on m1 5w30 all its life and never leaked or burned a drop of oil. Ive heard that the chains benefit from thicker oils and i had just found this site and begin mixing a quart of 15w50 M1 wi 3 qts of 5w30 and didnt even make it 1000 miles before it was totaled!!
Forgot to mention that the 241k hardbody lives on advance auto 10w30.
Im currently running 3 1/2 qts of M1 5w30 and 1/2 qt of M1 15w50 in my 04 frontier but will probably switch to M1EP 10w30. What do you guys think of ep in my ka24de?

 

[Geoff]

I think consumers just don't want a biggish ($300-$800) repair job hanging out there. This is not a big cost in the scheme of things, but nevertheless is out there. Of course, belts can break too.

Just changed the belt on our '99 Trooper. One big one that wraps both banks of the V-6. Not trivial (esp as I changed the water pump while I was "in there") but not difficult either. This was at 80K miles and the belt looked almost new.

By the way I changed the Trooper to the pink longlife antifreeze at about 24K. The passages in the block and inside the radiator were absolutely free of scale or other buildup.

 

[jtantare]

Volvos have used timing belts since the mid 70s but they never had any problems untill their first DOHC interferance heads. The first 960s (B6304 I6)were the worst with a 20k mile timing belt! Later Volvo upgraded the 92 at no cost to the 93 style belt with 30k mile interval. My 94 has a 50k mile interval and 95-98 70k miles.
In the B234 engines, the timing belt also turns the oil pump. Another poor design
That said, I wouldn't want a timing chain for the world.
T belt photo

 

[Winston]

There are trade-offs with belts and chains. One issue that has come up is that more engines have overhead cams. Overhead cam engines need longer chains/belt. The longer the belt, the more that the stretch affect timing. Belts and chains both stretch over time. But, as someone mentioned earlier, it is easier to change a belt than a chain. So, installing a $20-30 easily replacable part is a good idea to me since you can cheaply maintain peak performance. The proble comes in with some car/engine designs that require many hours to replace the belt. My Montero requires 4-6 hours if you are good, since you need to remove the radiator, and a bunch of other stuff. A porche 928 engine requires a minimum of 12 hours!!!

I am glad no one mentioned the conspiracy theory. I do not believe timing belts were installed to create maintenance revenue for the dealer. They are quiet, perform well and are cheap to replace (usually).

I would assume they are going back to chains because they have found a way to reduce stretch by using better metalurgy.

Oh, and as far as the auto companies wasting effort on trying to enhance mileage through better oil technology? Why not? A few percent makes a big difference for an entire country. Every little bit helps.

 

[Jay]

The biggest advantage of belts is that they don't lengthen as they wear as chains do, so valve timing is preserved throughout the life of the belt. The biggest disadvantage of belts is that they break eventually with catastrophic results if the valves can collide with each other or the pistons.

I think Honda is moving back to chains because more and more of their engines have iVTEC where the cam "floats" inside the cam sprocket. Since valve timing is dependent on closed-circuit iVTEC hydraulics, the chain can lengthen somewhat with wear and not affect valve timing.

 

[brianl703]

quote:

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Originally posted by Jay:
The biggest advantage of belts is that they don't lengthen as they wear as chains do

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If a serpentine belt lengthens due to wear, why wouldn't a timing belt?

According to Gates:

"Gates timing belts have high tensile strength cord construction, to minimize stretch, and a tough wear-resistant fabric on the working tooth surface."

 

[DR Racing]

quote:

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The biggest advantage of belts is that they don't lengthen as they wear

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Wrong, Both chains and belts stretch. Two reasons for the change over, the new chain designs are quiet and will last as long as the rest of the motor. Dan

 

[Cyprs]

Anthony, They are tough, I use my 720 series 1980 Datsun hard too, it has the 1952cc motor, low gearing so engine really revs high. The engine that had valve problems after the time chain went after 210k miles was a 94 Altima. Oil probabably does have lot to do with chain life, better oil and maintenance would make a difference. I have driven Nissan 28 years now, I am sold on them based on experience, good luck.

Cyprs

 

[wileyE]

With belts it's best (but hasn't always been done) to build zero clearance valve pockets in the piston crowns. This built in safety allows belt breakage with no major damage, a good thing. With modern combustion chamber efficient design and the ability to run higher compression ratios these valve reliefs are counterproductive to the combustion process. This is another reason for going back to a chain. New chain designs also can allow a lifetime service with NO adjuster mechanism needed.