Motor oil choices for optimum timing chain life

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Jul 7, 2014
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This is my (probably very incomplete) summary of a bunch of threads here on BITOG regarding optimum practice for longest timing chain life.

Desirable Properties of Oil:
- As thick as possible for hot operating conditions (i.e. xW-40 > xW-30 > xW-20)
- As thin as possible for cold-weather starts (i.e. 0W-x > 5W-x > 10W-x > 20W-x)
- As little viscosity spread as possible (i.e. 5W-20 or 10W-30 > 0W-20 or 0W-30 or 0W-40 or 5W-30 or 20W-50)

These properties are somewhat contradictory - an oil that's both thin enough for cold weather and thick enough for hot weather will have a large viscosity spread.

My compromise is to use 5W-30 or 10W-30 for the summer, and 0W-20 or 0W-30 for the winter.

Bear in mind I do live in an extreme climate, where we saw -40 C (-40 F) in February, and are now seeing 37 C (99 F) in early summer.

The other thing I've picked up is that clean oil is essential for minimizing timing chain wear. This might be much more important than viscosity. With that in mind, I try to keep up with the air filters too.

I service three vehicles - a 2007 Dodge Grand Caravan 3.3 (which specs 5W-30 year round), a 2009 Mazda 5 2.3 (which specs 5W-20), and a 2009 Kia Sedona 3.8 (which specs 5W-20 on the oil filler cap, but in the owner's manual specs 5W-20 or 5W-30 year round, or 10W-30 down to -20 C [-4 F]).

The Dodge is cam-in-block, with a short timing chain. I don't worry about it much.

The Mazda is DOHC, but one bank only, so again the timing chain, while longer than in the Dodge, is still fairly simple.

I worry about the Kia, with its long complex chain driving four camshafts. So far, so good though.

Thoughts?
 
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5w40 year round
This is my approach except in the brutal northeast winters, then it's 0w40. I would use 10w40 if it weren't for the fact that most A3/B4 0/5w oils are just way better overall. I also like my moly, really quiets down the valve train.
This is my (probably very incomplete) summary of a bunch of threads here on BITOG regarding optimum practice for longest timing chain life.

Desirable Properties of Oil:
- As thick as possible for hot operating conditions (i.e. xW-40 > xW-30 > xW-20)
- As thin as possible for cold-weather starts (i.e. 0W-x > 5W-x > 10W-x > 20W-x)
- As little viscosity spread as possible (i.e. 5W-20 or 10W-30 > 0W-20 or 0W-30 or 0W-40 or 5W-30 or 20W-50)

These properties are somewhat contradictory - an oil that's both thin enough for cold weather and thick enough for hot weather will have a large viscosity spread.

My compromise is to use 5W-30 or 10W-30 for the summer, and 0W-20 or 0W-30 for the winter.

Bear in mind I do live in an extreme climate, where we saw -40 C (-40 F) in February, and are now seeing 37 C (99 F) in early summer.

The other thing I've picked up is that clean oil is essential for minimizing timing chain wear. This might be much more important than viscosity. With that in mind, I try to keep up with the air filters too.

I service three vehicles - a 2007 Dodge Grand Caravan 3.3 (which specs 5W-30 year round), a 2009 Mazda 5 2.3 (which specs 5W-20), and a 2009 Kia Sedona 3.8 (which specs 5W-20 on the oil filler cap, but in the owner's manual specs 5W-20 or 5W-30 year round, or 10W-30 down to -20 C [-4 F]).

The Dodge is cam-in-block, with a short timing chain. I don't worry about it much.

The Mazda is DOHC, but one bank only, so again the timing chain, while longer than in the Dodge, is still fairly simple.

I worry about the Kia, with its long complex chain driving four camshafts. So far, so good though.

Thoughts?
I'm curious why a high viscosity index is bad?

Hyundai/Kia engines will run just as fine on a thick oil as they will a thin, so just use something thick. Fuel economy doesn't seem to vary, and the variable valve timing works the same on a 20 and a 40, but it sure as heck makes less racket on a 40.
 
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Joined
Nov 28, 2012
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Location
Ontario, Canada
This is my (probably very incomplete) summary of a bunch of threads here on BITOG regarding optimum practice for longest timing chain life.

Desirable Properties of Oil:
- As thick as possible for hot operating conditions (i.e. xW-40 > xW-30 > xW-20)
- As thin as possible for cold-weather starts (i.e. 0W-x > 5W-x > 10W-x > 20W-x)
- As little viscosity spread as possible (i.e. 5W-20 or 10W-30 > 0W-20 or 0W-30 or 0W-40 or 5W-30 or 20W-50)

These properties are somewhat contradictory - an oil that's both thin enough for cold weather and thick enough for hot weather will have a large viscosity spread.

My compromise is to use 5W-30 or 10W-30 for the summer, and 0W-20 or 0W-30 for the winter.

Bear in mind I do live in an extreme climate, where we saw -40 C (-40 F) in February, and are now seeing 37 C (99 F) in early summer.

The other thing I've picked up is that clean oil is essential for minimizing timing chain wear. This might be much more important than viscosity. With that in mind, I try to keep up with the air filters too.

I service three vehicles - a 2007 Dodge Grand Caravan 3.3 (which specs 5W-30 year round), a 2009 Mazda 5 2.3 (which specs 5W-20), and a 2009 Kia Sedona 3.8 (which specs 5W-20 on the oil filler cap, but in the owner's manual specs 5W-20 or 5W-30 year round, or 10W-30 down to -20 C [-4 F]).

The Dodge is cam-in-block, with a short timing chain. I don't worry about it much.

The Mazda is DOHC, but one bank only, so again the timing chain, while longer than in the Dodge, is still fairly simple.

I worry about the Kia, with its long complex chain driving four camshafts. So far, so good though.

Thoughts?
The best solution for long life timing chain is avoid long OCIs, this more than anything else will help.
 
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Dallas,Tx USA
I can agree with that, I have a longtime customer with a 2007 Cadillac SRX with a early chain eating 3.6L.....Just about 300,000 on the original Timing Components & he is excessive borderline obsessive with oil changes.
I agree as well. Everyone I know who seems to have cars that last literally forever are hard core 3K oil changers.
 
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Illinois
My 2L Gen Coupe turbo had the chain replaced at 100k. I used M1 0w40 for most of those miles changed at 5k miles. Oil dilution is an issue and they also upgraded the chain by shifting the stack order on the chain.

Manufactures are going with lighter chains for fuel economy. Isn't the newer GF6 oil meant to address timing chain wear?
 
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I can agree with that, I have a longtime customer with a 2007 Cadillac SRX with a early chain eating 3.6L.....Just about 300,000 on the original Timing Components & he is excessive borderline obsessive with oil changes.
My brother-in-law worked for a Caddy dealer during those timing chain problem years. He said that the only timing chains that never had a problem during those years was the ones from the rental car companies in town (that got their fleets serviced there). And he said, I don’t know what it is, but they come in regularly for their oil changes every 4 thousand or so miles and just use the conventional oil we have. And I said, you’re telling me that on conventional, with shorter intervals, you’re not seeing timing chains on those cars. Yup.

I want to say GM at that time dialed back their oil life monitors because they were extending them out too far.
 

Number_35

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Winnipeg MB CA
This is my approach except in the brutal northeast winters, then it's 0w40. I would use 10w40 if it weren't for the fact that most A3/B4 0/5w oils are just way better overall. I also like my moly, really quiets down the valve train.

I'm curious why a high viscosity index is bad?

Hyundai/Kia engines will run just as fine on a thick oil as they will a thin, so just use something thick. Fuel economy doesn't seem to vary, and the variable valve timing works the same on a 20 and a 40, but it sure as heck makes less racket on a 40.
They (the discussion was on BITOG, but I haven't found it, and don't remember who made the point) say that to achieve a high viscosity spread, the oil needs a lot of additives. These break down, making the oil a lot less effective.

Perhaps a large viscosity spread combined with shorter OC intervals is the way to go.
 

Number_35

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15w40 year round. The most dependable oil blend ever made.

Add some moly in it if you want.
15W-40 would not be appropriate for the severe winters here, but would work well in the summer. It's gotten rare, though.

I have added Liquid Moly at times in the past - good to know it's recommended for timing chains! May start using it again.
 

Number_35

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My 2L Gen Coupe turbo had the chain replaced at 100k. I used M1 0w40 for most of those miles changed at 5k miles. Oil dilution is an issue and they also upgraded the chain by shifting the stack order on the chain.

Manufactures are going with lighter chains for fuel economy. Isn't the newer GF6 oil meant to address timing chain wear?
I presume that the oil dilution would effectively reduce the 40 to something much thinner. I wonder if 3K OCIs would have helped?
 
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