0W-20 and excessive nylon tensioner arm wear

Status
Not open for further replies.
Joined
Sep 12, 2002
Messages
2,235
Location
SE MI
In a Ford OHC V8, they use nylon on the timing chain tensioner arms... Wouldn't a xW-20 or light oil cause the chain to wear out the nylon faster than say if you used a synthetic xW-40 or xW-50?
 
Joined
Apr 30, 2004
Messages
1,503
Location
Indiana
Isn't this in the category of cold start-up pumpability vs. high temp film thickness? And what operating condition causes the wear?
 

metroplex

Thread starter
Joined
Sep 12, 2002
Messages
2,235
Location
SE MI
quote:
Why do you think it would?
The way the Ford Modular engine works is there's oil that lubricates the chain, which rubs against a nylon coating on the tensioner arms. Would a thicker synthetic oil like M1 15W-50 provide more wear protection for the nylon or would something ultra thin like M1 0W-20 or regular 5W-20 provide better protection? Again I'm talking about the timing chain tensioner arms and the nylon components on the tensioner arms and chain guides... NOT internal engine bearings/journals.
 

tpi

Joined
Jan 25, 2004
Messages
200
Location
So. CA
I think this is a valid question, and the answer won't be provided by oil analysis. These are oil lubricated parts, but PPM of plastics aren't part of the package. [Big Grin] This is just the type of repair which could occur prior to wearout of piston rings, cylinder walls, and bearings/crankshaft.
 
Joined
Nov 25, 2003
Messages
2,602
Location
The Tropics of Antartica
I think of it differently . If I were a nylon timing chain tensioner operated hydraulicaly by oil pressure I would want tension put on that chain ASAP to keep it from slapping me till tensioned . I'd let thin oil protect me all my life which would be much longer without being whipped by that steel chain which is much tougher than little ole made of nylon.......... me .
 
Joined
May 27, 2002
Messages
302
Location
Chicago
quote:
Originally posted by Motorbike: I think of it differently . If I were a nylon timing chain tensioner operated hydraulicaly by oil pressure I would want tension put on that chain ASAP to keep it from slapping me till tensioned . I'd let thin oil protect me all my life which would be much longer without being whipped by that steel chain which is much tougher than little ole made of nylon.......... me .
That is, unless a thicker oil would remain on both the chain and the guides as opposed to thinner oil which would quickly drain away when the engine is shut off...
 

metroplex

Thread starter
Joined
Sep 12, 2002
Messages
2,235
Location
SE MI
quote:
I think of it differently . If I were a nylon timing chain tensioner operated hydraulicaly by oil pressure I would want tension put on that chain ASAP to keep it from slapping me till tensioned . I'd let thin oil protect me all my life which would be much longer without being whipped by that steel chain which is much tougher than little ole made of nylon.......... me .
I've gone that route. The chain doesn't really whip the nylon unless the tensioner (piston that gets pressurized by oil) is totally drained. From my experience, they are not totally drained even when you shut off the motor. THose little suckers are filled with oil and it keeps decent tension on the chain. You have to use a vice to compress it and drain it completely. This leads me to the question of which is better to protect the nylon: lightweight synthetic or slightly thicker synthetic? I've used dino 5W-30 and synthetic 5W-30, but got about 0.03" wear on the tensioner arms in under 10k miles. At that rate, they'd be worn out well before 100k miles essentially rendering the engine "useless". IMHO that is one of the major weak points in the Ford 4.6/5.4 V8 so that is what I'm focusing on. The oil that can provide the MOST protection for that nylon is what I would use. I firmly believe the crank/cams, roller followers, pistons, etc... are big boys and should be able to handle whatever oil you throw at it (within a logical range of choices of course... i.e. no SAE 60 please), it's the nylon surfaces that concern me.
 
Joined
Sep 28, 2002
Messages
39,802
Location
Pottstown, PA
Anything nylon in the timing set blows. I've never seen a replacement or aftermarket gear/chain set that comes in nylon. They suck and are made of that material for some other reason than longevity. I guess making them out of Hammerlite would be asking too much.
 
Joined
May 27, 2002
Messages
302
Location
Chicago
Well, I can only speak from personal experience. My Saturn also uses nylon tensioner guides for the chain. I ran Mobil 1 5w-30 for the first 103,000 miles, then switched to 10w-40 and 5w-40 Amsoil, Redline, or Delvac 1 (mostly Delvac 1) through the current 190,000 mile mark. The chains on these cars, especially single overhead cam engines like mine, are known to signal their impending doom quite clearly by making your engine sound like a diesel. This hasn't happened to me yet, and I don't intend to do anything about the chain until that happens. So, in my experience, if you run a quality synthetic oil of whatever weight of your choosing, that will do best for the chain. The worst thing that you can do for a chain is let the oil level drop (at least that's the case with Saturns). Keep the oil topped up, and keep clean oil in there and the chain will likely last a long time. Incidentally, someone somewhere recently posted a link to an article about significantly reduced timing chain stretch with Delvac 1. You might want to look that up.
 

metroplex

Thread starter
Joined
Sep 12, 2002
Messages
2,235
Location
SE MI
Gary: I understand where you're coming from. On my Ford 302 V8 (5.0), the original crank sprocket (or was it the cam sprocket) had nylon teeth. However, the vehicle in question in this thread would use a Ford Modular V8... The same style short block on the 4.6/5.4 V8s (I dunno if it'd be the same for the 4V versions) Where you have 1 crank gear that have 2 sets of teeth, and 1 cam gear for each head. Everything is steel/metal. The only nylon parts in this timing set are on the tensioner arms and chain guides. These are surfaces that rub against the metal chain! I believe Ford used this material for reducing NVH and increasing chain longevity. Your engine is totally useless if the chain starts to wear on the aluminum tensioner arms after it cuts through the nylon since its an interference motor (timing chain goes kaput means pistons play kissy face with the valves).
 

MolaKule

Staff member
Joined
Jun 5, 2002
Messages
22,187
Location
Iowegia - USA
quote:
If I were a nylon timing chain tensioner operated hydraulicaly by oil pressure I would want tension put on that chain ASAP to keep it from slapping me till tensioned .
I don't think the tensioner chain is operated hydraulically, just a Nylon rubbing block under spring tension (metroplex may want to clarify). Any oil that lubricates the quickest under cranking and startup has my vote. That would be a XW20 or 30, preferably in blends or synthetics..
 

tpi

Joined
Jan 25, 2004
Messages
200
Location
So. CA
quote:
Originally posted by metroplex: The oil that can provide the MOST protection for that nylon is what I would use. I firmly believe the crank/cams, roller followers, pistons, etc... are big boys and should be able to handle whatever oil you throw at it (within a logical range of choices of course... i.e. no SAE 60 please), it's the nylon surfaces that concern me.
I agree. These tensioners are just the kind of thing needing repair part way through the engine life. Nearly all OHC engines use some kind of composite tensioner guide. I do know neglect of oil will wear these parts prematurely, I know of a 98 Corolla which had 2 oil changes in 80K miles using dino. The chain and tensioner was shot at 110,000 miles. The engine ran pretty well otherwise with little oil consumption and good compression.
 
Joined
Dec 28, 2003
Messages
2,768
Location
Tn
The tensioners are pressurissed hydraulically by the engine oil. I would think the recommended viscosity is important here and also that the oil is relatively clean. The tensioner material is somewhat in itself self lubricating, so I doubt that a "thicker" oil would improve anything. The thinner syn's should still leave a required film and many do this very well. I would think a thick to mid-range 40 wt. might actually cause tensioner problems.
 
Joined
May 27, 2002
Messages
5,069
Location
Saratoga, NY
Wouldn't the boundary additives player a greater role here than weight? In other words, might a moly oil do better than a non-moly oil ... or do the temperatures fail to get hot enough for the moly "uptake" or "plating" to even occur? --- Bror Jace
 
Joined
May 12, 2003
Messages
7,798
Location
Oklahoma
Did someone say Moly??? Have others said that the lack of moly doesn't automatically mean the oil can't protect as well? With a Ford modular engine, seems having moly would greatly benefit you. Maybe that is why Motorcraft oils are loaded with additives to help prevent premature wear. This is also one the things that aren't being analyzed in an oil analysis, at least not for 20 bucks.
 
Joined
Aug 6, 2003
Messages
451
Location
Bribie Island, Oz
The trouble is, does moly have an affinity to plastic or nylon? Will it be adsorbed? The AF qualities of moly is that the platelets coating each metal part slip over one another and cause less friction. If the chain takes up the moly, but the nylon guide does not, does using moly make any difference? [I dont know] Dave
 

metroplex

Thread starter
Joined
Sep 12, 2002
Messages
2,235
Location
SE MI
Since the surface between the chain and nylon guide is NOT bearing-smooth, I would think moly plays zero role in protecting the nylon. [Confused]
 
Joined
May 1, 2003
Messages
9,448
Location
USA
All timing chain tensioners use some form of spring tension to augment the hydralic forces. Most use a cam and rack set up to prevent the tenioner from ever loseing tension. Once these tensioner move out you have to manualy push the little cam in to allow them to be retracted.
 
Status
Not open for further replies.
Top