Additive to help quiet a bad wrist pin?

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Originally Posted By: Trav
Are you 100% sure its a wrist pin making the noise?


yes sir. the noise pitch is right between a valvetrain noise and a bottom-end noise. i also had a mechanic diagnose the noise, who has seen this problem and that exact same noise before on another LD9 twin-cam motor just like mine. plus, countless youtube videos of bad wrist pin noises match my noise exactly.
 
I would question the diagnosis first. Most real wrist pin failures will normally quickly go catastrophic and fail.

Have you pulled the spark to that cylinder?

I can easily believe you could quiet it down but if there's already excessive clearance it may be time to plan for a rebuild.
 
Originally Posted By: Klutch9
Originally Posted By: demarpaint
Glad the Lucas worked, it did at the dealership I worked at. I'd change the oil in 3000 miles, you'll notice if you don't add the Lucas back the noise will return. All it is doing is masking the sound, you might find in a 1000 miles or less the noise could return, and it might not. These types of repairs are hit or miss
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I was thinking 3,000 miles for the OCI as well. But for the next fill, i was considering maybe a 15w-50 or something similar for the fill? what is it about Lucas that quiets noisy engines... is it simply the viscosity, or is it the stuff in Lucas that makes it cling to every surface and makes it all gooey and stretchy that makes engines quiet?(anyone who has ever poured a bottle of Lucas knows how clingy and sticky this stuff is). because if it is simply the high viscosity that makes Lucas the noisy engine cure, then maybe i'll try a really thick oil instead, no additives. hmm. anyone have any guesses?


I think it is the viscosity, and the fact that it seems to cling to metal with a thick gooey consistency. It sometimes acts like a thick insulation blanket muffling noise. Many wholesale units went out with Lucas Oil Stabilizer in the sump were I worked.

I had a used car manager that decided there was a lot of money in selling high mile trades instead of wholesaling them. He convinced the owner and GM of the Honda Dealership I worked at to try selling these high mile Gems. Something they never did because they felt it would hurt their rep, [they were right too!] I remember a clean Civic ~110,000 miles with a low end knock that was sent to the shop for some work to get it ready for the line. The mechanic called us and said the engine had a knock, do we want to wholesale it or try and quiet it down to sell. Naturally the manager said get it ready for the line as cheaply as possible. In went the Lucas, it worked, for a while. Funny thing was about 2 months later the guy came back complaining he heard a knock just after changing his oil. The used car manager sent the guy packing since his 30 day warranty was up, the customer went to the GM and they ended up cutting him a deal on another car. He was one of the lucky ones. We stopped selling high mile cars................
 
Originally Posted By: SteveSRT8
I would question the diagnosis first. Most real wrist pin failures will normally quickly go catastrophic and fail.

Have you pulled the spark to that cylinder?

I can easily believe you could quiet it down but if there's already excessive clearance it may be time to plan for a rebuild.


i'm not so sure of that. it may be true, but i've heard that when it comes to wrist pin failures, it'll either fail immediately or last a really long time. for example, in my situation, my wrist pin noise has been occurring for the entire 40,000 miles i've owned this car, and who knows how long it was occurring before i took ownership. i suppose all i can do is hope for the best at this point. other than the wrist pin, this car runs great. the transmission is spot-on, fuel economy is very good, and all-in-all it is a sound automobile. however, considering what i paid for the car and what it is currently worth, i would never invest in a rebuild. if i could find a good running motor out of another car for a reasonable price, i'd definitely consider that, and i'd swap the motor myself to make it more economical.
 
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If its a little quieter then run it until you can get a good used engine,no rush.Wrist pin noise usually goes on for a long time from what i have seen over the years. Not as common a noise these days as it was years ago,piston slap seems more common but that's also noise can go on a long time, or indefinitely.
 
Originally Posted By: Trav
If its a little quieter then run it until you can get a good used engine,no rush.Wrist pin noise usually goes on for a long time from what i have seen over the years. Not as common a noise these days as it was years ago,piston slap seems more common but that's also noise can go on a long time, or indefinitely.


I agree 100% on the piston slap issue. In fact, some engines are designed to have piston slap. My dad has the 3100 V6 in his '95 cutlass supreme, and that thing piston slaps like mad on a cold start. funny thing is, GM designed it that way to avoid "hot points", or something to the like, on the piston rings. on later versions of that same engine, they found a way to sound-deaden the piston slap somewhat. which is good, because boy is it loud!
 
There isn't anything that is going to quiet a wrist pin knock. The only thing thickening the oil will do is make the engine last a little longer before that wrist pin seizes and destroys the engine.

That is IF it is a wrist pin knock. The same advice applies to a rod knock or a main bearing knock. No oil is going to stop a serious mechanical failure.
 
Originally Posted By: Boss302fan
A heavier oil and a shot of moly may extend the engine life...


already been there. i have some lubro moly mos2 at home. i added it at the beginning of my last 2 oci's but not on this one, since i personally didn't perceive any difference when using it. i'm not saying it didn't help though. one nice thing about the moly is that you dont necessarily have to use it in every oci. since it embeds itself into the friction surfaces, the moly from a previous oci is still hard at work for at least a good portion of the next oci IMO.
 
You might also consider Schaeffers #132. It is on my short list of additives, and works quite well. It is actually a good additive, and might be worth looking into.
 
Originally Posted By: demarpaint
You might also consider Schaeffers #132. It is on my short list of additives, and works quite well. It is actually a good additive, and might be worth looking into.


how is it different from the lubro moly mos2?
 
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