Thick oil, engine knock?

[jstutz]

When using thick oils and you notice a knocking sound that sounds like its deep in the engine, what exactly is that noise? It sounds like the knock you get when you spin a bearing or something. It only lasts a few seconds and only when its cold. Just curious, my friend at work has a old 350 with over 200k miles on it and he uses 15w40 in it most of the time. He said it usually has a low knocking sound upon initial start up. Well he was out of town and his wife had the oil changed when she was out with 5w30 and now there is no more lower knock upon startup.

 

[Nick R]

Lifeter perhaps? My 2.2L has a very loud, clear lifter tick with thicker oils. Thinner oils it goes away. Could perhaps be the same thing, but then I've never heard what a spun bearing sounds like.

 

[Eddie]

Oil is to thick to reach bearings quickly on cold starts.

 

[OVERKILL]

Maybe she used a different brand filter?

 

[FL_Rob]

Maybe she knows more about engines than he does.

 

[StevieC]

Originally Posted By: Eddie
Oil is to thick to reach bearings quickly on cold starts.
No I have used 0w20 in my engine and had the same problem in the summer time after the vehicle has sat for a full day without being run.

It's lifter noise and nothing to worry about. I have UOA's to prove it.

I have also tried thick thick oils / thin thin oils to try an get rid of it. Now I live with it.

Turn up the radio.

 

[MrMeeks]

My Ford had bearing knocks at startup when I used those famous oil filters marketed nearly everywhere.They are painted orange.Now using Motorcraft filters with no problems.Best filter for the money.Amsoil sells a very good filter-they are expensive.Why use a 'thick' oil in modern cars? If and engine has worn noisy bearings and a differrnt filter and thinner oil won't help quiet the bearings try a can of 'RESTORE' oil additive.This additive requires about one week of driving to fully work.

 

[Johnny]

I want to know what your friend said when his wife had the oil changed with 5W-30 instead of his 15W-40.

 

[daves87rs]

Originally Posted By: Johnny
I want to know what your friend said when his wife had the oil changed with 5W-30 instead of his 15W-40.



Me too..

 

[sangyup81]

the 40 i'm ok with but why 15w? it's so easy to find good cheap dino 10w40 and synthetics like 5w40 and 0w40 are out there!

 

[jstutz]

Originally Posted By: Johnny
I want to know what your friend said when his wife had the oil changed with 5W-30 instead of his 15W-40.


I dont think he cared much. He uses HDEO is everything he has because he gets it really cheap. He works at a diesel engine shop so i think he gets it " really cheap".

 

[mechtech2]

If the knock is new, and from the oil change, it is from an improper oil filter [drain back qualities], or oil being to thick at cold start up.
Or both.
Rods can knock, or lifters can tick for a while. Rods generally don't knock like this unless they are already problematic - it is rare.
So a lifter tick is what I suspect as #1.

 

[jstutz]

Originally Posted By: mechtech2
If the knock is new, and from the oil change, it is from an improper oil filter [drain back qualities], or oil being to thick at cold start up.
Or both.
Rods can knock, or lifters can tick for a while. Rods generally don't knock like this unless they are already problematic - it is rare.
So a lifter tick is what I suspect as #1.


The knock is not new. He said it has done it for a long time. It just went away with the lighter oil change. Ill have to ask him what filter they put on there. I wonder if he will stick to the lighter oil now that there is no knock?

 

[crazyoildude]

i would not use a 15w50 i would use no heavier than a 10w40 in that engine

 

[mechtech2]

Doctor, it hurts when I do this.

Then don't do that!


Your friend should consider how the thinner oil shows clear benefits.