API SL to SM Oil Problems

[Tiggie]

I'm I the only one in the world who gets death sounds coming from motors after I change the oil from SL to SM?

I switched the Ranger over about the time SM came out. Immediately, the 4-banger started making a new sound - like a wet sloshing. I posted on several Ranger forums and no one had any recommendations. I've put 15K miles on it since and it still has the sound, but it runs fine and oil pressure is fine.

I switched the wagon over this weekend. Now it has a loud grinding sound for the first five minutes of running. It sounds horrible. I use Pennzoil conventional 10W-30. It's still holding 25psi of oil pressure hot.

I just would like to know if anyone else has had this problem. I know roller lifter engines aren't supposed to care if they get SL or SM.

[gadget73]

I've heard of increased flat tappet failures with more recent oil formulations, something with the removal of zinc from the oil but I don't know about roller motors. I haven't noticed any new weird noises from my car or truck with recent oils tho.

[85crownHPP]

whats SL and SM???

[Heretic]

Explaination: http://www.calsci.com/motorcycleinfo/API.html

[Tiggie]

So I'm the only one... somehow I figured that.

I'll get a sound clip later this week and maybe you all can help me out with some recommendations. It just sounds aweful.

[Grandmarchris]

Never noticed a difference with my 4.6.

As for the flat tappet cam failures a few years ago the EPA made everyone remove zinc from their oil. Just recently diesel oil has removed their zinc also so the days of running Rotella 15w40 in your hot rod is over. However cam companies are producing additives to combat the issue.

[Tiggie]

Okay, got the video. It's Windows Media, so some of you without Windows might not be able to view it. I have an .avi version too, but it's 249MB...

http://www.grandmarq.net/tiggie/88Tap-Knock.wmv

You can really start to hear the noise well about 30 seconds into the video.

[Nathan in MI]

Hard to tell just by listening to the video, but it kind of sounds to me like a collapsed lifter or three.

[gadget73]

I'd agree with that guess, worn out lifters tend to click and rattle a bit. You're not by chance running some really thin oil are you? That could also contribute to funny noises in an old motor.

[Tiggie]

Running Pennzoil 10W-30. I was running Mobil 10W-30 before the oil change and the motor ran really quiet.

It just bothers me that there was not even a hint of this sound before the oil change. I may change it back to Mobil.

[Tiggie]

Anyone have any recommendations on an oil additive? I'd like something that gave me the zinc back and didn't make the oil thicker.

[86GmLsCoupe]

I've had good luck with the 4 qts. Mobil One 10w-30 and one bottle of the Lucas. The Lucas is probably a waste, a little expensive, and I'm pretty sure it will make the oil a little thicker. Been doing the Mobil/Lucas combo for awhile now but I may try one change without the Lucas. I think you would do alright just running Mobil One 10w-30. I had heard about "miracle additives" that supposedly add metal to worn engine parts (zinc?) but I don't think thats possible. What was the zinc's purpose in the oil in the older formulations?

[Tiggie]

What was the zinc's purpose in the oil in the older formulations?

Generally from what I've heard, it helps protect flat tappet lifters and cams (especially during break in).

[P72Ford]

This is true; it acts as a "cushion" from what I've read. Lots of magazines I have been reading lately have been focusing on the issue of changes in oil composition; I have found it to be interesting reading. Zinc is important as an antiwear component as well, especially on older engines.