can slightly low oil volume cause valve clatter?

[snowshew]

I have a 2009 Elantra with 55k miles that has been making top end noise for years. It has always seemed to be a clattery engine. I noticed in the manual that inspecting the valve adjustment was recommended at 60k so I thought I would bring it to a shop to have it checked out. They kept it overnight and gave it a listen and determined that one sound that I was hearing was probably a wrist pin, but they noted that the oil was a bit low and they added 3/4 quart (it has a 4 1/4 sump) and once done the other clattery sounds went away. I can't verify that it was low on oil (if I knew it needed oil I would have filled it of course) but it does seem quieter now. (Aside from the slight knocking sound.) There was only several hundred miles on the oil change and I really doubt it was down that much. Anyway, the dipstick reads "1 qt" between the full dot and the low dot and it is at or above the full dot now.

Aside from the fact that it does seem a bit quieter now, is there any validity to the claim that a somewhat less than full oil pan can cause the valvetrain to clatter? This seems comical to me. How would the top of the engine know how much oil remained in the pan so long as there was volume there to be pumped? Again, it was only slightly lower than full.

Also, is there anything I can do with oil choices for a loose sounding wrist pin? The manual says 5w20 or 5w30 for my temps. Would trying a 5w40 be any value to longevity if there is play in some components like rods?

 

[vavavroom]

Common causes of valve clatter with hydraulic valve lifters include

- low oil pressure
- initial phase of the cold engine coming up to operating, which is common with some engines temperature
- defective ADBV
- defective oil retention valve(s) in the had

or the engine requires valve lash adjustment in the case of non-self-adjusting lifters

 

[FowVay]

This vehicle uses shim-over-bucket lash adjusters and is unaffected by oil quantity. It's not a hydraulic system.

If the valve clearance was outside of specification then it takes a replacement shim to correct. Adding oil to the sump does not correct this issue. You might have a clearance issue but unless someone takes it apart and uses their feeler gauge to check it then you will never know.

 

[Lubener]

What is more likely to cause lifter noise is aeriated oil from being overfilled than just being down a quart.

 

[dlundblad]

Is this the picky model of engine that only likes OE filters?

I agree the low oil shouldn’t have caused an issue assuming it was within the allowed lines.

 

[Propflux01]

Those engines in that era are pretty much bulletproof., except for the filters. They don't like aftermarket filters. I first try OEM if it isn't already in place. IIRC, Adjusting the valves requires the removal of the camshafts and replacing shims, and they are usually not an issue. What oil weight are you using? THose engines "like" 5w-30 much more than 5w-20.

 

[Jetronic]

I have a 2009 Elantra with 55k miles that has been making top end noise for years. It has always seemed to be a clattery engine. I noticed in the manual that inspecting the valve adjustment was recommended at 60k so I thought I would bring it to a shop to have it checked out. They kept it overnight and gave it a listen and determined that one sound that I was hearing was probably a wrist pin, but they noted that the oil was a bit low and they added 3/4 quart (it has a 4 1/4 sump) and once done the other clattery sounds went away. I can't verify that it was low on oil (if I knew it needed oil I would have filled it of course) but it does seem quieter now. (Aside from the slight knocking sound.) There was only several hundred miles on the oil change and I really doubt it was down that much. Anyway, the dipstick reads "1 qt" between the full dot and the low dot and it is at or above the full dot now.

Aside from the fact that it does seem a bit quieter now, is there any validity to the claim that a somewhat less than full oil pan can cause the valvetrain to clatter? This seems comical to me. How would the top of the engine know how much oil remained in the pan so long as there was volume there to be pumped? Again, it was only slightly lower than full.

Also, is there anything I can do with oil choices for a loose sounding wrist pin? The manual says 5w20 or 5w30 for my temps. Would trying a 5w40 be any value to longevity if there is play in some components like rods?

The only way I see oil volume having an effect on mechanical noises, besides being so critically low that the pick-up draws air, is if the lower volume impacts oil temperatures. Oils heat from shearing and on the pistons.. Maybe somewhat on the cylinder walls aswell. They cool down while draing down to the sump, while sitting in the sump and while being pumped and filtered. Low volume means the oil spends less time in the sump, so has less time to shed heat. This could lead to higher oil temperatures and less viscosity.

On engines with dedicated oil coolers this would be less significant, the coolers become more effective when hotter oil enters them.

I believe increasing viscosity after play has developped is of limited value, it could muffle the sound somewhat but a loose pin will have accelerated wear going forwards regardless.

 

[Graham Piccinini]

can slightly low oil volume cause valve clatter?

YES.
That answer comes from personal experience with 40-50 vehicles. Some of my friends and family aren't the best on keeping their oil level correct. But 9 times out of 10 I can hear that valvetrain clatter, and checking oil level reveals 1-2qts low. I top it off and it's instantly back to quiet. Until the oil level drops again.

Because of this I do not follow the common practice of simply filling the oil halfway between ADD and FULL marks on the dipstick, but always fill it to the FULL mark.

Not every engine I maintain does this, but good half of them are just more sensitive to oil level, and start that valvetrain clatter once the level gets near the ADD line on the dipstick. This is not isolated to a single manufacturer, or certain engines, or certain engines configuration.
So top it off and move on.
That 2009 Elantra is the last of the good Hyundai, in my opinion. Simple, comfortable, cheap, and both engines and transmissions last 200k-400k miles with basic maintenance, including a timing belt every 100k miles.

 

[BigCahuna]

When your engine is running, all the engine oil is not being circulated thru the engine. In a 4 qt capacity engine maybe 1 1/2 qts may actually be being pumped thru it at any given time. There's always residual in it.. You can check for a bad wrist pin, pull the spark plug wires one at a time until the noise goes away. I would doubt that's your problem as they usually get louder, more like a knock, the more the engine is driven.,,

 

[snowshew]

Thank you all.
I used 5-20 for the first 10 years but switched to 5w-30 for the last 4. I bought it new. It has always had a Napa Gold filter every 3-4k miles, sometimes that is every other oil change. I have always just poured 4.25 in without paying close attention to where that landed on the dipstick and then just checked it six months later to see that it was still between what I presumed to be "full and add" (the upper and lower dot). I'll repeat this procedure for the next change, note the sounds and level on the dipstick then fill it to the top dot if not already there and see if there is a change. If still clattery I'll look into a Hyundai filter.
I plan to keep the care for another 10 years, which might only be 25k miles. It has a new brake fluid and I'll replace the coolant and probably plugs and wires this summer. Anything else I should be looking into for a vehicle this old although low miles?
Thanks again.