Piston Slap: Tribulations of a 4.4-quart Oil Pan?

.

William writes:

Sajeev,

It is good to have another reason to contact the great and gracious Sajeev with a question that is more vexing than choosing the wrong flavor of Crest toothpaste at Walmart. (Not. Worthy. – SM)

I recently had my 2008 Acura TSX in for a filter and oil change at my local Oregon Honda dealer.

I requested that the oil being put into the car not exceed the maximum mark on the dipstick after the car had sat long enough to get an accurate reading. This occurred during the previous oil and filter change, leading to a most amazing conversation with the Honda Service Deptartment supervisor types.

I was told the oil would get thinner when warmed up, so it was not a problem that the oil level when cold was about 1/2 inch higher than the maximum mark on the dipstick. This would equate to around 1/2 quart of oil, maybe more. I could see the service dept. was up to its tush in cars, so I chose to leave the scene. Several days later I bribed a Jiffy Lube with Hostess cupcakes to drain off the excess oil.

This time around I took the car back to the dealer and discussed the excess oil with no intention of bribing anyone with Hostess cupcakes. The same service supervisor, who explained the thinning oil theory previously, determined that all of the oil would be drained and then refilled, but at a lower volume.

Honda’s service spec calls for 4.4 quarts of oil with a filter change for this 2.4 liter four-cylinder engine. It turns out that putting in 3.9 quarts without a filter change puts the oil level at just below the maximum mark on the dipstick. This led the Service person to conclude that a new filter would not hold 1/2 quart of oil. This leads me to believe Honda is choosing to overfill the engines with oil when doing an oil and filter change.

Please offer your humble opinion about this possibility and allow the best and brightest to bloviate at will concerning this issue.

Sajeev answers:

I consider myself lucky I’ve worked on only one vehicle that eschewed whole numbers when adding engine oil. Plus, it used a full half of a bottle (so to speak), at that.

Regarding the K24’s half-inch too high dipstick reading, I reckon you were charged for a full five quarts and someone ensured you got every penny of it. Who knows why, but it should have been fixed (i.e. drained) upon your initial discussion. I spoke to TTAC commenter psychoboy, a genuine Honda guru, and he agreed. He went further, suggesting it’d take an extra quart (5.4 quarts total) to foam things up via crankshaft aeration to seriously damage your engine. He is not alone in this assumption of you being in the clear.

But he also noted, “might not hurt anything, but still not good.”

I doubt Honda Corporate approves of your experience, and I’m glad the thinning oil malarkey wasn’t thrown at you a second time. So, trust but verify…if you own a vehicle that still has a dipstick.

[Image: Acura]

Send your queries to sajeev@thetruthaboutcars.com. Spare no details and ask for a speedy resolution if you’re in a hurry…but be realistic, and use your make/model specific forums instead of TTAC for more timely advice.