Sludged Engine Cleanup

[waypoint]

My project '07 Limited was neglected for 164k miles with oil change intervals averaging 25k miles. The original owner sold it this year (cheap!) when the P0016 valve timing error code prevented it from passing inspection, dealer quoted him a new engine. See my other thread for what was lurking under the valve covers...yuck.

I've been running Quaker State synthetic 5W-30 the past 2 oil changes, adding 6oz of Marvel Mystery oil the day before each oil change. Most recent change is shown in the pics below...2100 miles on this oil fill, the oil on the dipstick was dark brown again.

The oil & filter seem to be doing the job here. The coffee filter was inserted into my funnel, and the contents of the oil filter can were poured through it after it was cut open. The black goop in the center was left after sitting overnight, too thick to pass thru the filter.

This was the 5th oil change over nearly 9k miles since I bought it. First oil change was with Shell Rotella T6 0W-40 diesel truck oil and it really busted sludge, but it's very thick for cold weather use in this engine. QS synthetic oil has nearly as much calcium detergent, and plenty of antiwear additives. And it was on clearance at Advance Auto for cheap. Goal is to gently minimize the sludge before I open it up next year to replace the stretched timing chain, so the new chain isn't bathed in soot particles.

 

[Whammy]

Yuck!

 

[blackoutt]

Posting in here so I can find it later. I have a buddy with a V6 and p0016 right now trying to figure out if he really needs new timing chain or just clean the sludge he saw when pulling the valve cover on the new to him 4th gen. My recommendation was exactly what you're doing with the syn oils, detergents, and frequent changes but still not a guarantee. Good luck!

 

[Bumbo]

Made me think of this.

https://www.youtube.com/watch?v=o9RttyUQiws

https://www.youtube.com/watch?v=J-SC4OIb-I0

 

[techno]

I have an intermittent P0016 at the moment. Comes on for day, then is off for several weeks. Might have to look closer at my engine oil health after seeing this, but hoping it's a sensor issue first.

 

[waypoint]

Posting in here so I can find it later. I have a buddy with a V6 and p0016 right now trying to figure out if he really needs new timing chain or just clean the sludge he saw when pulling the valve cover on the new to him 4th gen. My recommendation was exactly what you're doing with the syn oils, detergents, and frequent changes but still not a guarantee. Good luck!

Good luck on your friend's vehicle, but it's unlikely cleaning out sludge will correct the P0016 unless the VVT oil passages in the intake camshaft and/or the OCV filter are obstructed.

Easy way to tell if the chain is stretched: remove the small 4-bolt cover plate on the front of the timing cover, just above the power steering pump. Stick a mirror or your phone camera in front of it and get a view of the timing chain tensioner. If the piston is over-extended as shown in the pic below, it's stretched. Mine runs well even in this condition, as long as I let it warm up in the morning after the first start each day before driving off. If not, P0016 and the check engine light are guaranteed.

 

[2UZ-FE]

Pennzoil conventional (PYB) on short OCIs of about 1500 miles. I wouldn’t bother using synthetic as a “clean up oil”, short OCIs on a good conventional will clean out without denting the wallet too bad.

 

[ghs215]

I would do 1/2 cheap oil and 1/2 Oil Eater® Cleaner & Degreaser.

That should do the trick :fear:

 

[waypoint]

Pennzoil conventional (PYB) on short OCIs of about 1500 miles. I wouldn’t bother using synthetic as a “clean up oil”, short OCIs on a good conventional will clean out without denting the wallet too bad.

A fellow BITOG'er! I went to Wal Mart to get PYB but found QSUD at $19.99. $4 didn't dent the wallet much...and then QSUD went on clearance at Advance Auto so I stocked up. My work commute averages ~430 miles per week and I've been changing at ~1300 mile intervals, this last OCI was the record long thus far. It's a good commute for engine cleaning, lots of time for hot oil to circulate.

This fill is Amsoil SSO 0W-30 which I've had in the stash for years and no other vehicles I'd want to use it in, we'll see how it performs. Seemed best suited to the upcoming cold weather, and I'd prefer a longer OCI over the Winter...I'll change the filter based on oil coloration change.

 

[Montego Murph]

In the Miata community, we do something called the 2Twisty Engine Cleanup when the valve lifters tick. Maybe a variation of this would help clean the buildup out of this engine?

You'll have to increase the fluid proportions for the larger engine. Our capacity is 4 quarts, so we use 3 quarts of store brand ATF, and 1 quart of SAE50 oil.

Drain the engine oil, install cheapo oil filter and pour in the fluids. Idle the engine for an hour or two.

When done, drain (and let it drip out for 30 min or so) then change the oil again with your usual products.

For extra credit, disassemble the old oil filter to see how much crud it dislodged.