ATS CRO Engine Flush Results

2020 Tundra SR5 2WD: 67,000 miles
-Bought used at 51,000 miles
I used the ATS CRO engine flush to try to remedy that diesel ticking noise and oil smell coming from the exhaust. Figure the last owner wasn't as frequent with oil changes as I am (every 3-5000).

I added the CRO to my engine oil with about 3000 miles on it. Ran it for 10 minutes at 2000rpm per the instructions. Changed oil and filter, drove 30 minutes and then changed oil and filter again to remove remaining CRO cleaner.

Results:
-Drained oil looked like normal. Didn't look jet black like some videos on youtube. smelled strong.
-Oil filter looked no worse for wear. Just smelled of the cleaner.
-exhaust doesn't smell like oil so maybe it cleaned the oil piston rings to seal better.
-*notice a clattering noise AFTER the flush. Sounded like tapping from inside the engine. Don't know how to describe it. Hope it isnt the piston hitting the head.

Photos are the oil and filter after the flush and the oil after draining a second time.

 

I’ve found that working an engine is better than a chemical flush. Hook up a heavy ass trailer and load and go and get it good and hot. Breaks everything up, helps seat rings, and doesn’t send chemicals places they don’t need to be.

 

First two oil changes after i bought the truck:
Metal in filter on first change



glitter in oil after second oil change. Haven't seen any glitter since the second oil change.

 

I use my truck to haul a 4000lb pressure washing trailer most of the time. Usually hour long drives at 70mph (4th gear 3000rpm). Recently did a 3000 mile road trip to florida and back. 80-85mph average.

 

Don't know if this flush messed with any seals however I noticed oil stains on driver side valve cover and under one of the spark plugs.

I pulled out the spark plug boot and didn't see any oil under the gasket or in the boot tube so maybe I spilled some oil in the past. The valve cover is more worrying. I usually dont spill oil. I sprayed some brake cleaner/MAF cleaner and removed the stains. Will check on it next time I drive.

was worried about this damaging the gaskets but everyone else seems to have had no issues. However the extra oil change seems essential. Smelled strongly of the CRO cleaner even after the first change. Will change oil again in 3000 miles.

 

Maybe check your owners manual...But usually manufacturers recommend putting anything but oil in the motor. Most call out specifically against using these chemical cleaners.

Primary concern (other than chemicals having adverse reactions to anything in the motor, such as the plastic chain guides) is that anything that might actually be broken up and dislodged in the motor does not go to the oil filter first...it clogs the oil pick up screen.

As you note the oil does not look dirty originally. If you are worried, pull a valve cover off and take a look inside the motor. Even if the previous owner did 10k mile oil changes, as long as they used decent synthetic oil I'd bet the motor looks just fine inside.

These motors are noisy. Adding a cleaner isn't going to help that. Run 5w30, turn up the radio and drive it forever.