C6_Racer_X

Anything like Gunk brand "Motor Medic" (Synthetic, optional) Motor Flush, or CRC "Fast Motor Flush."

One of the wife's friends (no pics) has a Chevy HHR with the 2.4L VVT engine. She's been running cheap (Iffy lube) oil, and although she swears she gets the oil changed every 3,000 miles, but the OLMS (same basic firmware as the early C6's) says 38% right now, and the oil looks pretty dirty. This is another engine that specified the same GM–6904 "high performance" oil spec as Corvettes and some of the other "high performance" engines of the era, which at the time that specification was for fully synthetic oil.

She's getting VVT related codes (cams more than 8° different from what is commanded). I'm suspecting the passages in the camshafts and cam phasers are gunked up. I'm hoping a flush and fresh Mobil 1 will fix this. I've seen that clean up engines like this before. I don't have easy access to the chemicals/flush kits I used in the past, I'm wondering what I can find at the FLAPS that might be "good enough."

I really don't want to have to do the cam phasers (basically a full timing chain job) on this old DD of hers.

dmaxx3500

a quart of tranny fluid works[high detergent],ive drained the oil on beaters and fulled with 5 qts of tranny fluid and a new filter,let run for 1 hour[do not drive] then drained that -filled with fresh oil/filter,and fixed sticky lifters/rings too

Snowwolfe

Kerosene works pretty good. Drain the oil and filter. Install new filter, add the correct amount of kerosene. Run for 5-10 minutes. Drain. Repeat with cheap oil and new filter. Drain and add good oil and new filter.

GTOguy

This^^^. And it won't strip the oil off of the bearings and cylinder walls like a solvent will. ATF is basically a super high detergent 15W oil.

White Out

It's a routine maintenance thing for me. But I run a bottle of seafoam in the crankcase on my GF's 1.8T VW (major oil build up problems) and haven't had any oil build up issues since. Prior to seafoam I had to replace the oil pick up, clean out the pan, etc. and she has routinely changed the oil.

C6_Racer_X

I thought I'd come back a week or two later, after I've done the flush and describe what I did.

I got one 32 ounce bottle of "motor medic" from the FLAPS and two quarts of Dex III/Merc IV ATF, plus two quarts of 5W30 (the cheapest available synthetic blend with a "Dexos 2" license #). I drained the thing, but did not change the filter yet. Then I filled with those 5 quarts (Motor Medic + 50/50 mix of ATF and 5W30 synthetic blend). I started the thing, let it run for about 20 minutes, with my scan app/blue tooth OBD-II adapter watching engine coolant temp to make sure it did not overheat. No driving beyond a little bit of "driveway shuffle" with that mix of flush agents in the crankcase.

After running it up to operating temp, and observing the electric radiator fan cycle a few times, I shut it down and drained the thing again. What came out was definitely black and dirty, so the flush agents definitely did something.

Then I changed the filter (who the hell designed that oil filter cap to require a special, extra low profile 32mm/1-1/4 inch socket) and put fresh Pennzoil Platinum full synthetic "high mileage" oil in the thing with the fresh filter and a new filter cap.

Then I cleared all the codes, and took it for a test drive on a few errands. Before I got back, after only 2 or 3 "drive cycles," the check engine light came back on and I had a fresh DTC, P0114 (exhaust cam actuator performance) with a freeze frame, and a pending DTC, P0113 (exhaust cam actuator solenoid fault).

At this point, I'm going to try a new VVT actuator solenoid valve for the exhaust cam. That's an external piece on the back of the head (the exhaust side). It doesn't look too inaccessible (not much worse than the oil filter), and it's a much easier job than the camshaft sprocket/phaser.

I hope it's just the solenoid valve. I really don't want to have to do the camshaft sprocket/phaser. On an engine with over 120,000 miles, if it's the actual phaser, I'd probably just do the timing chain at the same time. That's way more repair than this 10 year old "mommy van" is worth, IMO.