To change or not to change

[Falcon_LS]

The engine in question is a 12-valve Mitsubishi 3.0L (6G72) in my truck - current mileage is 291,000 km (182,000 miles). When I did my valve job at 284,326 km (177,703 miles), I put in 5 quarts of Motorcraft Premium Synthetic Blend 10w30 with a Hyundai 26300-35503 oil filter.

My owner's manual recommends 12,000 km (7,500 mile) oil change intervals, so I reckoned I would run this up to 10,000 km (6,250 miles) before dumping it and finally putting in 5L from my stack of Mobil 1 0W-40 with another 26300-35503 filter.

At the 5,000 km (3,000 mile) mark, I drained a quart of oil from the engine and replaced it with MMO. The oil currently has 6,674 km (4,172 miles) on it, and I can hear my briefly hydraulic lifters ticking. It's not loud, but you can hear them when the sound echoes off a wall or vehicle next to you. I reckon this is because MMO has thinned the oil down.

For the past 6,674 km, the engine has not used any oil at all (checked daily). But I'm wondering if the light ticking of the hydraulic lifters is anything to worry about.

Should I just go another 3,000 km (1,875 miles) on this oil or just dump it out now?

Thanks!

Edit: Correction - it's a valve lash adjuster, not a hydraulic lifter.

 

[ryan2022]

Well, I wouldnt say its anything to worry about, but I drive a Jeep, so ticking is a reassuring sound to me. LOL.

If youre concerned, change it out early for the 0w40.

If youve gone over 6K on the current oil, youve still gotten a good bit of use from it.

By valve job, do you mean, valve seats/ springs etc..? or an adjustment.

If youve replaced parts, I'd probably dump it and refill.

 

[panthermike]

It could be the thinning, it probably would have been better to use 40wt. oil with the MMO. I would run it a little longer and see if the tick goes away with the Mobil 40 wt oil. If it doesn't, it's probably something else. But it could be the MMO, since you're running about a 20 wt. oil now with it in there. Still, I would leave it in maybe 500 more miles and let it clean some more.


Edit: Just noticed you've had it in for 1,100 miles, which is adequate for it to work. Maybe dump it then. In the future though, use a Xw40.

Good luck and keep us updated.

 

[mechtech2]

Adding the thin MMO would almost certainly cause more ticky noises.
Were you trying to clean something in the bottom half of the engine?

 

[addyguy]

Just run it the full 10k km interval you wwere planning. Give the MMO some time to work.