Possible engine sludge. Any good flushes that work

[Charlie]

Have a ’78 F250 with a 460 that was neglected. Last oil came out straight black and cloudy but runny and had viscosity of water. I’m worried about sludge buildup in the engine. What are some good cleaners that work? I’ve heard kerosene, ATF, marvel mystery oil, diesel oil, etc… Do any of those work? What are the effects and how would I do it? My oil pressure also fluctuates but that could be anything. She does smoke but that I believe is a valve issue. I also plan on taking her to 40 weight after the flush. Why do I think it is a valve issue? She ticks and has PLENTY of power.

Topic

[Buggsy]

I would like to add a +1 to high mileage oil. My last car consumed about 1.5 quarts of oil over 2000 miles. After a couple of changes (specifically with Valvoline conventional High Mileage), I was down to about 1 quart over 3000 miles. It wasn’t a cure all, but that was a significant improvement. When my current car rolled over 100K miles, I switched to a high mileage synthetic. I didn’t have any issues to fix, so I didn’t really see any difference between it.

[EricTheCarGuy]

Don’t run synthetic, if you do every seal will leak and you’ll start to burn way more oil. This is due to the fact that synthetic has different flow rates than conventional oil, works great in new engines but is the kiss of death to an older worn engine. Seems counterintuitive but it’s true based on what I’ve seen.

I think you’ve done a fine job so far, let it run and see what happens. When an engine sits for that amount of time the cylinders develop rust in the bores and it takes a while to wear them back in. It also takes a little while for the rings to seat in again. The pressure change you spoke of is normal, as an engine heats up oil pressure will drop due to the oil getting up to temperature, I wouldn’t be concerned with that. My FE did the same.

Thanks for your comments, I really appreciate them.

[EricTheCarGuy]

Don’t run synthetic, if you do every seal will leak and you’ll start to burn way more oil. This is due to the fact that synthetic has different flow rates than conventional oil, works great in new engines but is the kiss of death to an older worn engine. Seems counterintuitive but it’s true based on what I’ve seen.

I think you’ve done a fine job so far, let it run and see what happens. When an engine sits for that amount of time the cylinders develop rust in the bores and it takes a while to wear them back in. It also takes a little while for the rings to seat in again. The pressure change you spoke of is normal, as an engine heats up oil pressure will drop due to the oil getting up to temperature, I wouldn’t be concerned with that. My FE did the same.

Thanks for your comments, I really appreciate them.

[Author]

Replies