Switching over to HM Oil

[Pablo]

Way back when (has it really been 10 years??) I soaked some automotive seals in pure Amsoil flush for days. The seals didn't change at all. I doubt the 10 minutes diluted in the oil wrecked the seals.

I had a 1985 Toyota PU that completely puked it's FMS. Blew oil all over the road. Cause? Toyota had a bad batch of seals. (seal material)

 

[demarpaint]

Originally Posted By: buster
Yeah maybe Bill. However seals weaken when exposed to solvents and that flush was solvent based.



Unfortunately you'll never know for sure, and no company will tell the truth if asked. I was always afraid of anything that could clean up an engine in 10 minutes.

I wonder how a new product is tested to see if it is seal compatible or won't damage seals. Soak seals for a week or a month in it then inspect and call it a day? After the soak are the seals exposed to the same environment they are in an engine for a year or more? Cold, hot, repeat a few hundred times? I doubt it. Maybe the damage occurs over time, and not instantly? A product that's been around for a few years and has a proven history might be a safer bet? JMO

 

[demarpaint]

I often wondered if seals that were marginal, could be holding leaks back via a false seal made from some slight sludge or something else. Now enter the fast flush, and it all gets removed in 10 minutes. Not all seals can go back to their original shape and pliability, after several years in use and stop leaks even with so called conditioners. The product can be 100% compatible and not at fault. Just a thought.

 

[buster]

Yeah who knows. I'll never know. lol.

Sounds like GF-5 is a step forward in overall seal compatibility.

 

[hominid7]

I was initially not a big fan of High Mileage oils, but have since become a convert.

I've replaced my valve cover gaskets twice, oil pan gasket once, trans pan gasket once, and then last year at around 110,000 miles my rear main seal started leaking. I need to get it fixed, but it's rather expensive. I tried Castrol GTX High Mileage oil and to my surprise it has helped a great deal. My first OCI reduced consumption by at least half. I'm now on my second OCI and hope for continued progress.

 

[buster]

I wasn't either. I still don't think they are necessary in most cases, but they have proven to serve a purpose and they do work.

I am surprised they had to up the GF-5 spec to include more seal compatibility.

Engine seals do eventually leak. If these oils do contain higher levels of seal conditioners, and have no ill effects, I think they are good alternatives.

Valvoline created the High Mileage oil. Their Maxlife Full Synthetic is probably the best. According to their website. Maxlife Full Synthetic also has the lowest friction and highest detergent level in their oil line.

 

[ltslimjim]

My sister just got a used Maxima, 1 owner with 230,000 miles. 1995.

Some oil leaks from above, hard to spot where yet but dripping off of some wiring near the oil pan/gasket area. I changed her oil immediately with some SM MaxLife I had from Kmart clearance + Bosch oil filter. We'll see if consistent changes with MaxLife change consumption and/or the leaks around the gaskets. I pulled the old PCV valve, looked like perhaps the factory part? Wasn't working. Lame. Added techron to a full tank.

Anyway, I'll post up results over time if the leaks minimize some at least.