M1 HM---maybe good results

[lukejo]

For 200k miles the Ford has had a steady diet of MC syn-blend 10w30 then 5w30. I was having small leaking in the rear main and the oil pan gasket. It looked like maybe 10 drops or so on the pavement after each time it was driven. Last OC I put in M1 HM 5w30. After 2,000 miles, I see absolutely no drops or sign of leakage...for the last 500 miles.
It might be too early to praise the success, but no doubt there is a change. I guess the M1 HM 5w30 is thicker than the MC 5w30, but I can't imagine that small difference would stop the leaking.

 

[Kuato]

In reading an article about synthetic oils several years back, the premise was that a conventional will form a slight crust, or hardened ring of oil, around a seal. Then that crust is what is making the seal and since it's not flexible it allows some leakage.

When a synthetic (or any good cleaning oil IMO) is introduced, it removes the deposits and exposes the seal, which then results in no more leakage...at least when the seal has not mechanically failed. I've seen this in more than one older vehicle.

 

[GaleHawkins]

Thanks for posting your results. M1 HM is a great oil.

 

[lukejo]

Yep, I'm surprised and encouraged to see such good results....especially having the documented history of MC syn-blend every 3k....and I read a lot more about VML and even PHM stopping leaks than the M1 HM. I'll update in another 2k or so.

 

[LocoTex]

I've been running M1 HM 5w-20 in my truck for the last couple oil changes. I didn't have any leaks before, just trying to prevent them. The oil seems to really seems to run well in my 5.7 hemi. Maybe it's just in my head but I'm pretty confident in M1.

 

[dlundblad]

I had about the same results when I ran M1 HM. Compared to M1 TDT, my Jeep ran fairly quiet once warmed up too.