Synthetics Incompatible with Certain Bearings?

[Mickey_M]

quote:

---

Originally posted by Terry:
I know of no currently available "synthetic" automotive lubricants that would be harmful or incompatible with any bearing or for that matter seal materials in engines built in the last 20 years.

---

Bearings, yes.

Although I hesitate to mention it, given the heated "discussions" on it I read in the archives, if you had the opportunity to look in the warranty files of automobile manufacturers, you'd find ester based synthetics overrepresented in claims involving seals and gaskets over the last 20 years.

Among the companies with one or more caveats in their owner manuals and/or service bulletins are Isuzu (largely with their diesels) and Mazda, and this is based on field experience, not theoretical considerations.

I would also be hesitant using some synthetics in engines with origins in Eastern Europe, Russia, or China where the gasket and seal materials may resemble American engines circa 1939.

 

[QuadDriver]

only 2 things and get rid of the lead in a bearing: direct wear, which would be caused by lack of oil, rather than makeup, or chemical reaction. I would *hope* that no oil OR additive sold would not be chemically reactive with any metal....kinda defeats the purpose ofa lubricant no?

 

[kbohip]

quote:

---

Originally posted by Silverado:
I called Blackstone Labs the other day about an oil analysis I had not recieved yet, so he went over it with me on the phone. I have continuing high lead #'s in my analysis which worry me. He continued to say that some bearings are just incompatible some synthetics. Is this true? I will post my UOA as soon as I get it, but I have never heard of this phenomenon regarding bearing wear.

---

I've now had two seperate samples come back from Blackstone saying my lead was too high. The funny thing is though, this was on two identical engines of almost the same mileage. One was using Mobil 1 5W-30 and the other was using regular Pennzoil 5W-30. The synthetic engine read 6 for the lead and the Pennzoil engine read 8. Keep in mind the Mobil 1 had 3k miles on it while the Pennzoil only had 2,500.

This leads me to believe that synthetic is not the problem.

 

[Geoff]

I guess I have seen this thread before and others have posted possibility of machining defects in the crank or some such. eg the oil holes may not be smooth around the edges or maybe too much crank end play and its bouncing fore and aft a bit stressing the rod/crank bearings and thrust bearing.

What kind of bearing cap bolts are you using? (Some hold only at the top of the bolt and get thinner down the shaft allowing the caps to move primarily in 2-bolts). Are they cross bolted? Were the clearances checked with plasti-gauge?