Ok, ive read all the posts about synthetic versus non-syn, I havent found any mention of damage from use of either one. Aside from sludge buildup and ash deposits. But I have a problem and i want to know if mobil one is to blame.
First let me describe my setup for a better diagnosis; I have an '84 GSL with a stock port S5 turbo II engine and tranny. I'm running a t04b turbo and front mount intercooler, bigger injectors, 3" exhuast, etc. Also I removed the factory oil injection and now run premix in the gas. The engine in my car is Mazda remanufactured engine. I just broke it in for 1100 miles on good 'ol Castrol GTX 10w-40 and 1/2 a quart of Lucas oil. I broke the engine in smoothly and never got on it. The other day I changed the oil for the first time and replaced it with Mobil 1 10w-30. Now broken in and with fresh oil, it was time. After running the car hard for about 30 minutes, I stopped at my house and let her idle to cool down.
THAT'S WHEN I HEAR " THE NOISE". It sounds like an intermitant squeeking, screeching, somewhat high pitched. THe noise is not constant, but rather pulses. It sounds like one screech for each revolution. At first I thought maybe it was my injectors or a loose belt or a small vacumm leak. But the sound seamed to be coming from back by the starter or the vent in the tranny bellhousing. With a long flexible hose used like a stethascope i quickly ruled out the starter. So I decided to take off the access cover to the tranny bellhosing. As soon as the cover is out of the way the noise gets louder, much louder. The noise is definately coming from the bellhousing. I quickly ruled out the tranny input shaft by pushing in the clutch. The noise didnt stop or change tone. This means it must either be the pilot bushing or the rear main seal. The strange part is, I never heard the noise before i changed the oil and got on it ( the car). And the noise does not effect performance.
My dilema is, could Mobile 1 have cuased the seal to swell and start making this noise, or could more horsepower cuase the pilot bearing to wear faster or become damaged. Will switching back to conventional (dino) motor oil solve the problem, or will it just go away and become a small leak. Or worse, could my engine be in danger. Has anyone encountered this before or have a theory? All feedback will be GREATLY APPRECIATED!!!

 

No.

 

Thurst bearing.


Michael Smith

 

Should I pull the tranny and replace the thrust bearing or say f%$k it?

 

iv had the same problem if you dont replace the bearing is just gonna get louder and louder

 

Sounds like you need a new spiggot bearing...

 

replace both the thrust bearing and the spigot bush while you have it apart. To remove the spigot bush fill it with grease and using a bolt the same diameter as the spigot drive it with a hammer your spigot bush will come out onto the bolt (hydraulic pressure).

Regards
Michael Smith

 

****!!! I hope this is not the same problem i'm having...............I hear the same noise and i cant figure it out...............

 

New update folks. It was my pilot bushing/bearing. I had my crankcase vent hooked up to a vacumm source. Someone told me this will keep oil from coming through the oil seals on the sides off the rotors. It did that, and kept oil from properly lubricating the rear main seal and pilot bearing. I capped the port on the manifold that i had hooked up to the crankcase vent. Then i ran my crankcase vent to a catch can, and vented the can to the atmosphere. Violla, no more squeeky, squeeky. And there seems to be no oil leaking by my oil seals. It is odd however that the bearing never made a noise before i switched to MOBIL 1. All is well now. Thanx for the support guys, it made me think in new directions.