Synthetic Oil and Engine Computer Systems

[ConfederateTyrant]

When I first began using Amsoil back in December 2004 I had an odd thing happen, I have taken care of it since then but just wanted other's input on what would cause this and has anyone else had any similar issues.

All I did was flush the engine and put in Amsoil 5w30. Next morning I went to crank the car and it stalled out immediately, so I cranked it back up and it rumbled for a moment then everything was ok. I let it stay like that for a week then I talked with Amsoil tech support and they suggested disconnecting the battery to reset the computer because of it being the engine's first time using a full synthetic. That definitely fixed it, also had to do the same with the Amsoil ATF so it could relearn the shift points.

I'm just curious, any explanation for this? Has anyone else had any issues like this? Any similar issues with Mobil 1, Castrol Syntec, Pennzoil Platinum, Valvoline Synpower, etc?

 

[mechtech]

Your problem was almost certainly due to the flush, and not the Amsoil. Residual solvent in the ring area and CC caused the problem.
Normal driving will accomplish the same thing as resetting the computer, over a little longer time, BTW.

 

[brianl703]

Some transmissions can adaptively compensate for the frictional properties of the transmission fluid as well as wear, apparently by monitoring how long it takes for a shift to complete and adjust pressures and solenoid duty cycles to compensate.

It's been suggested before by others on this forum that disconnecting the battery after a transmission flush is a good idea because of this. (Assuming, of course, you know what your radio's anti-theft code is if it has one..)

 

[ConfederateTyrant]

Mechtech, I did about 500-550 miles of driving, 400 miles were a long highway trip, before I disconnected the battery. Up until then it continued to stall every time when the engine had sat for at least 4 hours. I figured the continuous RPM and heat would help vaporize any solvent that was left in the engine, but as you mentioned, it may have just needed to go a little longer. BTW it was the Amsoil engine flush, I was uneducated about it at the time, but my engine is sparkling clean when looking through the oil fill hole.

What would the flush do to cause this?

As for the transmission, I disconnected the battery quickly, but my transmission was downshifting unecessarily and noticeably when coasting. So I disconnected the battery for a couple of hours and it no longer did that.

Thanks for the info everyone.