8.1 L Starting Problems, Vibration at 2100rpm

sutak · October 8, 2002

I have two major problems with the 8.1L engine. Whenever I pull in the gas station to fill up, by the time I'm done paying for the gas, the starter barely turns over the engine or may start on second attempt only. I didn't get stranded yet. However, I would expect that the starter would have plenty of power to turn over the engine. I'm on the third starter now and they all behave the same. GM does not have a cure for this and I am getting tired of taking in the truck to change the starter.

Any solutions for this? Someone suggested to place a heat shield over the starter. The starter works fine immediately after the engine was shut off but not after a 5 minutes wait.

My other problem is that the engine has a vibration at 2100 rpm in all the gears. I wonder if this vibration has something to do with my oil consumption. I find that, whether the truck is loaded or not, my oil consumption is not related to that. I use 1 qrt of oil per 1000 miles. I suspect I will have to live with this. At least it slows me down and usually drive at 60 mph.

I guess I should mention the transmission whines and becomes less noticable when it warms up. I suppose the diesel owners wouldn't complain about this one.

2001 Chev K3500 CrewCab Dually 8.1L, Allison tranny, 8000 miles.

CMNTMXR81 · October 8, 2002

I'm gonna go out on a limb here and say it has nothing to do with oil consumption (Oil consumption is normal on BBC's), and it has nothing to do with heat on a starter (they all get hot).

My guess is that it's in the flexplate bolts not being properly torqued which I believe is a TSB somewhere on these 8.1. Hence, the flexplate is loose enough where the starter gets wedged trying to engage against it. After you hit it the first time, it breaks itself loose and then when you try it the second time, it meshes and turnes it.

That vibration would also be associated with the flexplate being loose.

The Allison whines like a supercharger no matter what.