RS-Chevy-SS

Oil change time, she smokes when your first start it and/or when your revving high. So what oil do you guys recommend for this tired 150k mile motor? Been running Synthetic Q. Any of those high mileage oils worth it?

sailtexas186548

iTrader: (2)

have you tried replacing your valve seals? they may be the culprit for the smoke.


as for oil, I just stick to the same old oil I always run for the life of the engine, and add a half quart of "lucas oil stabilizer" when I get over 100k miles

red rock

iTrader: (2)

It isn't going to help much, but add some ENGINE RESTORE. Your valve seals are leaking, but the additive will help fill in any scratches in the cylinder walls.

sailtexas186548

iTrader: (2)

engine restore and similar products scare me... if it fill in scratches in the cylinder walls, what's stopping it from filling in bearings and lifters?

Blown 346

iTrader: (12)

I agree. Replacing the valve seals are easy. all you need is a air compressor, the new seals, and the spring removal tool.

RFmaster

What ever you do not use Synthetic Oil - worn out valve stem seals can not cope with synthetic oil. Suggest that you run mineral oil (dino) - 10W30 or 10W40 with a quart of Lucas Oil Heavy duty Oil Stabilizer.

Replacing valve guide oil stem seals alone may not be enough - worn valve guides allow oil to enter and accumulate in the combustion chamber when engine is off. Once you start it the engine will burn accumulated oil away until next shut down. A compression (leak down is even better) check should be done to verify that rings are in good shape. They should be - EFI motors tend to have almost no bore wear even after 150k.

IMHO, find a good set of 305 heads (rebuilt by reputable shop) and just do a swap as replacing valve stem seals on the old engine is a temporary band-aid. Valve springs are probably tired as well.

//RF

red rock

iTrader: (2)

Ok, now that's being a little paranoid. It doesn't fill in the bearings and lifter's, where do you people come up with this stuff? Any oil additive is just that, an additive. It's just a thicker oil additive to help lubricate at hotter temps.

sailtexas186548

iTrader: (2)

I know it wont actually "fill in" bearings etc. , but if it actually has something in it that will stick to the cylinder walls and prevent blowby, that means the additive is making it past the rings and into the combustion chamber... If that is really happening and truly reduces blow-by, thats some tough stuff considering it's replacing metal! The you have to consider, that same stuff is also in your bearings, lifters, timing chain, etc, what preventing it from sticking to everything else? it's not like it can distinguish between engine components. Now if your talking about an additive like lucas stabilizer that just increases the "stick" and viscosity of the oil thats totally fine to run, but it doesn't "fill in scratches in the cylinder walls"

I would not run most additives in my engine, granted they probably do little harm or good since most "wrenches in a can" are snake oil. to each their own though...

red rock

iTrader: (2)

So your snake oil is better than mine, Any motor with 150,000 miles or more on it that smokes is going to be in need of a rebuild anyway. All the OP was asking is some info to extend the life of the motor, and maybe not smoke as much?

UnderCover89TBI

iTrader: (25)

Ive seen engine restore work on smoking engines. but the problem your having it will not help, due to it being valve guides. your best bet is to change the heads, with a new valve job. maganese bronze valve guides installed. positive locking seals, on intake and exhaust valves. a lot of times its just o-rings on exhaust and umbrella seals on intake.