Thoughts or input on thinning 25 year old oil before an oil change.

[azmusclecar]

Thanks for all the posts, lots to consider here. Last thing I want to do is an engine rebuild. The budget doesn't have that in it. Removing a valve cover will at least
give me an idea of what I'm dealing with.

 

[TURNA]

Did you try to turn it over by hand yet?

The car has been sitting for 20+ years the only thing you will find under a valve cover is........NOTHING!!!!

The engine has been sitting not been used so the top end is dry.

Spay some lube in the cylinders change the oil and filter try to turn it over by hand if you cant disconnect the power wire to the distributor and crank it for a second or two.

If it sounds OK start it run it for a half hour, watch your TEMP gauge close.

Shut it down change the oil see what you see.


If a piston ring rusted to a cylinder wall, pretty much no matter what you do there is going to be some type of damage.

Bonnewagon just went through this with a Pontiac engine.


https://gbodyforum.com/threads/doing-the-unstuck.69747/


https://gbodyforum.com/threads/how-to-unstick-rings.70681/

 

[azmusclecar]

The engine is not seized, it does turn over and it does run. The seller bypassed the fuel system which was blocked and used a small
electric fuel pump to get the engine to run only for a short period. The fuel pump only filled the fuel bowls and then ran dry.don't
I have not ran or turned over the engine since that day. Without a fuel source I needed to address that issue first which is almost
resolved. I have installed new fuel tank, sending unit, new lines at certain points and fuel pump and filter. I also installed a
new water pump. So I was hoping to get the engine prepped to start AND run and check for leaks and figured the next thing
was what to do as far as the oil that is in the engine now.

Maybe with that info a clearer picture of what I have is now available for comments and suggestions.

 

[TURNA]

If it started and ran already just run it with some good oil and a good quality oil filter.

Any damage that was going to happen already did when the old owner started it.

I would worry more about the freeze out plugs and leaks.

like i said keep an eye on the TEMP gauge, or replace the thermostat

 

[fleming442]

I'd do some cheap oil on the first fire up with some break-in lube. Get it running right with a few heat cycles, then change the filter and put some good oil in it. It would be a shame to waste good oil after finding out the float is stuck washing down cylinders or the intake is putting coolant in the oil.

 

[azmusclecar]

If it started and ran already just run it with some good oil and a good quality oil filter.

Any damage that was going to happen already did when the old owner started it.

I would worry more about the freeze out plugs and leaks.

like i said keep an eye on the TEMP gauge, or replace the thermostat

Well in another post I mentioned a possible water leak with the freeze plugs.........so we shall see. There's an ulgy sort
of water inlet on top of the intake manifold at the rear of the engine. It has one of the radiator hoses connected to it. It
may have been the culprit to be leaking when I noticed the water running off the back of the engine on visual inspection at the sellers
place. The hoses seem to be of that age that all need replacing and didn't give the freeze plugs a second thought...until after I
bought the car. I hope it's not the freeze plugs. Considering the car spent all it's time in Tucson I'm hoping it got through the winters
without being subject to any hard freezes we have here. They happen but not that frequently.

 

[Turbolq4]

I've noticed that when I run diesel oil in junkyard engines that it cleans them out quite well. I can see where the oil cleans out pathways through the sludge that had built up.

Just my personal experience though, do whatever makes you happy.

 

[TURNA]

Well in another post I mentioned a possible water leak with the freeze plugs.........so we shall see. There's an ulgy sort
of water inlet on top of the intake manifold at the rear of the engine. It has one of the radiator hoses connected to it. It
may have been the culprit to be leaking when I noticed the water running off the back of the engine on visual inspection at the sellers
place. The hoses seem to be of that age that all need replacing and didn't give the freeze plugs a second thought...until after I
bought the car. I hope it's not the freeze plugs. Considering the car spent all it's time in Tucson I'm hoping it got through the winters
without being subject to any hard freezes we have here. They happen but not that frequently.

Those are famous for rotting and leaking

 

[azmusclecar]

Those are famous for rotting and leaking

Is there an alternative method to that ugly valve? I realize it won't be factory correct but I am just trying to get as much done as
I can to get the car safe, roadworthy and on the road......and within a budget that keeps shrinking as the parts list adds up.

Thanks for the posts too.

 

[fleming442]

Is there an alternative method to that ugly valve? I realize it won't be factory correct but I am just trying to get as much done as
I can to get the car safe, roadworthy and on the road......and within a budget that keeps shrinking as the parts list adds up.

Thanks for the posts too.

I'm not sure of the exact operation of that style valve, but it stands to reason that it could be replaced with a standard heater control valve in the heater line ($10 part) and installing a standard nipple in the intake port.