When to Change? Old car brought back to life....

[PReal]

Greetings! My overly conservative, oil stashing personality is telling me I want to change oil in a project vehicle that is running for the first time in around 15 years.

The car: a 1971 chevy blazer with a 350.
The history: hasn't run in around 15 years, oil filter was an obsolete puroclassic and I drained out about 3 qts. I rotated the engine by hand many times and had to get through some sticky spots due to rust. I have put wd40, pb blast and a healty amount of tranny fluid in the cylinders.

I changed the oil and filter with some free VNG and a free proline (puro clone) filter. I have circulated and primed the system a bunch with the carb of the vehicle. Had good oil pressure according to mechanical gauge and kept good oil pressure when I started it last weekend. I ran the truck for less then 5 minutes but I did dump a ton of gas in the oil due a stuck float. The oil is very dark. I have a couple more essentially free filters and a 190qt stash.

Should I change now or a little further down the road.

Seems to run pretty well for not running for so long!

 

[oldhp]

Change it. Drive it 500 miles, change it. But that's me.

 

[BowNisPar]

Oil is cheap and you have a lot of it. Change it, drive a few hundred miles, change again.

 

[TFB1]

Originally Posted By: PReal

I changed the oil and filter with some free VNG and a free proline (puro clone) filter. I have circulated and primed the system a bunch with the carb of the vehicle. Had good oil pressure according to mechanical gauge and kept good oil pressure when I started it last weekend. I ran the truck for less then 5 minutes but I did dump a ton of gas in the oil due a stuck float. The oil is very dark. I have a couple more essentially free filters and a 190qt stash.

Should I change now or a little further down the road.

Seems to run pretty well for not running for so long!


No question, change it now... A four or five percent fuel dilution in the oil would be bad, very bad...

Wouldn't hurt it to warm it for maybe 10 minutes and then change it...

 

[raytseng]

So you have less than 5min on the oil, but with possible fuel dilution?


I would wait to finish all the work you want to do on the vehicle done, take it for at least a regular drive, then change it as the final step when you're ready for the vehicle to exit maintenance mode and enter regular service mode.

 

[CT8]

Change the oil and filter now. The 71 is a great looking body style.

 

[Bobcatguy]

Fix the carb float, then change the oil. Keep a few spare fuel filters around. E10 will start to clean up the fuel tank which is likely the biggest issue beyond the carb.

The GM 350 is a great engine. They made many for cars/trucks and a whole lot for boats.

 

[Kruse]

If this vehicle has a flexible fuel line between the frame and the mechanical fuel pump, cut the line and install the largest inline fuel filter that you can in this area. (Of course, you probably want to replace this with new fuel line first)
Then change it again in a few hundred miles.

 

[Oldmoparguy1]

Is this yours??

 

[PReal]

My ride isn't nearly that nice. I'm just getting it running and driving so I can start the restoration process.

I've already added a large metal fuel filter next to the tank and have another large clear filter between the pump and carb. Carb float was repaired prior to startup.

I'll change the oil this weekend before I start it again.

 

[4wheeldog]

I would change it, for 2 reasons, first being the suspected rust that you have (Hopefully) rubbed off some parts, and second, getting that fuel out of the oil.

Run it long enough to get it warm, then drain it. Do it again in 500 miles. Assess the condition based on what comes out at that point.

(Cutting open the filter would be a good idea as well).

 

[PReal]

Glad I changed when I did.

Oil was noticeably thinner and smelled strong of gas. Put in a mix of castrol synblend from the stash and running smooth. Also replaced the pure line with drive works filter.

 

[Doog]

I would just do 2-3 oil changes at 500 mile intervals with PYB 10w30 and an orange can fram filter. By 1500 miles it should be clean.