305 serious sludge

[85_squares]

Howdy, I've never seen sludge like this before... '85 C10 with the 305. What would y'all recommend short of tearing it down? I'm not exactly in a position to tear it down at the moment.

Add some diesel & let it idle for a bit, then change the oil? The oil passages themselves are clear, I thought maybe get in there with a brush & run the shop vac to try and get some of the big chunks out, just curious what you guys might do.

Just got this truck, so I'm assuming either the PO did a lot of short runs, used Penzoil, or it sat for a long time.

Thanks!

 

[Chevy 88]

Easy. Put the valve covers back on and run it. Caked on sludge and grime are not a problem until YOU make them a problem.

When you drive down the road, do you worry about the mud in the ditches?

Don't do ****. Don't do engine flushes, don't scrape it out of there, don't do anything. Just change the oil as usual and drive it.

 

[edgephoto]

In my 40 years in the automotive service business I have seen much, much worse.

If it runs good buy a good synthetic oil of the proper weight, and change it along with the filter every 5,000 miles. It will, over time, dissolve the sludge. Make sure the engine runs at the proper temp.

I would not put kerosene, diesel or any snake oil in the engine.

That is from poor maintenance. Urban legend about Pennzoil but I think that is akin to fat people blaming their thyroid instead of admitting they eat too much.

Trying to scrape it out causes more issues than just letting your maintenance schedule get you back on track. The only concern I would have is the oil pump pickup screen. You don't want to scrape it because the chunks you miss can block the pickup screen and even the oil return passages.

 

[idahovette]

I'm sorry, but I disagree on the pennzoil, saw a couple of mid/late 70s Chevy engines in for warranty and our GM rep wouldn't buy them because they were running the pennzoil.........I wouldn't put pennzoil in a fored

 

[85_squares]

Thanks everyone for your replies, I'll get it back on routine maintenance & keep an eye on it.

Y'all should have seen the spark plugs

 

[Ricko1966]

I'm sorry, but I disagree on the pennzoil, saw a couple of mid/late 70s Chevy engines in for warranty and our GM rep wouldn't buy them because they were running the pennzoil.........I wouldn't put pennzoil in a fored

All I used to run was yellow bottle pennzoil. I hope we can still be friends.

 

[SquareRoot]

Easy. Put the valve covers back on and run it. Caked on sludge and grime are not a problem until YOU make them a problem.

When you drive down the road, do you worry about the mud in the ditches?

Don't do ****. Don't do engine flushes, don't scrape it out of there, don't do anything. Just change the oil as usual and drive it.

 

[vr1967]

I think it Quaker State that used to have the sludge problem, not Pennsoil. Quaker State’s refining process used to not get all the parafin out of the oil, which led to sludge buildup in engines.

 

[fast 99]

cs130-ad23-cs144-ad244

I'm sorry, but I disagree on the pennzoil, saw a couple of mid/late 70s Chevy engines in for warranty and our GM rep wouldn't buy them because they were running the pennzoil.........I wouldn't put pennzoil in a fored

All I used to run was yellow bottle pennzoil. I hope we can still be friends.

Not a fan of Pennziol. I used it and changed the oil religiously back in the late 70's on my first car. Lost the motor early about 70k. Interior of the engine was covered with brown gunk. Can't exactly blame Pennziol could be a lot of reasons, but never bought that oil again. Today formulations are much different than the 70's.

Later on our business bought NAPA bulk oil. I believe it was made by Ashland. Engine life was excellent.

Then got hooked on Mobil 1 when I was around race cars. Oil temps were lower with Mobil 1 [we tried several brands] engines were living 10,000 laps turning the high 7K RPM range. So today, no reason to buy anything else.

 

[YakkoWarner]

I think there WAS some truth to the "Pennzoil gums up" thing years ago - likewise for Quaker State. I remember reading about it (in magazines and printed articles! - that long ago) being a result of a quirk in the chemical composition of oil from Pennsylvania. I don't think it matters anymore since Pennsylvania is no longer a substantial oil producing region, refining and formulation of motor oils is much better now anyway, and oil itself basically all gets mixxed into a common supply from various sources - you can never truly say "this oil came from Texas" or "This oil is from Kuwait".

 

[DoubleDingo]

I think there WAS some truth to the "Pennzoil gums up" thing years ago - likewise for Quaker State. I remember reading about it (in magazines and printed articles! - that long ago) being a result of a quirk in the chemical composition of oil from Pennsylvania. I don't think it matters anymore since Pennsylvania is no longer a substantial oil producing region, refining and formulation of motor oils is much better now anyway, and oil itself basically all gets mixxed into a common supply from various sources - you can never truly say "this oil came from Texas" or "This oil is from Kuwait".

But I can say this oil came from the engine in my truck, car, lawn mower, etc...lol...

 

[SquareRoot]

The bigger issue......it's still a 305

 

[warrpath4x4]

my 89 suburban intake valley was full of crusty gunk, I scraped out and vacuumed what I could, ran some ATF in the oil for a bit and changed it. It hasn't really gotten enough miles on it to warrant pulling the intake again to check on it but I can tell you it used to smoke on start up and it no longer does.

 

[xm20k]

I think it Quaker State that used to have the sludge problem, not Pennsoil. Quaker State’s refining process used to not get all the parafin out of the oil, which led to sludge buildup in engines.

Quaker state was to blame around here for whatever reason but is mostly due to old school oil not being changed at 3k but more like 10-15k hey it's still full, so it'll be fine right?

Thats not even close to the worst I've seen. One 302 I opened up all that crap had solidified into one massive dry blob like a charcoal brickette and was so built up that there was just enough space for the valve train to move. No idea why it solidified, heat some kind of additive, every other engine was like grease/wax.

Find a modern oil with extra detergents like Mobil 1 or even Rotella diesel oil as it has more zinc and just change it more often for awhile.

 

[Catbox]

Run ATF in it for a bit (100 easy miles) and change it.