I agree with @dagosa here. The only way to get the job done right is to drop the pan and clean it out the old fashioned way. You’ll be glad you did. Make sure you also remove the valve cover pans and make sure the oil drain passages are clear on the upper end of the block. When they plug up…oil is sucked through the intake valve guides and that will lead to a smoking engine. It’s a common problem with small block Chevy’s.
What is the evidence this engine is sludged / gunked / varnished up?? Why the rush to tear this engine open when no evidence of a problem has been presented?
Well it is sludge and it was bad barely any oil flowed when the drain plug removed. Looks like its drop the pan time. This chevy 4x4 requires a major effort to do it but thanks for the feedback
@wizard451
It certainly sounds like you’ve got sludge
If you’re going to remove the pan, you should also remove the valve covers. There’s undoubtedly all sorts of nasty stuff under there, as well
To all, I stand corrected. Yes, you have sludge and a motor flush may do more damage as others have stated. I also vote for a pan drop and agree to pull the valve covers. The head drains in the back corners need to be cleaned out if any sludge build-up is blocking them as well.
Same problem in the 1950 caddy I recently acquired. Oil looked relatively clean on dipstick, but when I pulled the drain plug (engine cold due to it not running then) nothing came out. I had to poke it with my finger to come out.
I bought an engine flush but Im too nervous to try it. Im hoping to try and do a few oil changes when the engine is fully hot and try my best to cycle this crap out.
Other then that i’m sure an oil pan drop is in my future.
Fender (and the OP) I would strongly recommend dropping the pan and lifting the valvecovers rather than trying to cycle it out. It’s probably already plugged up some lubrication channels in the engine, hopefully only return channels from the heads.
And, Fender, the reason the oil on the stick looked clean MIGHT be because the oil isn’t circulating. The pickup screen might be totally plugged. Your main bearings and your rod bearings, and others are lubed by forcing oil through channels in the shafts themselves to be squeezed out past the bearing edges. This creates a pressurized fluid barrier between the bearings and their corresponding surfaces. If there’s no pressurized fluid barriers the bearings and their corresponding surfaces will wear prematurely, might gall (transfer material), and may even seize. You might even “spin” one or two. Trying to get gunk to work its way through the channels is highly risky.
In 1950, high-detergent oil was almost unheard of…And even after detergent oils were introduced, they left a lot to be desired…People changed their oil every 2000 miles or less…Engine sludging was considered unavoidable…People traded in their cars every 3 or 4 years in order to have a reliable vehicle…
If the oil isn’t circulating the engine would blow up.
When you add fresh oil to a sludged up engine the oil doesn’t have enough detergent properties to remove the sludge. So it remains clean while the layer of sludge remains in the engine.
If you want to see what a sludged up engine looks like, take a gander at this.
Tester
It wouldn’t blow up, it would seize. But I get your point. And I concur that the sludge stays on as the oil bypasses it… for the most part.
Allow me to change that to state that the oil is probably only circulating through areas and passages that aren’t totally clogged up… and most of them are probably partially clogged up. It only takes a few return passages open to let the oil run down from the valvetrain to the oilpan, but that doesn’t make it good. As a matter of fact it’s probably immersion in a slowly moving bath of oil that should be returning to the pan that’s lubricating some of the rockers and their associated parts.
Oil is the engine’s lifeblood. Just as I survived my heart attacks because the flow of blood to my heart wasn’t totally blocked, only blocked in arteries feeding specific areas of the muscle, and only pieces of muscle died, your engine would only fail in those areas starved of oil. But you don’t want that.
Great link. If that photo doesn’t support my point, nothing will.
Just stick a borescope through the drain hle, and you’ll get a good idea how much, if any gunk there is. Your pinkie finger If small enough) can also detect gunk close to the hole. Using a Q-Tip will also tell you if there is a layer of gunk there.
I also do this with the oil filler opening; hard, flaky gunk indictes all the evils mentioned such as long drain inbervals, overheating, running low on oil, etc.
So basically, if I take the valve covers off, and the oil pan (if its possible with the engine in the car still), what does one do to clean it out? Just by hand pull the junk out or do i use some sort of detergent to flush it out? (Sorry not trying to hijack the thread)
Scrape, scrape, and scrape. The crud is going to be fairly hardened, so scraping and throwing the chucks away is the way to go. Also, using a rod or something like it to clean out the oil drain passages in the heads is important. Also checking the oil pickup screen of crud and blockage is important. Usually, you’ll need to replace it if the crud is packed inside the screen. With the oil pan and valve covers off, a good cleaning with a powerful solvent will work. But, I don’t like using a solvent on the engine internals unless I’m doing a complete teardown. Just scrape it as clean as I can.
When i stuck my finger in the oil pan drain hole it was like sticking it into a layer of grease. The engine was ice cold but I basically poked a hole through that and then it slowly drained.
Engine does seem to run hotter then id want but that could also be due to rust build up inside. Whole other story for a different thread. Thanks
+1 to Busted Knuckles’ comment.
Once an engine gets to the point of having this type of thick ooze in the oil pan, merely cleaning out the pan and the area under the valve covers is not sufficient. The oil drain-back passages need to be “rodded-out”, and I would also suggest replacing the oil pickup.
Back in the day, the first step in an engine overhaul (a common procedure) was to disassemble the engine and place it in a boil-out tank, a large vat full of boiling lye solution. This was considered the only real way to de-sludge an engine…No aluminum parts in the tank please!
After 24-48 hours in the tank, the parts were removed, placed on the floor over a floor drain and hosed off. They looked brand new.