Engine cleaning after replacing cracked heads

RenegadeT

RenegadeT

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Swapping heads on a 2001 suburban, 5.3L. How do I clean up this milkshake mess before bolting on new heads? Of course drain the oil/coolant mixture first. Usually I use brake parts cleaner on about everything, but not sure in this case. After reassembly, I plan on filling with cheap oil (maybe with some cleaning additives, some diesel?), run it a few miles, then drain, refill with good stuff.
 
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Appears the most of the milkshake is on the old head? You are replacing them right?

Normally you would scrape the old gasket from the block, blow out the cylinders and clean over and over with work towels and an engine cleaner such as "gunk". You can keep turning the crank and repeat wiping the top of the cylinders after the rings sweep the mess upwards. A brass wire brush comes in handy cleaning the aluminum piston heads. Just stay away from the walls with the brass by only hitting the top of pistons at full up stroke.

The rest of the engine will take care of itself with a couple 500 mile oil changes and then a coolant flush.
 
A lot of the mess looks to be in the heads, and on into the block where the pushrods go. I guess I should take off the cover between the 2 heads?
 
RenegadeT said:
A lot of the mess looks to be in the heads, and on into the block where the pushrods go. I guess I should take off the cover between the 2 heads?
Click to expand...


I know any pro would recommend you to but I wouldn't... Seems another can of worms along with more work than really needed here. Your 500 mile oil changes along with a touch of kerosene in there with engine warmed just before changing would take care of all that. If you pull the valley cover, seems you'd have to dis-assemble the entire engine and clean the crank, cam and dizzy as well to be all crazy about it. Especially if the valley doesn't leak.

But then I'm not familiar with this specific motor so I could very well be wrong if there's prone-ness I'm un-aware of??? Just going on obvious instinct.
 
Use a decent oil, it has a better shot at having a useful additive package to help clean things. Cheap oil may not work as well. I wouldn't add anything to the oil, as you've already got coolant floating around and don't want to dilute the oil with other solvents. Everything in the engine is pretty well coated with oil, and you're really trying to bind and remove the coolant (which is already in suspension as the milkshake), not remove all the existing oil protection. It shouldn't take very long to remove most of the coolant from inside the engine, it's going to get diluted and then circulated around so you can change the oil after a few days and remove every bit as much as if you wait 500 miles.
Get new oil in there, get it mixed around well with the milkshake, and get it out of the engine. The less running with that gunk circulating around, the better.
 
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I'd suggest not putting 706 heads back on it :D Also, now is the perfect time to replace the lifters and lifter trays since the heads are off. You can pull the valley cover...but there's really not much in there except for two knock sensors.


Just pulled the heads off the 6.0 in my Silverado a few weeks ago to replace the lifters and lifter trays...I know your pain. It's not a bad job, but leaning over everything in the engine bay sucks. More so when you add 10" of elevation and 37s to the mix.
 
Last time I did that same job I changed oil 4 times in a week before it was clean and clear to me.
It would milkshake up in 15 minutes running in the driveway.
Drain and repeat. I did this with cheap straight 30 oil. After I got a clean oil change I put what I wanted to run in it.
 
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washing down with brake clean with drain plug removed, will get a lot of it, but not all, one of the favorites when I was at Chevy shop was pouring power steering fluid over everything, draining, then fill with new oil and filter, disable fuel/ignition, crank long enough to get oil pressure, then allow to start and warm up. then change oil and filter again. lot of Vortec intake gasket jobs went out that way.

only one that I know came back, seems leaving a red shop rag in the valley of a Vortec 4.3 isn't good for the balance shaft or oil pressure.... ( wasn't me, my claim to fame was fragging a Dmax )
 
It would take 4 oil changes on boat engines that sunk and got water in them.

If this motor has been run for a long time like this, the bearings could have damage. I'd roll the dice on that unless you really feel like getting into it
 
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