[Hacksaw]

I know, I know...This sound stupid crazy...But has anyone out there ever power washed or steam cleaned the sludge out of a running engine? A guy I work with gave me a running GM TBI 350. He pulled it because it started to loose oil pressure at an idle after a 30 min hwy trip. I got to thinking if this engine had a bunch of sludge in it, and in the pan, then maybe after the engine got good and warm, some of the sludge broke loose and started to clog the screen on the oil pump pick up? I heard this engine run, and it sounded fine. No lifter ticks, no smoke other then a little bit at start up (valve seals maybe), and it had plenty of power. It was in a 94 Z71 4x4. I was thinking...Since it would probably need a complete rebuildm and the damn thing runs now, then why not pull the valve covers, intake, and oil pan, tape the intake ports and exhaust ports real good, and power wash the you know what out of it. Get it back home, blow it out good. Spray it good with WD/40, or diesel fuel, or something to disperse the water. Put it back together with a new oil pump, fresh oil and filter. Fire it up, let it run awhile at operating temp, change the oil a couple times and see what happens? I really dont want to dump any $ in this engine. Worth a try?

[4 Jaw Chuck]

Ha-ha...no!

Just drive it as is, anything you attempt along that line of thinking is sure to make things worse or ruin the motor in someway...seen a few engines that were basically prevented from being smokers by the sludge.

Don't go there, trust me...rebuild when you have funds.

[1971BB427]

I wouldn't even think of mixing water and oil in the same engine. You might try running some oil additive, or even a little thinner oil in the engine, but I'd never do anything with water or a pressure washer.

[Torque454]

I've power washed engine parts but not assembled engines. Id take it apart and wash it then dry it off real good and re assemble it. I think you are wasting your time tho, sounds to me like its got some bearing problems and or worn cam/crank bearing journals. It likely needs main, rod and cam bearings.

[ericnova72]

On a serious note....The plan you have is a great way...... to totally ruin the engine, a way to guarantee that every machined surface on the crank, and the cylinder bores, will need machining at rebuild. It also adds the exciting risk of ruining more than that...It could spun a rod bearing too, and ruin the rod, possibly the crank...or spin a main bearing, which ruins the block and possibly the crank.

Water is not a lubricant, get it in the oiling system for a few minutes and it will ruin things fast in a running engine.

[345 desoto]

Try a quart of Rislone...

[DanielC]

Part of your post is a good idea. Do this, and only this:
"Put it back together with a new oil pump, fresh oil and filter. Fire it up, let it run awhile at operating temp, change the oil a couple times and see what happens? I really dont want to dump any $ in this engine. Worth a try?"
While you have the oil pan off it, clean the pan out.

[dinger]

There is some good advice here. A few things come to mind, you may want to ask the previous owner. How often was the oil changed? What type of oil sender is he using? How many miles on the engine? What weight of oil was he using when the problem arose?

The oils we have today don't sludge like they used to. I would take DanielC's advice and run it. Once you can take a look at the pan you will know a lot more about the engine.

[bigdog7373]

I say pull the pan and valve covers and clean them up. Put in a new oil pump. Then fill the motor with oil and put some seafoam in the oil, half a bottle i think. The seafoam breaks down the sludge so it can be circulated through the engine and into the filter where it will be filtered out. After like 200 miles or so, change the oil again and it will be good.

[sparkydog]

I'm not endorsing what you propose either but...

What you are talking about is similar to what boat guys ask after they have sunk their boats - they all want to know how much tear down they have to do to get the water out. There are several good threads about various techniques that guys have tried. I believe some of them involve using a lot of ATF but don't take my word for it. Try searching for "sunk motor" on www.socaljetboats.com or a similar site that has 70's style performance boaters on it.

Maybe it will give you some ideas.

[Torque454]

I'm really surprised no one else has mentioned the bearing thing. When you have good oil pressure on a cold engine that drops alot when hot, that is a sign that the bearings have excessive tolerance. The block and bearings expand as they heat up and that causes the tolerance to expand and thus the oil pressure to drop.

Had this happen to me before and to some degree, on everything ive ever owned. A new oil pump may help, and a high volume pump might even mask the problem for a while but its a bandaid fix.

I'm not saying that this IS your problem, i DO think that it is, but i AM saying that you shouldnt overlook it and that you should check atleast the main and rod bearings while you have the bottom end open. Scratches and visible copper are not good things to be seeing...

[wtatman]

I have had several mid 80s pickups that had sludged up engines when I got them. I always pulled the valve covers, intake, and pan and scooped out all that crap with one of my wifes tablespoons, I never told her! Then washed it all down with diesel fuel and a parts brush. Got to have a big pan under there to catch all that though. clean out or replace the pickup tube and replace the oil pump. Never had an engine fail after doing that.

[Torque454]

diesel fuel, kerosene, paint thinner, all should work ok. They're pretty oily. Diesel fuel is probably the cheapest.

[sjkonyndyk]

BG engine Flush

http://www.bgfleming.com/products/bg/engi.aspx


Pour in run engine for 10 Minutes at 2K rpms, drain. Then take a air hose and blow air through the center stem on the oil filter port. pushes out oil in oil pan and lifters... Usually get .5-2 quarts more oil out.

Refill engine with 6 quarts of oil. disconnect injectors crank for a few minutes to prime oil system.

Reconnect injectors drive for 1K miles and repeat.

Done this on a very poorly maintained nissan frontier mountain of gunk in the valve covers, it looks like a soso maintained nissan now. and it doesn't burn any oil.


I do have a pressurized oil injection system that I can pump oil into the lifters after I have purged the engine though.

[ChevelleSS_LS6]

I'd keep water out of it. Avoid loads with thinned down oil.

Advance Auto Parts sells melling oil pumps if you want a good brand. (stock, high flow, high pressure, whatever you want. I'd go with stock for your application).