Engine gunk

[Chuck52]

As described down there somewhere, I am in the process of changing out the distributor on my 91' F-150 300 ci inline. In the process......I only seem to have real time to play with these things on weekends, and some of those go to other tasks assigned by my immediate Supervisor for Life, She Who Must Be Obeyed. Anyway, last weekened I found time to pull the old distributor. Yesterday I squeezed in time to fit the rebuilt one back in the hole...lots of fun making my marks match, but I think I got there. This weekend I'll probably finish the job, plug everything back together, and see if a miracle happens.

In the meantime, I figured I'd ask for the communal wisdom on chemical additives to clean the crud out of engines. When I pulled the old distributor, the gear was not at all worn, but it sure was full of sludge. Semi-solid oil gunk. I know there are additives one can add to the oil, run the engine for a short time, and change the oil. They are supposed to clean out some of the sludge, but I don't know the risks and benefits. This old truck is mainly going to be used to haul soil additives, mulch, building materials, etc, and I don't do all that much of that stuff. If I clean out the sludge, am I likely to create more problems than I help? Leaky gaskets and the like? Truck was running fine before the current problems, and I'm sure this gunk was in there then.

Anyone got experience and/or opinions on Cleaner Engines Through Chemistry?

Chuck

 

[scott_vt]

Mornin Chuck,
Let me start by sayin that if the truck runs fine now and your only using it on a limited basis I would leave it alone as far as the crud goes !

I have heard that some people have drained the engine oil and filled the crankcase with diesel fuel and ran it for a few minutes to clean out the crud in the motor. I have never used this method before and am not advocating it, but have heard that it works !

 

[MrJimi]

WARNING!!! Do yourself a big favor and DON'T do it, I used a name brand product, did exactly per directions and I developed a knock at start up? not a good thing at all
I sold truck and disclosed "start up knock" to buyer, not a selling feature
Jim

 

[Bird]

Twice I've "flushed" an engine that had hydraulic valve lifters clattering. The way I did it was the way a very good old mechanic 30 years ago told me to do it, and that was to add 2 quarts of automatic transmission fluid (ATF) to a crankcase that was already full or nearly full of motor oil and the engine already warmed up. Then to start the engine and let it idle for about 10 minutes, no revving of the engine and no driving; just idle. Then drained that out, changed the filter, and re-filled the crankcase with fresh oil. Now that worked great both times on 1970 and 1975 Oldsmobiles. I don't know about more modern stuff.

In 1957, I bought a 1936 Plymouth to play with, and with the intention of putting a big engine in it someday. It ran reasonably well the day I bought it for $50, but appeared to have very thick, dark oil; probably 80W gear oil. So I flushed that engine by draining out what was there, then filled the crankcase by putting in one quart of motor oil and finished filling it with kerosene. Then I started the engine, only let it idle 10-15 seconds, shut it down, drained it, and re-filled with fresh oil. That sure made it easy for the starter, or anything else, to turn that engine - no compression left at all. It would still run, and I could take off wide open in first gear, hold the accelerator on the floor, never take my foot off the floor when it reached its maximum speed, and I depressed the clutch to shift gears. It simply didn't have enough compression to blow itself apart.

 

[Chuck52]

Wow. Sounds to me like I better let the crud be. Of course, this may all be academic (and not just because I am) because I'm not even sure I'll ever get the thing started again. There may be a '91 F-150 available for parts in the near future. Even if I can get it started, I may end up driving it to the nearest dealer to trade it in. Pretty good deals availabe on full-size pickups these days. As little as I expect to drive it, a new pickup should last me as long as the oil supply! I do hate the idea of hauling manure in one of those shiny new jobs, though.

Chuck

 

[MrJimi]

Wow. Sounds to me like I better let the crud be. Of course, this may all be academic (and not just because I am) because I'm not even sure I'll ever get the thing started again. There may be a '91 F-150 available for parts in the near future. Even if I can get it started, I may end up driving it to the nearest dealer to trade it in. Pretty good deals availabe on full-size pickups these days. As little as I expect to drive it, a new pickup should last me as long as the oil supply! I do hate the idea of hauling manure in one of those shiny new jobs, though.

Chuck

Sell it in your local paper,or your front yard, you will get more for it!
Jim

 

[jinman]

It simply didn't have enough compression to blow itself apart.

Did it smoke a little?...from the crankcase vent.


Chuck52: I think you are wise to let your sludge stay. A sludgy engine is probably one that has some cylinder blow-by and is heating the oil enough that is is decomposing and depositing itself as sludge. Taking the sludge out is a "band-aid" on the real problem and probably won't help anything. At least that's my take on it. With detergent oils, most modern engines that are not overheated seem to be relatively clean inside ( the few I've seen).

 

[RobertN]

Bird, the ATF sounds like the same trick as using Marvel Mystery Oil. With MMO though, should be able to drive it.

On your old car, sounds like you rinsed down the cylinder walls and the rings didn't seat. A trick is to take about the spark plugs out. Using a turkey baster, squirt/blow 1/2-teaspoon of Bon-Ami cleanser in each cylinder. Put the plugs back in and run it. Helps the rings seat better. It is not a long term fix, but will help for a little while. Of course, you have'nt had that particulr car for 40 years or more

 

[Chuck52]

I sure hope I get to see if the sludge causes me any problems....that will mean the truck is running!

Chuck

 

[Bird]

Bird, the ATF sounds like the same trick as using Marvel Mystery Oil. With MMO though, should be able to drive it.

On your old car, sounds like you rinsed down the cylinder walls and the rings didn't seat. A trick is to take about the spark plugs out. Using a turkey baster, squirt/blow 1/2-teaspoon of Bon-Ami cleanser in each cylinder. Put the plugs back in and run it. Helps the rings seat better. It is not a long term fix, but will help for a little while. Of course, you have'nt had that particulr car for 40 years or more

Robert, I never heard of the Bon-Ami trick. The problem may have been the rings not seating, although I really figured it was just a severely worn old engine.