85 351w HO Holley carb: I changed my oil about 2 weeks ago. I used a motorcraft filter and wal-mart 10-40 oil and added a quart of risoline (some sort of snake oil that said it would make the lifters quiet). I drove it for a week some times going up to 85 mph. I noticed it makes a loud growling sound combined with something that sound like a hammer hitting a hollow block really fast, but low pitched when I get around 60mph. Also my oil pressure gauge drops to nothing at when I stop at lights - I changed the sender, still does the same thing. 20w50 does not help much either. This has been going on for awhile and I think the bearings are going out (210,000 miles), but now I have a new development.

When I check the oil, the dipstick looks like it has brown rust all over it, but it wipes of. The oil itself looks ok (dark brown/black, but there are little light brown bubbles and specks of light brown in it. Is this bad? Should I try flushing the engine? Could gas or antifreeze be getting into the oil?

Thanks for any ideas.

 

That rislone is good for the lifters. It is a very high detergent additive and I bet you have so much gook in your engine, it's breaking some of it loose and it's going in the pan. You can actually clog the oil pickup by doing this. If you have an engine that the oil is not changed very often, your best bet is to use a cheap non-detergent oil to get you through till you fix it. I would start looking for another engine and put this one on light duty till then.

 

That hammer sound is prolly yer cam bearings wearing out. Main bearings sound are real loud.

 

Thanks, that makes a lot of sense. However, I can't put the engine on light duty and I can't afford a new one right now. I run this Bronco everyday. I am worried about the pickup getting clogged and I read before that if you flush the engine it can clean it out. I read something about tranny fluid or Kerosene cleaning out engines. Would that work to clean out a lot of the junk and how do I do it? Do you fill up the crankcase with say Kerosene and start it up or do you just let it sit in there and then drain it out? Or won't this help or will it make the problem worse?

 

Go to the parts store and buy a can of Motor Flush. Before doing anything, pour it in the crankcase and let er idle for about 10-15 minutes. Then drain oil and change filter and oil. The stuff works to clean sludge out of the motor.

 

I'll get a can of motor flush tomorrow and give it a shot.

 

Ok, I tried the Gunk engine flush. My oil pressure went up while I was running it through, but that is probably because it was a quart overfull. I also had a stream of oil running out of the rear main seal because the oil was so thin, but I was able to clear out a lot of junk. The oil was black, but looked clean otherwise, however on the bottom of the pan I drained it into there was some brownish sludge - looked like mud with metal dust all through it and a chunk of the old oil pan gasket I changed last year.

I took it out for a drive, and the oil is still clear, but on the dipstick there is still some light brown residue.

Also I have to run the engine real rich or else it stalls everytime I give it gas. I get about 6mph down from 11mpg, but running it rich is the only thing that stops the stalling. Could gas be seeping aound the rings and messing up the oil?

 

[updated:LAST EDITED ON 08-Mar-02 AT 09:06 PM (EST)]The metal dust you found is bearing material. That aint good when you find metal pieces. It definetely needs rebuilt, but the old 302 I had in my truck had bad main bearings and I drove it a good 6000 miles until I could replace it. The reason for low oil pressure is bad bearings, either cam or crank bearings. Runnin it real rich can ruin a engine because the gas seeps past the rings and thins the oil out. Same for a failed fuel pump. The diaphramn leaks adn gas goes into the crankcase and thins the oil out, which wipes the surfaces off the bearings. When lookin for gas in yer crankcase, rub the oil off the dipstick between your fingers and it shouldn't be very slick if thers gas in the oil. Now if there's water in the oil, it will look like chocolate milk. Water in the oil can be caused by cavitation in the cyinder wall, bad head gasket, or cracked cylinder heads or block. Check your water level in the radiator. Hope this helps any.