Engine knocking like a p'd off woodpecker

brainyass · 08-01-2008, 02:27 PM

1993, 4.0, 201K miles....

Well I posted earlier about my engine rebuild attempt under "I think I bit off more than I can chew". Anyways where I left off last time, I installed a broken sparkplug. Now up to date... It ran fine for about a month then had a loud whirling noise and a slight tap. I put in some extra thick " stop tick " stuff. Stopped whirling noise and tap for about a week. I removed distributor and removed buildup from shaft, greesed it up and I've had no noise for about a month now. But I do have a tap/knock noise at startup. When I start the egine it surges the idle and that is when I hear the knocking. Also, when I drive, just before it upshifts, when the RPM is about 1500, it taps. When it shifts to a higher gear, it's quiet again. If I drive really easy and don't load the engine too much, it doesn't tap. I did change oil and added some marvel engine oil additive. It was quiet for a few days, but now the dreaded tapping is back like Poe's Raven. So is it a collapsed lifter, which are all new; rod problem; or something else. And how do I test these things without pulling off the head again, cause I really don't want to do that again. Thanks in advance....Oh yeah, when I turn off the engine, the valves click. I had the valve cover off and felt some of them moving....

brainyass · 08-05-2008, 01:57 PM

Update: I ran some water dryer through the fuel sys, changed sparkplugs, added STP in the oil. I heard all of these things may cause knocking/tapping. I'll give it a few days, but it doesn't look hopeful.

MagicRat · 08-05-2008, 03:03 PM

Wow, a classic literature reference at AF!! That makes my day!

I do not remember if you changed the pistons, rings or bearings. These engines are notorious for developing odd knocking noises when they get some mileage; they are typical of piston slap, piston pin noises, bearing knocking etc.
But these engines can do many thousands (often hundreds of thousands) of miles with such noises.

brainyass · 08-31-2008, 05:41 PM

Alright,

After a long trip, 500 miles, the knocking is very obvious. I dropped the oilpan and inspected all of the bearings. All of the main bearings were looking great. The #1 rod bearing had a little wear, but not enought to make all of the racket. After I removed the #6 rod bearing, I found the culprit. It was pretty badly scored in addition to the Crankshaft. Now I need to remove the crank. The "almighty" Haynes says I have to pull the engine (translates to much $$$ at the garage). Is there a way to pull the crank out without pulling the engine?

Thanks in advance

brainyass · 09-03-2008, 11:13 AM

hello, hello, hello.....Must be an echo. Anyways, I have a master plan after I finally do get my crank out. i don't want to spend upwards of $500 to have my crank turned. So I plan to build a jig to grind it myself. I figure if I let the mains ride on my v-joint, it will be stable enough to spin with my HD drill. I figure a nice sanding belt will get the rod bearing nice and smooth. I think I will be the first one to create this thing. But I guess if my mic reads good, that's all that matters, right? Anyways, wish me luck, as I first need to get the thing out of there without yanking the engine.

Airjer_ · 09-03-2008, 02:14 PM

Seems like a lot off work when you could have replaced with a low mileage used engine and been ahead in the long run. The motors are very easy to pull and you can rent or even purchase a cherry picker for next to nothing. Why would you spend all that time on something that might work when you could spend it on a sure thing. Most Salvage yards offer a warranty on there engines. The one we use will take care of any problems in there shop on there dime. You can't beat that.

My advice (i'm not trying to sound rude) stop beating a dead horse and go for the sure thing. If you can drop the crank you can certainly figure out how to pull the motor.

brainyass · 09-03-2008, 04:02 PM

Well you see, I'm overseas right now. Donor Jeeps are few and far between. Besides, automotive parts are like gold to Germans. My $200 windshield replacement in the US was $900 over here. Thank goodness I filed my insurance. All of those nice tools in the US that are around every corner, and cheat too, are just too expensive over here. Besides, I have more time than money. If it doesn't work, I'll hit autozone for a rebuilt crank w/ matching bearing for around $350. But if I can accomplish the same thing for around $20, I'm all in. Who knows, if it works, I'll patent it and offer it up for sale.

fredjacksonsan · 09-03-2008, 06:55 PM

Since the crankshaft is a precision part, I'd bet that if you hand grind it with a drill, you will be taking the engine apart again very, very soon.

Best to replace the bearings and crankshaft with new parts. Ordering online and having them shipped might be a way to avoid the high cost of European parts.

brainyass · 09-15-2008, 03:28 AM

So now I know that it is impossible for me to pull out the Crank without pulling the engine. That pesky flywheel/flexplate, what ever it is, is completely in the way. I would have to unbolt the tranny, move the engine forward about 4 inches for the clearance. Since I don't have the shop to do it in, I have to come up with a different plan. Since the #6 rod journal on the Crank has about 5 grooves scored about 1 mil deep, how long would it last if I just put a new bearing on it and plastigaged it to fit? I just want it to last till I can ship it back to the US (about 8 months) and do a proper rebuild. Anyone ever do this to save up enough money to rebuild and what not?

Thanks

Airjer_ · 09-15-2008, 12:46 PM

You already now that you will need to replace the crank so why not give it a whirl. The pans off everything is right there. If you get 8 months out of it you did good. If it goes out again in a couple of weeks than ship it back stateside and do the repairs when you get back.

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