Need advice, motor knocking

[davidc11291]

Ugh... I've got a couple of cars that I've bought and am trying to flip. The car is question is a 97 Chevy Lumina V6 (3100 motor) with 221,000 miles.

I've put 2,000 miles on it since I got it (meant to sell it quickly, but that's a long story for another thread). I did a motor flush and changed the oil as soon as I got it, and it's been running great. Smooth, quiet, no knocking, good power, etc... way better than you would expect from a car with 221k miles. So yesterday I noticed that it was a quart low on oil. No leaks in the driveway, so it's burning a quart every 2k miles. Instead of using motor oil, I put in some Lucas oil stabilizer- stops leaks, improves lubricity, etc... Well I was pouring it from a gallon jug, and ended up over-filling by about a quart. No big deal, as I never cranked the car with it over-filled. The drain plug is rounded off, so I ran a thin hose down the diptick tube, and sucked a quart of oil/Lucas out, leaving it at the proper level. This morning, when I crank the car for the first time (headed home from work) the engine is knocking...HARD. Super loud knocking, and it goes away after the engine reaches operating temperature. It never knocked AT ALL before this morning. I drive home from work, let it cool, and check it again. Same thing. Knocks really loud until it reaches operating temp, then quiets down. My first thought is that the motor was probably already pretty gunked up and putting that thick Lucas in it clogged some of the oil pathways, not allowing the oil to get to where it needs to be, so I drop a quart of motor flush in it and run it for 20 min (hoping to clear out any clogged oil pathways), then change the oil/filter, and drop in some 10w40. No help. It's still knocking BAD at start up, then quieting down when it gets to operating temp. I can open the oil filler cap on the valve cover and see 2 valve springs. With the motor running (at idle and at 2000rpm) I don't see ANY oil movement in there. There's a small puddle of STANDING oil between the valve springs, but it's not flowing/moving at all. Is it supposed to be?

My mechanic is out of town till Monday night, and this car is advertised for sale now, so I gotta figure out if this is something I can save, or if the motor is shot.

Why did it suddenly start knocking hard, out of no where? Was it the Lucas? Did I mess something up running a hose down the drain tube? More importantly, is this easily/cheaply fixable?

It's been a great weekend....

[Flash Gordon]

Are you sure you got that extra quart of oil out?

This SUCKS!

[rider9195]

If I can remember correctly, Lucas Oil Stabilizer is an oil additive. I don't think it is meant to be used as a standalone oil for your engine. I would drain everything in the engine, put back in some synthetic engine oil and add some of the oil stabilizer with it.

[davidc11291]

Hey Gordon. I definitely got the oil down to the proper level. I saw how much I pulled out, plus I checked the dipstick. Also, since then, I've drained everything and changed the oil, but it didn't do any good.

If I can remember correctly, Lucas Oil Stabilizer is an oil additive. I don't think it is meant to be used as a standalone oil for your engine. I would drain everything in the engine, put back in some synthetic engine oil and add some of the oil stabilizer with it.

You're right. I used it as an additive. The motor was a quart low on oil, so I threw in the Lucas on top of the 4 quarts or so of oil that was already in the motor.

[Flash Gordon]

You're right. I used it as an additive. The motor was a quart low on oil, so I threw in the Lucas on top of the 4 quarts or so of oil that was already in the motor.

I'd imagine when you did this you clogged up a channel

I would continue to drive it and hope for the best

Don't do a motor flush again on a car with that many miles

[opie_7afe]

if its using oil then you probably have oil leaking into the cylinders a car will use some oil between changes but not much if its in tip top shape. doing motor flushes too often is not a good thing, my guess is the bearings are worn and when it reaches operating temp the metal expands calming the knock. i would use a mechanics stethascope on the engine block and see whats going on at start up, also might help to put a bore scope into the spark plug holes to see how the cylinder walls and pistons look. also check the compression.also check the coolant to see if you have any oil in there.diagnosing stuff like this is like a wild goose chase some times......i have almost same issue except mine is in transmission, sounds like crap until it warms up. good luck with it!

[rider9195]

You're right. I used it as an additive. The motor was a quart low on oil, so I threw in the Lucas on top of the 4 quarts or so of oil that was already in the motor.

Oh, I read your original post incorrectly. Sorry about that. Hopefully you can figure out what is wrong and fix it before someone comes to look at it.

[Flash Gordon]

Oh, I read your original post incorrectly. Sorry about that. Hopefully you can figure out what is wrong and fix it before someone comes to look at it.

If someone calls, tell them you are at work untill you get this sorted out

[mark58]

Sure sounds like you plugged something up. Try a pint of Marvel Mystery oil it should unplug for you.

[Flash Gordon]

Sure sounds like you plugged something up. Try a pint of Marvel Mystery oil it should unplug for you.

Good Stuff!