Need advice, motor knocking

davidc11291

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

This SUCKS!
 
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.
 
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.
 
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
 
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!
 
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.
 
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 ;)
 
Sure sounds like you plugged something up. Try a pint of Marvel Mystery oil it should unplug for you.
 
Sure sounds like you plugged something up. Try a pint of Marvel Mystery oil it should unplug for you.

I saw this stuff in Aubuchon Hardware a few days ago and wondered if it was any good. Might have to try it now!
 
I saw this stuff in Aubuchon Hardware a few days ago and wondered if it was any good. Might have to try it now!
Google it.
It has been used for 40 yrs that I know of,,LOL It will not hurt anything. It should work like penetrating oil for you.I think your oil is not circulating properly and your screen inside oil pan might be plugged.
Just my opinion
 
Really sounds like something is plugged up to me, too. That's why I did a motor flush, but if the motor flush didn't unclog things, would the Marvel Mystery oil work any better? What about Seafoam?

Thank you guys so much for the advice.
 
Really sounds like something is plugged up to me, too. That's why I did a motor flush, but if the motor flush didn't unclog things, would the Marvel Mystery oil work any better? What about Seafoam?

Thank you guys so much for the advice.
Like I said it works like penetrating oil. The other thing as I said before your screen in the oil pan might be clogged. Marvel oil should break up any sludge but again it is temporary solution. You need oil flow through the engine.
 
So Marvel wouldn't clean the sludge out of the screen in the oil pan? Is there any way to clean that screen without dropping the oil pan?
 
So Marvel wouldn't clean the sludge out of the screen in the oil pan? Is there any way to clean that screen without dropping the oil pan?
marvel would break down the sludge but your best bet if you have no oil flow is to drop the pan.
 
Really sounds like something is plugged up to me, too. That's why I did a motor flush, but if the motor flush didn't unclog things, would the Marvel Mystery oil work any better? What about Seafoam?

Thank you guys so much for the advice.

Seafoam is another viable option

If you do this, call me first. I wanna come over and watch :props:

[ame=http://www.youtube.com/watch?v=8MDMFhOPHGY]Sea foam engine cleaner in a Subaru WRX - YouTube[/video]
 
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....

A 1997 V6 Chevy motor with 221,000 miles on it is a lot of miles for this engine....

Is it a true knock or just lifter noise?

Knowing the car is being sold did you push it at all playing around possibly damaging something?

Adding a container of oil additive to 4 or 5 quarts of oils shouldn't have affected things at all.

Draining the oil through the dipstick tube is pretty common so I'd say no, you didn't mess anything up.

A knock might indicate a spun bearing on either a crank or rod journal. If this is the case you'll probably notice a reduction in oil pressure. If this is the diagnosis then the motor's junk anyway.

Does the car have an oil pressure gauge?
If so, what is the pressure at an idle when cold and hot?
What is the oil pressure while driving?

Removing the oil filler cap and not seeing a lot of oil moving around is normal.

Since the knocking basically goes away after the car warms up I'd say the oil channels are open enough. I'm concerned about your oil being too think to begin with.
 
Seafoam is another viable option

If you do this, call me first. I wanna come over and watch :props:

Sea foam engine cleaner in a Subaru WRX - YouTube


Seam foam is great, I use it in everything with a gas engine 2 or 4 cycle. You can put it in your gas tank, run through a vacuum line as a top engine cleaner or use it as an engine flush.

A 1997 V6 Chevy motor with 221,000 miles on it is a lot of miles for this engine....

Is it a true knock or just lifter noise?

Knowing the car is being sold did you push it at all playing around possibly damaging something?

Adding a container of oil additive to 4 or 5 quarts of oils shouldn't have affected things at all.

Draining the oil through the dipstick tube is pretty common so I'd say no, you didn't mess anything up.

A knock might indicate a spun bearing on either a crank or rod journal. If this is the case you'll probably notice a reduction in oil pressure. If this is the diagnosis then the motor's junk anyway.

Does the car have an oil pressure gauge?
If so, what is the pressure at an idle when cold and hot?
What is the oil pressure while driving?

Removing the oil filler cap and not seeing a lot of oil moving around is normal.

Since the knocking basically goes away after the car warms up I'd say the oil channels are open enough. I'm concerned about your oil being too think to begin with.

I was thinking the same thing. The oil plus the stabilizer might be too thick and on a cold start the old motor might not be able to circulate the weight, hence the knock. Once the oil warms up, thins out and starts to flow better the knock goes away.

Might try a Seam Foam flush and then another oil change with the correct oil weight for the vehicle, maybe an oil specifically designed for high mileage and see what happens.
 
gm had problems with 3.1 having intake manifold gaskets leaking coolant into crank case pressure test cooling system for leaks also lifters that take time to pump up
 
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