Excessive oil use opinions

[checkers]

96 rt10 seems to be consuming 5 quarts of oil every 1000 miles. You do not see a lot of smoke, there are no leaks visible (on garage floor or in engine compartment). There is oil evident on the rear bumper not wet but takes cleaner to get it off. There are not cats on the car.

In the cars history I believe it has had nitrous on the car. The current mileage is 19,800 miles.

Any ideas on what will be necessary to correct the problem?

 

[SylvanSRT]

you should have a leak-down test performed

possibly have your oil analyzed by one of those services to see if you have any coolant in your oil

also check the coolant for oil contamination

i couldn't tell you what the problem is but the above will help to figure it out

 

[dragon rider]

I'm by no means and expert, but it sounds like a piston/ring issue to me. Other more knowledgeable members will help with more sound advice.

 

[SylvanSRT]

if it is a piston/ring issue a leak-down test will diagnose it

 

[Tom F&L GoR]

You say you don't see a lot, so I guess you see some smoke.

As above, one source of consumption is poor cylinder sealing. This would consume oil under load. The other source is poor valve stem sealing. This will **** oil into the engine under high vacuum.

A sort of simple and fun test - have someone follow you. Accelerate sharply and keep engine in gear, letting engine slow car. If blue smoke shows under power = poor cylinder wall sealing. If smoke shows under decel = poor stem seals.

How do the spark plugs look? That's a lotta oil (half an oil change every 1000 miles.) Theoretically you don't need to ever "change" your oil.

 

[checkers]

You are correect Tom, I really don't need to change the oil much, just make sure it is full when using. The spark plugs look good and the car runs very well Its been this way for about 8000 miles(since I got the car. You really don't see much smoke except at night and I can see some when others car lights are shining on me. How do you test for bad valve seals?

 

[Slypopsracing]

Check prior post by Tom for bad seals (best test),however having an engine in a Challenger that was massaged with NOS by a previous owner your rings are most probably very tired. I keep driving the Challenger as its a 1970 motor, but it also uses about a qt per 1000 miles."The nitrous disease."

 

[plumcrazy]

leakdown test for sure. thats really the only way to know for sure and to what extent.

 

[dave6666]

You say you don't see a lot, so I guess you see some smoke.

Beat me to it... Yeah, there should be no smoke.

 

[checkers]

So what do think it will cost me if its rings and seals?

 

[plumcrazy]

gonna need machine work,parts,labor (gonna hurt) and a few "might as wells"

id be afraid to tell ya...lol

 

[1BADGTS]

My old modded GTS passed a leakdown BUT still had BLOWBY during heavy acceleration (esp over 5 grand rpm )As far as cost basically you will not know the entire picture (condition of cyl walls etc) untill you pull the heads.

 

[1BADGTS]

So what do think it will cost me if its rings and seals?

Rings and seals are not bad its the gaskets and bearings (over 1100.00 ) that hurt .Also can the cyl wall be cleaned up with just a torque hone or do you need a bore (may need pistons ).

 

[plumcrazy]

3000 just to pull and install the engine roughly

 

[Tom F&L GoR]

You are correect Tom, I really don't need to change the oil much, just make sure it is full when using. The spark plugs look good and the car runs very well Its been this way for about 8000 miles(since I got the car. You really don't see much smoke except at night and I can see some when others car lights are shining on me. How do you test for bad valve seals?

Hmmm... That's 40 quarts of oil (8000 miles and 5qts/1000 miles). That's the kind of consumption that you start to worry harming catalytic converter efficiency.

In older engines the valve stem seals would get hard, crack and fall off. Remove the valve covers and you can look at them. I should have added that in old technology engines (like that 1970 Challenger, which at 1000 miles/qt seems actually fairly normal) the valve guides would also wear. When the valve stem wobbles in the guide, good seals will only last so long...

Technically there is some good about a leakdown test. Perhaps if the nitrous use is a concern, a compression test might be more instructive. A leakdown will test cylinder seal at one piston position in the bore; a compression test will evaluate overall sealing during the entire stroke. (Unless someone tells me the leakdown is conducted at various positions?)

 

[plumcrazy]

Tom, youre right as usual. when i had my problems from using TONS of nitrous, it showed up in the compresion test

 

[dave6666]

(Unless someone tells me the leakdown is conducted at various positions?)

My guess is that at the bottom of the intake stroke the leakdown will be 100%. It all leaks out the intake valve.

Just guessing though.