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I had my 454 (LS-6) rebuilt last year and I have put about 3000 miles on it. The car has been burning oil very bad for the last 1000 miles. I brought the car back to the engine shop three times already and they said " We did a compression test and everything is perfect." In the last 1000 miles I burned 4 quarts of oil (Almost one quart per fill up). The oil is not leaking. I ocassionally see a dark puff of smoke when I start the engine. 2 months ago I put a new carb on the car and could not get it adjusted, so I took it to a local guy that knows his stuff. He told me that I either had a stuck valve or a bad carb. I changed the carb and still had the same problem so I told the engine shop that I had a stuck valve. I explained the process of my carb adjustment. They told me "We made some minor adjustments and it is all set".

Where should I start looking to locate the oil burning problem? I want to take the car back to the engine builder and show him what is wrong with the motor.
 

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I've got a similar situation with my 402, but my engine is old. The compression checks out good, but I've been told that a cracked oil ring will not show up as low comp...sometimes actually as HIGHER comp. because of the carbon buildup in the combustion chamber. Anyway, did the engine builder use teflon valve stem seals? It has been said that the exhuast side goes away quickly and then burns oil. It was explained to me that the stock umbrella type seals are best for the street unless you are running double valve springs that require the clearance the teflon seals provide.
You said you gert a puff of oil smoke at startup? How about when you get on it hard? Sounds like valve stem seals to me. Go see the engine shop again...that should be warranteed. Oh yeah, just my 2 cents.
 
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Look for the simple things first, like the intake may be leaking, allowing oil to be sucked from the lifter galley into the intake. The guides may have gone away, but that would be quick given the low miles unless they did some shabby tricks when the heads were rebuilt.

------------------
Wally
Gold #67
67 malibu

[This message has been edited by Wally (edited 07-13-99).]
 

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Wild guess, but do you have aftermarket valve covers? Some do not have good baffeling systems and oil can be sucked through the pcv valve. Note those fancy posi-lock valve seals will greatly decrese guide life, especally on the exaust side.
Harley
 

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I've got the same thing going on with my 468. I asked the same question a couple of weeks ago, and someone mentioned sucking oil through the PCV valve. I checked my valve covers, and they have no baffle to keep oil out. My PCV had a bunch of oil in it, and oil in the line to the carb base. Someone else mentioned that Moroso makes a PCV valve rubber grommet that extends a bit past the end of the valve tip, shrouding the end of the valve. There is a tiny slit for the valve to breath. I found one in the Moroso catalog, and just put one in. The oil even splashes through the tiny slit, but it has to help reduce the volume. I just need to put on some miles now to see if it helps.

Thanks to the guys who pointed this out to me.

OK, how does everyone else keep oil out of the PCV?
 

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Hey Gibbons, If I remember there is a small space down in that gromet under the pvc that you may be able to stuff a little fiberous material in. Like a little bit if one of them stainless steel kitchen scrubbers or something similar. May have to change it often but it will help keep the oil out.
Harley
 

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I made a post about 2 weeks ago in the "Troubleshooting" area about a similar problem. The subject was something like "Smoking 396". BillK gave me some excellent advice which you should probably read. The result of my quest was I had an exaust valve that was stuck open. This problem did however showup in a compression test.
 

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I was having this problem about a week ago.
Here are a few things you can check:
Like was mentioned about, take your engine to 3500-4000 rpm (in gear, about 50-65mph) and let off the gas. Do you see a cloud of bluish/white smoke coming out of your tail pipes? If not, are you running headers? As you know headers get extremely hot and if it is a stuck exhaust valve the oil will be blown through and hit the headers, you may not see much smoke because by the time it has reached past the muffeler the burnt oil disapated to almost nothing.

1. Valve guides, Your engine shop may have used the 'chevy' valve guides which are about as useful as ice cubes at the north pole.
2. Also mentioned above, check your manifold bolts, one loose bolt and it will suck oil like you'd not believe.
3. PCV

Those are the three main things it could be if its not leaking out on the ground.
With me it was just a loose manifold bolt *thank god*

Good Luck
Dan
 
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