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Need Help !!! Car burning oil after rebuild

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Old 10-15-2000, 02:59 PM
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Need Help !!! Car burning oil after rebuild

On my 87 Trans Am that I installed a 350 TPI in about 2000 miles ago is buring about 1-2 qts of oil a week. It smokes at start up and when I get on it. I pulled the plugs and found the threads were wet with oil and it has been burning oil. I was thinking it was the piston rings or valve seals that the machine shop did for me. I showed them the plugs and he said it may be coming from my Intake and buring it there and told me to pull the intake off. Well I pulled it today thinking it was a waste of time but I found the PCV valve was wet with oil, the runners also was wet with some oil inside and on the gasket mainly the lower end on the intake. I also can feel oil inside the exhaust port on the heads and inside the intake where the ports for the runners are you can also see some around the openings It this normal? If not It sounds like the machine shop is right and now I do not know what could be wrong? Is the intake not matching up to the heads? I'm confused on what this can be. I was so convencied that it was piston rings. Anyone ever had this problem or know what it could be? Thanks, Jason
Old 10-15-2000, 03:26 PM
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Car: 2002 SOM z28
Engine: LS1
Transmission: T-56
Did they put in a "high pressure" oil pump? What is your psi? Also, what weight oil are you running and what type of oil filter do you have? And did you change the oil/filter since you put in the new engine? Is it a plain-jane engine, or is it packed with "specialty shop enhancements"? Need more info on things...

------------------
1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock... all the suspension stuff... 9-bolt posi disk is in... K&N filter... 93 octane...

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Old 10-15-2000, 03:36 PM
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Yes it has a high pressure oil pump it's at about 70PSI. I'm runing 20w-50 Oil and I've change the oil filter twice on the car since the rebuild. The engine is basically a plane-jane 350 it was not bored out it has 10:1 Flat top pistons. The heads have been ported, screw in 3/8 studs and cut for larger valve springs. Thanks,
Old 10-15-2000, 04:59 PM
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Car: 82 Berlinetta/57 Bel Air
Engine: LS1/LQ4
Transmission: 4L60E/4L80E
Axle/Gears: 12B-3.73/9"-3.89
Were either the heads or block shaved? If so, the intake may not be setting down properly on the heads. The intake needs to be machined to match again.

How did the intake gaskets look? Were they compressed completely around each port?

------------------
82 Berlinetta, orig V-6 car. Rescued w/86 LG4/TH700R with all harnesses, sensors, ECM, etc. 2.73 open. Cat-back from '91 GTA, Accel HEI SuperCoil. AMSOIL syn lubes bumper-to-bumper. Daily driver, work-in-progress (LB9 w/ZZ3 cam, exhaust, paint, etc.).
57 Bel Air, my 1st car. Currently 396 .030 over, Weiand Action+, Edelbrock 1901 Q-Jet, Jacobs Omnipack, 1-3/4" headers, TH400 w/TCI Sat Night Special conv & shift kit, 3.08 10-bolt, AMSOIL syn lubes bumper-to-bumper. Best 15.1 @ 5800' Bandimere. Daily driver while Camaro was being put together.
Old 10-15-2000, 05:12 PM
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five7kid, The block or heads were not shaved. The intake gaskets looked as they were compressed around each port. I'm beginning to think that it may be the High Volume Oil pump I installed. I check the pressure with a direct gauge a few weeks back because my gauge inside the car was at 0 when I was driveing. So I checked it at idle and it was about 65 psi when I would rev it it would go to almost 80psi. Could that be the problem. too much oil pressure?
Old 10-15-2000, 05:16 PM
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Jazz,
I think 57 KID is on the right track. It sounds like you have 1 of 2 problems:

1) intake mismatch - which is sucking oil from the lifter galley into the intake ports, or.....

2)Excessive crankcase pressure. Check the routing of the pcv hoses and the valve itself. In fact, pull the hose with the engine at idle and confirm it is drawing vacuum.

More info on your combo would help a lot.

BOR
Old 10-15-2000, 05:23 PM
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What info would you need? I did not check for vacuum at idle before I tore it back down. This is pissing me off as this is the third time since July I had to tear into the engine. I can use any info at all to try to correct this problem. Thanks, Jason

Originally posted by Box of Rocks:
Jazz,
I think 57 KID is on the right track. It sounds like you have 1 of 2 problems:

1) intake mismatch - which is sucking oil from the lifter galley into the intake ports, or.....

2)Excessive crankcase pressure. Check the routing of the pcv hoses and the valve itself. In fact, pull the hose with the engine at idle and confirm it is drawing vacuum.

More info on your combo would help a lot.

BOR
Old 10-15-2000, 06:42 PM
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Well I dont know what it is for you but my engine was ****ed. When they assembled it two of the wrist pins werent pressed in on the rods so they walked out and carved a nice hole in my cylinder walls. There was LOTS of crankcase pressure and there was smoke coming out the PCV valve like a bitch. Anyway my block was trash... is any one of the plugs much worse then the others ? I'd pull em all and see what's up.

Also try to get a compression tester and do a compression test in the cylinders. They should all be about the same. If one is low, try pouring oil in the cylinder somehow and see if the compression goes up. If it does, then it IS your rings, or you have one of these nice holes in the cylinder that mine did Anyway... let us know how it goes.

------------------
92 Z28 L98 350
---------------
Ported and polished heads, ported stock TPI base, ported plenum, Comp Cams XR270HR-10 cam (lift .495/.502 duration 218/224 lobe separation 110), Edelbrock TES headers, LT4 valve springs, Crane AFPR, Flowmaster catback with LT1 style tips, MSD coil & wires...

"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)
Old 10-15-2000, 08:11 PM
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Car: 2002 SOM z28
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A compression test is not a bad idea. That would tell you if one of your rings on the piston is bad or if a valve is off.

But I think your problem is your oil pump. 60 psi at idle is WAY too high. And 20W 50 is WAY too thick for that psi. 5w-30 would help lower your psi a bit. Either way, that is too high a pressure. It usually should be 10 psi for every 1000rpms on average...

------------------
1984 z28 w/ a 357 cu in. monster engine which is looking like the posterchild for Edelbrock... all the suspension stuff... 9-bolt posi disk is in... K&N filter... 93 octane...

-=ICON Motorsports=-

[This message has been edited by Biochem (edited October 15, 2000).]
Old 10-15-2000, 10:31 PM
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Car: 87 IROC
Engine: LB9 for the moment
Transmission: T5
did you change to valve covers without baffles??? other wise it sounds like excessive blow by... maybe the rings have not seated properly... definately do a wet dry compression check and do not use 20w50 oil small block chevys have issues w/ anything more than 10w30...
Old 10-15-2000, 10:50 PM
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A high pressure oil pump has little to do with oil consumption.The rings control the oil on the cylinder walls and the guides and seals control the oil going through the valve stem clearence.Very little ridge is always to much.High mileage pistons will have worn ring lands and even a little is to much as it causes ring shake.All that is bad for power but a quart a week is alot.I've re ringed many tired engines and they didn't burn oil like that untill after a couple of years.
I know this sounds "wacked" but you may have allready read it before that back when GM came out with the 265 in 1955 the cylinder walls were supposed to be so slick that the rings wouldn't seat so the dealers recieved a GM service notice to mix Bon-Ami cleaning powder (like A-Jax) with water and spray it into the motor while revving it so the rings would seat.Wild huh!Good luck -Mike
Old 10-16-2000, 04:35 PM
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Car: 82 Berlinetta/57 Bel Air
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If it has done this the whole time since being rebuilt, and the intake is sitting on the heads correctly, it really sounds like you got a raw deal on the rebuild. Take it back to where you got it done. They owe you a properly rebuilt engine.
Old 10-16-2000, 05:30 PM
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Jazz,
Sorry it took so long to get back....work you know.

Here's the gig - either you got a bad score on the rebuild....or, somehow you've left the crankcase nowhere to vent pressure during the re-assy.

As mentioned, did you eliminate the valve cover breather? You must have one of these with a pcv. Or, you can vent crankcase pressure to the intake manifold (or plenum).

Or, you can vent it to the atmosphere - but that's nasty. It works, it's just nasty.

It takes a pretty good sized F!CK - UP to blast oil into the chambers as you indicate.

If that's the case,(have the rebuilder do the compression test - he may be buying this motor back from you) you may have to ****** the motor and try again.

I hate to say it, but this kind of crap happens all the time - Jeez H. Christobal...
I noticed where even hipo car magazine zoots build sbc's that spin bearings !

Slow, careful, and deadly accurate, with TRIPLE-CHECKS on everything is the way to go.
If you get tired, then go to sleep and work on it the next day. It beats the snot out of making a mistake because you're tired and fuzzy in the brain.

Anyway - look for sources of crankcase pressure OTHER than wasted rings and cylinders. If you cannot find any, well, you will have good reason to be miffed.

Good luck, let us know what happens.

BOR
Old 10-16-2000, 07:39 PM
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I kept the stock valve covers and did not remove the baffle in the cover. I took the intake to the machine shop today so the can check it to see if it's warp of something. I'll hopefullt hear something from them tomorrow on it. They still do not belive it to be piston rings because they said if it were the rings the plugs would not burn off the oil there it would acually look worse according to them it's burning after it runs for awhile. So right now I'm waiting and hopeing it's the intake. After I get it back together I'll see if someone can do a compression test on it. I'll post again when I find out what's causing this problem. Thanks for the info.
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