73-87chevytrucks.com
73-87 Chevy _ GMC Trucks => Engine/Drivetrain => Topic started by: Jay2D2 on September 25, 2009, 06:35:53 pm
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Well the trucks been sitting for awhile because of the un exceptable amount of oil she was burning when I parker and I just havnt had the time to work on it since Ive been preparing my house to sell.
I have a small puff of smoke when the truck starts but then clears up until engine is much warmer and I'm heading down the road with it and then poof I have a blue cloud that won't go away.
I'm wondering if this is more probable to be the seals or rings?
I did a compression test and got the following
1- 135ish
2- 145ish
3- 140ish
4- 150ish
5- 140ish
6- 145ish
7- 145ish
8- 150ish
Also when I pulled the plugs several had the threads soaked with oil and some seemed like they had loosened up, ie barely finger tight.
Although the last part could of been human error from the last person who had the truck.
I had bought the truck about 2 months before and it was not burning oil at all.. well maybe some up until a month and half after driving it.
However the truck had sat close to a year before I bought.
Recommendations or suggestions?
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The compression doesn't look too bad...fairly even. How much oil are you going through? I'd check the intake valley gasket, valve cover gasket, or rear main seal. I had an IH 304 that would burn 2 litres per hour on the highway...thought it was the rings cause the engine wasn't soaked with oil and wouldn't leak at an idle. Turned out the valley pan gasket was gone in the back and when the engine would get up to 3500 RPM on the highway it would just start blowing it out the back, run down onto the exhaust and make smoke.
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Mine is really burning off in the engine and coming out the tailpipe
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replace your PCV and see if that improves.
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PCV has been changed
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IMO somthing is wrong with #1 cylinder.. be it vlvs, or rings..
IMO 10psi between high and low is max difference..
pull the spark plug put a little bit of oil in then hole then do then comp test again see what happens ;)
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Sounds like valve stem seals and possibly guides. Ive replaced the seals before with the umbrella stlye while the heads were still on the truck and had good results. You have to have an adapter to pressure up the cylinder to hold the valve up, and a good spring compressor. That is if the valves arent burnt. A lleak down test will help pinpoint if you have bad valves or rings.
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Sounds like valve stem seals and possibly guides. Ive replaced the seals before with the umbrella stlye while the heads were still on the truck and had good results. You have to have an adapter to pressure up the cylinder to hold the valve up, and a good spring compressor. That is if the valves arent burnt. A lleak down test will help pinpoint if you have bad valves or rings.
puttign ~1oz of tranny oil in then cyclinder will tell you if is rings or not
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Sounds like valve stem seals and possibly guides. Ive replaced the seals before with the umbrella stlye while the heads were still on the truck and had good results. You have to have an adapter to pressure up the cylinder to hold the valve up, and a good spring compressor. That is if the valves arent burnt. A lleak down test will help pinpoint if you have bad valves or rings.
puttign ~1oz of tranny oil in then cyclinder will tell you if is rings or not
I agree, but the leak down test will be a good indication on the severety of the problem.
If it passes the leakdown test, then you can probably get away with new valve stem seals.
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The leak down test would be ideal however I do not have a compressor :S