1985 Pontiac Bonneville

QUENTICAR789

MEMBER
1985 PONTIAC BONNEVILLE
V8
2WD
AUTOMATIC
400 MILES

I just rebuilt a 305 for a 85 pontiac bonneville it ran fine for about the first 400 miles I took the vaule covers off and I noticed white smoke cmming from the left head. Then it started to come out of the left exaust and I have no clue why. And its only coming out of one side. I just took all the spark plugs out and

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MHPAUTOS

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31,937 POSTS

Are you using any coolant?

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Monday, August 8th, 2011 AT 6:01 AM

QUENTICAR789

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No its just straight water. I wasnt gonna put coolant in it till I get all the kinks out of it. Could that be the reason its doing what its doing?

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Monday, August 8th, 2011 AT 3:59 PM

MHPAUTOS

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I mean do you have to keep topping it up.

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Monday, August 8th, 2011 AT 10:47 PM

QUENTICAR789

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3 POSTS

No its holding it fine. I did a compression test and on the side its smoking from the first piston is reading around 20 to 25 psi and all the other ones are reading around 60. So should I go ahead and take that piston out or can you think of something else that could cause that piston to be so low?

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Tuesday, August 9th, 2011 AT 2:52 AM

MHPAUTOS

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31,937 POSTS

Pull the head and check the valves especially the exhaust valve, a leak down test will determine exactly where the leak is, that is if you have access to this equipment.