Well everybody I'm having trouble with my 71 f100. It has a fairly new 390 in it. The problem i'm have is at idle and deceleration my engine puffs out blue smoke. I've heard that this most likely the valve seals but i'm not for sure. This thing hasn't needed any oil at all in 2500 miles. So why does it blow smoke? It is only on one side of the engine. How can i find out exactly which cylinder is doing it? It is starting to blow more and more smoke but never needing any oil at all. this just stumps me. I'll take any help i can get.
Richard Boyd

 

Do you have power brakes? I've heard of power brakes causing this when they somehow pull fluid into the engine, do a search through old posts for it

 

Nope no power brakes
Richard Boyd

 

Richard, your symptoms sound a lot like Ryans a few threads below https://www.ford-trucks.com/dcforum/DCForumID7/68.html

Also, try disconnecting your PCV and see if it goes away.

Barry

 

You write >>It has a fairly new 390 in it. The problem i'm have is at idle and deceleration my engine <<

There is a slight chance that you are `pulling` oil in through the intake manifold gasket on one side.

Can be common with the intake gasket being inside the valve cover area. Have you Re Torqued the manifold after it was warm the first time!
Give a `slight`easy pull on the manifold bolts in the center of the manifold. If them seem loose ....there you go...

Pull each spark plug and have a look.... you should see a difference in the plugs.


__JOHN__Õ¿ö
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72 F-250
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