5.0 rebuilt : bluish smoke coming from the exhaust! HELP

[Liquid Snake]

Hi, I'm posting this for a friend who has a '87 mustang 5.0.

He got his engine rebuild this winter. Everything is new except the block which has been bored 0,002 inch. The cam, crank, rings, pistons, rods, bearings etc...all that is brand new. He also has edelbrock aluminium heads and intake. He's running the engine on 5w30 mineral Quaker State. The cam is a Ford racing one, the crank is stock but has been balanced.

So the problem is that when he starts the car, sometimes bluish smoke (oil???) comes out from the exhaust. But it doesn't happen everytime. It also occurs when he accelerates kind of aggressively without being WOT.

The engine has approx. 160 miles on it since the rebuild, and the problem doesn't seem to decrease.

What could be the problem? He's being told that the engine could stop doing it, but as I said, it doesn't seem to go that way for now...

Any input will be appreciated! thanks.

 

[blkcobra50]

Hi, I'm posting this for a friend who has a '87 mustang 5.0.

He got his engine rebuild this winter. Everything is new except the block which has been bored 0,002 inch. The cam, crank, rings, pistons, rods, bearings etc...all that is brand new. He also has edelbrock aluminium heads and intake. He's running the engine on 5w30 mineral Quaker State. The cam is a Ford racing one, the crank is stock but has been balanced.

So the problem is that when he starts the car, sometimes bluish smoke (oil???) comes out from the exhaust. But it doesn't happen everytime. It also occurs when he accelerates kind of aggressively without being WOT.

The engine has approx. 160 miles on it since the rebuild, and the problem doesn't seem to decrease.

What could be the problem? He's being told that the engine could stop doing it, but as I said, it doesn't seem to go that way for now...

Any input will be appreciated! thanks.

The bluish smoke is oil being burned. 160 miles is plenty of miles for the rings to have been seated. How did he break in the motor when it was first started? If it's the rings not seated oil is getting into the cylinder and being burned. Also valve seals could be the issue if oil is leaking through them down the valve stem into the cylinder.

The oil also could be coming from the intake. Being pulled into the intake from an improperly functioning PCV or blowby.

Have you done a compression test or a leakdown test to check if there are issues with a particular cylinder. That would be the first think I would do. Let us know what happens.

J

 

[Mr Grim]

If I had money, I would bet it on oil getting sucked through the PCV into the intake. A very common problem....take a look at the thread showing pics of the homemade baffle. Take the PCV hose off and inspect it for oil.
Good Luck!
-Grim

 

[mustanggt5pt0]

My new FRPP cobra intake manifold when I rebuilt my motor the first time caused my rings to never seat because of all the oil it was sucking up through the PCV. Bigger and better baffle this time has solved the problem. Pull the PCV hose off and see how much oil is in that bad boy.