stangman94

Alright I got my motor rebuilt (306) by a reputable shop. I have since put 100-120 miles on the motor. I believe within the first 20 miles my rings seated since their was barely any smoke coming out of the exhaust compared to when I first ran it. My problem is that I still have smoke that comes out of my exhaust but only after 20 minutes or so of driving. Once I put the motor back into my car I brought it to the Ford dealer I work at to have some mechanics look at it to make sure everything was alright. They did a compression test, a leak down test and threw a little camera thing down into valvetrain to check it all out. They said everything looked good but they said that there was an oil buildup since I didn't have a filter on my pcv valve so they put one on. They said that my car is going to smoke for a little bit until it burns everything out and my rings should seat pretty soon. But its been a while and it still smokes. So does anyone have an idea on what it could be? Could it be oil residue still left over? If it was an oil ring it would of showed on the leakdown test and my car would smoke all the time. If it was an issue with my valves I would have a puff of smoke on cold startups correct?
I'm gonna talk to the mechanics tommorrow but I figured I would get a 3rd party opinion.

mstngsule68

umm...you forgot one thing, what color smoke?

stangman94

Its oil its blue/gray color. I pulled all my plugs today and they all looked perfect.

mstngsule68

go take it back to the shop that built it. how many miles are the motor as of now?

brynfiv

Did they use a stress plate to bore it? Ford blocks are notorious for the cylinders changing shape when you torque heads down.

mjr46

I seriously doubt that is the issue^^^^^any decent machine shop uses the proper equipment.......as for the issue at hand.....what did the rebuild consist of???????? were the heads completely rebuilt ? what brand rings used???