jstanley

Hi guys,

I'm trying to get my rebuilt 289 to quit smoking...

About 2,000 miles ago we had it rebuilt. We put the engine back in the car and it puffed white smoke for a little while as it burned off the engine assembly lubricant.

But then it started puffing blue/gray smoke when under acceleration, particularly after idling at the lights for a couple of minutes.

I rang the engine rebuilder and quizzed them on it. They said it could be the valves not sealing right, and to bring it in for them to take a look at. So that's what we did. They checked it out and did a leak down test and assured me that all looked fine.

They suggested that the intake manifold gasket wasn't sealing correctly and oil was leaking into the ports --> hence the smoke. They also mentioned that some of the intake manifold bolts weren't tight, which I found very surprising since we torqued them down to the '65 mustang specs.

Their theory on the leaky ports proved to be correct when we removed the manifold - there was oil leaking into a couple of them.

So we cleaned it all up and reinstalled a new Felpro gasket and this time put RTV around the intake ports, as per the rebuilder's recommendation, and torqued it down to the original '65 mustang settings of 22lbs.

But, same deal... still smoking.

So we pulled the manifold again, cleaned everything up and used an Edelbrock gasket which has the seals built into the gasket (instead of the felpro + RTV). We used gask-a-cinch (spelling?) to stick the gasket down and torqued the manifold down again.

But, same deal... still smoking.

So I tightened up the intake bolts to 30 lbs... and there is less smoke, but it's still doing it.

The only thing I can think of is that the torque wrench might be out of calibration, but I really don't think it is. And I don't want to keep tightening up the aluminum manifold until it cracks...

We also checked the PCV valve to make sure it was working correctly and that no oil was being passed back in to the carb. It seems fine.

I'm really having a hard time trying to troubleshoot this and am wondering if anyone else has experienced this kind of thing? Or if anybody has any suggestions, I'd be grateful.

Thanks,

Jason

Jonk67

Were the heads rebuilt with the motor? did they check to see that all the valves seated properly? lapped the valves at least and that they changed the valve stem seals? This is another area where oil can leak into the cylinders = smoke.

Have you checked the head surface/ intake surface for being decked as level? A torqued/twisted intake would be hard to get to seal. You didn't mention if you saw additional oil leak in from the intake on the subsequent removals or not.

You may want to borrow a friends torque wrench against yours.
Jon

jstanley

Thanks Jon,

Yes the heads were completely rebuilt and they assure me that the valves are seated correctly.

I personally haven't checked the surface as being level. I assumed it would be as it never blew smoke before the rebuild.

And yes, saw oil leak again on the second removal even after the RTV was applied.

I think what I'll do is:

1) try a different torque wrench to double check the settings as per your suggestion

2) if that doesn't work, pull the manifold again and check it for being level.

Is there anything else that could be causing it?

Thanks,

Jason

urban_cowboy

You should probably post this in the tech section instead of the general discussion section...

It sounds like a warped intake or head mating surface or the block deck was machined to the point of moving the heads too much to seal against an intake (geometry issue).