Compression check...

[Hozer 88GTConv]

here they are...

Dry Wet (1.5 tsp of oil added)
5 - 178 182 (4 cranks)
6 - 170 182 (4 cranks)
7 - 176
8 - 178


Intake Manifold Vacuum at 750 RPM idle - 11.5 to 12.2 inches Hg

going to do PKRWUD's vacuum check now...

Well, I don't think it's rings...what do ya'll think?
I have a suspicion that I have the same problem as Skiwesser, that somehow oil is getting by the lower intake/head gasket.

[Hozer 88GTConv]

With all ports plugged (PCV and the other two tree ports underneath the intake) and the TB opening duct taped!
I got 3-4" Hg, that is the needle was whipping between 3 and 4 inches at about 250 cranking rpm.

Hmm, should it have been a steady reading? If it is just leaking at number 5, will that cause it to fluctuate on the gauge?

BTW, thanks in advance for the input (esp PKRWUD). I have been working on this problem for over a year. I have taken the heads off twice, rebuilt them and r and r'd the intake manifold half a dozen times with Fel-pro 1250's and 1262's.

[Hozer 88GTConv]

I took off the lower intake again. I really should consider investing in Fel-Pro stock.

I don't see any clear sign of a leak into the lifter valley.

I'm going to put a straight edge on the manifold and take some pics.

damn.

update: The manifold deck is true. Now I'm back to oil control ring. damn damn.

[jokergotcha]

does it smoke at all sitting stillit sounds like you have a bad oil control ring do you know what kind of rings are in the motor if it was a valve prob it would be apparent when you pulled the intake what do the top of the pistons look like the plugs looked alittle leando you know a diag tech with a four gas analyzerburning a ring isnt an uncommon prob on a motor thats driven hard

[TMASTER]

just pull the head off!!!

[skiwesser]

Hey , Hozer 88GTConv, I don't know if you put the upper back on yet, but I definetly had a leak at the intake gasket but you couldn't tell by looking at gasket (as I mentioned above ports were CLEAN on leaky port) how did your ports look? I put permatex ultra grey around ports on head and intake.

BTY PKRWUD, I had a mech. I trust tell me that you can check for intake gasket leak by simply spraying carb cleaner in the oil filler neck and if idle goes up, you got a leak at int. gasket.
You ever heard this?

[Hozer 88GTConv]

Hey Ski, how big of a bead of permatex did you put around your ports?

I used this gooey blue stuff "Ultra-seal" by permatex this time around the front intake port and water jackets and the oil problem seems significantly better.

And could you elaborate on how you could not tell that you had an intake leak? You say you couldn't tell at all by inspecting the gasket?

[RS_8007]

I mean the gasket looked perfect, no sign it may have been leaking.
I put a thin line around all the ports on both sides of gasket.
BTW I found out 2 quick ways to detect intake gasket leak.

1. spray a small shot of carb cleaner in oil filler neck, if idle speed increases, bad gasket.

2. Hold your hant over throttle body, allowing air through your fingers, if idle speed increases, bad gasket.

[skiwesser]

I made that last post some error called me RS_8007??