Small Block Intake Manifold Oil Leak
03-24-2007, 11:45 AM
#1
Instructor
Thread Starter
Small Block Intake Manifold Oil Leak
After installing a new basic small block crate engine, I installed an aftermarket aluminum 4 barrel dual plane intake manifold. It was torqued to specs, and a thread sealant was used on all the bolts that threaded into the valley.
PROBLEM: There is some oil seepage up through the inner bolts over the valley. Not a lot just running around town, but much worse if I drive a steady 60-70 on the interstate. The drivers side bolt, second in from the front of the engine seems to be the worst offender. The intake is new. It has been retorqued, and more sealant applied, but it still leaks. I have a breather on the drivers side valve cover, and a PCV valve and oil fill cap on the passenger side. Oil pressure is running about 50psi at cruise.
Anyone out there had this problem? If so, how did you stop it.
Thanks!
PROBLEM: There is some oil seepage up through the inner bolts over the valley. Not a lot just running around town, but much worse if I drive a steady 60-70 on the interstate. The drivers side bolt, second in from the front of the engine seems to be the worst offender. The intake is new. It has been retorqued, and more sealant applied, but it still leaks. I have a breather on the drivers side valve cover, and a PCV valve and oil fill cap on the passenger side. Oil pressure is running about 50psi at cruise.
Anyone out there had this problem? If so, how did you stop it.
Thanks!
03-24-2007, 02:26 PM
#3
Racer
Member Since: Apr 2006
Location: Alexandria Va
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I had the same problem. I couldn't drive 40 miles without losing a quart of oil. I said screw it and just installed a ZZ4. A bit overkill but at least the leak is gone. 
What kind of bolt sealant are you using?
What kind of bolt sealant are you using?
03-24-2007, 06:56 PM
#5
Team Owner
If you don't have vented and or PVC vacuum removing ring blow by, you can get leakage if your intake gasket did not seal.
Things like decked blocks and heads or even warpage can cause the intake to no longer seat correctly.
always use the longest bolts you can. Lots of trick dress up bolts are only like one inch total
Things like decked blocks and heads or even warpage can cause the intake to no longer seat correctly.
always use the longest bolts you can. Lots of trick dress up bolts are only like one inch total
Last edited by gkull; 03-26-2007 at 08:23 AM.
03-25-2007, 06:14 AM
#8
Racer
All Intake head bolt should be blind holes. So sealant is not required.
If you don't have vented and or PVC vacuum removing ring blow by, you can get leakage if your intake gasket did not seal.
Things like decked blocks and heads or even warpage can cause the intake to no longer seat correctly.
always use the longest bolts you can. Lots of trick dress up bolts are only like one inch total
If you don't have vented and or PVC vacuum removing ring blow by, you can get leakage if your intake gasket did not seal.
Things like decked blocks and heads or even warpage can cause the intake to no longer seat correctly.
always use the longest bolts you can. Lots of trick dress up bolts are only like one inch total
03-25-2007, 01:55 PM
#9
Team Owner
Not all SBC Intakes are blind holes, in fact the end ones can access the coolant, and most of the thers can get oil seapage, if the manifold surface/and/or bolt heads are not sitting flush. A good fix is to put a smear of RTV under the bolt head. BTW watch long bolts, if too long they can rub the pushrod. Good luck.
03-25-2007, 09:03 PM
#10
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I agree with thumprr. Bolts must have sealant from coolant and oil. Performer intake manifold required sealant from fluid coming up though bolts. Seal and you should be fine. My original intake had sealant on bolts.
03-25-2007, 10:53 PM
#11
Le Mans Master
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The third intake bolt from the front on the right side of my Vette started leaking a tiny bit of oil years ago. It pools up a little after a long drive but has never gotten any worse................
03-26-2007, 12:26 PM
#12
Instructor
Thread Starter
03-26-2007, 12:29 PM
#14
Instructor
Thread Starter
O.K. But what kind of sealant did you use? Someone had mentioned to me that they had good luck with teflon tape.
03-26-2007, 07:44 PM
#16
ARP thread sealant. No leaks in the areas you mentioned yet on my new engine. I also used this stuff on each one of the head bolts and I have no coolant leaks into the oil passages. Goop it in the threads nice and thick then torque to specs.
