1994 GMC C1500 engine oil leak

CARHOP

MEMBER
1994 GMC C1500
112,000 MILES

I have two small oil leaks at two of the intake manifold bolts. A drop or two of engine oil is collecting in the manifold low areas right below these bolts within a few weeks. These bolts are actually intake manifold studs located in the second position from the front of the engine, one on the drivers side and the other on the passenger side directly opposite each other. Connected to these studs with nuts are the negative battery cable to one and wiring harness ground to the other. The leakage is on top of the intake not at intake gasket. How can I fix these leaks? Thank you for your help!

Sunday, October 13th, 2013 AT 5:32 AM

3 Replies

HMAC300

MECHANIC
48,601 POSTS

If it's a big block try tightening them up bu tif it's a 350 not much other than doing the same. It may be coming from the valve cover

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Sunday, October 13th, 2013 AT 5:45 AM

CARHOP

MEMBER
21 POSTS

Thank you for your answer. What is the best procedure for tightening these studs. 1. Simply tightening from the way they are torqued now, if so what torque value should be used? (Manual specification is 35 lbs.). 2. Loosening slightly and then tightening. 3. Removing the studs, resealing them with rtv or medium locktite(blue) and putting back in intake. Which is safest method? What is a safe torque value at this time? Thank you for your help.

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Thursday, December 5th, 2013 AT 2:16 PM

HMAC300

MECHANIC
48,601 POSTS

You can try to tighten them but it may not help. It has to be leaking either at pcv hose or something similar. If it's not the intakes leaking which isn't normal for that engine. But try to tighten first. Loctite for bolts always not rtv

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Thursday, December 5th, 2013 AT 3:43 PM