Oil leak intake manifold

[South of Sydney]

Hi all

Have had an ongoing problem with 2 different 360's over the last few years & that is an oil leak that appears to be coming up thru the threads of the intake manifold mounting bolts.
 I have used a number of different manifolds on both engines but I always seem to end up with little oil puddles around the bolt heads. this mainly occurs around the 4 centre bolts (those directly beside the carb) but also appears around some others. I have used a special stud sealant each time & followed the correct tightening sequence & tension all to no avail.
Is this just a common problem with no fix or am I missing something?

Cheers SoS
 

[Chryco Psycho]

are you running a PCV system ?

[South of Sydney]

are you running a PCV system ?

Yes I am Chryco, any suggestions?

Cheers SoS
 

[Chryco Psycho]

well only 2 ways oil can get there either up the threads or between the intake & heads so either the gasket has failed or the boltts are loose or the threads are not sealed up well enough

[moparmaniac59]

I had problems with the intake leaking at the front from the head to block joint, but not around the bolts. What type of sealent have you used?? have you tried permatex #2? Also have the heads been cut down any?? This could change your mating face angles. Just a thought!!


                                               Matt B.

[Changin Gears]

I always use permatex #2 also.

[South of Sydney]

As I said I have used a GM brand stud sealant on the threads each time, could it be that I just need to use brand new bolts? Has anyone had the problem & then fixed it by some action or another?
I'm open to all suggestions.

cheers SoS
 

[loco440]

 :aussie:One way I fix stud leaks is use a very clean thread chasser washed in spirits (not scotch) each time after use and clean bolts on a high speed wire brush and again wash them, use Permagasket from the little white bottle,coat your bolt threads and insert carefuly so you dont get goop every where (mongrel to clean off) and tighten,sure fire fix.

[South of Sydney]

Thanks guys
I have the engine out at the moment so I'm going to get a new manifold gasket set clean up & check all threads & try thr Permatex no. 2 as suggested. The only common thing over both engines etc is the stud sealant compound I have been using.

Will let you know how it goes.

Cheers SoS
 

[71chally416]

I'm thinking your threads are out of tolerance. Screw the bolts in with the Intake off and see if they wobble in the threads. If they're really bad helicoils are an option. 

[South of Sydney]

I'm thinking your threads are out of tolerance. Screw the bolts in with the Intake off and see if they wobble in the threads. If they're really bad helicoils are an option.

Yeh that's possible but remember this problem has occurred on 2 different engines with different heads & bolts,
I tend to subscribe to the sealant being the culprit. I've just had a few replies on Mopar Market (Aussie site) to a similar post & a few guys have the same problem. Rest assured I will take your advice & check the bolts before reassembly. I'm just waiting for a gasket set to show up, only specialty shops in Australia keep Mopar small block stuff.

Cheers SoS   

[Aussie Challenger]

  I would be definetly checking the mating surfaces, if the heads have been machined the angles have changed. Also was the manifold new or 2nd hand, it may have been machined before, the flat surface mating to the valley may not have been reduced causing the inlet faces not to seal.
  The GM sealer is great thread sealer but not needed.   

[South of Sydney]

JS29NOB & Aus Chally

I agree with your thoughts but I have checked the mating faces on both sides of this current assembly & they are ok. What you guys have missed is this problem is consistent on 2 different blocks, 3 different pairs of heads, 3 different manifolds (2 of which were brand new) & over about 10 pull downs & reassemblies each time with new Felpro gasket sets. Also since starting this thread both here & on the Aussie Mopar Market site numerous others have put their hands up & admitted having the same issue, I will be refitting the engine in the next week so we will see if the Permatex has done the job.

Cheers SoS