[timmah333]

Hi everyone,

I am having a fun little issue on my Nova after driving for 45 minutes or so. I first noticed it when I got home one day and went to verify my oil and transmission fluid levels and noticed some small puddles of dark brown fluid in the valleys of the intake manifold. They are only on one side (passenger side) and right in the middle three valleys. The fluid could be fuel but it seems a bit dark for that. None of the fuel lines seemed to be wet like I was having a leaky fitting either.

Setup is a SBC 350/ TH350 with edelbrock intake manifold and edelbrock 1406 carberator. The build is only about a year old and with maybe 1000 miles on the fresh build.

Any ideas would be welcome.

Thanks

 

[Rupertflood]

check you anti freeze level....look for a leak at the Tstat neck. My car leaks there and the antifreeze turned black once it got into the valley and absorbed heat.

 

[timmah333]

check you anti freeze level....look for a leak at the Tstat neck. My car leaks there and the antifreeze turned black once it got into the valley and absorbed heat.

I'll definitely check that. Thanks for the idea.

 

[msaul]

Dark Fluid

I suggest you check the viscosity of the mystery fluid.
It could be oil that seeped from under your valve covers
and your 1000 mile gaskets.

 

[bracketchev70]

I am going to say its oil. The intake manifold bolts pass into the lifter valley through the head. It is very common for people to not realize this. The oil being splashed around the lifter valley can wick its way around the bolt and out into the intake. The easy fix is pull 1 bolt at a time, coat the threads in sealant and put them back in.

 

[timmah333]

I suggest you check the viscosity of the mystery fluid.
It could be oil that seeped from under your valve covers
and your 1000 mile gaskets.

The viscosity doesn't feel like oil to me. Is seems much thinner.

 

[timmah333]

I am going to say its oil. The intake manifold bolts pass into the lifter valley through the head. It is very common for people to not realize this. The oil being splashed around the lifter valley can wick its way around the bolt and out into the intake. The easy fix is pull 1 bolt at a time, coat the threads in sealant and put them back in.

Thanks for the information. Very interesting. I'll give that a try.

 

[dont]

I had the same issue on a 350. The two center bolts on both sides of the intake were wicking oil up to the top of the manifold. As suggested pull one at a time, clean the oil off the bolt and threads, put a little gasket sealer on the threads.

 

[Duntov]

Agreed with comment below and have had it happen on many SBC motors

I am going to say its oil. The intake manifold bolts pass into the lifter valley through the head. It is very common for people to not realize this. The oil being splashed around the lifter valley can wick its way around the bolt and out into the intake. The easy fix is pull 1 bolt at a time, coat the threads in sealant and put them back in.

 

[msaul]

Black ooze

Applying teflon sealant to the intake manifold's "through" bolts is a good idea, even if the fluid turns out to be coolant.
It is not unusual for the neck of chrome plated thermostat housings to leak at the hose connection.

 

[dokks6t9]

I am going to say its oil. The intake manifold bolts pass into the lifter valley through the head. It is very common for people to not realize this. The oil being splashed around the lifter valley can wick its way around the bolt and out into the intake. The easy fix is pull 1 bolt at a time, coat the threads in sealant and put them back in.

Bingo!! Very common problem with the Chevy smallblock.