94, 4.0 Oil leak after rebuild

tbunch · May 13, 2016

I'm probably abusing the need urgent help section, but I am working on this right now and need a little input.just completed full rebuild, new everything. Been breaking it in and have only put about 10 miles on it and I have an active drip. Since I've totally cleaned and painted everything I figured it would be a snap to identify the leak... Silly me for thinking things would be easy!

When I run the engine at 2k Rpms I am getting oil beading on the bottom edges of the driver side motor mount bracket, right next to the oil pressure sender. I've ruled out the level sensor as its bone dry and the leak is clearly above it, I feel like the pressure sender is dry too and I used thread sealant on it to make sure it didn't leak. All I can think would be dripping onto the mount bracket would be the valve covers, but the're bone dry as well. (So are the head gaskets)

The leak appears to be isolated to the driver side, towards the front and is running down the cross member and dripping off the center. I can't see any seepage from the timing cover either and the front crank is not dripping or throwing oil. I realize this is like asking to find a needle in a haystack so I'm really just trying to get any similar experiences so I don't end up pulling the motor out, or ripping everything off it again, just for kicks

Any help/ideas are appreciated!

Tedybear · May 14, 2016

Doing this from work, so I hope it works. I would use a vial of UV dye made for oil systems and leak detection. Wipe everything down and run it for a short while. The UV will show up under a black light. It should be a bit dark to see where the 'glow' is coming from. Might also get an inspection mirror with a light. These are just random ideas. Others know more about these engines then I do.

Sent from my SAMSUNG-SM-G530A using Tapatalk

tbunch · May 14, 2016

That's where I'm headed, I'm also thinking its possible its power steering fluid, it doesn't have a smell though, which is even more perplexing. That being said the location of the leak could really be P/S as there is not really anywhere oil would be escaping... Who knows.

tbunch · May 14, 2016

I grabbed some uv dye, drove around for about 25 minutes and checked it. It seems like the main leak is power steering since its dripping but there is no UV dye in the drops. I idled the truck at 2k Rpms and crawled all over it with a light and mirror as well and at that engine speed I can see fluid beading on the bottom of the P/S pump which confirmed my thinking.

Ill put some more miles on and check for signs of th UV dye that would mean I also have an oil leak. For the P/S pump I'll just run some blue devil stop leak until I get a chance to throw a new pump, gearbox and lines on, just don't have the time or money since I invested so much of both into rebuilding the motor and trans.

Tedybear · May 15, 2016

tbunch said:
I grabbed some uv dye, drove around for about 25 minutes and checked it. It seems like the main leak is power steering since its dripping but there is no UV dye in the drops. I idled the truck at 2k Rpms and crawled all over it with a light and mirror as well and at that engine speed I can see fluid beading on the bottom of the P/S pump which confirmed my thinking.

Ill put some more miles on and check for signs of th UV dye that would mean I also have an oil leak. For the P/S pump I'll just run some blue devil stop leak until I get a chance to throw a new pump, gearbox and lines on, just don't have the time or money since I invested so much of both into rebuilding the motor and trans.

Look at the bright side. PS pump is a heck of a lot easier then to re-gasket an engine. You can also use the UV dye in power steering fluid, but it might muddle up the results and throw false positives.

S-

tbunch · May 15, 2016

Indeed, the frustrating part would have been I just put all new gaskets on the motor so I was pissed I thought it was leaking. I drove it another 20 miles and checked it all over and there seems to be no trace of the UV dye so I think it's just the P/S.

Tedybear · May 15, 2016

tbunch said:
Indeed, the frustrating part would have been I just put all new gaskets on the motor so I was pissed I thought it was leaking. I drove it another 20 miles and checked it all over and there seems to be no trace of the UV dye so I think it's just the P/S.

I know the feeling. Just got done dumping almost 500 into our current project in parts, and still need tires.

You do all that work and it's like someone thumbs ya in the eye....

S-

94, 4.0 Oil leak after rebuild

tbunch

New Member

Tedybear

New Member

tbunch

New Member

tbunch

New Member

Tedybear

New Member

tbunch

New Member

Tedybear

New Member

Sponsored Ad

Sponsored Ad

Staff online

Members online

Member & Vendor Upgrades

Latest posts

Truck of The Month

Recently Featured

Follow TRS On Instagram

Latest Album Photos

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store

Sponsored Ad

Sponsored Ad

Sponsored Ad

Amazon Deals