Hey everyone I got an oil leak on my truck. And I was wondering what are some possibilities that it could be. It looks like the rear main seal leak

 

Could be:

Intake manifold
Valve cover
Head gasket
Oil pan
Camshaft seal
Rear main seal
Etc

The point being you need to crawl under the truck and look. If you think it looks like the rear main seal start looking there to try and confirm nif you need some help get some uv dye and a black light and let it idle forna while and check again. Don't driven it after putting the uv dye in asbit could cause it to spray and make it tough to track down.

 

check the oil sending unit first. did you add a oil pressure gauge? if you used ANYTHING other than steal break line tubing, THAT is your trouble.

 

Look for the general area where it looks wet and then use the uv dye, or you could guess and just replace stuff both that can be frustrating and costly and time consuming, a little bit of diagnostic can go a long way.

 

Oil pressure sender & Distributor o-ring as well.

I've been aggressive about getting rid of fluid leaks on my 96 (5.2, 4wd, automatic, 229,000 miles.) So in the past couple of months, I've replaced the rear main seal, replaced both differential cover gaskets, the axle seals in the front differential, intake manifold gaskets (and a new 1/4 in thick valley pan,) distributor o-ring, water pump and gasket (be sure to seal the bolts with rtv as well,) thermostat, housing, & t-stat gasket.

If you have a 4wd, you will probably have to take the front axle down to get to the oil pan. So you might as well clean it up and replace the seals.

I've got the engine tightened up enough that I've put the driveway catch pan away. Still have a leak on the front input shaft of the transfer case to repair.

Oil and coolant leaks are just not acceptable. Especially coolant leaks which can be toxic to pets.

 

Let us know what you find, Rocco. I agree with Brian, any kind of leak drives me nuts! Can't stand leaks.

 

If his engine is like mine was, there are multiple leaks and pretty much oil everywhere. So some general cleanup before you try to find the leaks(s) is generally in order. I got busy with the degreaser from Dollar Tree (LA Totally Awesome Degreaser) which is available in a 1/2 gallon jug for a buck. Spray it on, agitate with a brush (a parts cleaner brush from an auto parts store will do,) rinse off with garden hose. And repeat as necessary. Then wipe the suspected areas that you can get to with paper towels (have lots on hand.) Now you can try to hunt down the leaks.

Mine was the rear main seal and the plenum end gaskets (they came out in pieces.) The pan gasket was in good shape, so I sprayed it with Permatex Copper gasket spray (both the gasket and pan) and gooped the seal on both ends--and ended up only replacing the rear main seal down below. For me it was about a 4 day job, but I did a bunch of cleaning and replaced seals and gaskets in the front axle (4wd.) The rear main seal was the easiest part of the job, btw.

I would have preferred to do the projects with the engine out of the truck, but that wouldn't be possible where I presently reside.

Getting the front axle back in would be impossible, I think, without a motorcycle jack. (Later models have an aluminum front axle, mine was cast iron.)

Up top, I got the plenum off as I was still getting oil leakage and a coolant leak developed. The small hose that runs between the water pump and the plenum was also bad. I ended up replacing the water pump, and all the hoses. I don't want to do this again. . .

If you're working on a V8, Rockauto is the best source for your parts. Get the complete Dorman Intake manifold gasket kit--it's very complete and includes the intake gaskets, valley pan gaskets, new valley pan bolts, new intake manifold bolts, a thermostat and gasket, and an o-ring for the water pump pipe. Get the distributor o-ring--it's the cheapest way to get it is with an existing order. Get the rear main seal, and the valve cover gaskets, too. And while you're at it, you might consider new motor mounts. I think, total, I spent about $200 on parts for the oil sealing, coulda done better if I'd gotten them all from RockAuto, O'Reilly and Autozone most often can't even come close to Rock Auto's prices--be sure to get a discount code before you place your order. Be sure to do comparison shopping, of course.

Someone will mention Hughes Engine's 1/4 inch valley pan kit. I ran out of money on all this, and ended up getting a piece of 1/4" aluminum plate and fabricated my own. The Dorman gasket kit appears to be the same one that Hughes includes with their kit, I used the valley pan gasket as a template and rough cut the plate with a circular saw and did the shaping with a well oiled router bit chucked into my drill press--and drilled the holes with the drill press--used lots of copper RTV.