Well boys, been about a year since I had my last battle with the legendary oil pan on the 5.9 magnum and I am reluctant to say.... third time was not the charm! Leaked for the 3rd time using fel pro gasket, had dowels and rigisouly cleaned both surfaces and torqued bolts to spec yet still leaks so I am throwing in the dirty oil soaked towel on this one. My hats off to all that say it was an easy job and successfully did it.


Anyone have an idea what I can anticipate a shop?

 

Is it the oil pan gasket that's leaking or something else, like the rear main seal? Can you pinpoint exactly where the oil leak is coming from?

 

Yeah, I would throw some dye in it, and verify where the oil is coming from.

 

That is a very good point. The reason why I suspect it being the pan and not the rear main is because when I initially got the truck, I was trying to diagnose an excessive oil consumption issue as well as preparing it for a coast to coast trip. In the process, I removed the pan to check the oil pump and ever since its been leaking. Though, the location would be indicative of a rear main leak since its coming from the bell housing/dust cover on trans.

The dye idea sounds promising... how does it work

 

Clean the engine off good, add some dye to the oil. Drive it for a day or three, then use the UV flashlight/goggles to see where it comes from. Works REALLY well. It is patently obvious where the dye is.

 

I'll look into it. Any recommendations on brand/product? One on amazon is $26 bucks lol! Also, if it is the rear main, will I be able to actually see it from the source? or will it become visible at some point once the oil has gotten to a location? Just worried the trans/oil pan will prevent me from seeing

 

Also, might want to clean the engine up real good and also check for leaks coming from the top of the engine that may make it look like the oil pan or rear main seal is the culprit. The most common areas are the oil pressure switch (leaking) or the valve cover gaskets. The dye will also help with that, too.

 

On the 2000 MY where I recently did VC gaskets you knew it was responsible because the tops of the exhaust manifolds were noticeably "stained"

The last time I just grabbed a dye kit at an O'Reilly or AZ.

 

Also if it's rear main you'll get to do the oil pan again

BUT you don't have to pull the trans so that's good. There's a zillion YT vids for the Magnum rear main if you need it.