M1009 Oil Leak - Need help

[McCluskey]

I got my M1009 last week, and I have noticed a very small consistent oil leak. It is black engine oil not Tranny oil. The drip is coming from the front end, roughly dead center. It appears to be coming from above the oil pan, and whatever the other large pan directly behind it is. It is very small, but consistent: idling or sitting.

http://i79.photobucket.com/albums/j135/plisky/IMG00026-20110105-1903.jpg

http://i79.photobucket.com/albums/j135/plisky/IMG00027-20110105-1904.jpg

http://i79.photobucket.com/albums/j135/plisky/IMG00030-20110105-1904.jpg

http://i79.photobucket.com/albums/j135/plisky/IMG00033-20110105-1905.jpg

http://i79.photobucket.com/albums/j135/plisky/IMG00031-20110105-1905.jpg

Oil level has lowered.

http://i79.photobucket.com/albums/j135/plisky/IMG00037-20110105-1908.jpg

The original pic files are much larger, I can email them if you need.

 

[cucv1833]

Have you cleaned everything in that area and look for the leak again.
maybe just a simple oilpan gasket/seal
I dont recall that other hole in picture #5 maybe someone else knows what it is

 

[DokWatson]

Hard to tell from the pictures, you can't diagnose an oil leak from the bottom... you start from the top and see where it starts. Could be anything.

Looks like the pans used in winterization kits, its a cover that is welded on. The holes vent exhaust from the oil pan heater. If it was an actual hole in your pan, there would be about 7 quarts of oil on the floor. Don't know why it would be on a CA truck though, unless it came from somewhere else originally.

 

[CUCV85]

That hole appears to be the flywheel "flex plate" cover. It is suppose to be there. My CUCV M1009 does the same thing. I have replaced the old original rope seal for the rear main bearing. It didn't help a whole lot. Advise was given to start at the top. CORRECT. I have to take my flywheel cover back off spray it all up with break cleaner and see just where the oil is seeping from. I did replace the oil pan with Right Stuff Gasket Maker. I was told it was the best. I may take the oil pan off and use the preformed gasket type instead. I do know on here that it is discussed that some of these oil pans pre 84 I believe you had to use a gasket. Discussion was a flat type bottom or rounded oil pan. I am going to research that for myself. You have to appy some gasket maker "rtv" to the front. Sometimes a leak from that hole in the flywheel cover is from a failing or leaking Injection Pump! Usually the throttle shaft seals "o rings" fail and a pool of fuel will travel down toward the rea of the engine in the v shaped top to a little hole "that is suppose to be there"
Fuel runs down that hole by the Vacuum pump. It runs down the inside of the flywheel cover those running out that hole in the picture. You appear to only have an engine oil leak! Fuel will cause quite a mess under there and has a nice odor. I had my IP throttle shaft seals go and I replaced them. 3 months later the IP died and I rebuilt. If someone goes through the trouble to just replace those seals you might as well rebuild these 25 year pumps IMHO. I am taking a wild guess here and saying your rope gasket should be replaced. Although there could be another leak from up higher. Start at the TOP and work your way down. There is a page here that tells you step by step on how to change out the rear main seal without pulling the engine.

I got my M1009 last week, and I have noticed a very small consistent oil leak. It is black engine oil not Tranny oil. The drip is coming from the front end, roughly dead center. It appears to be coming from above the oil pan, and whatever the other large pan directly behind it is. It is very small, but consistent: idling or sitting.

http://i79.photobucket.com/albums/j135/plisky/IMG00026-20110105-1903.jpg

http://i79.photobucket.com/albums/j135/plisky/IMG00027-20110105-1904.jpg

http://i79.photobucket.com/albums/j135/plisky/IMG00030-20110105-1904.jpg

http://i79.photobucket.com/albums/j135/plisky/IMG00033-20110105-1905.jpg

http://i79.photobucket.com/albums/j135/plisky/IMG00031-20110105-1905.jpg

Oil level has lowered.

http://i79.photobucket.com/albums/j135/plisky/IMG00037-20110105-1908.jpg

The original pic files are much larger, I can email them if you need.

 

[91W350]

Looking at how thin the majority of the accumulation is and the drip pattern without accumulation on the area parts, the wet differential, I would guess that your lift pump is leaking or a hose there abouts. Many times the fuel leak will find the battery cable and run down the pan rail. Those faded oil spots on the floor look like diluted oil drops or diesel wash down. Glen

 

[rnd-motorsports]

I would go over the oil pan bolts and make sure they are all snug NOT tight just snug wipe it down fill the oil and start it let it run and check to see where its from the hole is in the flywheel cover and is a factory hole. Some very good advice above the fuel pump oilpan gasket if it leaks just idleing then I would cleanit and let it run be carfull get under it and find where its leaking from. You can take that cover with the hole you asked about off there should be 6 bolts holding it on it just a cover or gaurd if you will and then look up at the rear main seal with a light to see if its leaking do this with it shut off not running!!! if its leaking will be easy to see will have a clean streak from it WHAT I saw in you pics I would lean to the oil pan or fuel pump but you really never know with a small leak they will travelalong other parts sometimes and be hard to find!

 

[McCluskey]

The truck had just gotten back from being power-blasted at the local car wash. Just got back from picking her up from Denver, trying to get the salt off. The wetness and additional dripping may be from them. The winterizing kit may be that it was a Colorado Army truck. There is rubber matting and carpet insulation on the floor.

Today or tomorrow I'm going to lift it up and clean the bottom out and really try to track this leak.

 

[fuzzpuss]

From what I can see is your gasket on your drain plug is leaking, and that is your flexplate/ torque converter cover in the other photo and yes that hole is supposed to be there. The air is blowing the oil all over thew place.

 

[Napoleon_Tanerite]

Mine has leaked oil from the driver's side ever since I got the truck. I consider it to be a fluid presence indication. If it ever STOPS leaking, I get worried.

 

[DXTAC]

I replaced the rear main seal and that helped reduce my leaking quite a bit. I then discovered the P/S valve cover is leaking too! I went to tighten the bolts and I couldn't even see the bolt due to the buildup of sludge on the cover itself. That's gonna wait till it's warmer out to fix. The front pump seal on my tranny is also leaking a bit so I have trans fluid coming from the weep hole too. That may go into a shop to have them fix that, lots of specialty tools and experience needed for that!

Like people above have stated, start at the top and work your way down.

Good Luck!!!