Where to use rtv on oil pan?

[5.0fox]

I apologize ahead of time for the long post

When I first got the 1028 home I noticed it was dripping oil pretty good from the very front edge of the oil pan where it is turned down. It was leaking pretty good and after researching here a good bit I decided I would check the cdr first. I pulled it off and cleaned it (even though it did not seem dirty to me at all). Drove it for a few more days and it was still leaking bad. About 10 days ago Me and my brother pulled the pan and put a new gasket on it. I thought it was strange that there was no gasket except for the small rubber one over the rear main cap, but after reading the tm i understood this to be normal. I decided to use a full gasket when reinstalling the pan as I didn't want to have to do this twice. I i used a small bead on the pan and placed the gasket in it then ran a small bead on the block. Put everything back together and the leak was gone......for about a week.

I don't know if it would be related or not as I cannot imagine how it would be but I was driving on a back road and was pulling up a steep hill (so the engine was working pretty hard) and heard a noise all of the sudden. Kind of a low humming sound. Came to a stop and it slowed with the engine rpm it seemed. Checked the transfer case, transmission and all fluids everything seemed fine. But after that I noticed it was leaking oil out the converter inspection cover pretty badly. I tried to get the truck to duplicate the noise again but I could not. So I pulled the inspection cover and saw that where the pan goes over the rear main cap oil was leaking very badly over the pan lip under the rtv. So my question is where do I use rtv? are you not supposed to use it on that back edge?

 

[pigfoot63]

Each mechanic has thier own way of sealing . I never use a pan gasket on a 6.2 . I perfer the permatex ultra black.
On the rubber seal on the main cap I use a little gasket sealer suckh as # 2 permatex to hold it in place while I
install the pan. Sometimes you will find your self using more RTV. than you needed.

 

[5.0fox]

Ok, did the oil pan again. This time i used permatex right stuff, which was a very good product I thought. I let it idle for an hour after the job, then took it for a drive and no leak. Today we were heading to a jobsite and got a flat tire. I had to leave the truck and get a jack and spare and come back with another truck. By the time we got back to the truck I immediately noticed it was steal leaking a considerable amount of oil.

Brought the truck back to the house and pulled the inspection cover...which had oil covering the inside of it. It is still dripping oil off the bottom edge of the pan where it goes over the rear main cap. Seems to be very wet along both sides of the bell housing inside and out. It's dripping off the starter and the front driveshaft. I checked with a flashlight and mirror up top at the vacuum pump and oil sending unit and I see nothing leaking this amount of oil. The valley looked slightly oily but it looked to dry to be causing this much leaking. The only oil that I can see actually moving is right near the starter on the outside edge between the block and bell housing. It almost looks like it is bubbling out between the two. Is it possible the block cracked along the top two bell housing bolts? I don't really know where to go from this point except pull the tranny and take a closer look. Any ideas or wisdom you guys can share? thanks

 

[doghead]

Rear main seal(crankshaftt)?

Or, does the 6.2 have a "freeze-plug" at the end of the camshaft, like a gas V8 does? Maybe there?

 

[pigfoot63]

Yes you do have a cam plug but they rarely leak. You may have a valve cover leak annd it is running between the bellhousing. Check to see if what your leaking is not diesel sometimes the pump leaks and runs down the back of
the block.

 

[5.0fox]

I checked the back of the engine pretty well with a mirror but I will look again tomorrow. I felt all along the back of the heads etc and it felt dry. I looked at the rear main pretty close both times and even now it looks dry. There is no oil on the flywheel itself, just running down the inside and outside of the bell housing and back of the block. What seems weird to me is that it wasn't leaking at the back of the motor like this before the first gasket I did or at least I did not notice it. It started leaking after the humming sound I described in the first post. I will check the valley again, as it did seem a little oily but nothing serious. Hopefully I just missed something simple..

 

[CUCV85]

exactly the same

Ok, did the oil pan again. This time i used permatex right stuff, which was a very good product I thought. I let it idle for an hour after the job, then took it for a drive and no leak. Today we were heading to a jobsite and got a flat tire. I had to leave the truck and get a jack and spare and come back with another truck. By the time we got back to the truck I immediately noticed it was steal leaking a considerable amount of oil.

Brought the truck back to the house and pulled the inspection cover...which had oil covering the inside of it. It is still dripping oil off the bottom edge of the pan where it goes over the rear main cap. Seems to be very wet along both sides of the bell housing inside and out. It's dripping off the starter and the front driveshaft. I checked with a flashlight and mirror up top at the vacuum pump and oil sending unit and I see nothing leaking this amount of oil. The valley looked slightly oily but it looked to dry to be causing this much leaking. The only oil that I can see actually moving is right near the starter on the outside edge between the block and bell housing. It almost looks like it is bubbling out between the two. Is it possible the block cracked along the top two bell housing bolts? I don't really know where to go from this point except pull the tranny and take a closer look. Any ideas or wisdom you guys can share? thanks

My M1009 does exactly the same thing. I had a small leak at the rear main seal so I changed it out with the rubber one (Very Careful not to puncture or tear) I also used RIGHT STUFF on the entire Engine Oil Pan. I leak up front, the back and exactly the way you discribed up by the Starter. I will eventually have to re due the entire job. I must have installed the Rear Main Seal incorrectly!? I remember you have to off set the 2 peice. Pan bolts are at correct torque. I go through a quart and a half per 3000 miles so not to bad for now... Let us know how you turned out. I do believe start with the rear main seal, sorry not to fun of a job. Search on here there is a post that tells you step by step what to do. I tell you what, I am sick of seeing my rebuilt starter covered with oil! I wipe it off at every oil change. By the way Just turned 80k.

 

[5.0fox]

Well, rear main has been installed for probably 2 weeks and it is still leaking almost as bad as before. I followed the tm exactly using anaerobic sealant on the main cap where it recommended and a small amount of pipe sealant in the seal groove on the main cap. Also offset the seal by ~1/2". I don't know where to go from here but it's still leaking as before. I will check the Back of the block for ip leakage and around the Vac pump and oil sending unit again but it was all very clean before. If that is clean I guess the next step is pulling the tranny and checking the plugs in the back of the block?? I'm still wondering if the block isn't cracked or something. It's irritating though especially after pulling the pan 3 times .

 

[lavarok]

You most likely have a blown head gasket that is pressurizing the oil pan.

I had the same EXACT issue with one of my CUCVs. I changed the rear main and redid the pan at least three times before I swapped out the engine. I also had excessive pressure in my cooling system.

I still need to tear the old one apart to know exactly what the problem was but my bet is the head gasket.

Good luck.

 

[kassim503]

I prefer to use permatex orange, laying a 1/16th bead smoothed with finger across the entire sealing surface of the pan, with a little extra around that back circle part and the angles on the front part. I think the key is waiting that hour before going from finger tight to torqued down.

Oh and a wee bit on the dipstick hole

Using a quart or two per oil change really isnt all that bad, How bad are all of your driveways getting ruined?

 

[5_TON_TOMATOE]

Silicone with gaskets

I never use silicone on a pan gasket. The silicone is slippery, and tends to let the gasket squeeze out from between the pan and the block. I use High Tack, or my favorite is Coppper Coat. I only use silicone where the timming cover/ rear main gaskets meet the pan rails

 

[JAsher45]

it is very improtant to clean all sealing surfaces with alcohol prior to assembly... if there is any oil residue it will not seal... i had a similar leak on the rear... my oil prssure sending unit was leaking down the back of the engine.... if yyou get it sealed good you should and will almost damage the pan when you take it off... i normally have to use a putty knife to cut the right stuff betweent he pan and block ti get them apart.

 

[5.0fox]

I used right stuff on the pan thiis time as well and it works awesome. It is not leaking on the pan this time around. It still appears to be leaking from rear main, but as said before i can visually see oil almost bubbling out of the gab between the bell housing and block on the starter side. I can't figure out how the starter is getting so saturated unless it's just blowing over there while driving. I checked and cleaned the cdr valve and it looked new. And it doesnt's seem to have any blow by that I can detect. At this point I am just going to run it and add oil as needed