My Gigantic Oil Leak - Your advice welcomed

[Veg_Out]

Hello all,

I have had an oil leak on my Burb for a couple months now, and every week or so, I replace a seal, or a part thinking I must be correct.

Here are the symptoms. Drive for 5 minutes, no leak. Drive for 10 minutes, pancake sized leak, quickly too. It's dripping out after shut down pretty quickly, then stops. One pancake's size leak, then no more dripping.

1st thing I replaced was the Oil Pressure sensor since it seemed as though oil pressure was causing the leak. As soon as it leaked off, voila, no pressure in the sensor, but to no avail, still leaking.

2nd idea came from a friend of mine, change the seals in the 4WD adapter. I thought for sure this was going to do it. I got her all bolted back together, and drove for 5 minutes, no leak. Jumped up and down with joy in a parking lot. Drove home, looked again, and my joy turned to sorrow in an instant. (I must admit I swore loudly.)

3rd thought was a stretch I'll admit. My fuel manager was leaking, so I thought it must be leaking a bit under pressure, picking up oil in the valley and down the back of the motor (running B100) and making it look like an oil leak. So I rebuilt the fuel manager. While this was not fun, it was educational (a new thread on that shortly). My fuel manager now holds fuel pressure alot better, but the oil leak has not ceased.

I'm down to possibly 3 more ideas. Valve cover, running then through the valley and down, turbo drain tube seal and of course, the dreaded rear main.

Your thoughts are welcomed.

 

[Turbine Doc]

Orings at block oil cooler line quick disconnect fittings

 

[DieselSlug]

Orings at block oil cooler line quick disconnect fittings

X2, check your quick connect fittings. Are the oil lines stock metal to rubber crimp?

 

[Veg_Out]

X2, check your quick connect fittings. Are the oil lines stock metal to rubber crimp?

Another intriguing clue. Does not leak while running. Shut it off, and voila, a pancake of oil comes out, then nothing.

Stock oil cooler lines, new within the last 2 years, but that's not unusual I think.

I just tested it as I got home, it almost has to be on or near the bottom of the motor, since at shutoff, it's instantly leaking. Serenity now, serenity now.


How would a person change those o-rings?

 

[mfgguru]

I think you have to pull the retard clips, and the orings reside in the fitting on the block, could be mistaken though. Correct me if I am wrong.

 

[Turbine Doc]

If leaking from those locations, undo spring clips and lines come away from block, possibly no leak when running as they possibly seal under heat/pressure as they move away from block fittings under pressure, you say lines 2yrs old, did you put new orings on lines when replaced ???, are spring clips intact, possibly one "fixin to" fail

 

[Veg_Out]

If leaking from those locations, undo spring clips and lines come away from block, possibly no leak when running as they possibly seal under heat/pressure as they move away from block fittings under pressure, you say lines 2yrs old, did you put new orings on lines when replaced ???, are spring clips intact, possibly one "fixin to" fail

I don't know, as I hired that work out. I'd like to think they changed the I rings, but I have since abandoned that shop because I've gotten to be a better mechanic. Can a person get the clips separately? Sounds like it might be time for a new oil cooler set.

 

[DieselSlug]

If you buy an new set go stainless, they dont have reducer couplers and quick connect fittings that are prone to leaking. If it was your rear main or something like that it would seep out all the time,and since its not while its running its not like the cdr is plugged....

 

[Matt Bachand]

Have you wiped it all down and then run it good and lay underneath it on top of cardboard to REALLY try to see where its seaping from?.

 

[Turbine Doc]

If your leak is from the lines, now would be a very good time to replace with stainless, staying with GM designed lines is like trying to make a lame dog hunt

 

[Veg_Out]

OK,

It appears to be coming from the weap hole in the bottom of the bell housing. Yes, you'd think a rear main would leak all the time. Why they painted the motor bla

It isn't the cooler fittings into the block
it's not the 4WD adapter
it's not the fuel manager
it's not the OPS

I have placed dye into the thing, and went into the dealership. Of course, they believe it's the rear main, but I've just spotted oil pooling on the top of the passenger side head. I've cleaned it up and will be heading for a drive. This is driving me crazy, and I need the vehicle for large summer travels in 3 weeks. It's leaking about a quart per day of around town errand running. My love for this burb is waning. It's lucky I don't have fuel to purchase.

Could a head be cracked and leaking oil?

 

[Veg_Out]

OK,

It appears to be coming from the weap hole in the bottom of the bell housing. Yes, you'd think a rear main would leak all the time. Why they painted the motor black?

It isn't the cooler fittings into the block
it's not the 4WD adapter
it's not the fuel manager
it's not the OPS

I have placed dye into the thing, and went into the dealership. Of course, they believe it's the rear main, but I've just spotted oil pooling on the top of the passenger side head. I've cleaned it up and will be heading for a drive. This is driving me crazy, and I need the vehicle for large summer travels in 3 weeks. It's leaking about a quart per day of around town errand running. My love for this burb is waning. It's lucky I don't have fuel to purchase.

Could a head be cracked and leaking oil?

Also replaced the CDR yesterday. You guessed it. Still leaking.

 

[DieselSlug]

Where exactly is it pooling oil?? In the valley by the passenger head??

 

[Veg_Out]

I will attempt to recreate the conditions and photograph the problem.

Thanks.

 

[Rodd]

I think I figured out why your truck is leaking. The last repair that I recall you posting about was your new crack repair kit. If you go back to the way it was before the crack then that should stop your motor from leaking. Lol. ):h

I just couldn't resist. Sorry for your pain.

 

[Missy Good Wench]

If the oil is running out of the weep hole in the bell housing then the oil is either coming from the rear main or is running down the valley and into the bellhousing then out.

Look down under the intake manifold with the engine running. If there is wet sloppy oil there, then go further to find why.

Best

Robyn

 

[Veg_Out]

If the oil is running out of the weep hole in the bell housing then the oil is either coming from the rear main or is running down the valley and into the bellhousing then out.

Look down under the intake manifold with the engine running. If there is wet sloppy oil there, then go further to find why.

Best

Robyn

Well, we are going in deep to get the rear main. Mechanic says "sometimes the crank gets a groove, and you need to place a sleeve on the shaft."

Is this true of our 6.5's? Is anyone seeing a rear main groove on their crankshafts, and if so how are you addressing it when putting one back together?

Thanks for your help.

 

[Rodd]

If it is the rear main I just saw a product on horsepower tv that helps the rear main to swell so it wont leak. You put it in w/ each oil change. I think o'reileys has it. It's worth a try.

 

[Veg_Out]

Sadly, it was the rear main, possibly the rear cam
shaft plug, I'll never know as we changed both. Leak is gone.

While apart, I did the golfball test on my crossover, and it failed. New warpseed from the bay fit perfectly. I did try a vendor first, but he was out. I joked that he will only get 95% of my business this year.