PITA oil leak diagnosis. (1 Viewer)

[jpneely]

Long story short, been trying to find this oil leak for close to a year now. It started as 2 tiny ones, one of which I took care of. The oil filter housing oring was leaking. Fixed. Everything cleaned up, then the next oil change, more oil on things. Never enough to drip onto the ground so it takes a while to show up.

My gut keeps telling me it’s the upper oil pan gasket but my mechanic keeps telling me there’s no way. Could be steering rack, but the oil level doesn’t drop at all. I’m going to post up some pictures of the area that I think it’s coming from. Let me know What y’all think.

It also crossed my mind That it could be the dipstick tube but I think that’s the least likely culprit. Also not the valve cover gaskets. That area is clean as a whistle.

Excuse the crappy pictures. I was laying on the ground trying to hold the flashlight and get the phone to focus on the right thing. I’ll keep monitoring but see if something sticks out to y’all. These are driver side oil pan area.

 

[delz05]

Only an opinion... I would clean up the entire area and begin with the easiest repair.. the oil tube o-ring, when you do your next oil change.

 

[suprarx7nut]

These leaks are always the most annoying.

I'd clean it up like crazy (arguably the hardest part) and then add some UV dye to the oil. Follow the dye in the dark with a UV flashlight and glasses.

 

[excessive]

looks like the dipstick tube o ring, which is super simple to replace.

 

[jpneely]

I’ll start with the oring and see where that gets me. Thanks guys.

 

[2001LC]

All dipstick O-ring, eventually weeps. The rubber O-ring shrinks with age. Over the years/miles, the oil builds up around pan. Eventually, moves around oil pan and forming a drip. Many have though this to be and oil pan leak. It's not a pan leak!

Scored 00LX w/557,333 Km, Emerald! No start condition. needs a ton of work. No Problem!

What is the ID size of the clear hose/tubing you used? Sorry just now saw this question. Anyway, I just now went out and measures OD of pipe coming from oil cooler behind grill. It's 12mm OD hard line. So a ~10mm ID would fit very tight. 11mm ID likely sung and 12mm ID my be a bit on loose side.

forum.ih8mud.com

 

[anthonydiaz85]

I thought I had a lower pan leak. I replaced the dip stick o ring and it stopped. But then I found the bolts holding my lower pan were barely tightened. I torqued them down and everything is dry. I did the UV dye and glasses and lead me to the two sources. I did an oil change after I replaced the dip stick o ring just incase I dropped some crud down there. So far no leaks. This all took place over the last two weeks. My dip stick o ring was completely hard and flattened. I will probably change it every other oil change just to be safe because it is pretty damn easy and cheap insurance.

This is what I found….

This is the replacement

If you have an automotive mirror with a light I would start poking around the upper and lower pan.

 

[2001LC]

I thought I had a lower pan leak. I replaced the dip stick o ring and it stopped. But then I found the bolts holding my lower pan were barely tightened. I torqued them down and everything is dry.

What Torque spec did you use, on oil pan bolts?

The head cover bolts, are ones I frequently re-torque to 54 INCH-lbf. To date, this has stop all factory installed head cover leaks. I've lost count of how many 4.7L 2UZ, I've done this on. Why does this leak happen: Because the bolt's washer and the head covers, have rubber seal. The rubber shrink over time, as its loses its plasticizer. So when we re-torque these bolts. We taking of slack/gap created by shrinking rubber, and re compressing the rubber. One day this won't work, as our fleet ages. But it does until it doesn't.

I, once though my first 01 land cruiser oil pan was leaking. I had it about 13 year and was 16 years old with ~150K, at the time. I saw, dips were coming from its oil pan bolts. But after replacing the dipstick O-ring and cleaning engine really well (top to bottom), of all oil. There was, NO oil pan leak.

4.7L engine Oil Pans (both), are FIPG (form in place gasket) sealed. The FIPG, mashes to a very thin layer as pans installed, then cures. It also gets into the threads of the bolts, glueing them in. In 22 plus years of working on 100 series. I've yet to see a factory sealed oil pan leak. Just to separate pans, takes a special tool, to cut through glue (FIPG). The factory even installed pry points to aid in busting loose the glue. They are a PITA to separate.

What I have seen, is many oil pans that appeared as if they're leaking. But, in every case of factory sealed oil pans. Once pan cleaned, of oil and all areas surrounding it cleaned. They didn't leak a drop. Re-torque oil pan bolts, would have little to no effect, on this very thin layer of curied FIPG.

Here's a pan that appears to leak. It was actually "salted" with oil. By a ripe-off shop. To make look like a leak.
They put a drop of oil on oil pan bolt, to make look like a leak. It was NOT leaking!

What happens is. As oil builds around the dipstick area, from its O-ring weep. Over the years, the oil builds up and spreads. Evenulty, enough accumulates, it moves down around seam of oil pan. Which appears to be a leak. NOT!.

If area cleaned really well, and O-ring NOT replaced. We'll see oil weep (sheen) only at dipstick seal (O-ring). We'll not see a any at oil pans seal. Or at least I never have as if today.

I did the UV dye and glasses and lead me to the two sources. I did an oil change after I replaced the dip stick o ring just incase I dropped some crud down there. So far no leaks. This all took place over the last two weeks. My dip stick o ring was completely hard and flattened. I will probably change it every other oil change just to be safe because it is pretty damn easy and cheap insurance.

This is what I found….
View attachment 3912323


This is the replacement View attachment 3912324

If you have an automotive mirror with a light I would start poking around the upper and lower pan.