Leak from lower oil pan

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Joined
Mar 2, 2025
Threads
6
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109
Location
Vacaville, Ca
I traced a an oil leak back to my lower oil pan. I cannot find any videos or posts on it. I've looked it over and I am fairly certain I can lower the front diff slightly and access all the bolts on the lower oil pan to take it off, to clean it up, and replace the gasket material. But when I called my local shop they told me I would have to pull the engine and the price to redo the lower gasket is the same price as it would take to redo the upper pan gasket. Somewhere in the ballpark of $2500. Seems kind of over the top based on what I am seeing under the vehicle, my UV light test, and what looks like a job I think I can do on my own on the side of my house.

Anyone have any experience with doing just the lower oil pan gasket?

EDIT: 2000 Lexus LX 470
 
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I highly doubt your 4.7L oil pan is leaking. Unless it has been resealed before. I've never seen a factory sealed one (either pan), leak. We do see a very very mild weep, at front 3 point (BK2: oil pan, pump block) seal corner.

It's much more likely oil from elsewhere. Rule of thumb. Degrease and clean spotless, all oil off engine (all). Watch for first reassurance, to pinpoint leak(s).
I.E. (2000 4.7L)
  1. Head covers (retorque to 54 INCH-lbf)
  2. Oil dipstick O-ring. (replace)
  3. Timing belt tensioner bolt threads (not sealed during T-belt service). Can you live with, until next Timing belt service!
  4. Crank seal, if not factory install. Can you live with, until next Timing belt service!
  5. Cam seals, if not factory install. Can you live with, until next Timing belt service!
  6. Oil filter, its bracket or oil sending unit.
  7. Oil pump O-ring and or rear O-ring, often called remain. (Happens if: engine run too long on cheap oil between changes, run on High Mileage oil, Overheated or prolonged running hot). PCV system not opperting to spec, can result in leaks. We can mitigate these.
The where and why of a leak, and how bad the leak. Dictates course of action!

Can pans be resealed, without pulling engine:
Whereas oil pans, can be removed and resealed, in-suti. It difficult. It also 50/50 chance it will leak in time, between block and upper pan (more so than lower). Why? Any oil on FIPG sealing surfaces, it will not hold. It takes supper care to make sure block, does dip/run/weep oil onto seal surface of block for upper pan. A block right side up, will retain oil on walls, for month or so, once pans off.

If we remove engine, it easy to keep surfaces clean and reseal.

Remove frt diff to do in-situ. Is labor intensive also.

Personally, I pull engine to replace oil pump or it's O-ring. Which requires pulling both oil pans. While out, there are the while in there stuff also. It can get expensive.
 
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I highly doubt your 4.7L oil pan is leaking. Unless it has been resealed before. I've never seen a factory sealed one (either pan), leak. We do see a very very mild weep, at front 3 point (BK2: oil pan, pump block) seal corner.

It's much more likely oil from elsewhere. Rule of thumb. Degrease and clean spotless, all oil off engine (all). Watch for first reassurance, to pinpoint leak(s).
I.E. (2000 4.7L)
  1. Head covers (retorque to 54 INCH-lbf)
  2. Oil dipstick O-ring. (replace)
  3. Timing belt tensioner bolt threads (not sealed during T-belt service). Can you live with, until next Timing belt service!
  4. Crank seal, if not factory install. Can you live with, until next Timing belt service!
  5. Cam seals, if not factory install. Can you live with, until next Timing belt service!
  6. Oil pump O-ring and or rear O-ring, often called remain. (Happens if: engine run too long on cheap oil between changes, run on High Mileage oil, Overheated or prolonged running hot). PCV system not opperting to spec, can result in leaks. We can mitigate these.
The where and why of a leak, and how bad the leak. Dictates course of action!

Can pans be resealed, without pulling engine:
Whereas oil pans, can be removed and resealed, in-suti. It difficult. It also 50/50 chance it will leak in time, between block and upper pan (more so than lower). Why? Any oil on FIPG sealing surfaces, it will not hold. It takes supper care to make sure block, does dip/run/weep oil onto seal surface of block for upper pan. A block right side up, will retain oil on walls, for month or so, once pans off.

If we remove engine, it easy to keep surfaces clean and reseal.

Remove frt diff to do in-situ. Is labor intensive also.

Personally, I pull engine to replace oil pump or it's O-ring. Which requires pulling both oil pans. While out, there are the while in there stuff also. It can get expensive.
This is awesome info. Thank you. I hope it is a simple find. My PSP came to a grinding hault so I am currently replacing that. Then I can start driving it and track down the leak. I have the UV dye in the oil it right now. Just need to clean it off really well and go from there. Once I get it on the road and driving I will let you know.
 
also have a 2000 LX and experiencing a very mild weep for almost a year now. shop keeps telling me it's the lower oil pan

Curious to hear what you find out
 
also have a 2000 LX and experiencing a very mild weep for almost a year now. shop keeps telling me it's the lower oil pan

Curious to hear what you find out
I went under there in the pitch black last night with my UV light. It all illuminates around the seal between the lower and the upper on the passenger side rear of the pan. Then it follows a path around the passenger side an eventually down the underside of the lower pan. I have a mirror coming today to double check the upper is all dry. I’m convinced it’s the lower but I’m going to keep checking.
 
I went under there in the pitch black last night with my UV light. It all illuminates around the seal between the lower and the upper on the passenger side rear of the pan. Then it follows a path around the passenger side an eventually down the underside of the lower pan. I have a mirror coming today to double check the upper is all dry. I’m convinced it’s the lower but I’m going to keep checking.
It sounds like you might be dealing with a similar situation I encountered with my 2002 Land Cruiser, which had about 280,000 miles at the time. I noticed a pretty significant oil leak that seemed to be originating from the oil pan. Interestingly, this happened the day after my usual mechanic performed a routine oil change.

To pinpoint the source, I took it to a service center closer to my home. They diagnosed it as a lower oil pan gasket leak and quoted a hefty $4,500 for the repair! That sounded excessive to me, so I called my regular mechanic for his opinion. He was quite surprised, mentioning that oil pan gaskets on these vehicles typically don't leak unless the pan has been physically damaged.

Deciding to trust my regular mechanic's experience, I brought the Land Cruiser back to his shop. He took a closer look and discovered the actual culprit was a leaking o-ring on the dipstick tube. He replaced it for a very reasonable $145, and thankfully, the leak vanished completely.

Hopefully, your situation will have a similarly straightforward and less expensive solution. Best of luck in resolving your leak!
 
The issue with flowing leaks around the pan. Is oil travels. Down by gravity, in direction air blows.iy and up by capillary action. So depending on age of leak, how much of a leak. It can be all around the pan, and look like pan(s) seal(s) FIPR.

I've seen enough, I can guess at source(s). But still I clean spotless after taking pictures. Once clean take more pictures, making sure I good it clean. Then watch very close.

It easy and cost nothing more, than a good degreaser and washer/hose and some time.
 
It sounds like you might be dealing with a similar situation I encountered with my 2002 Land Cruiser, which had about 280,000 miles at the time. I noticed a pretty significant oil leak that seemed to be originating from the oil pan. Interestingly, this happened the day after my usual mechanic performed a routine oil change.

To pinpoint the source, I took it to a service center closer to my home. They diagnosed it as a lower oil pan gasket leak and quoted a hefty $4,500 for the repair! That sounded excessive to me, so I called my regular mechanic for his opinion. He was quite surprised, mentioning that oil pan gaskets on these vehicles typically don't leak unless the pan has been physically damaged.

Deciding to trust my regular mechanic's experience, I brought the Land Cruiser back to his shop. He took a closer look and discovered the actual culprit was a leaking o-ring on the dipstick tube. He replaced it for a very reasonable $145, and thankfully, the leak vanished completely.

Hopefully, your situation will have a similarly straightforward and less expensive solution. Best of luck in resolving your leak!
All boils back down to basic troubleshooting of problems. I've seen countless people throw parts at leaks before de-greasing, washing down, and monitoring closely to find source of leak. Glad you didn't get screwed on a big repair bill, nice work
 
It sounds like you might be dealing with a similar situation I encountered with my 2002 Land Cruiser, which had about 280,000 miles at the time. I noticed a pretty significant oil leak that seemed to be originating from the oil pan. Interestingly, this happened the day after my usual mechanic performed a routine oil change.

To pinpoint the source, I took it to a service center closer to my home. They diagnosed it as a lower oil pan gasket leak and quoted a hefty $4,500 for the repair! That sounded excessive to me, so I called my regular mechanic for his opinion. He was quite surprised, mentioning that oil pan gaskets on these vehicles typically don't leak unless the pan has been physically damaged.

Deciding to trust my regular mechanic's experience, I brought the Land Cruiser back to his shop. He took a closer look and discovered the actual culprit was a leaking o-ring on the dipstick tube. He replaced it for a very reasonable $145, and thankfully, the leak vanished completely.

Hopefully, your situation will have a similarly straightforward and less expensive solution. Best of luck in resolving your leak!
I have looked for videos about the dipstick and replacing that o ring. Have you seen any or does anyone reading this know of a write up?
 
I have looked for videos about the dipstick and replacing that o ring. Have you seen any or does anyone reading this know of a write up?
Get a light down in there and try to locate the bolt holding the bracket / tube in place. Remove bolt, pull tube up, remove and replace o-ring

Oh and clean the area really good before removing to keep grime from getting in
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Best way to search on Mud... Go to Google... " Enter Topic " 100 series ihm8ud. It will pull up all the forums relevant to that topic
 
Get a light down in there and try to locate the bolt holding the bracket / tube in place. Remove bolt, pull tube up, remove and replace o-ring

Oh and clean the area really good before removing to keep grime from getting in
View attachment 3900284
Thank you!

This site has amazed me over the last couple of weeks. I have been on Ford forums forever. The quick quality responses are so much more here than others. It definitely motivates me to write up my problems and what I did to fix them.
 
Thank you!

This site has amazed me over the last couple of weeks. I have been on Ford forums forever. The quick quality responses are so much more here than others. It definitely motivates me to write up my problems and what I did to fix them.
Agreed, I've had my fun with a lot of different makes and motors across the years and having MUD forums available is a huge perk to buying into the cruiser game. A lot of issues are well known and can be sorted quickly. Some issues are so rare, like this fourm here, where experienced techs like 2001LC can chime in and be like, nah that usually doesn't happen look elsewhere
 
I highly doubt your 4.7L oil pan is leaking. Unless it has been resealed before. I've never seen a factory sealed one (either pan), leak. We do see a very very mild weep, at front 3 point (BK2: oil pan, pump block) seal corner.

It's much more likely oil from elsewhere. Rule of thumb. Degrease and clean spotless, all oil off engine (all). Watch for first reassurance, to pinpoint leak(s).
I.E. (2000 4.7L)
  1. Head covers (retorque to 54 INCH-lbf)
  2. Oil dipstick O-ring. (replace)
  3. Timing belt tensioner bolt threads (not sealed during T-belt service). Can you live with, until next Timing belt service!
  4. Crank seal, if not factory install. Can you live with, until next Timing belt service!
  5. Cam seals, if not factory install. Can you live with, until next Timing belt service!
  6. Oil pump O-ring and or rear O-ring, often called remain. (Happens if: engine run too long on cheap oil between changes, run on High Mileage oil, Overheated or prolonged running hot). PCV system not opperting to spec, can result in leaks. We can mitigate these.
The where and why of a leak, and how bad the leak. Dictates course of action!

Can pans be resealed, without pulling engine:
Whereas oil pans, can be removed and resealed, in-suti. It difficult. It also 50/50 chance it will leak in time, between block and upper pan (more so than lower). Why? Any oil on FIPG sealing surfaces, it will not hold. It takes supper care to make sure block, does dip/run/weep oil onto seal surface of block for upper pan. A block right side up, will retain oil on walls, for month or so, once pans off.

If we remove engine, it easy to keep surfaces clean and reseal.

Remove frt diff to do in-situ. Is labor intensive also.

Personally, I pull engine to replace oil pump or it's O-ring. Which requires pulling both oil pans. While out, there are the while in there stuff also. It can get expensive.
If I ever see you on the trail I’m giving a special case of beer to you. I got my mirror in the mail and stuck it above where the dip stick tube meet the oil pan. Sure as s*** it was wet. And the o ring looked to be very slightly cracked. I couldn’t not get my phone up there for pictures but I cleaned it off really well. Once I get the power steering pump in I’ll keep driving it and look back with mirror. But it looks like this is it. Very wet up top and seeping down and around to the bottom of the lower oil pan.
 
If I ever see you on the trail I’m giving a special case of beer to you. I got my mirror in the mail and stuck it above where the dip stick tube meet the oil pan. Sure as s*** it was wet. And the o ring looked to be very slightly cracked. I couldn’t not get my phone up there for pictures but I cleaned it off really well. Once I get the power steering pump in I’ll keep driving it and look back with mirror. But it looks like this is it. Very wet up top and seeping down and around to the bottom of the lower oil pan.
Scotch, Signet Glenmorangie, case would worth is about what you saved. ;) PM (DM), your email, I'll respond with address for shipping
scotch  genmorangie.JPEG

I've actually caught a Toyota/Lexus speciality shop in Denver. Salting (squirting oil on pan bolt) oil pan, and quoting 16 hours to fix.

The dipsticks O-ring leak, is typically a very minor weep. That over the years, area becomes saturated.

Very easy to get picture and clean. I can get to dipstick O-ring area for pictures and cleaning, from 3 points.
  • #2 Undershield off. Come in form back side with camera and Power washer attachment. I use a household roof gutter cleaning wand, which has 90% head. I also use straight wand.
  • Through fender well (remove mud shield) is helpful access cleaning and when R&R.
  • From top down, the with mirror. As cleaning with 90 degree wand.
Oil dip stick guide tube seal 1.JPG
004.JPG


Oil dip stick guide tube (4).JPG


Make sure to clean area spotless before, pulling dipstick and R&R O-ring. Or risk sand getting on seal surface of new O-ring and in oil pan.
oil dip stick guide tube seal, Leak confirmed 013 (1).JPG


oil dipstick o-ring 6-7-20.JPEG


Some of the other points oil leaks from, I mentioned in post #3 above. Can be much worse.
 
Scotch, Signet Glenmorangie, case would worth is about what you saved. ;) PM (DM), your email, I'll respond with address for shipping
View attachment 3900767
I've actually caught a Toyota/Lexus speciality shop in Denver. Salting (squirting oil on pan bolt) oil pan, and quoting 16 hours to fix.

The dipsticks O-ring leak, is typically a very minor weep. That over the years, area becomes saturated.

Very easy to get picture and clean. I can get to dipstick O-ring area for pictures and cleaning, from 3 points.
  • #2 Undershield off. Come in form back side with camera and Power washer attachment. I use a household roof gutter cleaning wand, which has 90% head. I also use straight wand.
  • Through fender well (remove mud shield) is helpful access cleaning and when R&R.
  • From top down, the with mirror. As cleaning with 90 degree wand.
View attachment 3900768View attachment 3900773

View attachment 3900769

Make sure to clean area spotless before, pulling dipstick and R&R O-ring. Or risk sand getting on seal surface of new O-ring and in oil pan.
View attachment 3900770

View attachment 3900771

Some of the other points oil leaks from, I mentioned in post #3 above. Can be much worse.

Haha. That bolt under the valve cover was being a PIA until I took a step back and looked in the driver side wheel well! I text my mechanic who recently did my exhaust manifold and he informed me he removed the dipstick tube during that process. And this leak showed after that. I'm going to replace the o ring while I am doing my power steering pump and then drive it around to see what, if anything, is still leaking. I cleaned it really well around the area but for good measure I might just do an oil changed after I change the o ring just incase any small debris does get stuck. Plus there is a WIX oil filter on the truck right now and I want that off. Put on the toyota filter instead.
 
Sorry. Still have posted a picture of the new o-ring. I did install it though and also did an oil change. No leaks from the dipstick!

However, I saw there was still some seepage from the area where the lower meet the upper pan. The leak looked to be predominately from the front stud going into the pan. I got my socket out and decided to be easy and see if I can tighten it any. Well, it seemed like it was on about hand tight. IN fact all the bolts on the driver side were extremely lose. I would say there were barely torqued, if any!

I gave them all an easy tightening with my ratchet. I did not crank on the bolts. Anyone know the torque spec on the lower pan bolts?

Anyways, after tightening the bolts the seepage has seemed to stop completely. Its been dry for two days. Moving forward I will keep checking daily until I am satisfied. Then when I re-gear down the line I will use that time to put on fresh gasket material onto the lower pan.

Thanks for everyone's help!
 

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