Upper oil pan arch seal renew

Oil pan arch seal project

I tackled re-sealing the famous arch seal this weekend. This project is a little involved but fairly straight forward. While I had the engine raised, I took the opportunity to replace the motor mounts. I'm an ameteur so I'm sure there're more efficient ways to do this! I'd say this to be job.

It went something like this:
- wash the underside of your vehicle thoroughly at a car was. You'll thank yourself later!
- park on top of 4x4 or 6x6 wood or a set of ramps. Just make sure that you can still reach everything w/o tiring yourself
- wear safety glasses to prevent oil & crud going into your eye
- drain engine oil
- remove the oil filter (facilitates access to motor mounts)
- remove hood and mark where the brackets went (only if you're using an overhead hoist to pull up on the engine)
- remove the radiator cooling fan from the water pump and push it aside
- raise the engine as much as possible. Keep a close eye on the radiator fan and radiator shroud coming into contact with each other. An overhead hoist stays out of your work area the best.
- remove the two nuts per motor mount.
- remove dip stick holder.
- remove the single bolt that holds the ATF dipstick to the side of the bellhousing. During installation this thing WILL PISS YOU OFF so just bend it out of the way a tad. Edit 5/27/25
- Remove the two bolts that attach to the a/c compressor main bracket. In order to do this, you'll need to move the lower radiator hose metal bracket thing out of the way. I tied it with a zip tie out of my way. Edit 5/27/25
- remove two connectors (one is oil low level, the other one is for a sensor pickup)
- remove the front sway bar completely. You can keep it in there but just ain't worth aggravation or head bonking!
- I also removed the front DS. Edit 5/27/25
- remove the lowest (smaller) oil pan. The longer you let the oil drain, the less mess for later! Use the oil pan spreading tool.
- remove LOTS of bolts and four nuts from the higher oil pan. Make careful note of what bolts go where. I used a old shipping box to place the bolts as they came out of the engine. There are several lengths/sizes/grades of bolts.
- make sure to remove the four bolts that are INSIDE the large oil pan.
- work the FIPG loose by working the larger oil pan. This will take some elbow grease and maybe some heat from a propane/butane torch. Resist the urge to use a chisel/screwdriver/pry bar to separate.
- Put the lower oil pan back on with two bolts in order to protect the oil pickup. This also helps with the drippage. Edit: 5/26/25
- work the large oil pan out while paying close attention to the oil pickup screen. Edit: 5/26/25
- Place the large oil pan such that the oil pickup screen isn't disturbed. Edit: 5/26/25
- clean off the old sealant on both surfaces. You can use a Dremmel tool with round wire brush disc thing to clean things out of the grooves.
- Apply new sealant or FIPG and wait for it to become less tacky. If it's too tacky, then you'll smear as you install the large oil pan. Use the cool tool mentioned below.
- Reverse the above steps for installation
-Once the upper oil pan outer bolts are installed, remove the lower pan and install the remaining bolts. Edit: 5/26/25
- Clean off old FIPG from the smaller oil pan. There Are grooves in this oil pan that needs to be cleaned out well before the new FIPG is applied.
-Install the smaller oil pan
-Add oil, filter, tighten motor mounts, install fan, hood, etc.

Edit: 5/26/25
Now would be the time to replace the following seals: Crankshaft position sensor O ring, oil level sensor O rings (yes, there are two), square seal under timing cover, and engine oil level dipstick O ring (why the F*&^k not!). Do it, DO IT NOW. Everything will be brittle and may need to be cut off.

Gotchas to avoid:
-Protect the oil pickup screen. If you reinstall the lower oil pan before removal of the upper oil pan, this will protect the pickup screen. Edit: 5/26/25
-while cleaning old FIPG, be sure to pick up bits and pieces from the large oil pan as you're working. If you're using "a spin real fast wire brush" thing, this might fling a shrapnel into the "sensitive" area of the crankshaft, so be mindful. I used a shop vac.
-keep the dust level down while everything exposed. Don't sweep the shop floor!
-have assistance for hood removal, if needed. It's not heavy but can be unwieldy!
-I try not to use air tools to remove the bolts, don't want a broken bolt head here!
-have LOTS of clean rags. This is not the place to be reusing old, dusty rags.
-pay close attention to the torque values of the various bolts. Don't confuse IN-LBS with FT-LBS numbers in the FSM.
- use the tools I mention on this post, and your life will be mobetta.

No.1 (upper) oil pan

12mm head bolts- 15lb-ft
14mm head bolts- 32lb-ft
Oil pan to transmission 53lb-ft

No.2 (lower)
78 in-lbs



Pics to follow. Let me know if anything seems unclear to you!

Ali

Oil level sensor O ring. Be very mindful of the orientation of this seal, it has a lip on one side.

Crankshaft position sensor O ring x 2 (PM me and I'll send you a set). These are NLA from Toyota.

Close up views of the leaky areas of the pan.

Notice how I'm resting the foreward end of the oil pan on 2x4s to protect the oil pickup screen.

Thanks Ali, nice write-up.

Did you have a motor mount break?

-B-

Beowulf said:

Thanks Ali, nice write-up.

Did you have a motor mount break?

-B-

Click to expand...

Thanks.

No, the mounts are intact However, Dan and I noticed that the engine seems to rotate more than normal upon starting and power braking. I'm also chasing another issue and that is the movement of my Transmission shift lever under load. The tranny *maybe* is moving fore/aft.

Upon visual inspection, both mounts seem fine but I bet the driver side is softer. At least I hope so anyway

This was a classic *while I'm in there...* move!

Ali

Nice, Im going to do exact same thing within 3 weeks from now.When you mention replace the engine mounts.How many are they? Also do you have part # for it? Got more pics?

LX_TREME said:

Nice, Im going to do exact same thing within 3 weeks from now.When you mention replace the engine mounts.How many are they? Also do you have part # for it? Got more pics?

Click to expand...

there are two motor mounts. Have Dan quote the price/pn info. I can't remember what I paid since i bought them long time ago. I tend to store up on parts and then do a big project. Unfortunately, I tend to lose smaller parts this way

I don't have any pics of the motor mount project but it went somethig like this:

- have an assistant
- remove motor mount nuts (four total).
- remove radiator fan and push it aside
- loosen four bolts per motor motor mount brackets x 2. On the driver side, removal of the oil filter will improve access to the bolts
- raise engine
- start on the passenger side. One person moves the engine from side to side while another person is playing with the motor mount from underneath. This alone took about an hour or so! Install new motor mount.
- driver side - remove the tranny oil dipstick bracket (push it aside )so that you can back out one of the four bolts out of the block.
- move the engine to the driver side while the assistant works the motor mount out. Install new motor mount.
-tighten the motor mount to engine bracket nuts (four total)
-Torque everything to spec.

GAACK.

I might just buy a lower miles cruiser

Nice writeup, thanks for taking the time to document it for the rest of us.

Well i just made quick phone call to my guys (local Toyota parts) now according to what they said it would be better if i also replace the trans mounts? so 3 totals?
- 2 engine mounts and the part # 12361-17011 -$ not cheap.
- 1 trans mounts also the part # 12371-66030 -$ more than you thought.
(P.S)- sorry i dont quote/ post the parts price here.

So is that right?

I don't know if the p/n s are right but you do need three total for the vehicle.

terry.mc said:

GAACK.

I might just buy a lower miles cruiser

.

Click to expand...

Yes, you can do that but she's gonna be a high mileage cruiser eventually and guess what?

This is a routine PM that needs to be done just like the head gasket r/r. Unless you can stand to see your 80 leak oil for the rest of her life!

Ali

WOW, that looks like a lot of work!
I am surely glad that the RotellaT Syn 5w40 somehow sealed up my arch pan leak, "knock on fake wood dash "

What's that hoist setup.. is that steel beam in your garage?

Nice work Ali. So you raised the Engine to replace the motor mounts or that is required to change the seal as well? How does the Arch seal look like? Is it a RTV type material or a gasket? Also is it required to take out the #2/small oil pan to do this job?


Thanks

landtoy80 said:

WOW, that looks like a lot of work!
I am surely glad that the RotellaT Syn 5w40 somehow sealed up my arch pan leak, "knock on fake wood dash "

Click to expand...

Funny you mention that...I looked around after completing the job and not one case of Rotella. I have all sorts of syn 5w30. Off to Wally world I went!

Riad said:

So you raised the Engine to replace the motor mounts or that is required to change the seal as well? Also is it required to take out the #2/small oil pan to do this job?

Click to expand...

I'll try to answer for Ali. You must remove the lower oil pan before you can remove the upper oil pan. You must raise the engine slightly to enable removal of the upper oil pan.

C-Dan had to remove the upper oil pan before he could remove the front timing chain cover and therefore had to do all of the steps in Ali's post; plus some.

-B-

Riad said:

So you raised the Engine to replace the motor mounts or that is required to change the seal as well?

Click to expand...

Yes

Riad said:

How does the Arch seal look like?
Thanks

Click to expand...

?? incomplete sentence??

Riad said:

Is it a RTV type material or a gasket?
Thanks

Click to expand...

Formed in Place Gasket (FIPG) sealer on both the upper and lower oil pans.

Riad said:

Also is it required to take out the #2/small oil pan to do this job?

Click to expand...

He's sealing the upper pan arch, so both pans have to come out. There are some hidden bolts under the lower pan, that you have to get to in order to take the upper pan out, so you couldn't just pull them as a unit.


Rookie2

Thank you Rookie2. So that's what FIPG stands for . I wanted to see what this FIPG looks like is.

Thanks

Riad said:

Thank you Rookie2. So that's what FIPG stands for . I wanted to see what this FIPG looks like is.

Thanks

Click to expand...

It looks a lot like 3M weather striping adhesive. Comes in a toothpaste like tube. You just squeeze it on, and it sets up in about 15 minutes, cures within 24 hours.


Rookie2

alia176,
Great write-up on a job I have been putting off for some time. My driveway is starting to look pretty bad so I plan to do this soon.

I have been thinking this whole project over and have a question. Would it be feasible to just drop the front axle to remove the pan instead of unbolting the motor mounts? I plan on installing a lift in the near future and this would be a perfect way to kill two birds with one stone.

lowtops said:

I have been thinking this whole project over and have a question. Would it be feasible to just drop the front axle to remove the pan instead of unbolting the motor mounts?

Click to expand...

Several comments on this, and in addition a search would yeild others experiences with this item as well.

First off: the 20 plus nicely bulletized items listed above don't do this job justice. It's a PITA. If you've got a "seep" with little to no drip accumulating on the driveway, you're going to be kicking yourself in butt for messing with this once your asses and elbows deep into it.

Second: There's no guarentees it's the pan arch, although percentages have shown it to be the most common out of it vs. rear main seal. I found it really hard to tell by doing the mirror investigation.

Now to answer your question: Everybody that's done this (including C-Dan) has had to raise the motor some to get the pan out. When I did mine, I put the frame up on 3 tons jacks on a very high setting, and dropped the axle down onto 3 ton jacks on the lowest setting, then removed the DS sway bar bracket, and that was enough to get it to clear (this took me about 6 hours to find the right combination). I did not need to remove the fan and fan clutch, although it's probably not a bad idea. Loosening the fan shroud, and jacking the motor about a 1" to 1 1/2" is enough (mine started lifting the whole front end at this point, I'm assuming the bell housing was engaging the body so there is a limit to the amount you can lift the motor). If you've using a standard engine hoist, there's no need to remove the hood.



Rookie2