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Subject: 3.5L oil pan gasket rebuild (fully documented) Author: shogun (moderator) : member since March, 2004 : 16310 posts Posted on: 2010-02-01 00:16:52

between semesters I finally got around to changing my oil pan gasket. I have a few pictures, but mainly i can give you good pointers and things to watch out for in the event you need to do the same as I.

I started at 8am and went till 1am along with the next day spending an hour of just clean up.
but i go at a casual rate and if i were able to read my own thread beforehand i bet it wouldn't take longer than 4 hours.

I have the pictures uploaded on photobucket, should be visible for all.
I will post a link to the picture. All were taken with a 12.1 megapixel camera so it should be very clear.

My car is a 1991 735i automatic.

reason for replacing the oil pan gasket.

As you can clearly see, P.O. tried the good ol' gasket sealer caulk type fix. you can even see the fresh oil on the furthest right side of the gasket. And it has not been changed since it was built. It was time. The new gasket was a cork type whereas the old one was more of a plastic. kind of odd to me. Was very cheap though, around $15 for the new one.

Here's just a view of the garage.


Heater makes your hands feel better in the Wisconsin weather.
The giant air compressor helps as well and of course a cherry picker is necessary for this.

Now to start the work.
Right away i put the car on two jack stands on it's lift points. Makes for more room and is still sturdy enough to lift the engine later. Get a large piece of cardboard to save your garage floor and drain the oil.

whatever you have to help get to them all.
Also in the last picture in front you can see two brackets on both sides of the pan. These are support / line up your AC and power steering ? pulleys. Just one bolt on each bracket and they are out of the way.
On the front bottom of the pan is the oil level indicator. that is held in with just the three small bolts and pulls right out. let it hang there.
When you get to the back of the pan when taking out bolts there are two long length bolts (10mm) these go up into the rear main seal. just remember which hole it was to save time later.
There is also a small black plastic bracket that holds your trans. coolant lines onto your pan. a single bolt goes through it to a nut (it is actually very hard to get back on. I broke the plastic part into bits somehow. I don't know what tips to give there. careful is all i guess)

Now for the worst part of the entire course.

Nasty little buggers.
these 7mm ? bolts go from the back of the bell housing into the oil pan.
I didn't even realize they were there for the longest time. Well over and hour was spent using a putty knife at the old gasket thinking it was just stuck solid. until i looked back and saw these...

here is a picture of them before

The one with a spotlight on it is just one of four.
Basically the problem is that the bell housing is aluminum while the bolts are steel. and over time heat and cold expansion differences, i believe, causes the washer to hold all the torque onto the bell housing. I went to just cut the bolt heads off with a dremel until i cut off part of the washer and released the pressure, then it just came out by hand. The fourth one is the hardest to get as the pan goes up and gets surrounded by your two trans cooler lines.

After that fiasco it's pie.

Here is the engine bay.
If you look at the oil canister follow it straight down and you see the engine mount. Get a long enough socket and take the nut off along with the other side.
Also in the picture see the strap going behind your fan is a convenient engine lift plate. The hook on the end of that strap actually broke, but i had a huge chain that i used after. < (good advice to always use a chain)
In the top right of that picture is your coolant reservoir held in with two small plastic nuts. Underneath that is a metal plate protecting some wiring also held in with plastic nuts.
Also a vacuum line running to the master cylinder should be pulled off so it doesn't get split.
Remove these to make for more room to lift the engine.

You will have to lift your engine a good 2-3 inches in order to clear the oil sump. It can go higher than that, there was plenty of room to, so don't worry there.



Here is the lower end where you can see right in front is the sump that hangs down which requires the engine to be lifted.


Here is the oil pan taken off. Not too sludgey. Clean off the gasket chunks.
The gasket was trash. It was this weird plastic type gasket that just flaked and seemed really crappy over all this time. Really glad i finally did this.

To clean your pan use gasoline. Lay down some paper towel and get a very large paint brush style brush. Be very liberal with the gas too. Use a wire brush if your pan has more built up grime. Also clean the outside to make it look better! Along with the engine too.


Now that it is ready to go back on, a good tip is to use zip ties to hold the gasket onto the pan while you lift it back into place.


Unfortunately i was out of zip ties. So i used a piece of wire. Anything works here really. Zip ties just seem to be best.

wiggle it back in place and start with the bell housing bolts.
These bolts will pull the pan towards the back and line up the other bolts.
Put these in place loosely as when you tighten these it will be harder and harder to cut and remove the zip ties safely without ruining your gasket.
When you grind the washers off (if you needed to do so) careful for the fact you want to reuse these
then replace all the 10mm bolts on the pan,
Put the pulley brackets back into place,
Your oil level indicator,
and the trans. coolant line bracket.
Lower the engine back into place and torque down your mounts.
Replace your wire bracket, coolant reservoir, and don't forget the vacuum line (like i did when i tried to start it for first time, hehe.)

take it off the jacks, refill with oil (let it settle for an hour or so as your engine was just bone dry)
umm, try not to forget anything else
and start it up.
Let it get up to temperature and check for leaks.

Of course all of this can't be done without a peanut gallery to mock you and do absolutely nothing along the way...


Me


That about covers it all. Hope this helps some others.

Take care of your car and it takes care of you.
(hope you like it shogun!!)

Author and pics: Emilios
Location: Milwaukee, Wisconsin
Car: 1991 735i

E32 750iL 11/88, E32 750iL Highline 03/90
SHOGUN'S TRICKS AND TIPS FOR THE SEVEN SERIES

• 3.5L oil pan gasket rebuild (fully documented) (pic) - shogun 2010-02-01 00:16:52 (2019 views)
  • Re: 3.5L oil pan gasket rebuild (fully documented) - cspargo 2010-02-02 00:02:09 (251 views)
  • Nice, you're not far from me either! (nt) - 92735i 2010-02-01 18:01:38 (215 views)
  • Jeez, the guy lives in my back yard ... don't even know him... (nt) - rv8flyboy 2010-02-01 16:05:06 (174 views)
  • Good work! Remarkable to finish the project during the - Patrick C 88 750 170K 2010-02-01 15:55:52 (168 views)
    • Finally getting back to you. - emilios 2010-02-06 23:57:30 (202 views)