This is probably the second worst job in the e30 to do (the first is replacing the oil pump).
Seriously, it is a bitch. Not the worst job I have done, but sucks non-the-less.
You will need another person helping, prefferably 2. You also really need to get the whole car off the ground, not absolutely required, but it makes it way easier. I used ramps and stands after getting annoyed with jacking one end or the other up several times. Shake the car for stability before getting under (I see lots of people who do not do this).
Be carefull as you will have an open tank, which can ignite very easily. No lights in the car and diconnect the battery before starting.
The driveshaft does have to come out, as does the exhaust, as well as the rear seat, the covers, fuel pump, lines, dirt sheilds, dust sheilds, and a crossmember or 2. The subframe stays in, it does take some fiddling about to get it in and out, but it goes.
Honestly, the worst part is the lines and header collector bolts, the worst of those being the filler line. You cannot get a good hold to remove it due to location, and it is too short to lower the tank more.
In the end I had to cut the filler hose. This led to lost of grief, it winds out into the wheel well and up a tube, which gets filled with dirt. I could not get it out, in the end, I cut the last 4 inches off of it at the tank and put in a 6 inch peice of copper tubing (to which I attached a grounding wire) and then replaces the last few inches of rubber to make it long enough again. I also ended up replacing the collector bolts (which are welded in place). If you do the copper thing, use a grounding wire (or else!).
Take pictures of how the lines go, draw diagrams, etc... There are 3 (I think) that go into the top of the tank, one on the drivers side and the filler tube. Use wires and coat hangers to hang them in place. Hopefully somewhat in the proper order.
Shop around for your tank. Some places want $600, I got mine for $145 with free 2 day air.
Make sure to put in new guibo bolts, I did not and after a trip across 2 states and back a bolt fell out and trashed the guibo. You may want to do the C.S.B. while you are there as well.
Also, pre order the tank crossover tube. You will not likely be able to save yours. Check realoem.com for the part number as the local dealer will have absolutely no f'ing clue what you are talking about. Do not forget a new header collector gasket as well.
It gets expensive as you start doing all of the other random stuf, but a lot of this is a hassle to do if you only have the one thing to do.
I also got some undercoating to cover the tank with hopes of adding some extra rust protection. Do not do this where the exhaust passes, undercoating can ignite. I used normal paint there. Anything to keep from doing this again anytime soon.
Sorry for how random this is, but it is as I remember it. Not a how-to.
It is not fun and is a lot of work.
If you have more questions just ask.
I would rather do 2 steering racks, a power steering pump, and an alignment than do the gas tank again.
Topic: Gas tank removal? (Read 4166 times)