acercomp71

Anybody got a good writeup how to remove upper oil pan and change the gaskets? The car is a '97 and has almost 300K on it, oil seems to be seeping from upper oil pan, and hopefully not main rear seal. As of main rear seal, it is impossible to tell where the leak originates unless upper oil pan is gone.

Also, any recommendations how to support the engine? Two of motor mounts will have to go, according to FSM. I do not own engine hoist, but heard you can rent one.

An lastly, FSM mentions liquid gasket for the LOWER oil pan, however, auto parts store sells a Felcro one instead. Which one is best to use- liquid or real gasket for the lower pan?

thanks in advance!

internetautomar

iTrader: (30)

ultra grey permatex for the mating surfaces. no gasket

oldngivout

iTrader: (8)

Correct, use only silicone on the upper & lower pan. The upper pan does use two o-rings though to seal the oil pump passages. These must be replaced as well.

Just so you know, the leak you have may well be coming from the back of the timing cover. The point where it seals to the face of the engine block is also sealed with o-rings and silicone gasket material. These are known areas to leak on high mileage Maximas.

dan1el

I am an expert at the pans. I have changed the oil pan gaskets 3 times in the last 6 weeks trying to find the source of my leak lol. I used a friend’s hoist the first time but discovered it wasn’t necessary by releasing tension from the hoist slowly. The next 2 times I did everything below.


*FSM says to remove the lower pan first, but I leave it on until just before removing the upper pan so I get less oil on my face and in my clothes.

Steps:

• Remove front passenger tire.
• Drain engine oil.
• While oil is draining, disconnect both heated O2 sensors from the wire harness up top, drop the front exhaust tube, and move it toward the driver’s tire to get it out of the way. I usually remove the 3 14mm nuts in front of the pan, the 3 behind the pan, the 2 12mm bolts between that support the tube. Then I unbolt the 2 front-most exhaust bushings to get some extra room. To do this you will need the smallest ratchet you have with a 12mm socket, and also a 12mm wrench. It takes some time, but it’s worth it since it makes installing the pan much easier.
• Next remove the crankshaft position sensors (one between upper the oil pan and the transmission, and the other just over the lower pan on the passenger side of the oil pan). Then disconnect oil pressure switch wire from the back of the upper oil pan just above the lower pan.
• Remove drive belt, AC compressor, and its bracket
  • After removing belt, remove the 4 14mm bolts holding the compressor to the bracket
  • There are 4 more 14mm bolts holding the bracket to the engine and upper pan. Also there are 2 smaller 2-bolt brackets on the left of the AC bracket (looking at the headlights) holding it to the engine and pan. You can either remove all bolts for organization purposes or just remove the 2 14mm’s on the top and the 1 smaller bolt on the top left side. This will leave the bracket attached to the oil pan, and at least in my opinion it’s still easy to clean and put back.
• Set a jack stand under the transmission just to the driver’s side of where it meets the upper oil pan.
•  
  • Pull exhaust tube to the driver side tire so that the jack stand holds it out of the way.
  • Lift the stand as high as it goes.
  • Place jack under the front of the center member and raise slowly until you can get the jack stand up one notch.
  • Slowly let down jack so the stand is supporting the transmission. Since it is bolted to the engine, it will also support the engine enough to remove the center member.
• Remove center member
  • I leave the mountings on the engine because it’s easier for me to remove the center member from the mountings than the mountings from the engine. Plus I think it makes it a little easier to line everything up when you put the center member back on.
• Remover rear cover plate
  • This is the small cover plate with 2 12mm bolts where the upper oil pan meets the transmission.
• Remove 4 14mm bolts holding pan to transmission.
• Remove lower pan.
  • Remove 10 10mm bolts.
  • FSM says not to use a screwdriver, but I’ve done it 3 times and mine is fine. Just be careful and USE YOUR HEAD. Wedge driver between pans and work it up and down a little until you can get something in there to really pry it off. I use a small allen wrench (standard size of course since I don’t care about my standard tools).
  • Expect oil to still drip and have something under to catch or be prepared to get really dirty putting everything back on.
• Remove the upper pan.
  • Remove 12 12mm bolts.
  • REMEMBER WHERE EACH OF THE BOLTS GOES and take notes because there are 7 long and 5 short. It’s a pain to hold the pan up while installing bolts so make it easier on yourself.
  • Pry pan off at pry point located toward the front of the car at the top of the oil pan near where it meets the transmission. I use a small wrench (again standard size) to stick in it and then use whatever is handy to push up on it like a lever. Works well. Once it pries a bit, work your way around until it’s off.
  • Make sure the 2 o rings and the 2 U shaped rubber seals come off of the engine.
• Use a scraper to remover all traces of silicon gasket from the lower pan, the upper pan, and the engine. I just use a box cutter and a razor blade.
  • After the surfaces are scraped, clean them with something. I use Clorox wipes, but I have heard lacquer thinner works better. Dry off after cleaning.
• Practice putting the pan in place a few times before applying gasket so you are familiar with how it goes on. If you screw up the gasket, it is a pain to clean off when it’s still wet. By practicing you can increase your chances of having a good seal.
• BE SURE YOU GET THE GUIDE PEGS IN THEIR HOLES PROPERLY. These are 2 holes located on the front and back of the upper pan. They are the only 2 holes that bolts don’t go into. If you’re not careful, you can crack your pan. If you do, check salvage yards in your area. I got one for $65. Be sure to take a bolt and a ratchet with you to make sure the new one doesn’t have stripped bolt holes.
• When you feel confident you can put it on right, get a big tube of ultra grey RTV and apply per spec (at least 5mm thick). Be generous with it and remember to stay to the inside of the bolt holes. Make a continuous bead all the way around the surface of the pan. Make sure the U shaped rubber seals (strongly recommend using new ones) are in their proper places and put some RTV on the bottom and top of these seals.
• Dab some RTV on the 2 o rings (strongly recommend using new ones) and stick them to the engine in their proper places (actually one mates to the oil pump and the other to the cylinder block). This step is important to make sure they are situated properly when you install the pan.
• Wait about 5 minutes and install upper pan after applying the RTV and then install the upper pan. Tighten in order with a torque wrench. Spec is 12-14 ft-lbs. I can’t upload pictures yet, so if someone can provide a diagram of the tightening sequence, it would help. It’s in the FSM.
• Do the same thing with the lower pan, but tighten to 5 ft-lbs (60 inch-lbs). BE CAREFUL! IT IS EASY TO STRIP THESE BOLT HOLES!
• FSM recommends waiting 30 minutes before filling pan with oil. I don’t know if this is enough or not since it takes me a couple hours to reinstall everything. But after the 2 hours it is definitely ok.
• Reinstall everything else in reverse order.

dan1el

Where does the leak hit the ground? The likelihood of it being the rear main is next to nil from everything I have researched. Does it hit right below the oil filter and oil pressure switch? If so, unfortunately I would agree with oldngivout that the o rings in the rear TC case is much more likely the source. That is where mine is as I found out recently. If it is, I am going to do a write up on it this weekend hopefully.

I used the solid one the first time on the lower pan. Itleaked. I replaced it with RTV later and it is bone dry.

acercomp71

Oil seems to be pretty much everywhere, yes, drips right below oil filter, also where engine meets transmission area is all wet as well. Thank you so much for input everybody, will start working on it soon and let you know how it goes.

dan1el

If it is dripping from multiple places then it very well could be the pan gasket. Did you just recently buy it? Or have you had it for a while? It is rare that the oil pan gasket leak unless someone worked on it and didn't replace it well.

Again, from all I've heard and read, the rear main is a very rare leak and it is very unlikely you have to change it.

acercomp71

Car was 97K when I bought it, I doubt pan was ever dropped. If it is not a rear main than lower pan or upper pan or maybe even both, there is nothing else out there to leak really.

Do you have part numbers for those 2 O-rings by the oil pump by any chance? Are there aftermarkets for those or they are dealer parts?

So long story short, it is RTV for both lower and upper pans, 2 half moon shaped rubber seals, and 2 O-rings to replace, correct?

dan1el

That's it to replacing the oil pan seals.

Call Dave Burnett down at South Pointe Nissan: 1-888-254-6060 for the o rings and u shaped rubber. He'l know what you need.

Hectorcarrazana2011

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I have an 98 maxima and I'm changing the oil pan and I'm having problems with the o-rings.i put the original ones and it keeps on leaking what can I do to fix it? Or what may seem the problem??

Hectorcarrazana2011

I have an 98 maxima and I'm changing the oil pan and I'm having problems with the o-rings.i put the original ones and it keeps on leaking what can I do to fix it? Or what may seem the problem??

Snypa

iTrader: (35)

Very fun job. While ur there, may wanna change some other stuff.

sqaeng

After reading post #4, I would just place a piece of cardboard under my car instead. My exhaust must be rusted together by now