I finally replaced my leaky oil pan gasket this past weekend. What a job that was. I thought I would post my experiences here, maybe it'll save someone a little bit of time and aggravation.

Parts needed are as follows -

1. Oil pan gasket - I bought the Fel-Pro single piece gasket from Advance Auto Parts. It comes with some really nice plastic studs that help you locate the gasket on the block and also hold the pan in place while you install the bolts. Cost - $30

2. Upper intake gasket - Again, I went with Fel-Pro. They sell either a kit for the upper intake plenum or a complete kit for the plenum and manifold. I bought the kit for the plenum, which includes the gasket between the plenum and intake manifold, the gasket for the throttle body, and a few items I didn't need - an o-ring for the distributor, and two other gaskets. Cost - $5.

3. Oil and Filter - You have to drain the oil, duh. I went with Mobil 1 and a Motorcraft FL-1A filter.

4. New oil drain plug washer - Mine was shot, so I replaced the drain plug with one of those nifty Fram SureDrain spring loaded valves. Works like a champ on my CRX, should be good enough for the 5.0L.

5. Engine degreaser - You might want to clean the underside of the engine as you go, so you can detect any leaks if you didn't do the job right.

6. T-40 driver, either a right angle wrench or a socket - One of the bolts holding the upper intake on is a T-40 torx fastener instead of a hex head bolt. It's directly underneath the runners where you cannot see it. I bought a set of torx drivers that are similar to allen wrenches in size and shape and was able to break it loose. I'm not sure that there is enough room under there for a socket and ratchet.

7. Liquid Wrench - Needed for rusty bolts on the exhaust flanges.

8. Engine Cleaner - No one likes a dirty engine, especially after working on it all weekend!

Now, I read through my maintenance manual and couldn't believe that I'd have to remove the intake plenum in order to change an oil pan gasket, but I found out pretty quickly that is was totally necessary. Here are the steps....

1. Disconnect the negative terminal from the battery. I usually skip this step, but you have to remove the starter and you probably don't want the battery to short out while you are under the truck. Safety first!

2. Remove the two bolts the hold the fan shroud to the radiator crossmember. Lift the shroud up and let it hang on the fan.

3. Remove the upper intake and all the stuff that attaches to it. This will allow the engine to be raised high enough without hitting the firewall.

4. Drain the engine oil and remove the filter

5. Remove the two bottom nuts on the front engine mounts.

6. Remove the starter - you need to do this so you can get to the exhaust flange bolts on the right side of the engine.

7. Remove the exhaust flange bolts - you may need to saturate the bolts in Liquid Wrench or something similar.

8. Jack the engine and support with wood blocks between the engine mounts and the frame. Jack on the oil pan, using wood blocks on the jack plate of a floor jack.

9. If you plan on removing the oil pan from the vehicle completely, you must remove the exhaust system, which includs unbolting the transmission from the tranny crossmember and removing the crossmember. The oil pan cannot be removed completely unless the exhaust is removed. The exhaust downpipes to the catylitic converter are in the way. I opted not to pull the pan all the way out.

10. Remove the oil pan bolts and whatever you call those long steel pieces that are bolted up to the oil pan.

11. Remove the old gasket and wipe the mating surfaces clean. If the oil pan has one of the older cork gaskets, it's probably a good idea to remove the pan completely from the truck so you can clean all the old gasket material off the block and the pan. Mine had the one piece rubber seal, so I just pulled it off.

12. The Fel-Pro gasket came with some nifty blue plastic studs that are screwed into the four 1/4-20 bolt holes next to the front and rear mains. This studs are tapered, so when you slip the gasket into place, they hold the gasket in perfect alignment to the engine block and keep the gasket from dropping back down into the oil pan.

13. Since I didn't remove the oil pan from the truck completely, I just fished the new gasket into place. The oil pump, dipstick and pickup tube extend down from the block, so it's a little tricky, but not too bad to do. Pop the gasket over the blue studs.

14. Wipe the gasket and the oil pan one last time and pop the oil pan over the blue studs.

15. Install the 18 bolts in the oil pan, don't forget the long steel whatchamacallits. I did and had to remove all the bolts to reinstall them. Be careful not to overtorque this or you day is ruined.

16. Remove the blue plastic studs and install the four 1/4-20 bolts.

17. Lower the engine back onto the engine mounts, don't tighten them down yet.

18. Chances are the two exhaust pipes don't exactly line up with the manifolds now, so you may have to manhandle the engine a little to get the alignment right.

19. Bolt up the exhaust downpipes, don't tighten either one until both are close to snug, or you'll have to loosen one in order to get the other one to mate up.

20. Tightend the engine mount nuts.

21. Reinstall the starter.

22. Install the new oil filter.

23. Reinstall the upper intake plenum, using new gaskets on the intake manifold and throttle body. Be careful with the bolt that secures the plenum on the rear part of the engine. I dropped it twice, what a pain!

24. Fill with oil.

25. Start the engine and check for leaks.

26. I choose to clean the engine afterwards. The aluminum plenum just didn't look very good after I handled it with my greasy hands.

So far so good, I drove the truck about 80 miles immediately after completion and it hasn't leaked a drop yet.

Greg

 

Been there, done that. And I agree....it's a JOB. Pretty involved to just change the oil pan gasket. I did mine last year on my 87 302.

 

Did you have to put any type of sealant on the new gasket?

I replaced mine also with a Felpro gasket along with the rear main seal and still have a leak in that area. I just can't seemed to pinpoint where the leak is coming from. The oil seemed to come down the rear u- section of the pan...

1990, F150, 302

 

The instruction sheet that came with my Fel-pro gasket specifically said not to use any sealant on the gasket, so I did not. Ford recommends a "dot" of RTV and four spots on the block when using an OEM gasket.

Hmmm, if you replaced both the gasket and the rear main seal, I'm not sure where else it could be coming from. Was the crankshaft in good shape where it mates to the rear main? Are you sure the rear main was installed straight and square with the block? Is the pan straight were it mates to the block?

I don't know much about these engines as it's my first Ford. Luckily, I haven't had to do too much to it yet other than the oil pan gasket.

Greg

 

I replaced my pan (rusted out) with out removing the upper intake plenum. It is tight, but if you unbolt the oil pump you can get the pan out with the intake on. I did however use an engine hoist to lift the engine. SO maybe that gave me more room. I also replaced the exhaust manifolds with shorty headers at the same time.


You are right it is a big job. Took me most of the day.


Doug