AMC Eagle Den Forum

The Mighty 258 => The Engine => Topic started by: Billman on May 08, 2013, 09:27:37 PM

Title: Bad oil pump?
Post by: Billman on May 08, 2013, 09:27:37 PM
Has anyone ever tried to change an oil pump without pulling the motor? i just went on a test drive and I think the pump failed. Even if I've got to lift the motor up a bit I'd like to do it under the car.
Title: Re: Bad oil pump?
Post by: vangremlin on May 08, 2013, 11:01:37 PM
I think you could do it by supporting the motor up top, and removing the front drive train, which will allow you to pull the oil pan.  I think the TSM recommends that procedure for removing the oil pan and replacing the rear main seal.
Title: Re: Bad oil pump?
Post by: carnuck on May 09, 2013, 01:37:50 AM
Did the gauge go to zero? If so it could be a bad sending unit. Re-check with a mechanical gauge (only crank the motor. Pull the coil wire so it doesn't start until you ensure there is so pressure) It's possible the oil pickup tube snapped off. I've seen several myself (not mine thankfully!)
Title: Re: Bad oil pump?
Post by: Billman on May 09, 2013, 08:54:32 AM
I only have the idiot lights but the engine did start clattering when the light came on so I'm gonna assume its a bad pump. I will be getting a rebuild kit and doing a write up when I get to it
Title: Re: Bad oil pump?
Post by: rmick on May 09, 2013, 07:02:13 PM
Yes it can be done I have done it. Change the rear main seal while your at it and get a high volume pump instead of the normal pump. Support the engine from above. I have a  bar that sets between the fenders with a chain with adjustable J hook connected to the chain. Drop the cross member from the frame and engine mount. Drop the front axle from the engine support brackets This should get you enough room to drop the pan.
Title: Re: Bad oil pump?
Post by: eagle87 on May 09, 2013, 08:33:16 PM
ive had the eagles oil pump get sludged up by sitting, change the oil and filter (optional) and remove oil sending unit and distributer (mark location) and use an oil pump priming tool or cut off screwdriver (careful not to drop it into the engine) and spin the oil pump drive with a drill at high rpm and oil should literally shoot out of the oil sending unit hole, reinstall distributer and sending unit add engine flush run engine as per product instructions and change oil and filter again, this may fix the problem
Title: Re: Bad oil pump?
Post by: Billman on May 09, 2013, 08:39:40 PM
This is the same one that I drained 4 gallons (yes gallons ) of oil/gas out of. Carb accelerator pump was maladjusted. I'd bet it burned up the impeller with all that gas. I drove about 15 miles the day before and had no problems.
Title: Re: Bad oil pump?
Post by: eagle87 on May 09, 2013, 08:47:37 PM
eagles use a gear pump for the oil which has no impeller, i would still try priming before undertaking the removal, as i have 2 eagles garages diagnosed a bad oil pump and that fixed both of them
Title: Re: Bad oil pump?
Post by: vangremlin on May 09, 2013, 11:33:29 PM
Quote from: eagle87 on May 09, 2013, 08:33:16 PM
ive had the eagles oil pump get sludged up by sitting, change the oil and filter (optional) and remove oil sending unit and distributer (mark location) and use an oil pump priming tool or cut off screwdriver (careful not to drop it into the engine) and spin the oil pump drive with a drill at high rpm and oil should literally shoot out of the oil sending unit hole, reinstall distributer and sending unit add engine flush run engine as per product instructions and change oil and filter again, this may fix the problem

Great thing to try before messing with pulling the oil pan.  Egg to you!
Title: Re: Bad oil pump?
Post by: carnuck on May 10, 2013, 10:59:59 PM
I use a spare dist with the gear ground off with my drill to prime the motor. You can run the flush through that way too. Gas in the oil more likely knocked all the buildup inside the pan and block loose, which is clogging the oil screen. I have hooked up engine flush to the oil sender port and spun the dist backwards to push the crud out of the screen too. I had to do that when I picked up an old Rambler. Driving home the oil light came on at 50 mph so I coasted to the shoulder. I drained the murkiness that was passed off as oil and force fed a quart back down the sender port by turning the motor backwards (with the plugs out and my torque wrench) until the whole quart was sucked in. (I grabbed the oil and pipe fittings from an Irlybird hardware that was nearby)
   Then I poured 3 quarts of diesel fuel down the valvecover, caught it on the bottom and fed it through again several times (sans the crud in the bottom) until it came out clean. Then I put in the fresh oil and changed the filter and drove it home. I pulled the pan and there wasn't much crud left in there, but I figure it drove 50,000 miles without an oil change before I got it (going by the sticky on the windshield)
Title: Re: Bad oil pump?
Post by: Billman on May 12, 2013, 02:03:35 PM
Hey thanks guys, work schedule and jeep repair are gonna put this off till next weekend. I will give that a try then. Sounds alot easier and way less expensive.
Title: Re: Bad oil pump?
Post by: Billman on November 24, 2013, 07:48:44 PM
Time to revive this thread. I had run old gas through the oil pump backwards per Carnuck's suggestion and method. The car was doing good with oil pressure at around 5lbs heated and then when my son was driving it stopped pumping again :censored: :banghead: Now its a wonderful time of the year to tear into such a project. Anyone got any suggestions on a reputable place to get a crank? I'll be looking up a high volume oil pump before putting it back together.
Title: Re: Bad oil pump?
Post by: carnuck on November 24, 2013, 11:55:44 PM
Did you try compressed air? On my Ford van I hooked a pressure can full of ATF to the oil pressure sender and spun the motor backwards with the drain plug out till I could hear the air bypassing the oil in the pump. It's also possible the screen may have been knocked loose. The high volume aftermarket pumps sometimes require the dist drive tang to be shortened slightly or they bind up from too little endplay and too much pressure.
Title: Re: Bad oil pump?
Post by: Billman on November 26, 2013, 08:20:43 PM
At this point the motor has developed a bit of a knock so I'm gonna have to have the crank either reground or replaced so I will probably just pull the engine out of the brown wagon (weak transmission) and put it in and then find an xj for a 4.0 aw4? drive train in the brown wagon. With 4 Eagles I can just move stuff around but I have an issue with scrapping any of them.
Title: Re: Bad oil pump?
Post by: IowaEagle on November 26, 2013, 08:43:59 PM
I have just the XJ you need.  Cheap!   '95 HO with a AW4.
Title: Re: Bad oil pump?
Post by: Billman on November 26, 2013, 09:41:48 PM
PM me the goods (miles, condition of tires, drive-ability  cost  ) yada yada yada