oil pump?

[warriorpluto]

well i have a 90 mustang gt 5 speed. all stock 114,000 original miles. i noticed that when i drove the car previously the oil pressure gauge would jump from the middle mark to below past zero. ok.....everytime i get on it the oil pressure gauge dropped to zero. well today i got on it again to around 5,000 rpms. never really even pushed the car hard since i had it. oil pressure dropped below past zero again. on my way home i could now hear tapping. got home opened the hood. i hear a little loud tapping under the driver side valve cover. before the motor ran like a quiet sewing machine. i hooked up a mechanical gauge. reads 40 psi at idle but as soon as i rev it up the oil pressure drops to 20psi then sometimes zero. i didnt drive it anymore. but when i cranked it up again i heard slight tapping then all sounds went away. no tapping. oil pressure at 40 psi still. broken shaft? oil pump bad? was about to try to get rid of the car since it was in really good condition mechanically and interior was above average. just needed a paint job but i guess that has come to an halt. anyone ever change oil pump with engine in the car?

 

[Beasty306GT]

it should have 50 psi at least on cold start and like 25 at hot idle

 

[mr_josh]

I would guess a failing pressure-relief spring in the oil pump. The tapping... that's bad. Replace the oil pump, and while you've got the oil pan off, you might take a look at your rod bearings.

 

[thethirdeye88]

quit driving the car immediately...i lost my bottom to a situation similar to this...

 

[warriorpluto]

what if i wanted to just go on ahead and replace the bearings while im in there? how would i do this? it would be my first time messing with the bottom end. i think the bottom end is ok though but if a possibility its not can i just go to parts store and get new bearings? any special tools?

 

[stykthyn]

at this point for simplicity sake i wojuld find a low dollar explorer block and swap everything over.

 

[Beasty306GT]

agreed if u have no expierence ..just swap it with a good explorer motor and swap parts

 

[warriorpluto]

this put me in a real bad spot cause i i already have another mustang with a fresh rebuild i cant even get started. money is really tight right now. i just have to gamble on this one. i wont mess with the bearings ill just change the pump and shaft. i have a ford racing hardened shaft. is this pump any good? a ford racing standard? http://cgi.ebay.com/ebaymotors/86-8...ptZMotorsQ5fCarQ5fTruckQ5fPartsQ5fAccessories

 

[stykthyn]

to be perfectly honest if you have been running low oil pressure the bearings have suffered. the ones that take the most abuse are the rod bearings and you have no way to service them while they are stiill in the car. changing the pump is a bandaid that most likely will only buy you a short time.

 

[warriorpluto]

when i do a cold start oil pressure stay at 50psi. rev it up past 5000rpms and oil pressure drops to 20 psi. could be the shaft? if i could find a nice running gt40 engine for 300$ i can afford that. no junkyards have 5.0 explorers out here.

 

[Haus]

when i do a cold start oil pressure stay at 50psi. rev it up past 5000rpms and oil pressure drops to 20 psi. could be the shaft? if i could find a nice running gt40 engine for 300$ i can afford that. no junkyards have 5.0 explorers out here.

check craigslist.org in your area

 

[warriorpluto]

check craigslist.org in your area

already did. a no go. i checked the whole ark-la-miss

 

[harvey86gt]

I would go ahead and pull the motor and rebuild the bottom end. You can rent a hone from Autozone, and if this is your first problem with your oil pressure, you should not have excessive wear on your crankshaft but a machine shop will normally charge about 20 bucks to polish it and mic it so you know wether to order standard or undersize bearings. 107.99 for a complete gasket set from autozone. 48.99 sealed power main bearing set. 46.99 for a new ring set sealed power. 46.99 for new rod bearings sealed power. for about 250 to 300 bucks you can rebuild the entire bottom end. add another 50 bucks for a new oil pump and pickup tube and you have a fresh motor.

 

[warriorpluto]

i might go that route. but if i were to buy a stock pick up tube there shouldnt be any reason to adjust it right? even if i were to reuse the stock pick up tube? cause i read somewhere that people had to adjust where the pickup tube sits between the oil pan. and what about the oil pump drive shaft. where should i put the stop?

 

[v8only]

Lot's of negativity here...nothing wrong with a poor mans bearing swap down below. You've got to do what you've got to do to keep your **** running.

fire it up one more time, since it does have pressure at idle...take a screw driver and put it to the valve covers and to your ear, then to the pan and to your ear. If you don't here the rod bearings down below knocking, just swap the pump and leave it alone. If you do, then swap out the bearings, making sure the crank isn't damaged.

 

[warriorpluto]

no knocking at bottom or up top anymore. but im still going to change it out.