I need to replace the failed oil pump on my '89 F250 351 V8. Haynes manual says I need to drain coolant and remove radiator before lifting up the engine, so I can eventually get the oil pan out. This is a bit nuts. Do I really have to remove the radiator, or can I jack the engine up enough so it does not touch the radiator while allowing me enough clearance to slide the oil pan out?

When my oil pump quit this morning, I had to drive the truck back home about two miles with drivetrain knocking (no oil pressure). The temperature stayed normal. Do you think I hurt the engine? How much can it tolerate? The truck got 150k on it.

thanks

 

yes I would say that you done damage to the engine driving it for 2 miles with no oil pressure and a knocking sound coming from the engine , the knocking was an indication of something being loose or worn which means something was probably damged. as far as having to remove the radiator to take the engine out , the radiator is not a very big deal at all , I would be more worried about getting the engine out if I were you. If you don't think you could handle taking the radiator out , I would not recommend you taking the engine out.

 

I am not sure what engine and tranny you have, I did not see a signature on your post. From the tech article below, you do not need to take out or disconect the radiator. This was for a 302/351 with E4OD. Hope this helps.

https://www.ford-trucks.com/articles/2003/18.php

 

Thanks for replying! The article does help. I took another hard look into the engine compartment, and there is plenty of space between the engine fan and the radiator. I think the Haynes manual recomends removing the radiator, because it has this procedure written to cover all models of Ford trucks, and some are so tight, you can't raise the engine without hurting the radiator. It looks like my F250 has enough space.

The noise I was hearing when I drove the truck back home with no oil pressure was not really "knocking". It was more like "loud tapping". I am pretty sure this was from lifters running dry. I hope it's not too damaging.

 

It's worth trying the pump anyway. As soon as you lose oil pressure you start getting noise from the engine and it's not a definite indicator that you actually hurt it. It's just telling you something is definitely wrong (no oil pressure). I have personally witnessed engines driven for up to 25 miles without oil pressure, usually oil too low to pick up) fill them back up with oil and they are still running today. I hate to give you false hope. If it was me personally I would have shut it off right then and drug it home, that's how serious it is. It's the blood your engine runs on. But most oil is good enough to hang on for 2 miles (still would not try it).
Just curious, how do you know for sure it is your pump?

 

I was filling up at the gas station when the pump went. I first heard the sound from the oil pan. It sounded like if someone stuck a piece of paper in the fan (could be the broken oil pump shaft?) I thought this could be the oil pump, so I looked inside the cabin at the oil pressure gauge. Sure enough it dropped to zero. A few seconds later tapping started. This truck is not worth much and I was in a hurry, so I just drove it back home, about a mile or two.

I will try to work on replacing the pump this weekend and will post results. If anyone else had experience driving short distance with oil pump going, similar to mine, please post. I would be interested to learn the outcome.

 

Take the fan shroud loose, or you will break it. Also this is the time to check the rod and main bearings to see if there is any damage. I would say you may have a rod bearing knocking. I have done several over the years.

 

Update: Finnaly got to replacing the oil pump. Took me a few days, on and off, but I was not in a rush. Did not have to remove the radiator or disconect any hoses. Here is the procedure for 1989 F250 5.8L 2WD XLT Lariat:

1. Raise the front of the truck by the frame. It's important to take the load off the shocks and springs. Otherwise you won't be able to raise the engine later. The engine is heavy and pushing it up without previously raising the frame just raises the whole truck. Make sure to support the frame securely on stands or solid wood blocks.
2. Disconnect negative battery terminal.
3. Disconnect the fan shroud from radiator. Leave it in place, hanging on the fan.
4. Drain the oil. Remove oil filter.
5. Disconnect the starter (it will be in the way, so just take it out).
6. Disconnect exaust pipes from exaust manifolds (otherwise the oil pan will not drop low enough for you to work around it). This took a lot of PB Blaster (soaking overnight) and a long socket with a couple of extensions (you will definitely need extensions on the passenger side). Soak it good, don't rush, and take it easy. The nuts (or studs) will eventually come off.
7. Remove engine mount nuts.
8. Raise the engine with a jack under the oil pan (put a solid piece of wood between the jack and the pan, so the pan is not damaged as you jack it up). Raise it as high as it will go, but don't force it! Put small wood blocks between the engine and the mounts to secure it in raised position, remove the jack.
9. Unbolt and lower the oil pan (I used flexible socket extention on some hard to reach bolts). The pan won't drop completely, even with engine raised. Exaust pipe is still on the way (even with exaust disconnected from the manifold). I did not want to drop the exaust completely so had to work with the oil pan resting on the cross-member. Don't worry, you will have plenty of room.
10. Unbolt the oil pump, disconnect pick-up screen from the pump while still in the pan, then remove them from the pan separately (there is not enough clearance to get the whole assembly out as one piece or without spilling oil all over the place). I used a flexible socket extension to separate those two pieces while still in the pan.
11. Clean out the oil pan and engine block from old pieces of gasket. Remove junk and clean the oil pan with break cleaner (cuts through the grease perfect).
12. Prime the new oil pump with oil.
13. Place the new oil pump and pick-up screen in the oil pan (separately). Bolt pickup sceen onto the pump (don't forget the little gasket).
14. Insert the new oil pump shaft. This was a bitch. You can't see where it's going, so you have to work blind and guess. Took me 15 minutes of trying to finally find a spot where it goes into the end of the distributor shaft. Also, there is a climp-on ring on the oil pump shaft. Make sure the end with the ring goes up (towards the distributor shaft). This ring prevents the oil pump shaft from disjoining and falling out into the oil pan when distributor is pulled. If you do it right way up, someone will thank you in the future!
15. Allign the oil pump assembly with the oil pump shaft and bolt it in place. It was a bit hard as you have to hold a few pieces at once (the shaft from falling out, the pump assembly, a little gasket, the bolt and the wrench). Took me 10 minutes to get good feel of it.
16. Install a new one-piece Fellpro oil pan gasket.
17. Put everything back together. Don't forget to bolt the fan shroud back to radiator! Don't forget to install the new oil filter and to FILL THE ENGINE WITH OIL!
18. Disconnect the central wire from the distributor. Crank the engine a few times. This will prime the oil pick up system with oil.
19. Reconnect the central wire, and start the engine.

This procedure worked for me. The new pump is working fine. I got the pressure up and all noises went away. So far so good. Hope I get a few more years out of this old beast.

flanker

 

What exactly failed on your old pump? I've seen several where people thought the pump failed when actually the pickup screen was clogged with gunk. Also had a peice of the nylon from the timing gears break off and "jam" the pump.

 

Thanks for writing the procedure. I want to pull my pan and this helps.

 

Yeah. I totally forgot to explain the reason. The pick up screen was totally clogged with gunk, just like you said. It was not even worth cleaning. This was the primary reason for total loss of oil pressure. I guess the previous owner did not care to change oil all that often.

I took the old pump apart, and it was a bit worn out (some deep scratch marks inside the cover). The whole thing also felt loose compared to the new one, so I just replaced it. Good thing it's not expensive and would save me aggravation of going though this again in the near future.

 

You make it sound easy. <grin> I've done that procedure too many times than I care to count... one thing I usually do is pull the distributor. Then after the new pump and shaft and pan and oil are all back together, I use a 5/16" socket on a 1/4 drive extension to my cordless drill and turn the oil pump shaft (counter clockwise) to build pressure and prime the engine before starting. Then re-install the distributor. Your way works fine, mine is just a little more "cocky." ;-)

 

The key is to "take your time" as with any other project, no matter how large or small.

 

To quote Buford T. Justice, "WE GOT NO TIME FOR THAT CRAP!!"