OIL PUMP SEIZES, BREAKING OIL PUMP SHAFT

[Apollo9]

Hello everyone,

I'm writing about the oil pump for classics. I have a 1966 v8. About six months ago I was driving and suddenly lost oil pressure. My lifters started ticking, the whole works. I removed the distributor and sure enough, the oil pump shaft had snapped. When I removed the shaft, it was stisted through the entire length of the shaft, very uniformed. Using a longer screwdriver that accepts bits, I added a new shaft and worked the oil pump free again. This has happened maybe 7 times. In December 2007 I decided to pull the oil pan and completely replace the pump. I cleaned everything out and replaced everything. I bought a reinforced shaft thinking I'd outwitted the car. Sure engough a month later, same issue. I've replaced it another 3 times since then and it's beginning to become a problem. This is my daily driver and I keep it in good condition.

So my thoughts are that there's something that's getting lodged in the oil pump. Some debree is in the oil and gets into the pump seizing it up. When I changed the oil pump (and oil of course) I noticed that the screen that roughly filters out the oil going to the pump was covered in a film or layer of pulp-like material that I was thinking might have come from a gasket. In any case, this was cleaned. I had thought at that time that it was plausible that the oil pump was becoming starved for oil. I had considered this until last night when, once again, the shaft breaks and I try to work the pump loose and each direction, as I move the pump, (from above) becomes tighter and tighter as though something is inside the pump it's self. I'm thinking that there are some metal shavings from somewhere getting into the oil. Maybe the rings as they wear?

Is there anyone out there that has had this problem? Has found a solution? I'm to the point that I'm ready to just rebuild the engine. If you have any ideas, suggestions, or experience with this problem please let me know.
Thanks !

 

[rbohm]

pull the pump apart and see what is inside the pump. if you have a lot of metallic debris in the pump, then rebuild the engine. by the way are you using a high volume or high pressure oil pump? if so then STOP. use a standard oil pump that is all you need.

 

[D.Hearne]

If you've seized the oilpump that many times, you should pull the engine and rebuild it. Any little piece of just about anything, if sucked into the pump will seize it. GAsket material, silicone sealer, burnt carbon (this stuff builds up over the years in tight corners thruout the crank case) Pieces of rings, pistons (the stock cast pistons were notorious for loosing their skirts) Ring lands off the pistons (detonation causes this and shatters the rings too) Time to stop going half assed here, time to bite the bullet and pull the engine and see exactly what's going on.

 

[C0V3R]

Sounds like your drive shaft looked exactly the same as mine.

I had a pump fail on the outlap on a track on a brand new motor. Seems that the pump came built in with free bits of gasket junk. These lodged in the rotors between the rotor and the pump body wall seizing it. No amount of force would set it free without disassembly. I pulled it apart and cleaned it meticulously with gas, lubed it and tested it. Seemed ok so it went back in. Havent had any issues since.

I agree with dhearne. As much as I hate to say it, after you got through 2 pumps you should have to wonder whats going on. If you haven't already you should check your bearings, they may well be toast.

How long did you run it for each time after the tapping started? If it went for more than a minute your bearings are very likely to be toast unless you significantly overfilled your engine (like I did for the track day).

 

[gtss]

I agree with the tear down and inspect, there must be some damage/ wear going on.
i would additionally suggest replacing the pick up tube if you haven't already done so. based on the crud you described in the screen it could well still have some debris lodged in the tube

gtss

 

[C0V3R]

Yeah. Time for the block to be flushed professionally (you probably have crud all through the oiling passages now), new pickup, new pump and probably new bearings.

If I were you I'd go grab a cheap running motor from somewhere to keep you on the road.

 

[TD68302]

by the way are you using a high volume or high pressure oil pump? if so then STOP. use a standard oil pump that is all you need.[/QUOTE]

Whats wrong with High volume oil pumps.

 

[Fast63]

by the way are you using a high volume or high pressure oil pump? if so then STOP. use a standard oil pump that is all you need.

Whats wrong with High volume oil pumps.[/QUOTE]

They break oil pump drive shafts!! If you use a stock one, you have a good chance of twisting it like a twizzler. If you have a high volume/pressure pump, get an ARP one or somethign made for it. It is also unnecessary unless you have loose bearing clearance, turn rediculous rpms, etc.

 

[66HertzClone]

The debris is likely pieces of your valve stem seals. These once rubber like seals become petrified and eventually break apart. These are small enough to pass thru the bypass hole in the pickup screen and become wedged in the pump. I remember from my days in the parts business, TRW included a printed warning in the box with every new pump.

 

[rbohm]

Whats wrong with High volume oil pumps.

They break oil pump drive shafts!! If you use a stock one, you have a good chance of twisting it like a twizzler. If you have a high volume/pressure pump, get an ARP one or somethign made for it. It is also unnecessary unless you have loose bearing clearance, turn rediculous rpms, etc.[/QUOTE]

they also have a tendency to shear distributor gears.

 

[woodsnake]

As I understand it, the 221-351W series of Ford engine have a very good internal oiling system.
The 385 series, 429/460 (335 series 351C) are known for having a need for more oil in performance applications.

For a street driven small block Ford, a new, quality brand oil pump will usually do quite well. Unless, your engine lives at 7K, etc etc...

 

[CraigMBA]

The HV pumps also use more horsepower to turn.

I had the pressure relief stick open on my Melling HV pump. I replaced it with a standard one. No issues. If you break a ARP oil pump shaft, you've got big big issues.

 

[66Runt]

While you're in there, might as well take a close look at the shear pin for the distributor gear.
Mark my vote for a stock volume, quality oil pump and a good shaft.

 

[65ShelbyClone]

The debris is likely pieces of your valve stem seals. These once rubber like seals become petrified and eventually break apart. These are small enough to pass thru the bypass hole in the pickup screen and become wedged in the pump. I remember from my days in the parts business, TRW included a printed warning in the box with every new pump.

I was just waiting for someone to say this. I went through several oil pumps and shafts years ago because the old 289 heads on the engine had stem seals that were coming apart and going into the pump. After twisting off two FMS pump shafts, even the distributor shaft split. The screen on the pickup was also separating from the body and letting that garbage get sucked up. It took a new pickup, new heads, and a good cleaning to get the pump seizures to stop.

 

[chromedog]

as was stated by rbohm, a hardened shaft WILL take the cam gears out (ask me how i know...)

 

[MdntRanger50]

My experience a few years back when my dad and I built my first 302 engine. It went into my 84 Mustang. We put a mild speed pro flat tappet cam in. To make a long story short. I basically used the wrong combination of parts with the timing set, fuel pump eccentric ring, and timing cover. The fuel pump eccentric ring was touching the inside of the timing cover and kindly shaving off little slivers of aluminum for my oil pumps to eat. After the second pump seized and twisted the shaft I pulled the engine out and found the cause. Good lesson learned.