HELP! Post-oil pump seal replacement problem

[WorldTraveler]

Hi all,

I just completed the front crank and oil pump seal replacement on my 96 LX450.

All seemingly went well but the oil pressure gauge now is dead on 0, no movement at all. It had read near the middle of the gauge at idle.

I am reluctant to run the engine without being sure that oil is flowing. The gauge was working fine before I started working on the engine.

I did clean a ton of caked on oil and dirt off various spots on the engine, removed the lower radiator hose near-ish the oil pressure sensor (figuring I'd remove the radiator, which I didn't in the end). It's possible the wires connecting the sensor were near end of life and broke in the process but nothing is obvious. I also removed the oil filter (Toyota) and replaced it with a new one (Mobil 1). I did not drain the oil from the pan. The dipstick reads full. I was very careful to prevent anything from entering the oil pump.

So here's are my questions:

How can I tell if oil is flowing?
Is it possible for the oil pump not to pump, assuming the intake isn't clogged?
Could there be trapped air in the system from the filter?

Thanks in advance!

P.S. I owe great thanks to the posters on this site who shared their ideas and experiences on how to do the oil pump cover gasket repair. I got 6 out of 7 screws out using the tapping method and a battery powered Makita impact driver (highly recommended if you go slow and did all the tapping). The last one needed to be drilled and then removed with a screw extractor bit.

P.P.S. You can protect your radiator fins while working with a piece of plywood (heavy cardboard would probably do as well).

 

[96r50]

Is it possible for the oil pump not to pump, assuming the intake isn't clogged?

Yes, if you didn't tighten the crankbolt tight enough (304 ftlbs). The oil pump and power steering pump are both powered off the crankshaft by a gear that is only held in place by the friction created from the 304 ftlbs on the crankbolt. How did you retorque the crankbolt?

 

[MARLIN375]

Have you got enough room to put a half litre of oil in the top. I have a feeling you have air in there.
Why would you change the filter and not the oil? Ive heard of changing the oil and not the filter but never the other way around. I am thinking that after you change the filter and the oil the new oil pouring in from the top of the head most likely re-primes the system.

I will also add that in my experience idling your engine for a couple of minutes with no oil pressure or even no oil is not going to hurt anything (no-oil like between changes, not new motor no-oil if that makes any sense)

 

[OGBeno]

Did you unplug any oil sensors?

 

[WorldTraveler]

Torque, most likely...

I'm guessing it's the torque issue. I know I didn't get close to 304 ft/lbs. in tightening it. I figured I'd take it to a shop that had the needed torque wrench and socket and have them do it. I'll try to get a solid strap on it and cheater bar on my breaker bar and get close, then proceed with plan A again (if there is some pressure). Either that or try to find the tool for rent somewhere.

In digging further I see, as Adam says, that the torque is needed to drive the oil pump. Seemingly strange design. I would think it's directly driven by the shaft. I'm sure there is a good reason, though.


Answers to other questions:

No room for 1/2 qt. of oil (unless I drain it).

Changed the filter since the oil's been being changed via the old leaky gasket at the rate of 1 qt. per 1000 miles and I just drove coast to coast with it. Oil looks nice. Filter was about due. Weird, I know.

I think the sensor is still connected. I was thinking of a wiring problem on the sensor but further digging has led me to the torque issue.

Thanks for the feedback!

 

[landtank]

my money is on a loose crank bolt as mentioned earlier.

 

[mrdstr]

Your oil idea is very sound actually. There was a report floating around showing the effect of doing filter only changes and top offs every 3000 miles out to some pretty high mileage numbers. After the initial first full oil change, the analysis showed far less metal contaminant and oil breakdown as time went on. As soon as the test was complete and the full oil change was repeated, everything spiked in the analysis. The conclusion was that the detergents in the oil were too agressive at cleaning. So everyone who changes oil at 3000miles vs the recommend mfr intervals (some cars now going beyond 15000miles) may be doing more harm then good.

 

[powderpig]

Some one may be able to post a link to the thread where a guy uses a 6" 1/2 drive extension to stop the torque convertor drive plate. This is put in the inspection area at the back of the engine. This will hold the engine to allow a good tightening of the bolt in the front.
If you do a Mud search for this Job, there are few discussion on this oil pump drive gear and the design. Good luck

 

[arndog123]

I used that method when I did the crank and oil pump seal on my '97 and it worked like a charm. I used a 14 mm deep well socket. On my wife's '96 I used the chain method and using the 14mm socket on the torque converter bolt is so much easier.

 

[azcromntic]

Some one may be able to post a link to the thread where a guy uses a 6" 1/2 drive extension to stop the torque convertor drive plate. This is put in the inspection area at the back of the engine. This will hold the engine to allow a good tightening of the bolt in the front.
If you do a Mud search for this Job, there are few discussion on this oil pump drive gear and the design. Good luck

If that is true then I don't understand why a person couldn't just put the vehicle in gear and tighten it?

Probably good idea to have coil wire off during this operation though.

 

[landtank]

my preferred method is to take some synthetic rope that I got from Home Depot and loop it around the frame and wrap it around the crank pulley so it tightens as you tighten the crank bolt. Works like a charm and you aren't jamming anything into the mechanics of the drive train.

 

[RedTacoma]

Ok that thread is actually what I wanted to ask. I am about to start engine after the same job (oil pump seal) I was wondering how can I prime pump with oil?
My only idea is to remove oil filter and put some oil in the outside pipe where oil filter is bolted.
Do I have this right. Oil flows from outside of the filter to inside then through threaded pipe back to an engine, right?
BTW sorry for slight hijack but that maybe your solution too. I am thinking oil pump will have no prime after seal job so oil pressure will be zero until it primes. Depending on the state of o-rings that maybe long time unless there is a way to help it.

 

[theallpowerfulme]

Where are you located? I just did the pump cover gasket/front seal on mine and purchased 200-600lb/ft torque wrench to do the job. I can let you borrow it. I am in Knoxville, TN.

 

[theallpowerfulme]

Ok that thread is actually what I wanted to ask. I am about to start engine after the same job (oil pump seal) I was wondering how can I prime pump with oil?
My only idea is to remove oil filter and put some oil in the outside pipe where oil filter is bolted.
Do I have this right. Oil flows from outside of the filter to inside then through threaded pipe back to an engine, right?
BTW sorry for slight hijack but that maybe your solution too. I am thinking oil pump will have no prime after seal job so oil pressure will be zero until it primes. Depending on the state of o-rings that maybe long time unless there is a way to help it.

priming your oiling system is not necessary after this job. Startup will be the same as it is after an oil change. Yes, the oil flows into the filter through the middle hole and out through the outside. The pressure of the oil actually pushes the filter cartridge against a spring inside the filter, this way as the filter becomes clogged a bypass valve is opened by the cartridge sliding back and doesn't starve your engine for oil due to a clogged filter.

 

[theallpowerfulme]

my preferred method is to take some synthetic rope that I got from Home Depot and loop it around the frame and wrap it around the crank pulley so it tightens as you tighten the crank bolt. Works like a charm and you aren't jamming anything into the mechanics of the drive train.

this is the way I did it, except I used a chain instead of a rope. I secured it to the crank pulley using the threaded holes where you attach a puller to the balancer.

 

[orthotist]

puller

this is the way I did it, except I used a chain instead of a rope. I secured it to the crank pulley using the threaded holes where you attach a puller to the balancer.

Do you need to use a puller for the balancer to come off? I haven't heard of it being mentioned much!

 

[arndog123]

I didn't need a puller on either of my 80's. All it took was a couple taps w/ a rubber mallet and the pulley's slid right off.