Dumb Timing belt mistake = Oil Pump trouble

[Riff]

Are you ready for this? It is a very long and painful story that does contain a question if you can make it to the end.

Not long ago I bought my second Tercel 4wd, because I liked my first one so much (more on that later). This new one has about 170K miles and there are some indications that prior owners maintenance schedules weren't exactly on time. So rather than take a chance with an inconvenient timing belt failure, I decided to change it.

Unfortunately, this timing belt swap over several weeks in the evening after work. As I disassembled the front of the engine, I was careful to arrange bolts and parts so I would be able to put them in the right holes when I finally got into the reassembly phase (I've discovered my memory is frequently faulty, a point my wife also won't leave alone). This has worked well for me before, but in this case, there is one bolt for the timing belt cover that is longer than all the rest. It is longer because it is supposed to go through both the upper and lower covers, however I did not remember this on reassembly, and installed it in the lower cover only. This basically made the bolt too long for the hole, which is a threaded hole with no bottom in an ear of the oil pump casting. I spun it in and the end of the bolt hit the block and broke off the ear of the oil pump casting. The chunk that broke off the casting happened to contain enough of the pump to basically put a hole iin it. The hole was not in the section with the cresent gear that pumps the oil, but it did basically open the crankcase. I have photos and will figure out how to post them for anybody who is interested.

Agonizing right? Should I just try JB weld? Super Glue? I bought this car because my first one has 356K miles, survived rockfall and running into a grader, and seems to soldier on, but I don't know how much longer I can expect it to go, it seems tired-- probably need rings soon. No, I figure the right thing would be to replace the oil pump, reliability is what I want not a cheap and easy quick fix. So I take a deep breath, get a new Aisin oil pump coming in the mail and spend several evenings a week for several weeks trying to get the oil pan and old pump off. This is not easy as others will tell you, but it is not impossible either. I did find it easier to get to some of the oil pan bolts out with the driver side axle out (it was due for replacement anyway). Several more weeks pass trying to get it all back together. Reassembly wasn't exactly smooth, getting the strainer on the new pump and putting the pan back was much more difficult than getting it apart. Right stuff on the oil pan, new front oil seal, replaced timing belt, radiator back in, new oil filter and 10-30w. Finally two months later, everything was back together and ready to try out.

I started the engine and it sounds fine, let it idle for about a minute, tightened some the hose clamps at the radiator, and get in the drivers seat and discover the oil light is still on. Immediately shut it down. Low Pressure? Pulled off the new oil filter and there is no fresh oil in it. Where do I start? Tear down and check the oil pick up tube? I can't believe I have to rip it apart again. Is there anything else I should look at?

[ARCHINSTL]

I don't have anything to contribute - sorry.
Just wanted to Welcome you to the Club. We do have a FSM available at the top of each page which you could look at until someone more knowledgeable gets back to you.
Tom M.

[Riff]

Thanks Tom,

I downloaded the FSM about five years ago at the Library (!) and it has been very useful, unfortunately it appears the average Toyota mechanic is smart enough to avoid this problem altogether. The pump looks pretty simple, either I'm not pulling any oil up into the pump due to the seal on the strainer tube, or there is something wrong with the relief valve. I guess i was just hoping once again that there was a simple easy fix or that I had missed something.
I have stopped by from time to time, with different little problems and have nearly always found solutions. This is definitely one of the best forums around.

[Petros]

welcome to the list. Sorry to hear about your troubles, I have done similar repairs. much easier with the engine out of course but doable with the engine in place. Presuming the sump had oil in it and it is not pumping it out a missing plug (you would see that), it sounds like the oil pump is sucking air. so either the pick-up tube is damaged, or it was not connected at the bottom of the oil pump. Or it could be the oil pressure relief valve is stuck or malfunctioning. It is also possible the pump itself is junk, but not likely. In any of these cases the pump has to come off unfortunately.

It will go faster the second time at least.

[rer233]

sounds like the pump wasn't properly primed before installation (i stuff 'em full of vaseline before installation to make SURE it doesn't loose prime.) if that's the case, you might be able to prime the pump by taking the oil pressure sender out, attaching a line to the block, attatch the other end of the line to an elevated container of oil, and turning the engine over BACKWORDS by hand. try it first with the oil filter off 'till oil comes out, then re-install the filter, and keep at it! might also help to rig up a way to pressurize the container to force the oil in. the alternative (as petros noted) is to do the job over. good luck- let us know how it works out!

[john]

My memory is pretty bad too. I often end up with a pile of spare parts. As far as the timing covers are concerned, I leave the top cover off. Put the bottom one on, it has the timing marks! It will make the next belt change a 15 minute job, instead of a couple hours. I really have been towed to a parts store with a broken timing belt and back on the road in 15 min.

[xirdneh]

My memory is pretty bad too. I often end up with a pile of spare parts. As far as the timing covers are concerned, I leave the top cover off. Put the bottom one on, it has the timing marks! It will make the next belt change a 15 minute job, instead of a couple hours. I really have been towed to a parts store with a broken timing belt and back on the road in 15 min.

I must be missing something here. i do not see how leaving the top half of the timing cover off could speed up the job.
pulling the top half of the timing cover is the easiest part of the job
the crank pulley still has to be pulled to get the lower timing cover off. or did you cut the lower cover in half so it could be removed somehow with out pulling the crank pulley.
or did you mean to say you left the lower half of the timing cover off?

[Riff]

I had not considered priming the pump-- it always works fine after an oil change. I suppose the pick up tube doesn't drain during a change? Ok-- will try priming first-- thanks.

[Riff]

Update: Spent most of the day trying to prime the pump. Pushed oil into the oil pressure tap and turned the engine backwards by hand. Got oil coming out of the oil filter fitting, replaced the filter and kept pumping oil into the oil pressure sensor hole and turning the engine. Added 3/4 of a quart of oil but no oil pressure when the engine turned over. Then tried blocking all openings in the crankcase except the pressure tap and pressurizing the crankcase with an air compressor. All I got was air coming out of the pressure tap. So now I have oil all over everything-- oh and a knuckle chopped open, but still no oil pressure.

I will work the pan off today and see if the pickup tube is damaged, I remember having a terrible time getting the tube installed and the pan on before the silicone skinned over on the lip of the pan. Maybe while fighting it on, the tube got a kink or something, developed a leak and the pump is pulling air. Not looking forward to breaking the seal on the pan, I put it together intending it to stay.

When you 'pack the pump with vaseline' do you take off the cover inside the pump or do you smash it in through the pick up tube opening? If it is the second option, maybe I can prime with vaseline only taking off the pan, and not having to remove radiator, timing belt covers, crank pulley, timing belt and oil pump.

[scouttster]

Sounds like your working on this thing after a long day at work... Working on stuff when your tired just brings frustration. I suggest taking a couple days off and getting all set-up for in AM work-out on the Tercel.. Have your coffee and relax.. Wrap your head around the problem and it will all go much smoother. I would even consider letting the car sit for a month and not going near it... Just my 2 cents.. I have 2 cars and when I get frustrated, when working on one - I WALK away from it for a couple weeks.

[Petros]

It is a lot easier to get the pan off if you loosen the front engine mounts and remove the radiator hoses, than jack the front of the engine up (by putting the jack under the transmission). That gives you more room to get to all the 10mm pan bolts, you can remove them all with a socket with extention, expcet the one or two over the diff (those come off with an open end wrench).

I have never had to prime an oil pump, even on starting completely rebuilt engines with new oil pumps. On a new engine start-up I ground the spark plug wires and crank the engine until the oil pressure light goes off (or if with a gauge, when the gauge come up off the peg). than connect the sparks plugs and start it. Priming should not be necessary.

[rer233]

normally i take the pump apart to pack it, but in your case, i'd remove the pickup, pack vaseline into the pump itself, turn the engine by hand in the normal direction of rotation till you can see it start to suck the vaseline in, pack some more in, turn some more, etc. also, make sure the gasket between the pump and pickup is good (i use a little bit of permatex ultra black just to make sure it can't suck air.) sucks you gotta pull the pan again tho. good luck!

[Riff]

scouttster:

I would love to give this a rest, the thought of taking it all back apart again was quite depressing, but I have one week off between my seasonal jobs and need to get this put back in order. I did get a little time clearing the "cabinet shop" out of the my 12x16 garage, and then pulling the thing inside with a come-along. Now I can fire up the wood stove and work comfortably. It isn't terrible cold yet, but chilly enough in the mornings. I don't want to get caught in the snow, which usually starts to appear here around Halloween.

Petros:
Your experience made me think I must have some pickup tube problem. I got the pan off today and I must've overlooked the gasket on the pickup tube when I put it together-- it was missing. I plan to reinstall the pickup tube with a gasket and hope that will fix the problem. Since I have it all apart right now and don't want to go for the third round of pan pulling, I might just go ahead and prime with vaseline, per rer233, even though it may not be necessary.

Yes, it really does go quicker the second time.

[Petros]

I also put a light coat of sealant on this pick-up tube gasket as well. If it was sucking air at this joint than yes, it will not pressurize the system.

While you are there you can pull the pin on the pressure relief valve and inspect the parts (if it is an new pump I would not bother), sometimes crud can hold the piston open and it will dump the oil back into the pan. The parts can be removed and cleaned when the pan is off from under the oil pump, just to make sure it functioning properly.

There is a piston, the spring and a washer that is held in with a cotter pin, make sure you get is all out, clean the parts and the bore the piston goes into, lubricate with clean motor oil, and put them back in.

[larry mcgrath]

After reading your post I went to the s/m to look at the break down of the pump. Ive rebuilt 2 of these engines, and a lot of others. Im getting a little older and my memory isnt what it use to be, just seems their would be a Woodruf Key (looks like a Nickel cut in half) that would drive the driven oil pump gear. Just a thought. keep us posted when you figure this out. Good luck Larry: