Oil pressure light!! What to do?

[4wdEconoBox]

Ok, so here's what happened...I started my car and drove it uphill to the carport and turned it off and went inside for a few minutes. I came back out and drove the car back down hill to the garage (on level ground) and put it in neutral. Then I noticed the check oil light flickered on and stayed on so I immediately turned the car off and checked oil level, the oil level was sitting perfectly at full. I started the car back up just to see if it was a fluke or not and it wasn't, within about 10-30 seconds the light flickered back on and stayed on, and I revved it up to maybe 3000 rpms just to see if it would go out at higher rpms and it didn't. It just stayed brightly lit. I even thought the wire to the oil pressure switch may be shorted out so I unhooked it and started the car again and the light stayed off.....So I know that the wire is good and not grounding out...I never heard any unfamiliar noise other than lifter tick, which the car has done ever since I got it. But, I didn't hear any bottom end knock or anything like that. I can't find an adapter to hook up an oil pressure gauge, I know I need a 1/8 bspt male to 1/8 npt female, but no one can seem to find one for me...

Anyway, here is my plan, I ordered an oil pump and oil pressure switch, and picked up some new oil and a filter and was going to put everything on and see if it made a difference until I got the parts to do a rebuild.

Is this a good plan, should the engine hold up for another month or so, considering I drive this car everyday for work?

[irowiki]

It could just be the pressure switch!

[4wdEconoBox]

I mean, I definitely hoping that's what it is, but I've had really bad luck when it comes to cars and oil pressure.

Case and point: On my 3000gt, I had just rebuilt it and the factory gauge showed low oil pressure and everyone told me that the oil pressure gauge was just wrong or messed up so I went about my business, after I finally put mech oil pressure gauge on it hardly had any oil pressure and it almost spun a bearing, the 3000 is now on its 2nd rebuild within 267 miles(yes, thats the exact number) haha.

But anyway, that has nothing to do with anything, that's just why I'm so paranoid about oil pressure and my brain automatically goes to worst case scenario now, especially with a car that has 241,000 miles on it... I never used to be this cynical haha, I'll report back tomorrow after I put the oil pressure sender/switch on and let everyone know if it fixes it!

I still plan on rebuilding it no matter what anyway, just because I can do so for pretty cheap with parts from rockauto(less than $300, with a clutch kit)!

[Petros]

It sounds like the pressure sender might be bad. When you run without oil pressure the engine tends to chatter and make more noise.

if the bearings are so shot it will not hold oil pressure the new pump will not help. The oil pump is a major PIA to install with the engine in the car (I have done it, you have to drop the oil pan, not easy to reach the fasteners over the front differential), so I would save the oil pump for the rebuild. Even than, it would have little to no pressure at idle, and tend to raise the pressure enough to turn the idiot light off once reved above idle (the light comes on at only 6 or 7 psi, so it does not take much to get it off).

But just to be safe, do not drive it until you can verify the oil pressure. you need to put a proper pressure gauge on it to know if you have oil pressure or not. I used a soft brass NPF fitting and sealant, it grips enough of the oddball British thread to get it to tighten down and seal, and than connect the gauge.

ONce you verify you have oil pressure, than install the new sender, than you can relax.

If the oil presser is indeed very low, you should not drive it either, or you may have to replace the whole engine. I had that problem once with an old Toyota 20R powered pick-up, the oil light flickered on and off between shifts and at idle. Guage showed it about 4 psi at idle and reved up to about 7 or 8 when reved. I did not have time to fix it, so I filled the crank case with STP and kept driving it. One day soon the engine threw a rod right through the side of the block and I had to be towed home (I saw engine parts bouncing on the road behind me in my mirror, and cars were swerving to avoid them). so I still had to rebuild the motor, but also had to replace the short block and head too.

[dlb]

put a mechanical gauge on it, let the engine get up to normal operating temp, and check the oil pressure. or buy another temp sender, put it in, and see if the light goes away. it's only about $8 and you will have to run the engine for 5-10 minutes with either the mechanical gauge or the new sender, and both should tell you what you need to know.

the BSPT adapter shouldn't be that hard to find. once i knew what i was looking for, the shop was like "oh that, yeah we have those. lots of the japanese cars used that."

my ford has an oil pressure gauge. after i changed the oil when we first got it, the gauge would read pretty low at idle after warming up. i was pretty worried so i put my mechanical gauge on it, things were fine so i kept driving it without issue. but i noticed after the next oil change, the oil pressure readings were more in the middle of the 'normal' range. i have heard of faulty filters causing low OP so i guess that filter was marginal. it was a quaker state filter, btw.

[rer233]

My money's on the OP sender- had the same symptom on a former gf's terc 17 or 18 years ago. Replaced the sender, and the engine's still running today (60 k miles later.) Good luck!

[4wdEconoBox]

Alright, thanks y'all! I'm praying and hoping that it is just the sender! It makes the most sense because this is the first time my oil pressure light has ever lit up, I've never seen a flicker or anything. But I'm picking it and the oil pump up after work tomorrow and I found a place that said they should have the right adapter for it (like 5 mins from my house, who woulda thunk it? haha). I'm going to pick it up too and check to see what the actual OP is with a mechanical gauge just for good measure and peace of mind, I might just leave it hooked up full time and make a mount for it on the outside so I can see it while I'm driving. But yeah, trust me, driving it with low oil pressure is the last thing on my mind, because I don't have the money or the hook-up to get another block...

I'll hopefully be back tomorrow with good results. If I get bad results, there might be some "not so pretty" words coming out of my mouth....haha, but either way I'll let y'all know what happens, I'm probably just worrying too much for nothing, but sometimes thats not a bad thing, I guess...

Thanks again!

[4wdEconoBox]

Ok, well I never found an adapter to hook up an oil pressure gauge so I just went and picked up the oil pressure sender and put it and changed oil and filter. I started her up and the oil pressure light went off and never came back on!!!! I'm so glad that it was only that sender! Now I'm about to start saving parts so I can have a fresh engine(new rings, bearings, oil pump, clutch kit and gaskets). Is anything I should know before tackling a rebuild? It'll be a month or two before I have all of the parts and time, but I just like to see before I start that project because I'll have to pull the engine rebuild it, and put it back in the car in a single weekend maybe 3 days if I'm lucky! Is it possible as long as I have all of the parts?

[Petros]

if you need to drive your car you should try and find another "core" engine to rebuild. It will only cost about $100-200 for a rebuildable core, and than you can take your time to have it machined, cleaned and rebuilt while you are still driving your car. Than swapping out the engine can be done on a weekend no problem, and you will be driving it to work on monday.

If you try to rebuild the engine after you get it out, you will likely, or could, find parts you have to replace once it is all apart, or parts that need to go to the machine shop before you can put it back together. Almost certainly adding days to getting the engine back in the car and running again. Than you have a whole spare engine to either sell, or rebuild and have waiting as a "spare" engine.

[4wdEconoBox]

Ok, I think finding a core to rebuild would be my best way to go. Where would be the cheapest place to get one? Pull a part, or on here somewhere, or should I just be looking around?

[Petros]

Pull a part is having a 15% off sale this weekend (starting today), it is a good place to get a core. But make sure you pull the head and the oil pain and get a good look at it before you buy it. Pull off the number 4 connecting rod cap and inspect the bearing and the crank journal. Too many cars end up in the wrecking yard because they were neglected and ran without oil, trashing the engine internally. If the car body is not wrecked, be suspitius the engine or trans is bad. If the body is wrecked, good chance the engine was running when it was wrecked.

If you buy the engine make sure you put the bearing cap back on the same way, and just snug it down (torque it properly later), put the pan back on. Take off the flywheel, intake and exhaust manifold (or they will charge you for them). You might also look for a 4ac out of the same year corollas, everything bolts on exactly the same as the 3ac, and it weights the same, but is slightly larger and gets about 20 more hp for "free". You just want the head and block assembly (put them back togehter to buy them), what is known as the "long block", none of the extranal accessories or they will charge you for them (so keep them only if you want spares, but make sure they are the same for your car first, not all extrnal parts are interchangeable).

many forum members have extra engines sitting around too, I am fresh out, but typically I have several sitting around. I have some spare heads is all (two heads are better than one!).

[4wdEconoBox]

Sadly Petros, my local Pull a part doesn't have any tercs or corollas that are the right year models, nothing before 1991 :/. I'll have to wait till one comes in, when it does I'll be all over it haha. I'm signed up to receive an email when either comes in, hopefully it'll be soon! I'll keep all of that in mind when/if I get to look at one. I've posted on a few part out threads on this site and I'm just waiting for a reply at this moment, I'm thinking about seafoaming and adding restore here soon to see if that helps any. If that doesn't help I think my next move is pulling the head, getting it redone(new exhaust valves, intake valves resurfaced and reseated, new valve seals/stems?, and following your head and block shaving, I think it was your how-to) and a new head gasket, and see if that helps, if it doesn't then the only thing I'm out of is a head gasket since all of the head work will still be good when I go to rebuild everything. How does that sound for a plan? I think having all of the head work will fix it, since the car runs really good and doesn't really blow huge clouds of smoke, but it just steadily blows, ya know? It makes me think that its just valve seals honestly. I check and refill the oil everytime before I drive it and if I drive about 150 miles by the time I get home the oil will be on the bottom mark of the dipstick, so its burning quite a bit of oil. I just keep a large jug of new oil in the car at all times.

[Petros]

first gen Tercel long blocks are the same.

Also look for 4ac engines in 81-87 corollas, they are 1.6 instead of 1.5 but long block is almost identical and fully interchangeable, and you get some 20 more HP in the deal too. Engine would be the same cost from picknpull, as would rebuild parts.

Usually valve stem seals will not stop that much oil consumption, likely you have a problem with the rings. try a sea foam treatment and Restore as a temp measure, might save some motor oil costs anyway. Also, verify you are not leaking that much oil somewhere, might be a front seal or something.

A new or rebuilt engine is in your future, you can try doing a head overhaul first, as you say, the head will still be good for putting on a rebuilt short block, but I think you will be disappointed. Might as well save the extra effort of redoing your existing engine and find a rebuildable engine, or borrow a temporary car for a few weeks.

[irowiki]

I had a tercel which burned a quart every 100 miles, I tried everything, nosmoke, seafoam in the crankcase, seafoam soaking down the spark plug holes, Restore, stem seals, ATF in the crankcase, DELO diesel oil, engine flush cleaner, marvel mystery oil.

She did not burn huge clouds of blue smoke either, just little bit while driving.

We ended up having to rebuild that engine, the rings were gummed up and stuck!

[4wdEconoBox]

Well the compression test results are in....

Cylinder 1: 75 psi - 90 w/oil

Cylinder 2: 100 psi - 145 w/oil

Cylinder 3: 80 psi - 120 w/oil

Cylinder 4: 100 psi - 130 w/oil

So I would say the rings are definitely worn.... I guess I'm going to buy a rebuild kit and wait for it to come in, I don't really have the extra money to find a rebuildable donor at the moment. My mom said I could drive her truck if it takes longer than a weekend to rebuild it.

My next question is, are there any special things I should know about this engine before I tear it apart? I know this is all going to depend on if everything is within tolerances or not, but should standard sized bearings be fine? I'm going to do the cylinder honing at home with my dad, as long as I don't remove to much material from the walls, can I just throw some standard rings on it an it'll be fine? Or would it be better to take it to a machine shop and get them to check everything out as far as tolerances go?