Flickering Oil Light

[mrmora]

While out driving my car today, I was at a stop and noticed a bit of a flicker out of the corner of my eye. I paid no attention to it at first, but when it happened a second time, it was then that I realized what was in fact flickering. It was my oil light. I pulled in to a park lot, checked my oil, turned out to be fine. I turned the car back on and let it idle there for a bit. Eventually the flickering light came back, but I noticed that the oil light flickers at about the same rhythm as my car idles (My car idles a bit rough, I need to get it adjusted or figure out how to do it myself). To me it seems like there is a short, it's not a consistent flickering and it doesn't occurring when I drive, just a random times when I idle. I cleaned off the OPS (oil pressure switch), plugged the connector back into it, seemed to work fine for a while for a while, until it started to flicker again.

Not sure what's going on... does this sound like a short? Or is there a problem internally, perhaps with my oil pump? I read a post earlier today, I think dlb had the same issue, not sure if it is quite the same, but sound similar.

I bought a new OPS, so I'll put that it and see if that has any thing to do with the flicker light.

[rer233]

good move on the OPS- had the same symptoms with a former GF's 2wd wagon 16 or 17 yrs ago. she said the OP light came on so she dumped 3 qts of oil in. never bothered to check the level (natch.) anyway, i installed a Toyota OP sender, corrected the oil level and it was fine. as a matter of fact, that engine's still running today (with 195k on the still- original bottom end.) 'course it's in my '83 sr5 (hers got wrecked.)
'course your problem could also be low OP- if the sender does't fix it, maybe check the OP with a mechanical gauge (think dlb posted about that a while back- maybe he'll chime in.) Good luck- let us know how it works out!

[dlb]

yup yup. new OPS's are cheap (about $6) and easy to replace so i would either jack the driver side up a bit or drain the oil and swap the OPS out. however, if you are curious or if the flickering light at idle persists, check out my thread about my similar adventure. it sounds like you already saw it, mrmora, but here's the link again just in case.

https://tercel4wd.com/forums/viewtopic.php?f=4&t=8126&p=59512

the important detail in that thread is that you will likely need a 1/8" x 28 BSPT male to 1/8" NPT female adapter for any generic oil pressure mechanical gauge if you want to check what your OP readings are. these adapters are not hard to find, it was just hard to figure out exactly what adapter was needed in the first pace.

[mrmora]

Thanks for the quick replies guys!

@dlb: So before I can install a new OPS, I need to drain the oil out? Is that just for precautionary measures or how it's supposed to be done? I was looking at a service manual, it shows that the OPS is located towards the back of the engine, kind of near the distributor. Yet when I actually looked in the car for where the OPS was located, I found that it was to the upper left of where the oil filter is located... is that correct?

[dlb]

you don't HAVE to drain all the oil out but if you don't at least tilt the engine to reduce leakage, it will leak quite a bit while you fiddle with threading the new one in. if you're due for an oil change, i would drain it, remove the oil filter, replace the OPS, and the replace the filter and oil. if not, just jack up the driver side a bit.

yes, the OPS is located underneath the alternator bracket on the driver side, toward the front of the car. it's a bit of a pain to access. marlinh once mentioned that there are special sockets for using on OPS's but i've just used big crescent wrenches on them. you have to make sure the crescent wrench is good and tight though since OPS's have those weird round indents where the corners of the hex would normally be.

[larry mcgrath]

The OPS is located on drivers side of the engine, behind the altinator. there is no need to drain the oil to replace the switch.

[Petros]

I had exactly the same symptoms with mine, started several years ago. I also check oil level, it was fine, and it was running quietly as well (low/no oil pressure usually makes lots of tapping and clacking noises from engine) so I assumed it was fine. It is pretty rare for an oil pump to suddenly stop working, though it can happen and I have seen it a few times on other cars. But seeing the oil light flicker on and of spooks me too much, so I bought and installed an after market oil pressure gauge ASAP (they do not cost much and it is far cheaper than replacing an engine), a mechanical one that uses a nylon tube to measure pressure directly. As I suspected the oil pressure was just fine, and I have left the oil pressure gauge on to this day. To install the oil pressure line I had to completely remove the sender, and the wire is just hanging loose in the engine compartment, yet my oil pressure light still flickers on and off occasionally.

Now I know for sure it can not be the oil pressure, and the wire all looks okay as far as chaffing goes, so there must be a short somewhere in the dash or perhaps internal to the wire bundle. I have not found it yet. I want to remove the bulb from the dash to stop it.

Even though I know my oil pressure it okay, when I see that red oil light comes on my eyes flash instantly to the gauge in a panic reflex. funny how rationally I know that light is now meaningless, but my reflex is to want to protect my engine. I guess it is a good reflex to have, yet there have been a few younger drivers on this list who had kept driving when their oil light came on, and did severe damage to their engine. The dumb "Check engine" lights on the newer cars have trained most drivers to ignore all warning lights.

A friend's 20 year old son recent trashed the engine on an old Camry by driving with the oil light on for four days, he said he thought the light was to tell him it was time to change the oil. He called and ask me to come over and help him find out why it was not running, when got a look at it and I pointed to the fist size hole in the side of the block, I said we do not need to look any further. first thing out of his mouth was "that is not supposed to be there?" Naw, all manufacturers put viewing ports in the side of the block to inspect the crank shaft, right? The real tell-tail was there was no oil spray all over the engine compartment, it and the hole in the block was dry and clean. That was when I asked him to show me the light on the dash he thought was the "change oil" light. It was the oil pressure light. I said there is a reason the manufacturer has an owners manual.

When you see an oil light come on STOP THE ENGINE, until you know for sure it is not due to loss of oil pressure.

So you are likely okay, but put a gauge on it make sure before you drive it!!!!!

[tercel4wdrules]

I had an OPS go bad when I was driving a Tercel down from Washington state. I had been driving all night then all of a sudden the oil pressure light came on and first thing that came to mind was to shut off the engine and I coasted to a stop. The sun was coming up and it was a bit spooky to sit on the side of the road with big tractor trailers whizzing by. I checked the oil level and it was fine. I was about 300 miles away from home at this point, so if the engine had catastrophic failure I was going to have to abandon it anyway. It's an uneasy feeling to feel stranded 6 hours from home, with no one nearby to come and pick you up. I just decided to risk it and drove it to the next exit, which was several miles away. The engine was not knocking at this point, so I felt less apprehensive about it. It was going to be too troublesome to get an oil pressure gauge and finding the right adapter would have been another complication. I had to wait for Napa to open and see if they had an OPS. No such luck, so I had to drive to Autozone, which was probably 10+ miles away. I was out in the middle of the Central Valley in CA, so everything is far apart unlike Los Angeles. Autozone had it so I bought a socket to remove it and they lent me some tools and I replaced it in the parking lot. I just moved the alternator out of the way and swapped it out. I was good to go for the rest of the drive home as that cured the problem. In retrospect, I could have just kept driving with the light on, but psychologically it would have had bothered me like Petros pointed out.

[MR2Di4]

Had a similar close call this evening. Was headed home from my evening coffee trip when the oil light came on suddenly. I pulled over and noticed oil underneath the car. Fearing the worst I started checking around the oil filter, but instead spotted oil dripping from the OPS. It was too late at night for anywhere with oil to be open but I was only 12 miles from home so I took it easy and checked the oil as soon as I pulled in the garage. I had lost roughly 3/4 of a quart, but the engine still sounded fine. Have to go to NAPA in the morning to get the new sensor, but I really hope they have the socket to get the sender out...

MR2Di4

[dlb]

I really home they have the socket to get the sender out...

mr2di4, i have removed and installed a few OPS with only a large crescent wrench with no problem. marlinh mentioned that there is a special socket for OPS but i haven't needed it yet.

[marlinh]

Some sending units are in the block pretty tight, I haven't found that with our cars. You can usually get away with improvising if you're careful.

[Petros]

if all else fails a small pipe wrench, the old fashioned kind with the hardened steel teeth, works well for removing the sender, or any thing else that you can not put a socket on it. The teeth will even grab a rounded off bolt or nut, or a broken off stud, as long as you can get a few teeth on it. It is a handy and inexpensive tool for removing stuck items. It is the perfect, and only tool, that can free up the front tie-rod sleeves when rusted in place on the front suspension. These tend to trap moisture inside and rust up soild, if you are trying to do the alignment, or replace the inner or out ball joint or the boot, this sleeve MUST come loose and nothing else will grab it good enough.

It looks like this:

[MR2Di4]

Oh, I went and got the socket anyways, and I do have some old-fashioned pipe wrenches like that but unfortunately the sender is surrounded by the mounting bracket for the goddamned A/C pump. I can't even fit the short OPS socket in between onto the sender, much less get a decent grip on it with anything else in my toolbox. It looks like I'll have to unbolt my alternator and A/C pump just to get at the damned thing...

MR2Di4

[dlb]

It is the perfect, and only tool, that can free up the front tie-rod sleeves when rusted in place on the front suspension. These tend to trap moisture inside and rust up soild, if you are trying to do the alignment, or replace the inner or out ball joint or the boot, this sleeve MUST come loose and nothing else will grab it good enough.

man, i wish i had thought of this last week when i was having this exact problem!

https://tercel4wd.com/forums/viewtopic.php?f=4&t=8982

next time i have that car over i will try the pipe wrench on the tie rod that stymied me.

I can't even fit the short OPS socket in between onto the sender, much less get a decent grip on it with anything else in my toolbox. It looks like I'll have to unbolt my alternator and A/C pump just to get at the damned thing...

yes, i have had to remove at least the alternator to access the OPS on 3a and 4a engines. the AC adds another step. if your AC doesn't work, i would rip it all out anyway. more space to wrench in the engine bay.

[rer233]

swapped out the OP switch on my "new" '87 yesterday eve. used a inch and 1/16 open end wrench. was a bit of a weasle-job, but the only thing i removed was the oil filter (and yes, the car has a/c, p/s AND a/t. took maybe 20 min. the wrench i used was kinda short (it was a double open end.) maybe get a cheapo combination wrench fom horrible freight and cut it off?? Good luck!