my daughters car - a 2001 Galant, has about 179K miles, was rode hard and put up wet by the previous owner. Picked it up for next to nothing, put some money into it and we've had it for about 3 years. It was the boys car for 2 years before she took it.

The past 6 months I've noticed that the oil light flickers on at idle after we've driven it awhile. Replaced the sending unit - they are notorious for those things acting up - didn't change anything, so I figure the oil pump is going out - which probably means the engine isn't far behind. It has a noticeable valve tick that I've ignored since we bought it.

I decided to roll the dice a bit. Bought some marvel mystery oil and put it in the crankcase, drove around the neighborhood for about 10 miles. Now the oil light no longer flickers at idle, but stays on - and it makes sense because that stuff thins out the oil. Thought maybe if there is some sludge gumming things up that will help.

So I drain it, flush it once with some cheap no name brand and then put in STP oil treatment and 10W-40 synthetic. If they had 20w-50 I would have used it. I'm looking on the shelf and I see some Royal Purple 75W gear oil. screw it, I throw in about 3 tablespoons of that as well.

Level it off, let the car heat up, drive it another 15 miles and no oil light at idle. I doubt I've completely solved the problem but hopefully I've pushed it off down the road for another 2K miles or so until she gets her license and I can sell it - with full disclosure to someone else.

( I have a little 5 speed VW for her once she gets her license)

Lucas.....their I fixed it for u

I have lucas - I just don't know how much to put in there.

Wore out bearings. Ed k

Yep

They are right. Lucas Oil Stabilizer will probably help get some more miles out of that engine.

Don't put gear oil in an engine. The sulfur additives cause problems from what I remember. STP etc will increase viscosity which is what you're aiming for.

gwrench is right about gear oil.

Straight 30 or 40 weight will be thicker than 10-40 synthetic. Little too thick in an Ohio winter though...

I have almost 150K on my Suburban. I recently replaced the regular Mobile 1 synthetic with their 10w-40 high mileage and I get much better oil pressure with it.

Might be a good place to start.

You don't need high oil pressure at all times, just when driving! Lucas as said above will help! My guess is the bearings are worn! Higher viscosity oil will help, be careful and don't go to thick. Power Punch might be be better than STP, in this case! Good luck!!

Have a mechanic put an oil pressure gauge on it and see what the pressure really is. The sending unit/oil light combo is notoriously unreliable, I'd figure out what the real oil pressure is before I decided what to do.

I've got an oil pressure kit.

I'm not sure I care enough about it to be honest . Its a $900 car that I need to get 3 more weeks out of.

But I hate to ruin a car just out of neglect.

Right now I don't have an oil light.

I'll pay attention and see what happens over the next couple of week and then decide. I figured that STP was so thick it would help..at least for awhile

Anything you do short of rebuilding will only last for a short time.

When that happens the bearings have reached their life span.

You might get some time with Lucas stabilizer and putting oil with a higher viscosity but it will be short term.
Might go for a year or 2 but also might go next week.

yea, that's kind of what I figure too...I've read enough from other people's experiences to know its got a limited shelf life. Its served its purpose.

Don't wrap it up up and speed shift, you may end up with a rod through the engine side. It is probably the rod bearings and mains letting too much oil flow past instead of making a film on the bearings. The previous abuse before you had it is the clue. That "dirt" in old oil is the worn part of the bearings, rings, carbon from blowby, and it is abrasive, so wears things a little quicker.

Don't wrap it up up and speed shift, you may end up with a rod through the engine side. It is probably the rod bearings and mains letting too much oil flow past instead of making a film on the bearings. The previous abuse before you had it is the clue. That "dirt" in old oil is the worn part of the bearings, rings, carbon from blowby, and it is abrasive, so wears things a little quicker.

A lot of bad information on this thread so far. For the real scoop...google bitog. You will get real advice from people who know What they are talking about. I would avoid any snake oil...I.e adding junk like lucas to your oil.

Could be a bad spring.

Good advice above...

My 200K mile Frontier oil light was flickering and driving me crazy, in fact, that is why I bought the HF oil pressure test kit. It had good pressure and it turned out to be the sender. I do understand the sender was replaced. But if that sender is designed to illuminate at 15 psi at idle and the pressure is dropping to 13 psi, that is perfectly fine. Heck, if it was dropping to 5 psi I would not care as long as the goofy light was not flickering on a car I was planning to sell.

The oil pump is generally the last component in an engine to go. It may fail due to a drive/shaft failure, but oil pumps just failing is a pretty rare occurrence.

AI the combustion chambers and seat the pistons about .020" off the head.

Annealing the rods will also help.

Trust me. I'm an expert.

Good advice.

Sometimes the shims can also wear.

It could a bad o-ring. They don't cost must but the labor to replace one is more than the part.

BTW,

What color is the car?

And ...

Doe it have a grey or tan interior?

I had the problem many years ago. A mechanic told me to replace the sending unit and it fixed the problem.

I got more responses that I expected. This afternoon I'm going to put a manual oil pressure gauge on and see what it really is

Put 20w50 in it or straight 30 or 40. It is worn bearings and will likely still go another 100,000 regardless. If it is easily accessible you could shim the spring in the oil pump. I wouldn't sweat it past the thicker oil for three weeks.

That's the only and right way to find out if there is a problem.

10 psi at idle wouldn't bother me as long as the pressure rises as rpms increase. Some motors are good to go with as little as 20 psi @ 2000 to 2500 rpms. Instead of additives run 10w 40w and replace the filter. Oil filters can cause variance in oil pressure but usually on the high side.

Low oil pressure is not necessarily a sign of worn out bearings and that the motor is on its last leg. I'd look for other issues way before considering that diagnoses.

Ignore all the other BS I posted. I was just having fun with the variety of posts made that weren't on track.

We used to run 15 40 in everything. Cars, pickups, lawn mowers to Terex Scrapers.


Once I started running 5w30 as recommended in the gas burners I noticed the oil pressure actually went up.

I wonder if the heavier than spec'ed oil would cause the bypass to be open for longer.

30 PSI at 900rpm

might want to go to a lighter weight oil!

welp...now its down to 18psi after running for 20 minutes. 70psi at 2500 RPMS.

doesn't seem like I have too much to worry about at this point.

Sensor could be bad, oil pump could be weak, bearing could have so much clearance from wear that they just leak out a lot of oil and drop the pressure. Try the sensor first if that doesn't fix it look elsewhere or dump it.

Bad sensory unit