Just curious if anyone has had an oil level sensor failure. Mine display occasionally flashes a low oil level warning, but there is plenty of oil showing on the dipstick, and there is zero damage to the wiring harness, so I can only assume the failure is in the sensor assembly itself.

Anyone else had/having an issue with this?

 

08 with 216k miles here and no issues. Didn’t even know the ISF had a low oil light until this post lol.

 

Have you tried correcting it with a scanner ?

 

That worked for me.

 

It doesn't set a DTC. It just flashes on the display for less than a minute like the wiring has a short circuit.

 

This started at 226k.

 

2012 107k miles here. This one tripped the low oil light on only when i was changing the oil. I have the dreaded timing chain tensioner rattle on the drivers side. I was trying to put exactly to the full line on the dipstick. I had it on rhino ramps with approximately 9 quarts. I took it off the ramps & as soon as I put in the rest, it went away.

A very long time ago when I had a 2011 IS F, after an oil change at the dealership. Not too long after I drove off the low oil light came on. I turned back, notified my advisor. Him & I walked back to the master mechanic who worked on my car. My advisor knew I was very meticulous about my car. He asked the master mechanic how many quarts did he put in my car…he responded “Lexus IS F V6…6.5 quarts” my advisors jaw dropped. Told him to stop what he was doing & change my oil & filter again. Anyhow, I think under those 2 circumstances. The system worked as intended.

 

All sounds normal. Mine occurs randomly while driving. No common circumstances at all, and it doesn't come on and stay on. It comes on, lasts 5 seconds to 30 seconds and goes away. I have the car up on stands now and I've looked at all the wiring (thinking it must have been damaged by coming in contact with my headers) and there is zero indication of any problem with the wiring. At this point, I can only surmise something is wrong with the switch assembly itself. I'll be pulling it out today to examine it, but this is the weirdest thing I've ever seen for any sensor on any Toyota/Lexus/Scion I've worked on. US sources for a new switch are ~$200, Japanese sources are ~$90 + shipping. It makes no sense to me that it would fail because they're so simple.

 

Interesting enough, from time to time at work. Working on B747-400/ -8 I have to replace fuel, hydraulic & oil quantity meters. Oil & hydraulic meters are the most common. They either give false indications & I’ll see fluctuations in the quantity on screen. Very annoying to replace since I have to drain out the reservoir or system first. The cause of failure is usually mechanical wear & tear, temp changes, or contamination. Very intriguing to know what you find in the IS F.

 

This would make me insane. Oil lights have always worked for me and I relied on them heavily as a kid before my 455 was rebuilt - once even in a life/death situation.
I've not seen one in the F yet, but I did have a malfunctioning gas gauge which resolved when I found a bad LED bulb in the map light cluster. Have you done anything electrical recently? How old is the battery?

 

Yes, it's bugging me to no end. I really thought I was going to find a melted harness because of the headers, but not even close to any damage at all.

No electrical work of any kind. Not even replacing a bad connector body. I still need to replace the big power steering ECU connector because the locking mechanism broke the last time I had it out.

Battery is Anti-Gravity and shows excellent health in all measures.

Alternator was replaced when I did the cam chain tensioners, a little over a year ago.

Side note - I'm seeing the A/C compressor turned off on very cold mornings (sub 35F) when I start the car, and idle is at 500 rpm. I can turn it on manually and it stays on, but I've never seen that behavior before. It makes me wonder if I am slightly low on R134a despite carefully measuring the charge with a reliable scale. The low level light ONLY comes on when I am at idle. Thanks for the trigger - it has me thinking of other possibilities.

 

**UPDATE**

I have the car up for new O2 extender(s) and I figured I'd take a look at this. I discovered the low sensor is not short to ground when the level is low, it's short to ground when the level is up, so the light flashing means the circuit is briefly going open. Given this, I removed the sensor to see if there was a problem with it internally. I found cold solder joints, and probably some of the poorest soldering I've ever seen - definitely from the bigger the blob the better the job school. So, I removed most of the excess, applied fresh flux, and reflowed the three soldered connections. I have a feeling I won't be seeing this error again.

FWIW, while the right side header was off, I did a full inspection on the wiring, and there is nothing in the wiring that's even slightly suspect. No physical damage whatsoever. The connector also shows no signs of damage. If this issue continues, I really will be struggling to figure out where the root cause of the problem lies.

 

Well, this "fix" wasn't a solution. I am now experiencing the low level warning on almost every drive, totally at random times, but annoying as all hell. I hit up ChatGPT and asked if this is a known issue, and it came back with a yes. I can only assume the material used for the float is absorbing something in the oil making it slightly heavier than it should be and causing the float to stop floating when the oil gets warm enough. New sensor arrives today. The part is revised, but the new part number is the same as the GS F part, and the wife's car did this not too long ago, so I am not confident this will be the ultimate fix. I different float material that doesn't absorb oil is the real solution. FWIW, there is zero varnish in my engine even at 234k miles.

 

Final follow up to this. I had an oil change due for both the engine and transmission, so I replaced this sensor at the same time with a new one from Amayama. Three days now and zero issues with low level. Apparently the float absorbed some component of the oil over time and got just a little too heavy. All is well again, and the transmission is much happier - I found one of the rubber hoses from the transmission to the cooling system is weeping over time, so the level in the gearbox was slightly low. New hose and clamps are on order, but for now just having the level set correctly again is worth the effort.