STV8261

Good day,

MY PROBLEM: Oil pressure light

On my ’03 RL with 241k miles, I’ve been having the intermittent oil pressure red light come on on the dashboard in the last 20k miles. It has happened 3 times now: At 222k miles, at 237k miles, and today at 241k miles.

It is always the blinking red light (meaning pressure dropped below 4PSI and then recovered). Always the same pattern, as soon I saw the light I stopped, turned off engine and then restarted it to see the light go away.



WHAT I HAVE DONE:

The first time it happened at 222k miles I panicked (I also had a five hour drive scheduled for the next day) so I went and bought an oil pressure gauge and measured the oil pressure at the sensor port. The pressure was well within spec: ~15 PSI at Idle and ~70 PSI at 3000RPM, spec is 10PSI & 50PSI respectively. Finding nothing wrong, I replaced the oil pressure switch with an aftermarket type. Also, at the next oil change I bought and used some Seafoam (4oz then idle for 30’ then drain oil and add new oil). As I wrote above, I never saw the red oil light again until 14k miles later and then today after another 4k miles.

QUESTIONS:

I read in other forums (e.g. the Acura Legend forum) that the oil pump pickup screen may be dirty. If I remove the oil pan on this 1st generation RL will I have access to the oil pump screen? Is there even an oil pickup screen on this car? I don’t see one in the manual.

OTHER THOUGHTS:

This light obviously worries me because the sensor is set at such a low pressure, and the whole engine is at stake. As I said, I had found the pressure well within specs at measurement, however, if there’s some intermittent issue where the pressure is say 8 PSI at 3000RPM for a long time, the light will still not give me a warning and that would not be good.

The pressure sensor seems to be a simple on/off pressure switch with a mechanical spring set at 4PSI. So I imagine the computer logic is rather simple: Upon engine start give it a few seconds for the switch to close, then if you ever see the switch close (say for a second or some other short period of time) then start blinking the red idiot light, and if the switch stays open then turn on the idiot light steady (personally I’d prefer the blinking light for the more serious permanent drop in pressure and steady for the intermittent, because the blinking light grabs your attention sooner, but that’s not the main topic here…).

Inspecting the oil pump seems like a non-starter because the section of the manual referring to Oil Pump Inspection starts with the phrase: “To remove the oil pump, the engine must be removed from the vehicle..”. As much as I love this car and as well as it has served me, I will not remove the engine at 241k miles just to inspect the pump on a speculation. Besides, the oil pump seems to be just two gears directly tied to the crankshaft. It does not look like something that could fail unless the engine falls apart.

MAINTENANCE:

The car has been well maintained. I change oil with synthetic 10W-30 every 4-5k miles, change filter, transmission oil every 60k, differential oil every 30k, spark plugs and timing belt changed twice at suggested interval, air filter and coolant flushing at suggested intervals.

OTHER ISSUES:

These seem all unrelated, but just in case,

· I do have several small oil leaks. Probably so many that they have all mingled together. But there’s never any oil on the street and there are no noticeable oil drops between oil changes in all systems, with the exception of the steering fluid where I typically have to add just 30ml (6 tablespoons) every oil change (level drops ¼ of the way between the high and low marks every 4k miles, but that is a small reservoir). That being said something is leaking at least a few drops on the exhaust because I often smell burnt oil when I stop. But I may make another post about that, this is already too long…

· My steering column no longer adjusts up/down or in/out (I think control unit is gone because it moves temporarily if I disconnect the control unit and reconnect it), but I don’t care much about that, steering wheel is in a good position.

· Paint on top has several deterioration patches

· One vacuum solenoid failed and I replaced it

· Replaced one of the two front axle to differential seals

· Occasionally key lock would not recognize the key, but it stopped doing it all by itself

· Occasional SRS light (happened three times in the life of the car) from seat belt latch switch. I simply cleared the codes and they never reappeared for years.

· The Acura emblems have come off and I put them back with clear silicone (works well and it’s UV proof).

· One oxygen sensor failed at 140k miles and I just replaced it.

· A couple of annoying rattles in cabin which I fixed

· Some tar like substance was periodically dripping and hardening on the oil filter sometime in the middle of the cars life, but has since stopped. Sometime the engine used to smell like mesquite when that happened. It went away and I never figured out what it was. Whatever melted (I presume) has stopped.

· Rotors may be bent since I have some vibration when braking, but not always.

But these are all minor issues for a car this age. Other than that battery every 4-5 years, tires every 60-70k, brake pads just once… and go! Car still drives very well.

I love the car as it has given me very little trouble throughout its long service life – and I’d like to take it to 500k miles if I can.



P.S. Sorry for the long post but I wanted to put down the whole story right from the start.

projektvertx

iTrader: (2)

What kind of aftermarket sensor is it? Is it possible the sensor is going bad?

STV8261

I'm not sure, but probably the sensor I replaced 20k ago was something generic like stuff you'd buy from AutoZone. I bought it from Winchester Auto Parts, a local chain in Northern California. I was in a hurry doing that repair (had long trip the next day) and did not take photos or other documentation as I normally do.

However I did replace the sensor on the speculation that the original might have gone bad (since my oil pressure test showed pressure within spec), so isn't it unlikely that the new sensor is defective in exactly the same way as the old one? BTW, that HAS happened to me but only once, to buy a part that was defective in exactly the same way as the original OEM, a Mass Airflow Sensor on my Nissan pickup. Sure that coincidence threw me for a loop and I was debuginng the thing for two months, including two garages and the dealer who all failed to successfully diagnose it. I finally bought an OBD2 dongle and monitoring the MAF output in real time I was able to see the MAF output go crazy after 30' of drive, under certain conditions, ...which caused all the Long tern Fuel trims to go out of wack...(sorry for the babble but that was a traumatic experience as you can probably tell...)

STV8261

Well, I got a hold of a diagram and it does seem like these cars do have an oil pickup with a screen that should be accessible once you detach the oil pan.

Anyone has detached the oil pan on their 1st gen RL and knows what's involved? The diagram I have shows 4 O-Rings which I imagine I should replace if I remove the pan, so I should get those first. What about the seal? Diagram shows a liquid gasket. Use HondaBond?

STV8261

I just found the box for the Oil Pressure Sensor I had put in 18 months ago. It is a Beck/Arnley.

STV8261

Well, I just did another fuel pressure test and I had 20 PSI at idle and 85 PSI at 3000 RPM. The spec calls for 10 PSI and 50 PSI minimum respectively. So I'm well within spec. Also, I did not notice the pressure meter needle fluctuating (as in intermittent lower pressures). Pressure meter needle was steady.
BTW, the pressure was higher when I started the engine, at about 75 PSI. That seems normal because a) the oil was cold and thus more viscous and b) the engine fast idles when started (about 1400 RPM I believe was my fast idle). As the oil warmed and the fast idle dropped towards the normal 600-700 RPM the pressure dropped and stabilized at 20 PSI. I took my final measurements after the radiator fan came on (engine fully warmed up). So everything seems fine with the oil pressure.

So what to do now?

Could it be something truly intermittent? Some crud that gets sucked against the oil screen and then somehow is released?

I did buy the O-Rings that the manual recommends you replace if you open the oil pan (5 O-Rings $60 from Acura, not cheap but I can return them) and also bought some Hondabond for the gasket. Expense aside, I don't want to drop the pan. I'd have to remove the compressor and possibly the power steering pump to do that. With oil pressure seemingly ok seems like the odds are low of the oil intake being clogged up.

Just SeaFoam it for now? Or some other detergent?

RL98

It's possible that the sensor is fine, but the computer occasionally gets bad readings (perhaps 0) due to communication problems with the wiring from the sensor. In a case like this, the warning itself is incorrect.

STV8261

Yes, thanks for the hint. I read a lot about older Acura Legends having issues with the electronics triggering false blinking oil pressure warnings, but not RLs. Of course I get the impression there are not that many of these RLs around...

So I decided to use Seafoam one more time for now.

I addeed 8oz to 4 liters of oil. I want to see if a lot of sludge comes out, so I put in cheap new oil and a cheap mew oil filter. I'm going to drive the car with the Seafoam in the oil for about 50 miles over the next few days.
I'll drive easy, perhaps low velocity in town, perhaps with the transmission in D3 so that I can have freeway like RPM (higher oil pressure) without that much torque (less wear) since lubrication may be a bit compromised with 8oz of thin Seafoam. Normal dose is 4oz of Seafoam per 4 liters, but I think Seafoam instructions imply longer use.

BTW, I also measured the pressure sensitivity of the old original OEM Acura Oil Pressure switch and the Back/Arnley I have currently on. They do trigger at slightly different pressures:
Original Acura OEM: 3.25 PSI
Beck/Arnley: 4.75 PSI
I measured with an ohmeter, a vacuum/pressure gauge and a bicycle pump.
Of course this does not tell me if the devices are electrically noisy or there's some other intermittent electrical issue.
Electrically, the pressure switch works by grounding the wire connected to it. Below the trigger pressure it grounds and above trigger pressure it opens the circuit.
So if you disconnect the wire the oil warning on the instrument panel never comes on. It's up to you to see that it does not light up when you first turn on the ignition and take some action.

Removing the oil pan seemed like too much work and unwarranted given the successful tests on oil pressure. Seems like you actually have to remove the axle to remove the oil pan, the axle goes through the oil pan. So that likely means popping ball joints, ...did it once... but not quite justified now.

STV8261

Well, I Seafoamed the engine.

I used about 6oz of seafoam in the oil and drove the car gently for about 50 miles over the next 3 days. I always drive gently, but this was extra gently, slow accelerations, 60mph max, sometimes in D3 at lower speeds to keep the RPM and oil pressure a little higher.

I put a cheaper oil in the car and a cheap oil filter before doing this because I wanted to see if the oil would come out dirty. I think the oil I took out was indeed dirty for having driven only 50 miles but not overly dirty. Perhaps the Seafoam did release some sludge after all. When I was done I changed the oil again to Mobil Synthetic and used a Honda oil filter. I checked the oil today, having driven 150 miles and the oil looks pretty clean.

In any case, I don’t think there was enough sludge to clog up the oil pump pickup, so the oil pressure warning light remains a mystery given the normal pressure readings.

About 4 weeks have now passed and I have not seen the oil light so far.

STV8261

Well, the Low Oil Pressure Warning Light happened again today. This time there’s more evidence it’s an electrical problem. My tachometer also showed 0 RPM while it happened.

More specifically,

I was on the freeway in the night and at some point I accidentally looked down at the tachometer and saw the needle down to 0 RPM (how often does one look at the tachometer… but I just happened to...). Oh no, I thought, the tachometer went bad. The oil warning light had not come on at this point yet. I kept my eyes on the tachometer half glancing between the road and the tachometer. After what seemed about 5-10 seconds, I saw the tachometer needle recover to what seemed the correct RPM, and at the exact same time saw the red Oil Pressure Warning Light start blinking. I’m pretty sure the light started blinking at the same time that the tachometer recovered, that red blinking light is hard to miss in the night.

Having seen the oil light on a few times in the past and having verified that the oil pressure is within spec, I did not stop immediately but drove about 1 mile to the next exit. Once stopped I turned off the engine and then restarted the car and everything was fine. I drove another 15 miles to my destination without further incident.

So the coincidence with the tachometer malfunctioning (and having verified the oil pressure being ok several times now) seems to indicate some electrical problem which makes the computer see a temporary grounding of the oil pressure switch indicator (the low oil pressure condition).

So, what is there that is electrically related between the tachometer and the oil pressure switch?

I2canfix

Always check for frade wire at sensor first, Oil switch use acdelco or genuine Honda sensor!

mellowcream

I have the same exact issue. The tach drops to 0 and the oil pressure light starts flashing. It's done it twice. I immediately stop and restart the car and boom, its gone. I also have an '03. It has 230k~

mellowcream

This was likely the resin like material in the cam position sensors. it's known to melt down over time.

I2canfix

If oil sensor is leaking any oil change out! As oil could be entering circuit! Also check wire harness it’s in driver side wheel well, skim wire by wire as breaks could be very small and only break once you move wire around!

Ytown97RL

Your fuse box next to your left foot is damaged because water is getting into it. Acura says the problem happened with the 2002 RL but they fixed it in the 2003 model. That is a lie. If it was fixed, my 2003 would not have the exact same problem. The tachometer shuts off for a while and when it comes back on the oil light flashes even though there is no oil pressure issue. This is usually a problem that shows itself after it rains

Hellcura

What are we supposed to do about this

Hellcura

I need help so bad

Babafats

STV8261 do you still have the car?