2019 Tundra oil pressure issue?

Hi everyone, first post here mainly due to a stressful situation but long time lurker. 2019 Tundra TRD Pro, 5.7, 93k miles - bought the truck certified used in 2019 with 4600 miles. Oil changes every 5k (once at 7k due to road trip) and overall maintained perfectly with transmission fluid changes, diffs, transfer case, etc. I use it as a truck, tow cars relatively often and off road as well. Just to give some background.

Tried doing some forum searching but couldn’t find what I’m specifically having an issue with. Currently on a cross country road trip in Colorado (based in New York) and out of no where today I pulled up into a line of traffic, transmission left in drive, A/C off - and I noticed my oil pressure gauge after about 15 seconds started slowly dropping down until it got to 1/4 mark. Popped it into neutral and it went right back to normal. It has absolutely never happened before - it always sits just a hair bit below the 1/2 mark (which my research shows that’s correct for these trucks?) - I was able to recreate the issue by doing basically the same thing (stop, in drive, A/C off, wait 30 seconds) - long story short, very stressed out because it’s never happened before and I’m quite far from home currently. Oil change right before I left, oil looks clean and at the proper level. The engine doesn’t sound any different - just has that 5.7 clatter that it seems like they all have?

Any suggestions or insight on this situation?

Unrelated but figure I’d toss it in here if anyone has information - fighting a transmission flaring issue on downshift at highway speed (70-80mph) specifically once I’ve been driving for a while and the transmission has some heat in it from a long drive. Transmission fluid changed at 49k miles and at 90k miles. Talked to the dealer and they had zero information and couldn’t recreate the issue. Running 285/70R18s is the only thing that comes to mind? Essentially I’ll cruise along and if I need to add a little gas to go around someone it will come out of 6th and into 5th but the RPMs will go up about 500 over the point needed and then “lock” back down to where it needs to be.

Sorry for the long post but I’m supposed to be driving to Moab tomorrow for some off roading and now I’m super stressed out that something is going on with my engine oil pressure since I’ve never had this happen previously in the years I’ve owned the truck.



Any suggestions or information would be greatly appreciated.

 

Oil pressure issue could be the "sending unit" that is mounted on the filter housing block. It may be faulty sending erratic signals to the instrument cluster. Or a mouse chewed up a wire.

Instrument cluster could be faulty and not displaying correctly.

A collapsed or faulty oil filter, oil pump, or main bearing issue could lead to loss of oil pressure.

You might be able to get a mechanical gauge at an auto parts store and connect it where the sending unit is.

Lastly, if you had severely low oil pressure your cam timing and crank timing monitors would be going off quickly. In overhead cam engines it is usually the first code stored. P0012 and P0022 with a gauge reading low would cause me to be very concerned.

 

Use 5w30. For offroading in Moab use even higher viscosity oil.

 

Curious of your RPM when this happens. Wondering what your battery voltage is when stopped in drive with the AC on. As far as the 500 RPM jump when shifting, could it just be the torque converter unlocking?

 

You replace the oil filter cap with a metal one?

 

Good question!

 

It is, 100%

 

Xmsn "flaring" is normal. On kickdown it almost always unlocks the torque converter for a second.

 

For the oil pressure issue, I'd connect a mechanical gauge to ensure it's not a sending unit issue or wiring. You can buy them from most parts stores for diagnosis. Or have a shop check it with their gauge.

https://www.autozone.com/shop-and-garage-tools/oil-pressure-tester

 

Hi everyone,

Thank you for the replies. I made the drive to Moab without any weird issues. Oil pressure gauge stayed just a hair below the middle line and would increase to a little over the middle line when under heavier acceleration. No strange engine noises outside of the 5.7 "diesel" noise and the typical valvetrain noise. Did not seem to have a lack of power or knocking or anything else when accelerating. I was driving within Canyonlands today and when I stopped at the one entry gate, the gauge went down just a hair but not all the way to the 1/4 mark. Otherwise there was no issues. Oil is still clean and at the correct level - no lights on the dash or check engine lights.

To answer questions:

Regarding the sending unit - I was thinking about this more and I did give my truck a good wash before I left for my trip. More specifically I did power wash into the skid plate area on the sides and also directly in the front to clean out some mud and dirt. I wonder if I somehow messed up the sending unit from this because the more I think about it, the sending unit I believe would be located almost directly behind where I was cleaning out from the front? However, if it wasn't functioning correctly, wouldn't it be a bit more all over the place instead of just very randomly showing low pressure?

Regarding the oil filter collapsing, oil pump, main bearing issues and the cam/crank monitors - I would assume any of these issues would be a consistent low oil pressure issue, engine knocking, warning / check engine lights or overall a much more significant issue that would've likely killed the truck over the 6.5 hour drive I had to Moab or from the multiple hours of off-roading today. If I am mistaken, please let me know.

For the 5w30 oil, I have read that before but never changed due to not wanting to have any issue with my warranty. Could the 0W20 be an issue with the higher elevation and temperatures? I was out here around the same time last year and never noticed this issue so it would seem odd to be an issue this time?

With the A/C off, in drive at a stop - the RPM was very low. Less than when in park or in neutral. I noticed it bumped up just slightly when the A/C was turned on and it did not happen with the A/C on. Unsure regarding battery voltage but I do see the idea.

The oil filter cap is original, not replaced with the metal one.

I am going to see about possibly hooking up a mechanical gauge to make sure the engine still actually has oil pressure. I believe I was reading that once warmed up at idle the engine should be 10psi? Although to again add to my confusion, if there was not enough oil pressure the engine would likely sound very unhealthy? I was able to recreate the 1/4 mark oil pressure gauge situation once shortly after it happened the first time - I had a friend listen to see if the engine sounds worse or different and he said nothing seemed to change nor could I hear any change from in the truck. Just overall seems like a very strange situation especially since the engine itself does not seem to show any signs of issue. I had a 92 Toyota pickup with a 22RE that had oil pressure issues due to sitting for a long time and I vividly remember how much knock that engine had for the short period it was running before fully tearing it down for a rebuild and luckily this 5.7 does not show any signs of issues like that.

For the transmission - I can feel the torque converter locking up and unlocking. No issue there. I have a video that just barely shows what it does but I have had a few times where it will flare hard enough to knock my head into the headrest. For a breakdown the best I can - cruising at 1800 rpms - get onto the gas a bit but not to the floor and it will shift from 6th with converter locked to 4th gear - it will go up to like 4500rpms and then harshly knock back to roughly 4000-4100rpms. It did not do this up until I would say around 70k miles. Could the converter be worn out from how often I tow? Fluid is fresh within a few thousand miles so it just confuses me since it was certainly not like this when I got the truck. Just ideas, I honestly am not super familiar with automatic transmissions as most of my vehicles have been manual.

Very sorry for the long messages - just trying to be as detailed as possible. I appreciate the responses greatly. Thank you all.

 

If you made it to Moab without any issues and the gauge acted normally, then your problems are far less severe than previously thought.

 

Running 5W-30 won’t affect your warranty (assuming it’s Toyota 100k powertrain that comes with the CPO).

in our 2019 manual. Toyota essentially admits that 0w-20 is recommended for “improved cold starts and better fuel economy” and suggests that in higher temps and/or higher load driving situations heavier weights could/should be used.

Personally, I wouldn’t run 15w-40 in Saskatchewan in January, but 0w-20 to 5w-30 should give you no trouble at all in your use cases.

 

OP, I’m having same issue in my 19, started around 158k. Curious if you’ve figured the issue out?