My 03 Tundra has oil pressure issues after changing to synthetic. Help???

[03LimitedYoda]

When I first start the truck the pressure is fine at halfway, as the vehicle warms up it will drop to the low line and spike up as I push down on the gas. I have read some of the other postings and other people have the same problem, if you could call it that. What Im getting is a rough running engine when the oil pressure gauge reads on the lower line.

That cant possibly be good. No leaks, everything is fine there.

Mobil 1 synthetic 5w30 6.5 quarts in my 4.7 liter V8. Can anyone clarify that this is not an issue at all or that its not connected to the oil pressure gauge issue?

[Mongoose]

Thats Strange... I've been considering swapping to Mobil 1 synthetic, so I'll be watching this thread topic.

[Remmy700P]

The 2UZ-FE's oil pump is crank-driven, so oil pressure is a function of engine RPMs. Your oil pressure gauge is functioning exactly as it was designed. Your idling issues have nothing to do with oil pressure.

Welcome to the forum.

[03LimitedYoda]

Its not an idle issue. I have read through the forums and DO know that the pressure gauge is "crank driven". What Im experiencing is when the pressure "gauge" is on the low line, not idling, the vehicle is at lower rpms, the engine feels as though its running rough, a faint sputter or bog if you will. Is this connected to the crank driven gauge reading low? Or is this something else entirely.... Thanks for your detailed responses, hopefully someone will know whats going on.

And thank you, Ive been a reader and user for sometime, this site has lots of intelligent people and posts. Decided to register finally

[Remmy700P]

Its not an idle issue. I have read through the forums and DO know that the pressure gauge is "crank driven". What Im experiencing is when the pressure "gauge" is on the low line, not idling, the vehicle is at lower rpms, the engine feels as though its running rough, a faint sputter or bog if you will. Is this connected to the crank driven gauge reading low? Or is this something else entirely.... Thanks for your detailed responses, hopefully someone will know whats going on.

To clarify, the oil pressure gauge in your dash is not "crank driven", the oil pump -- and the resulting pressures -- are.

Further, let me repeat: oil pressure is not causal to poor idling, stumbles, stutters, etc unless you essentially are running it with no oil and it is on it's way to complete seizure.

I suggest standard maintenance first, i.e. cleaning the throttle body, MAF, replacing the air filter (if needed), replacing the spark plugs (if needed), etc and see if you can narrow down and isolate the problem.

[INDYMAC]

If this is something that happened immediately after an oil and filter change, then change the oil filter. You may have been unlucky and gotten a defective filter. I'm assuming by your description (low line) that the guage is reading zero psi at low RPM's. This is certain disaster.

[03LimitedYoda]

Air filter is clean as a whistle, spark plugs are great, throttle body is being cleaned now, MAF? As my profile states Im a rookie lol cut me a little slack this is my first yoda and Ive had it for 4 months. Also, would there be a reason why before I switched to synthetic the needle on the gauge did not do anything of the sort?

[03LimitedYoda]

If this is something that happened immediately after an oil and filter change, then change the oil filter. You may have been unlucky and gotten a defective filter. I'm assuming by your description (low line) that the guage is reading zero psi at low RPM's. This is certain disaster.

Crap. That sounds bad... I did use a filter that came with the truck, and apparently was from Japan not sure if it was OEM or not... I will change the filter immediately.

[SuckersWalk]

You have no idea what your oil pressure was before OR after the switch to synthetic. Why? Because the oil pressure gauge in your dash is a "dummy" gauge. If you really want to know what your oil pressure is, hook up an aftermarket oil pressure gauge. However, since you are convinced synthetic oil is the problem, run down to wally-mart and buy 6.5 qts of dino oil and do a drain and fill; problem solved.

[kerryman71]

Some more info may help. Did you change the oil yourself and if so, did you do one of those engine flush in a can deals? Did the problem start immediately after changing the oil, meaning you changed it, started the truck and presto, it was there? You say you've had it for four months. Do you know the previous owner or have any maintenance records?

Mongoose, do the switch, you shouldn't have a problem. I switched to synthetic (Mobil 1 0W30) 35K miles ago with no problems.

John

[asc08]

I had a Chevy some years ago. Driving on the highway, everything was fine. Came up to a traffic light, and when I stopped, the oil pressure dropped to zero, and the light came on. Not hearing any engine noise, like lifter tap, or bearing knock, I pulled over, checked the oil level, and it was fine. Turned out to be a bad oil pressure sending unit.

I think what Remmy was pointing out was the rough running engine should not be caused by the low oil pressure reading, but the low oil pressure reading may be caused by the rough running engine.

I have no idea where the oil pressure sending unit is on the Tundra, but a good old dial gauge connected in place of the sending unit will put your mind at ease, and let you know if you are actually experiencing low oil pressure.

When the engine is running rough, what do the RPMs fall down to?

[SuckersWalk]

OP - you made no mention if the oil light in your gauge cluster comes on; a MUCH better indication there is an oil pressure issue. if you don't know where it is, just put your key in the ignition and turn the key to on without cranking it over.

To "clarify", Mobil 1 5W-30 is not an issue at all and is not connected to your perceived oil pressure problem.

[tundrunk]

Hello 03limitedyoda,
Go back and check the dipstick, my truck takes 7qts, not 6.5. You'll want the oil at the higher end of the indicator markings. Also, I don't think rough running would be caused by oil, more likely a fuel/ignition related issue.

From your description, it sounds like your gauge is working normal. Mine has mid level pressure at start up, as the motor warms the pressure lowers, and as I accelerate the pressure builds. When you say it goes to low level line, to you mean the gauge pins at the very bottom, or just in the lower range?

[SuckersWalk]

i had to put on an oversized filter to get 7 qts into mine. before, only 6.5 qts. did you?

[tundrunk]

I always run Toyota filters, the D3 one. I don't think larger filter will hold half a quart, unless you're talking a huge filter. The Toyota one only holds a few ounces before it gushes back out.