2003 4.7l 2UZ-FE stopped after 220k - Single Owner

Single owner, 2003 SR5, 4.7L, 2UZ-FE with 220k miles. Truck has never once been in the shop or on back of a tow truck. While coming home from work, I noticed that the stock oil pressure gauge bottomed out suddenly and I heard a faint “ticking” sound, appearing to come from the passenger side of the motor. I had no noticeable loss of power, smoke, fluid, smells, nothing. I immediately pulled over into the nearest parking lot (less than half mile) and killed the engine. After letting it sit, briefly, I checked the oil and showed oil on the dipstick, touching the top level indicator. Cranked the truck up and did not hear the noise. Still saw no fluids leaking, smells, nothing. I started back home and saw that the oil gauge was slowly dropping. Within less than 3-5 miles, it bottomed out and didn’t come back up. Still had no loss of power, no noises, smells, temp increase, nothing. Made it home with no issues.


The next day, I did an oil/filter change. Replaced with Mobil1, 5w-30, full synthetic, and a new Wix filter. Pulled the oil pressure sensor and put a manual test gauge on it. Once the engine warmed, oil pressure read around 10psi at idle (I believe 4.6 is the minimum). At 3000rpm, it held steady at about 38-40. Needle was dead steady with no jumping or dancing. Still no odd noises, leaks, smells, nothing. Ran my gauge up under the hood and secured it against my windshield, where I could see it, and took ol’ girl around the block a bit. Drove her around about 10-15 minutes. Dead steady needle, no dancing, and within spec the entire time. Never bottomed out. Power still good as usual, nothing out of the ordinary.


Brought her home and replaced the stock oil pressure sensor. Checked oil level, fired her up and sensor seemed sluggish but otherwise acted normal. Put a scan tool on her and only had two faults for bank 1&2 O2 sensors. They've been that way for years, however, with no detectable issues. Later, discovered that the oil pressure sensor is analog and apparently won’t throw a code... supposedly. Drove the truck around, again, and noticed the oil pressure sensor, slowly read less and less. Stopped at the local parts store and installed a new “Import Direct” sensor, on the spot. Checked the levels, and drove away. Seemed to be a responsive gauge and appeared as if that was the problem. After about 10 minutes of driving, however, the gauge bottomed out. Again, no noise, no smell, no loss of power, no temp spike, nothing.


Then it happened. I pulled out onto a main road and hit the gas. Thought I heard a noise when I came out of the throttle. I can only describe it as a faint, high pitched, noise that almost sounded as if something on the truck was spinning faster than the motor for a split second. I hit the gas again, and heard it again, but just for a split second after letting off of the throttle. Still no loss in power, just the noise this time, that now seemed to be toward the driver side, under the hood. I hit the throttle a third time, and not hard either, and heard one “pop” sound that seemed to be on the passenger side. Loud enough to hear but not loud, if that makes sense. The engine immediately lost power but kept running for about 15-30 seconds, then shut off. No smells, smoke, fluids, nothing. She’s just dead.


Coasted to a parking lot, popped the hood, and checked what I could. Still couldn’t see/smell anything unusual. Let her cool down a bit and bumped the starter, quickly. Maybe not the best diagnostic choice but I did it. Anyway, motor turned over without any noises that sounded like they shouldn’t be there. However, it was almost like a motor that had jumped timing. She wouldn’t start.


Got a tow home, grabbed a ratchet and broke the drivers side, timing belt cover loose where I could see the timing belt and get a finger on it. No visible damage from that view and you could still feel tension on the belt. (This is the second timing belt kit. Changed the original out at 100k) Ol’ girl won’t hit a lick tho. Never had the first mechanical issue out of this truck but when she went, she went. Guess it could’ve been worse tho.


Anybody got any experience with something like this, that found out what it was?

 

My first thought was maybe the oil pump was going out. But you sound more mechanically inclined than I am.

 

This is a head scratcher. Sounds like you know a thing or two. She gave it all until the very end. RIP 03’!

 

I don’t think it was your sensor going out I think it was your oil pump. I know you tested it, maybe something was going on under load. Especially since you said you noticed a ticking at first.

What about your O2 sensors? I know that can give bad gas mileage. You drove around for years with failing 02 sensors. What’s happening when they have failed? Is a lot of raw fuel getting dumped into the combustion chamber causing it to wash out cylinders or contaminate the oil.

Reason I say that is, thest engines typically don’t fail. There had to of been a component that failed causing the death of the engine. Because as you said, everything for the most part sounded normal until it seized up. Sounds like a spun bearing from lack of oiling. I’m not master mechanic though.

 

A spun bearing will give you almost a rod knock sound that gets louder and louder and doesnt stop. But it will affect your oil pressure. Won't throw a code either. If you heard a pop maybe an injector come out? Or a coil? Maybe check the fuel pressure in the rail. The pop could've been a backfire back into the intake. I'd maybe look around there. I dunno, just spit balling here.

Edit: I hate Samsung's autocorrect.

 

Timing belt was done at 100k miles, was the water pump, idler and tensioner pulley changed at the same time? OEM or aftermarket? You only broke the cover loose and put a finger on the belt? Take off both covers off and check the belt. Turn the crank with the covers off, do the cams rotate? Take pictures of the belt, report back.

 

Welcome from NC! Sorry to hear about this but it sounds as if your mechanical skills will figure this out. Looking forward to see what you find!

 

Sorry to hear this. I thought oil pump as well. Could it be an intermentant issue randomly causing the pump to shut off? If the motor seized I’m sure the oil would show signs of it.

 

I also would check the timing belt. I would tear down to the water pump and check everything.It is odd that it acted the way it did.You can also take an oil sample and send it off to be checked for any metal or odd things in the oil.It is like having your blood tested.

 

I would also check the crank shaft sensor. I changed my timing belt this year and some how pulled a wire loose on the sensor plug and it wouldn't start,it just cranked.Just throwing some things out there to check.