When warm, engine runs rough then dies. Oil light flickering

Hey all. First post.
I drive a 2000 Tacoma prerunner 2.7L 2wd. Got just about 170k miles on it. I take excellent care of it. Just did a tune up and oil change.
I bought it in 2020 from someone off FB marketplace, had it inspected at a mechanic before buying. It's been in great condition. This just abruptly started.

From mechanics notes:
-Performed compression test- all 4 cylinders have good compression.
-150 psi w/ 3-5 psi delta
Passed head gasket test
-Once engine warmed up, starts rattling from top end, and engine loses all power.
-Low oil pressure light comes on-flickering or steady.
-Suspect oil pump is failing causing low oil pressure and engine is either starving for oil in upper cam area and/or timing chain tensioner is losing pressure, causing timing chain to rattle.

If it is the oil pump, he said it would be less cost prohibitive at that point to replace the engine. I trust my mechanic and the other mechanics at the shop. He just said maybe its something he hasn't seen before as it would be incredibly unusual for a Tacoma with this low of miles and in good condition to have a faulty oil pump.

At this point I'm just asking the great wide world of the internet to see if anyone has seen this issue before and thinks it could be something else. And if not, what would you do in this situation? Would you rebuild or swap a new engine in? Or sell the truck as is and get a different vehicle (im not attached to having a truck anymore).

 

Does check engine light come on?

 

My truck seems to have the exact opposite of this problem, with almost 195K miles...

The engine starts and runs fine, but when it has been sitting overnight (especially when it's cold), the oil light flashes and flickers on startup. This does happen over the course of the day at subsequent startups, and as stated above, it's more prevalent in cold weather.

 

No it doesn't.

 

the oil pump isn't particularly labor intensive to change, personally I would gamble a few hundred on that before dropping several thousand on a new/used engine. probably also worth checking the strainer in the oil pickup is not clogged and the gasket for the suction tube is OK too.

 

Thanks for your response. Apparently it's labor intensive and cost prohibitive because it's an engine out procedure in this truck, is what the mechanic said. He was even recommending against it because it was cost prohibitive.

 

So wouldn't the first thing to do be to stick an oil pressure gauge on it and check what the pressure actually is?

 

Thanks. Ill double check and ask em if they did that.

 

i would be inclined to get a second opinion on that because the link I posted shows someone able to do it with the engine in the vehicle

 

Thanks. Def getting a second opinion! That tutorial is for a 4runner right? Would it be the same for a 2000 Tacoma? I did look up if you had to take the engine out and what I'm reading is that you don't have to but you have to remove lots of other things to get to it.

 

that procedure should be the same for a 6 lug Tacoma or 4runner with 3rz

 

Does it stall at idle or cruise?

Is the idle speed super low? What happens if you raise it off idle slightly?

If the engine isn't spinning fast enough it'll want to stall, oil pressure will be low because the pump isn't spinning very fast.

 

Engine does not need to come out for oil pump RR



For 2.4/2.7 100% sure

THatt can confirm as well

 

After OP cause of oil light……
Would look at oil pickup tube or oil pickup tube screen inside oil pan