Blown Engine, Worth putting in a new one?

[JohnMc]

Yeah, +1 on the 'more diagnostics' approach.

How does the motor sound as it cranks? Uneven cranking speed? Or is it pretty evenly slowing over each compression. That's a sort of shade tree 'compression test' to see if it's some overall issue or something isolated to only a small number of cylinders, like a HG or stuck/broken/burnt valve. Any clanking noises? Throwing any P030X codes for misfires?

 

[BuffaloBass]

For sure pull the front covers and check the timing marks. Throw a new cam position sensor in while you're at it. Its right there. I am not sure how to test it.

My son buried a "hilux" in frozen water and when we tried to crank it , the ice around the balancer caused the belt to slip. For real. It took us a while to figure that one out, but it can happen. And to John MC's point, the engine will sound quite odd when cranking when the cam timing is off!

PS I am in the middle of "restoring" a 99. I cannot for the life of me understand why anyone would put a junkyard engine in a nice 4RNR. It is 10X harder to R&R the engine in the 4RNR than any old car I have worked on. IMHO I would NEVER EVER put a junkyard engine in. Not worth the time when a rebuild can be had for not much more. But I am an OF and nothing is as easy as it used to be.

Jury is still out on the LKQ " Henco en Mexico" reman I am installing, yet its been so much work, I am happy about the fresh innards and 3 year warranty.

 

[Tanis911]

Yeah, +1 on the 'more diagnostics' approach.

How does the motor sound as it cranks? Uneven cranking speed? Or is it pretty evenly slowing over each compression. That's a sort of shade tree 'compression test' to see if it's some overall issue or something isolated to only a small number of cylinders, like a HG or stuck/broken/burnt valve. Any clanking noises? Throwing any P030X codes for misfires?

When I try cranking all I can hear is whirring like sound, but consistent. Like something is spinning. After a few tries, it will try to turn over, but will hesitate and then cut out completely, back to whirring. No clanking, just rough sounding when it wants to turnover. Late 2022 I had a p0300, and P0304 code. Checked plugs and they looked ok. For good measure, I swapped out the plugs, replaced wires and coils with NGKs, and sent injectors out to be cleaned and rebuilt to Witch Hunter Performance. Ran some Blue Devil through the cooling system and replaced the radiator. After all this was done, all codes clear and was running great. Thanks for all of the input so far. With the Holidays and work it's been hard to reply, let alone take a look at what's going on with the engine. Have a day off coming up, so plan on taking look then.

 

[Bad Luck]

When I try cranking all I can hear is whirring like sound, but consistent. Like something is spinning. After a few tries, it will try to turn over, but will hesitate and then cut out completely, back to whirring. No clanking, just rough sounding when it wants to turnover. Late 2022 I had a p0300, and P0304 code. Checked plugs and they looked ok. For good measure, I swapped out the plugs, replaced wires and coils with NGKs, and sent injectors out to be cleaned and rebuilt to Witch Hunter Performance. Ran some Blue Devil through the cooling system and replaced the radiator. After all this was done, all codes clear and was running great. Thanks for all of the input so far. With the Holidays and work it's been hard to reply, let alone take a look at what's going on with the engine. Have a day off coming up, so plan on taking look then.

Is the crankshaft rotating when the whirring noise is occurring? It sounds like your starter plunger is stuck and not extending to engage the flexplate/flywheel teeth.