Replacing engine questions

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thebarneyhouse

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I have a 2015 TRD Pro that I purchased wrecked. We have tried everything to start it and we are at the point (the various mechanics) that we are going to put a running motor in it. We think it has something to do with the variable timing because we get varied compression readings and it just tries to start with no visible problems. The history of the vehicle is a little vague but I found out from the young man that 1) he hit a bridge and went over it and 2) they never started it again after that.

And no I haven't taken it to the dealer because one of it's wheels is hanging on by a thread and I can't take it to my local/nearby frame shop until it is running :(

Questions:

1) Am I to assume I will need to get a toyota reprogrammed key to match the new longblock?
2) anyone out there changed out an engine and what problems did you encounter?
 

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Is the hood looking like that because the entire powertrain is pushed upward from this Dukes of Hazzard bridge jump ?

The only thing I could perceive especially if the motor is cranking over freely is timing chain jumped or broke from that impact and now your valves are all out etc. etc. in that department. Someone has to pull off the oil pan and look up, pull off the valve covers and look down there to ensure everything is in its place, if your compression readings are slightly off thats one thing but way off - scope it out and see why, the motor should not have grenaded itself from a jump and if it did - damage will be obvious when the pan comes off. I'd hold off on a new motor just yet. Nice project though ! :cheers:
 
I hope you did not pay true market value for that Pro.
Curious why he sold it. I thought once a vehicle is totaled and the insurance cuts you a check, the car belongs to them.
 
Signess said:
I hope you did not pay true market value for that Pro.
Curious why he sold it. I thought once a vehicle is totaled and the insurance cuts you a check, the car belongs to them.
Click to expand...

If you look at the pictures you will notice they are insurance auction pics. I'm guessing the current owner bought it from the insurance auction as a pink slip vehicle.
 
Does VVTi affect compression ratios? Enough to show up in a compression test at starter range RPM's (like <100RPM)? Just curious...
 
If you're going to replace the engine, I'd strongly consider seeing if you could swap in the 4.7L V8 from the GX series....
 
Randyman... said:
Does VVTi affect compression ratios? Enough to show up in a compression test at starter range RPM's (like <100RPM)? Just curious...
Click to expand...

Variable valve timing is accomplished by changing camshaft profile ( the cam lobe extends ). This is through oil pressure, controlled by sensors monitoring RPM, which is very advantageous at high revs.

Typically VVTi failures occur with cam bank sensors and throw a code, the engine would still run but you would notice reduced power or depending upon manufacturer the vehicle may go into limp mode.

So with that said it is highly unlikely that highly varied compression across your cylinders has anything to do with VVTi, there may indeed be a bad valve seat or you may have a bad piston ring, intake gasket failure, cracked head etc.

None of this ever happens to these motors right? :boxer: I doubt it, I would think you'd have to beat the daylights out of one.
 
You shouldn’t need to get the key reprogrammed if you’re just replacing the engine but you would need to get the keys reprogrammed or replaced if you were replacing the ECM as well. Replacing the engine should be pretty straightforward as long as the replacement engine is the same. I would recommend finding an engine from the same year vehicle.

I do agree it would be pretty cool if you replace the 4.0 with a 4.6 and 6-speed from a GX.
 
Randyman... said:
Does VVTi affect compression ratios? Enough to show up in a compression test at starter range RPM's (like <100RPM)? Just curious...
Click to expand...

It can not effect the compression ratio, that is a fixed ratio based on the cylinder and combustion chamber volume when the piston is at the bottom of its stroke, compared to the volume when the piston is at the top of its stroke.

A compression test is looking for cylinder pressures not compression ratios. If the cylinder isn’t sealed on the compression stroke, in this scenario because cam timing issues hold the valve open to long you blow air out of the cylinder instead of compressing it resulting in lower readings.

Ideally compression tests should be done at operating temp, with fuel injectors disabled, and the the throttle body wide open.
 
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Signess said:
I hope you did not pay true market value for that Pro.
Curious why he sold it. I thought once a vehicle is totaled and the insurance cuts you a check, the car belongs to them.
Click to expand...

What do you think happens to them after that? They get handed out to executives as bonuses?

Let's back up a bit here. What troubleshooting have you done? Have you verified that you're actually getting both fuel and spark? Have you verified valve timing?

As far as the key goes - you program that with Techstream.....but are you planning just a long block replacement or a full replacement with ECM and everything? Either way you'll need Techstream. If just the long block, how do you know that'll solve anything?

VVT is unlikely to be the issue. I don't have much experience with the 1GR-FE (mine runs like a Swiss watch) but in general an engine with a VVT issue will start just fine then run poorly at either high or low RPMs.

Don't mean to be insulting. If the answer to all of the above is "We know what we're doing and we've tried every troubleshooting step in the book and have come to the conclusion that it needs a new motor - just wanted to see if there are any known gotchas" then fine. It just sounds a little like "it won't start so were going to try a new motor" which is not a great recipe for success.
 
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Launching a vehicle like that will probably kill more than the engine.

I'm guessing the shafts, diffs, and transmission won't be too happy after that excursion.

Also anything and everything attached to the frame probably experienced some degree of shear.
 
thebarneyhouse said:
And no I haven't taken it to the dealer because one of it's wheels is hanging on by a thread and I can't take it to my local/nearby frame shop until it is running :(
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Just reread this part - you do know a towing company could solve both of those issues quick, right? A dealership would be the last place I'd take it (can you imagine? LOL) but if you're feeling like you need to have some qualified technicians put eyes on it then YOU SHOULD. A full engine replacement is going to be a costly and time consuming job. It would really suck if you did that only to figure out it was something simple like a loose sensor wire or something. And what happens after you go through the time and expense only to figure out that in addition to body work the thing is completely FUBAR underneath? You'll be wishing you had just gone out and bought a new one!
 
LandCruiser said:
Launching a vehicle like that will probably kill more than the engine.

I'm guessing the shafts, diffs, and transmission won't be too happy after that excursion.

Also anything and everything attached to the frame probably experienced some degree of shear.
Click to expand...

This. That poor thing has lots worse problems than the motor. When the OP said something about "taking it to the dealer" ..... well, hmm. :tsk: :tsk:
 
Sounds like your "mechanics" are clueless as far as these trucks go.

First question is the same question I ask everyone with an engine problem.. Have you scanned it with TIS. It does not matter if a check engine light is on or not.. there could be very useful information stored. If you don't take this step you are wasting your time and money.

If you don't have it.. it's super cheap to get setup.. just takes a little effort. Or you can reach out to someone in your area who has it.

If that shows nothing.. you go back to basics.

Is it getting fuel (injectors pulsing, fuel pump making pressure up to the rail, are they being pulsed in the right order)

Is it getting spark (are the coils arcing the plugs, and in the right order)

I say the right order... because in a situation like this, you have no idea what has been removed or fiddled with (or even hooked up in the wrong order) These auction vehicles can be messed with in transition.

Another factor is that modern cars can sometimes require a special crank position re-learn procedure. I've seen that stop many motors from starting.

As far as the vvti goes.. it's very doubtful that is a factor. It requires oil pressure to do anything and you are not going to get that cranking the engine. The cams will always fall back to their normal advance.

As far as replacing the motor goes... Not sure why you would do that without first verifying the issue. If you do replace the motor...Most would just replace the motor and keep the existing ECU. There is no electronic synchronization check between the business side of the engine and the ECU. However, there is definitely a synchronization check between the ECU and all the other modules via the VIN.
 
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You guys have given me a lot to think about.

The auction said "starts" and the engine did not appear to have damage done to it. The oil looked good, no radiator damage, etc. Had a hard hit to the oil pan but it appeared in good shape structurally. OBVIOUSLY I am no mechanic and have relied in the past on my local mechanics that have done okay to this point. I've bought a couple minimally wrecked vehicles and I know a great frame shop, so I figured for sure frame damage and steering but never thought that there would be a problem with the engine (Being a Toyota and all). This will be my 5th 4 Runner, and I think the excitement got the better of me when I saw this one. Obviously I am over my head with this one. mgprodfit is right - I shouldn't have bought it.


FYI - yes we got spark and yes we got fuel. It turns over like it wants to catch but just can't.

At this point the engine is taken apart to the valves since we (me and the mechanic thought it must be a valve job) and I have to say I think my mechanic is not the best for this but I'm kinda screwed at this point to take it to the dealer (in pieces)

My only hope now is to put in a known running engine and get on with the repairs to the frame/steering :(

So, unless I am reading wrong on my initial questions, the key should work when I use the existing ECU with the new engine.

I guess if I do this and it still doesn't work, it is an expensive stupid tax.
 
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Did the car get submerged in water? Did it ingest water?

VVTI has nothing to do with cylinder compression.

Is the bottom picture after they cleaned it up for auction?

Hope you didn't pay more than $1K for it.
 
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