I'm starting a new thread to discuss my issue, as my previous thread focused on the valve stem seals, which I now know is not the issue.

I have a 2015 SR5 that smokes when cranked and will smoke when accelerating from a red light. I was hoping it was a valve stem seal issue, but the problem didn't get better after replacing them. Here is a video to show the results.

https://www.youtube.com/shorts/-lfSVm2UmvQ

So, now to determine if I should 1) Rebuild, 2) Replace long block or 3) Replace with used motor.

Rebuild would be my preference to save money, as I can do the work myself. I just don't know how to determine if the motor can be rebuilt without pulling it and having a machine shop tell me. Is there another way without pulling the motor. I have a borescope, so I can look in the cylinders, but not sure what to look for. When I pulled the plugs, all looked great and identical, except number 6 which had a good bit of oil build up. My assumption is that cylinder is the issue.

My assumptions would be to first do a compression test on all cylinders and scope them to see if something alarming stands out.

Any assistance you all can provide would be greatly appreciated.
Keith

I'm not an expert but I've always read these engines are not able to be rebuilt due to the cylinder liners used.

Your options are used motor, or short block. Toyota doesn't sell long blocks in most cases. There will be a part number, but it is not orderable, anywhere.
You can't rebore these blocks either.

Take a look with your borescope, you'll probably find vertical scratches in the bores.

Sorry to hear it didn't work. What's the compression look like?

Have you tried Valvoline Restore and Protect? This has helped many people with stuck rings-if that's the issue.

I have not tried Valvoline, but have use Mobil 1 High Milage for the latest 1K miles or so to try and resolve this.

I haven't check compression yet, although I did use air to install the valve stem seals and the cylinders seemed to hold pressure well when I disconnected the air hose and had the ball valve on the hose closed. That was my simple test to see if all the air was leaking past the valves or rings.

Keith

I've seen remanufactured long blocks for sale, as well are rebuild kits. I know the block can't be bored, so I'm not sure what a rebuild kit would accomplish unless the block had no wear. And I'm not sure how to know that without taking to a machine show to have them measure.

Keith

I would try everything in an auto parts store to free up stuck rings. At this point you might just get lucky. In the crankcase, in the gas and directly in the combustion chamber.
How about Seafoam soaking in the combustion chamber of #6 for a couple days. Slurp it out, install spark plug and test drive.
There are lots of these hand vacuum suction devices that might help you slurp oily products out of the combustion chamber. Could buy you time with the existing engine.

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Great suggestions. After doing some additional research, my next steps will be:
1) Leak down test
2) Compression test

Depending on results I will either look for solutions to possibly unstick a ring, like suggested or may have to do a valve job.

The vehicle sat up for a while before I purchased it, as I have found several dirt dauber nests. Also, there was a bit of sludge in the motor, although I did add a seafoam treatment to it recently and have only changed the oil once since. So maybe the seafoam loosed some things up and helped create that sludge.

It will be a while before I can get back into the engine, as my son has taken the car back to college. I'll keep you posted as soon as I can get into it again. Please keep the suggestions coming, as I REALLY hope to find any solution that doesn't involve the block.

Keith

Dont buy that $25 bleeder at HF. POS failed after one bleed. I needed a vacuum testor as well. Waste of money.

Good luck with the engine. I cut filters apart to gugae wear, although in this case its all sealing, not wear.

LS SWAP!

I have a Mighty Vac already I can use. Also, I have a borescope to make sure I don't see any scratches prior to soaking.

Keith

just swap the tundra engine ,

pretty straightforward


5th Gen 4Runner Super Charged 5.7 Tundra Swap

Unable to view as video is marked private, but I was able to view in the other thread. That smoke on cold start up looks like water vapor as it clears up quickly. You should do your compression tests and any other minor tests, then just drive the car to get a good feel of what's going on. I'm afraid you are scratching around at things such as valve seals and making things worse.

I'd get a salvage take out motor with low miles and be done with it. I would do a compression test on the take out motor before sealing the deal.

I just changed the video to unlisted instead of private.

I don't disagree that I'm scratching around and I'm trying to avoid causing additional issues. I think compression, leak down and borescope are good next steps to avoid causing additional issues.

Keith

This is certainly an option I have, but trying to save it to my last option. Cost is $5-$6K for a lower mile engine and there is no way to know if it's a good motor. Crap shoot.