Help with 3RZ Engine

My understanding is that, with a non-interference engine, when the cam-crank connection breaks down, there is no way that the valves will come in contact with the pistons.

However with an interference engine, it is possible, but not a certainty, that they will come in contact.

 

Any updates on this?

 

Negative. With the holidays here I stepped away from this project for a bit. I plan to resume next week and I'll update when I have something. Thanks for checking in! Merry Christmas!

 

Okay, so I've finally got an update. Everything is fixed and running perfectly. I don't know if it has ever ran this great since I've owned it. It turns out that I'm actually a moron. I thought that I had perfect timing with TDC, but it turns out that my crankshaft pulley has TWO notches on the outside. One on the front, which I now have no idea what this is for, and one on the back, which is what I was supposed to use to line up for TDC. Needless to say, once I realized this, which is only because I have another 3RZ that I'm rebuilding and I happened to see this other notch, I corrected the timing and it started right up. Thank you everyone for your help with troubleshooting this issue. I'm sorry for the runaround and lackluster results, but hopefully someone else will learn from my mistake if they read this.

 

Thanx for letting us know what the solution was. Good to know.

 

So interestingly enough, I just did an emergency roadside head gasket repair. And I have the same symptoms that you were having, no start. I have since double checked my distributor, pulled the valve cover, and made sure that the timing marks were all lined up. I have been using the notch on the harmonic balancer pulley that is on the inside next to the engine for TDC. my compression is all around pretty low, but fairly even all within about 1 pound of 76. I’m not sure if my head got warped when I overheated and began this entire process. Basically, the only thing I haven’t checked yet is my coil but I believe I’m getting spark off at least the first plug wire so I have no reason to believe my coil would be bad.
There was one really strange thing though. Before I took the cams out, and the timing chain sprocket off, I marked the cams, the sprockets and a few of the bearing caps with sharpie. At first, I did not see the factory marks on the two cam sprockets because they were on the back side. I marked the front side where the teeth mesh with some lines that match up. I put it all back together and trying to start it with no luck. It sounded like it wanted to go here and there, sometimes more than just cranking, but could be a timing issue, one tooth off on the distributor?… I started by double checking placement of the distributor gear at TDC. Pulled the valve cover. Then I noticed that some of the sharpie marks on the left passenger side cam were slightly off of matching my original alignment. That is when I looked around the back side of the cam, sprockets, the side that faces the windshield and noticed the factory marks. To my surprise, the factory timing marks were not lined up, however, the marks I had originally made on the front side of the sprockets did line up. This is causing me to question whether they were installed properly in the first place? but my truck was running great before this happened. Without anything else to try, I loosened the cams and the timing chain sprocket and set the passenger side cam shaft to match the factory, dimple marks on the cam sprockets. Since trying to start it again still nothing, almost seems like it’s wanting to run less than it was before. Any ideas or thoughts?