5vz-fe suddenly lost power and knocks/ticks

Hey all, I just recently had my 2001 supercharged Tacoma develop a constant knocking/ticking sound, but I am struggling to figure out what the issue is.

I just replaced the spark plugs with some Denso dual electrodes after having some misfire codes in cylinders one and two. I also ran some Seafoam through the fuel system multiple times to clean the injectors, and this seemed to fix the issue.

About two weeks later I started her up and let the engine warm up (was a cold morning) and then pulled out on the highway. I accelerate to about 30 mph at 3000 ish RPMs and the suddenly had a huge loss of power causing the RPMs to drop to around 1500. I was still pressing the accelerator until I heard a small crunch from the engine followed by a constant pound tick or knock. I pulled over and popped the hood to listen to it and it seems to have come from the driver side valve area. Hard to pinpoint where it was coming from really, but I limped it back home and haven’t driven it since except into the garage to work on it. The surprising thing is I had no check engine light or oil pressure light at all.

I have taken the throttle body, supercharger, and fuel rails off to check the injectors, but all read around 13-14 on the ohms form a multimeter. I’ve done some research and it seems that the knocking could be valve, injector, flex plate, or emissions related. I’ve heard that it could be an O2 sensor issue, and I have and a P0420 and P0421 code come up about three times a year ago, but nothing recently.

Would love some advice on what this could possibly be, and unfortunately I don’t have a video of the knock sound since the engine is currently taken apart.

 

*Update*

Since posting this I’ve taken the engine apart to the valves and check all the valve clearances. Everything seemed within spec. I also checked compression and I got about 60psi in Cyl 4 and 80psi in Cyl 5. So, because of these results, I can concluded that the ticking is a head gasket leak or a warn out lifter. It’s more likely a head gasket issue because I looked inside the problem cylinders with a borascope to find coolant burnt inside.

I have put the engine back together and when I started it up for the first time the exhaust smells like a mix between burning rubber and a sweet smell. The sweet smell is most certainly coolant burning in the engine. So again, this points to a leak in the head gasket or even the heads themselves.

I wish I could add a video to show what the ticking sounds like, but if you run into this yourself you’ll definitely be able to hear it. It’s more pronounced when it’s in park.

 

I'll put my money on a bad head gasket.

 

With the radiator full and the cap off and the engine cold start her and see if there are bubbles immediatly. Hopefully all you are smelling is coolant in the exhaust.