Top end knock with metal in oil

Hey everyone, first post here so not sure what this community is like, figured I’d give it a shot.

I bought a 1997 4Runner, 5VZFE Engine with 263,916 miles on her as a project car (she’s certainly a project, sheesh).

Well we bought it with a knock and metal in the oil, and immediately jumped to “she needs an engine”, which is whatever I’m not too worried about it, until a few days later I wanted to dig a little deeper and found the knock was coming from the top end, which in my experience has (almost) always been better than the bottom end. I’m not going to purchase and replace a whole engine if it’s not needed, so I checked the timing (which is good) and popped the valve cover on the passenger side.

It has a cylinder 1 misfire, and that’s exactly where I think I hear the noise under the valve cover (Could be coincidental, unknown yet). The last guy used an absurd amount of gasket maker, doesn’t seem to be anywhere detrimental, but it definitely needs to be cleaned up. I didn’t see any horrible damage either, nothing that stuck out to me.

I’m curious what y’all think I should check, and anyone more experienced with 4runners have to say. I’ll put some pictures as well.

metal in oil
Cams
Valve cover, what’s interesting about this is there’s a metal tab bent downward near the middle (cylinder 3) spark plug hole, kind of between cylinder 1’s spark plug (bottom hole in the pic). It was bent ALL the way down towards the cams when i took it out, not sure if it’s supposed to be like that.

tried posting a video of the sound. Can’t seem to get it to work, I’ll see what i can do. Thank you all for any input!

 

I'm not surprised it's knocking, that engine was abused badly. The varnish, the deposits on the bolts and around the cams, someone didn't change the oil and the engine paid dearly. It's safe to assume every bearing and pump had metal run through it. Taking off the exhaust cam, which is very easy to do, and looking at the journals and cam will give a good incite. The engines are resilient luckily, but you can't undo any bearing wear that already happened.

I would run some Valvoline Restore And Protect, it's an oil made to clean up sludgy varnished engines just like this. I've heard a lot of good things about it, you have to keep an eye on the filter because it can overwhelm it if there is a lot. Cleaning the engine would be a good step.

The blue felpro gaskets you have suck, replace them with the oem ones. I had some and they filled my spark plug tubes with oil, which can cause a misfire. I'd check the transmission or anything else that has fluids, bad owners treat all components equally bad.

I'd check compression, brown oil like that often means water contamination from a head gasket or cracked head. The valves have likely never been adjusted judging by the condition of the engine. If you wanted a project, you certainly got one.

 

Welcome from Wisconsin! As long as you're prepared to replace an engine why don't you? It will save you alot of time trying to diagnose this engine, you'll have a fresh engine maybe for another who knows how many thousands of miles. Good luck on your project.

 

welcome

 

A bit of an old school trick but you can usually use a stethoscope to locate where a noise is coming from. I've used this before looking at engines on our simulation test stand.



There will be plenty of other noises from the radiator fan, injectors etc. But I keep one handy when diagnosing engines in cars or on the Sim

 

I love the fact you're taking this on and trying to restore a legend - hats off to you. As others have mentioned though, if you're seeing metal in the oil, why are you proceeding to try to find if it is fixable. You're going to spend a lot of time and at the end you will need to replace it. Just replace it now. What were your plans on a replacement? Junkyard, rebuilt?