Valve noise

[Billy's]

I have a 04 tacoma3.4 and have developed a noise on drivers side I used a stethoscope against manifold I think it sounds like metal to metal but when I listen to the rest of the engine sounds smooth engine doesn't miss no check engine light same fuel mileage nothing has changed would be grateful for any help or ideas

 

[tbplus10]

I can honestly say Ive never heard of valve issues in the 3.4.
I have had one with a bad cam bearing.
A recomendation would be change the oil, cut open the filter to look for shavings and strain the oil with a magnet, look for metal shavings. If you dont find any add new oil and a little Marvel Mystery oil to the crank case.

 

[Billy's]

We'll thanks I've only got 157000 miles on it and I've taken care of it I will change oil and try that I have noticed that it seems to be intermittent but when I do hear it it seems to be coming from the manifold the most

 

[tbplus10]

Are we talking intake manifold or exhaust manifold?
If its exhaust check for hot air leaks around the mating surface, leaking exhaust gaskets can sometimes sound like metal on metal tapping or scraping.
If this is the case all you need to do is change exhaust manifold gaskets.
Check the donuts between manifold and pipes while your at it, not real common to leak on Tacoma trucks but it does happen.

 

[Billy's]

Yes it is exhaust manifold I've looked for evidence of a leak but have not checked by fill u said the doughnut gaskets don't normally leak but does the manifold

 

[tbplus10]

Yea the donuts at the bottom of the manifold can leak, in fact that happens more than the gaskeys right at the heads.

 

[toyotafan]

Wait, I missed something. What lead you to put the stethascope on it in the first place? What type of issues are you having overall, you're hearing noise all the time?

 

[toyotafan]

Did you get it fixed any better?