wow guys im in deep truck had blown head gasket on cylinder 5.i shaved had the heads put new gaskets . timing marks lined up coils firing plugs to. cylinders are full of gas truck ran good even with blown head gasket.sounds like popcorn in the breather ?????????????

 

if you hear a tapping sound like a marble is in the engine while it is running then that is generally knock. In your case it would be pre-ignition most likely.

Most likely cause is the wrong timing although it should effect the whole engine and not one side. If you are too rich that could do it too. Sounds like something was not put back together right, I would retrace your steps.

 

I had a similar situation. I rebuilt my engine and after 2.5 years of running perfect I tried to start it one morning and it wouldn't start. After 3 days of working on it i found that my timing tensioner just flat failed. I found I had no compression in 1,3,5 cylinders. The other 3 had decent compression. What had happened is whaen the tensioner failed it allowed just enough slack in the belt for the passenger cam to jump out of time. With a new tensioner it was back in running order. I had never heard of the tensioners ever failing on these 3.4 v6 engines so it was something I didn't even think about until I found the issue. I thought I would post this to maybe be of some help to someone in the future. Good thing is that these engines are Non-interference so you can just line up the cams again and put it back together, as long as your timing belt and other components are ok.

 

That makes sense^ That is where I would start, retrace your steps and make sure everything was put together properly.

 

i hooked it to a snapon modis and it has large numbers for misfire on cylinder 1 at so many rpms says missin on 2 an 6 to and new coils an knock sensor wire on the way.

 

how to align the cams on rh - lh of a toyota 3.4 5vzfe