Engine shakes after replacing head gasket but no consistent codes

Hi All,

Replaced a head gasket on a gen 3 with 240k miles on it. Before reassembly I checked the head and block per the Toyota manual and they've better than required tolerance. Completely cleaned out the EGR system and intake with a combination of purple power and a 0 degree pressure washer. I did release the timing chain tensioner and visually verified that the hook was released and the tensioner arm was engaged.

Engine shakes on start up but at higher RPM (not driving it, just pressing the gas) shake goes away at about 1500 RPM and above. Shake does not go away if left running at lower RPM.

Code reader initially reported a misfire on cylinder 1, started testing that by swapping plugs/coils/injectors, code went away but the shake didn't. I think the initial misfire on cylinder 1 was related to the initial start with a drained fuel system, but am not sure. It's hard to troubleshoot without codes.

I need a sanity check please.
If the timing was off, there should be misfire codes or at least some code being thrown. Is that correct?
If it were you, what would your next step be? I was thinking of getting techstream operational and trying to pull codes with that rather than my little handheld reader. Is that a reasonable thing to do or is there something else I should try first?

Thanks

 

Thank you for the reply.

Sorry, I left out some information. This engine was running fine prior to being reassembled. Very slight shudder on start up that went away in a few seconds, classic early head gasket failure symptoms. No coolant in oil that I could identify. Unless the piston got bent during the reassembly process, which I don't think it did, I don't think it's a piston or I would think it would have been running poorly before the head job as well. That's what's so puzzling about this to me. I took an engine that was running well, replaced the head gasket, and now it's running horribly. I clearly did something wrong, but without codes it's hard to tell what. I find it especially puzzling that it runs fine at higher rpms but shudders violently at lower rpms.