Repair-It

Current score - 6/8 manifold-to-head bolts removed. I have had to weld on and break off more washers and nuts then I think on any other project to date. Access is really bad so it's hard to get a "good" weld. I bought CRC freeze-off from Autozone, hoping that would help. I don't know if it has or not, but I got two of the 4 most stubborn ones out this morning since I bought it and tried it...

Got all of the remaining bolts out last night and finished installing the new manifold this morning. Still has a nasty wrap or knock but no exhaust leak noise. I’ll have to do something to improve my troubleshooting. Smoke and earlier failed emissions tests indicated a failing injector. A real hole in the exhaust manifold indicated failed manifold. Now that those are corrected I wonder how to troubleshoot knock. Pull valve covers and look at rockers first? That requires removing injector lines, temporarily reinstalling…

Oil pressure is still 80 psi on startup. I wonder if I should let it warm up fully to see if it improves

Seems quieter after running it. Only evident when at low load/part throttle. Goes away under heavy acceleration. Still have 45psi oil pressure at idle. No sign of blow by. My guesses are valve train noise or a noisy new injector. If it’s an injector it might go away. Or a lifter stuck after sitting for 2 months might also clear up. But I seem to never ever be that lucky.

Apparently there’s a very common “typewriter” tick that there are even tsb’s about it.

Well ticking isn't knocking.

It is most evident below 1500 rpm and blower max or radio can almost mask it.

Based on what you have described it seems safe to run it and just monitor.

Yeah - I think. I have been worried about partially kinked fuel hoses resulting in low rail pressure since I put on custom stainless lines with slightly incorrect hose crimp orientation in the two rubber sections. I should cut those off and reorient, just in case the suction pressure is hurting injector performance. I could also ask the injection shop I bought the injectors from to listen to it to get their opinion. But I’d want to fix the suction line before I brought it there anyhow.

Realigned the fuel hoses so there are way fewer kinks. Pumping the priming pump by hand while idling seems like it might be changing the noise slightly? I wonder if I have either a lazy injector (they were Bosch authorized remans) or a weak/marginal cp3 high pressure pump. I would’ve thought a marginal cp3 would set a fuel pressure response related code. There was some check engine light code when I first started after injectors, but it went away after 2 or 3 drive cycles.