Installed new hybrid battery 2010 prius and now the engine knocks. Need Help!

how many miles on her?

what is the history beforethe battery went out?

have you cleaned the egr circuit?

 

pleasure

 

Unfortunately I have no answer.
But I'm curious as to what you may discover.
Could it be just a coincidence? If you were working directly with the battery, and it is in, and conceivably working fine, then "how" the engine is working should be, I would think, a totally separate thing.

This "knock" is ONLY on start up? It's smooths out as it runs? -So far no codes or warning lights?
There have been posts of Gen 3 Prius knocking on start up. Usually it's an intermittent problem. You could look up some of the threads as their are various opinions and suggestions about this problem.

But I'm not sure we are talking about the same problem. If it's the "intermittent" knocking problem, it should go away for a while. If your vehicle is knocking badly on every single start up?

Well I'll finish as I started, Unfortunately I have no answer.
Let us know what the problem turned out to be, once you track it down. And good luck.

 

Dutch uncle time:

The questions were asked:

And you responded:

You've got 3 threads going, on the same car, same problems. Slow down, read and answer the questions. FWIW, the knocking symptom almost invariably is tied to clogging of the (aforementioned by @bisco) EGR circuit. (Exhaust Gas Recirculation).

Boilerplate info:

The simplest way to see where you're at, is to check the degree of carbon build up in the EGR pipe, a stainless steel connecting pipe between the EGR valve and intake manifold. Watch @NutzAboutBolts video #16 here:

Nutz About Bolts Prius Maintenance Videos | PriusChat

Two or three other videos linked there too, for the full cleaning of the intake manifold, full EGR clean, and Oil Catch Can install.

Good thread:

EGR & Intake Manifold Clean Results | PriusChat

Another:

Oil Catch Can, Eliminate that knock! | PriusChat

Some tools worth having:

E8 Torx socket (mandatory)
E6 Torx socket (optional, but good to have, to remove the throttle body studs from intake manifold)
3/8" ratchet wrench, regular and long handle, flex head, you can never have enough (or 1/2 plus reducer)
1/4" ratchet wrench, or 3/8" to 1/4" reducer
Ratchet extensions: you can never have enough
Long needle nose piers, straight and bent tip
Ratcheting 12mm box wrench (optional, but makes disconnection of the EGR cooler from exhaust easier)
Torque wrench (3/8" and 1/4" both good to have)
Floor jack and safety stands (or ramps): basically some method to raise front, if you need to take underpanel off, which you may need to, both for access and to recover dropped items.

 

crickets...