1997 Acura RL sprockets

Sure, but to be safe, turn the crankshaft away from top dead center to insure no pistons are all the way up. Even if you leave it at top dead center, you aren't likely to bend any valves when you turn anything by hand unless you really get on it. If you feel the cam suddenly get hard to turn, don't force it. Move it back a little, then turn the crank. Set the camshaft, then bring the crank back to TDC.

Hopefully the head wasn't warped. Overhead cam cylinder heads can't be machined for warpage. Doing so leaves the camshaft journals out-of-line. In severe cases that can lead to the camshaft breaking.

What don't you have completed yet? I never trust myself until I see the engine run, and since I hate taking things apart a second time to fix my mistakes, I usually start the engine before I put the covers on. That way I can verify the cam timing is right and any tensioning devices are working and adjusted properly.

Timing belt covers and engine mounts aren't needed to run the engine. Be sure all the sensors are connected though. If one is not, that will immediately set a diagnostic fault code when you turn on the ignition switch. If you have a running problem later, you'll want to read those codes to know which circuit or system to diagnose. Codes set previously will confuse the issue.

There are core plugs in the engine block, and sometimes in the head but those are smaller. They are called core plugs because those holes are used to knock out the sand after they make the casting, also called a core, but many people call them freeze plugs because if the coolant is too much water and it freezes, those plugs may get pushed out by the ice. That might save the block from cracking.

I doubt you have a cracked block since you didn't have this problem before. There's usually one or two plugs on the back of the engine block that are not visible when the transmission is bolted up to it. It is somewhat common for them to corrode and leak. The coolant will run out in front of the bottom of the transmission. Replacing those requires removing the transmission but you didn't cause that by removing the cylinder heads.

You might be able to find a sensor or access cover that you can remove so you can look down in there to see where the leak is. If you don't see any water at the back of that cylinder head, those rear core plugs become a good suspect.

I can't remember what your engine looks like, but if it's anything like the Mitsubishi 3.0L V-6 in my Grand Caravan, there's a metal pipe running under the intake plenum from the back of the water pump housing, and it exits above the transmission where the lower radiator hose attaches to it. If you have that same design, there's an o-ring on the water pump end of that pipe that could deteriorate, and that tube could have a hole in it. Water leaking from either of those places will run to the back of the engine and down in front of the transmission. Typically that tube can be removed rather easily without taking anything else apart.

The right way to do this is to remove the transmission or the engine, but if it was mine, I would probably try removing the bolts, then prying them apart enough to get in there and at least see for sure what the cause of the leaking is. You'd have to support both the engine and transmission on blocks or with jacks, and I don't know if the engine mounts will give you enough movement to do that.

You'd probably need a gap of at least two inches to get tools in there. If a core plug is just corroded, you have to hit it on one side to turn it sideways so it can be grabbed and pulled out. The new plug needs to be tapped in to a fairly specific depth, and that might be hard to accomplish. There are rubber core plugs made for fast repairs and for inaccessible places. You simply push those in, then tighten a nut or wing nut to expand them.

If the old plug is corroded badly enough, you may be able to run a pry bar through it and pry it out that way. If you attempt this, you have to remove the bolts holding the flex plate to the torque converter, then be sure the torque converter doesn't slide out of the transmission. If it does, getting it back in can be a lesson in frustration. It's a real good idea too to wedge a couple of small blocks of wood under the converter between it and the housing to hold it up. The rubber seal in the front pump of the transmission often gets hardened from age and heat. Allowing the torque converter to droop lets it rest on that seal and can crack it. Then you WILL be removing the transmission.

Every block I recall looking at had those plugs on the back. They need that access to be sure they got all the casting sand out. It was real common for the left one to corrode on Chrysler's small block V-8s in the '70s. That happened on the 340 in my '72 Challenger. I ran it like that for three or four years with the radiator cap loose so no pressure would build up in the cooling system and push the coolant out. The leak was actually plugged by the sand that always accumulated there.

Had all of the plugs replaced when my students rebuilt the engine. Now if I could just get the body finished in my friend's body shop, I can put the car back together and go out and pass people when necessary!

I can't say for sure either way, but I've never seen a block yet without them. There needs to be a way to get the casting sand out. The exception, I suppose, would be for a "wet sleeve" block where they slide the cylinders in after the rest of the block has been machined. Those engines aren't real common.

The definitive answer should come from those auto parts store guys. They have books that list the number and sizes of core plugs for every engine. If they say there aren't any, I guess there aren't any. Then I'd be looking for something related to the new head gaskets. If there are dowel pins that set the position of the heads, one of those could be sticking up too far. The new gasket could have been scratched if a corner of the cylinder head dropped onto it or was slid along it. Even a little piece of old gasket that got overlooked, including right around those dowel pins, could prevent the head from sitting all the way down on the gasket.