Rocker arms from the intake valves on cylinder 1.

 

Rocker arms on the 4 cylinder engine can fall out if the valves are bent. I would check compression before going any farther.

 

If one of the rockers are damaged just put the good one back in if you can. If it is loose and won’t stay in just leave it out but you need to check to see if it is junk.

 

Whoa!! If # 1 piston isn't moving and the other 3 are, then there is definitely an internal problem. Can you tell if the piston is stuck near the top of the cylinder or middle or low? Sounds like POSSIBLY the rod cap came loose from the crankshaft and once it rotated and pushed the piston into the cylinder, that it stuck there on the down stroke. Sounds like it MIGHT be time for another engine or a rebuild of that one. Further investigation is needed. If it was mine, I'd drop the oil pan and see what's inside there.

 

Thank you for the clarification, Andy.

(I'll delete that mess shortly)

If the #1 piston is not moving, with the crank/at all, it'll by definition have zero compression since the valves have opened since the "event" and you aren't building any with no movement.
Seems like you'd need to do something akin to a leakdown test on #1 by putting compressed air into cyl 1 through spark plug hole and rotating the engine to TDC #1 at top of the compression stroke, all valves closed.
You can use the timing marks on the crank and hopefully the cam sprockets (should be far enough exposed) to verify TDC. I believe this would also correspond to #4 being at the top, about to begin its intake stroke, so you can find indirectly.
Watching the valves open and close will also help you confirm where # 1 would be at top of the compression stroke (TDC).

Anyway, once at TDC (by def #1) all valves should be closed for the power stroke. So if you get the engine internals positioned as such, and you do the equivalent of a leakdown test w compr air into the plug hole,
------if you hear any air hissing through the intake manifold /air intake route, your intake valves are damaged.
------If you hear hissing through the exhaust system, the exhaust system, the exhaust valves are an issue.
------ if you pull the oil dipstick or filler cap and hear hissing, the piston rings are an issue, though this might happen anyway since the piston is not necessarily centered in the bore and parallel to the direction of travel. especially since we don't know where it is in its travel. If you're lucky it is sitting at the bottom. If it is hung up somewhere in its travel, the rings might be damaged enough to wedge everything in place, possibly some cylinder damage from that.

------------

You already know the engine has been damaged badly enough for 1 cyl to break loose -- and possibly hit the intake valves in the process.
Whether or not you turn out to have valve issues, to me it then becomes an issue of whether you believe the remainder of the engine internals, particularly the bottom end will hold up for a significant amount of time to justify the cost to fix it, given their exposure to the same insufficient lubrication.

Oh -- and there's theoil leak to track down that led to all of this...
If you do your own work, that sways the decision somewhat -- but in the end, it's your call

food for thought

 

As usual, Rube and I type simultaneously, but my responses are overly verbose and partially inaccurate so his posts hit the board ahead of mine......at least we seem to independently agree in theory....Rube knows internals, Andy knows internals. I try to learn as much as I can from them. My guess was implausible enough for them to give it the polite "that's f'ing wrong" silence which is fine. I'll delete.

 

This is great!

Thank you for the detailed information. I am doing my own work, and only have limited experience, and you guys have been a great resource.

I know what I need to do to figure out what kind of damage I'm really looking at. Or at least I have some starting points.

Thanks again. I will update when I can.

 

I missed your post about the number 1 piston not moving. My advise is to start your repairs by locating another engine. Your engine is damaged beyond repair if a rod has come off the crank. I have had two of these engines fail in this way when run out of oil. I purchased these cars as either projects or parts based on how nice the cars are. My current driver had tossed a rod and I replaced the engine and have been driving it now for two years. I purchased a rolled L200 for $100 and used that engine in my car.
Car-part.com is a site that lists wrecking yard inventory by zip codes, it is very handy and will give you an idea what an engine for your car costs and what else they are used in. You may find that the base engine will fit many cars and you can use your manifolds and mounts.
Look and see what is out there near you and decide how much you want to spend on this car. I can advise you once you decide if you have questions.
Andy

 

Looks like your engine is popular in the Chevy Malibu model, also it is in some Pontiac G6 and some Saturn Aura as well as your Vue. Since there are a lot of Malibus out there the engines are reasonable in price.

 

Broke

Really broke
I dropped the oil pan to see what's up. I guess it's what was expected, but it was interesting for me to see it in person.

This is what I'm thinking, hopefully you can tell me where I'm crazy.

First, I need to source an engine. But I'm wondering if I could just do the engine block, and reuse the head. Assuming the head is ok. My guess is the rocker arms came lose due to the impact of the piston.

I was already planning to do a head gasket job, and I might as well check all the valves.

But will that really save me any money, and in the long run, is it just better to do the whole engine?

My experience is limited, but I'm not shy. I recently did a head gasket and valve job on a 2000 Volvo V70.

Not afraid of work, and budget is limited.