Something Broken In The Head

DomMc

Member
Oct 17, 2015
58
8
18
Frisco, Tx
Found this piece just lying in the corner when I took the cover off the top of the passenger side.
piece.jpg

Since there is a groove am guessing its part of the mechanism that holds the push rods...
am starting to wonder if this car did 'run when parked' after all...

top-location.png


Am going to take as much of the engine out today to see if I can see why it's seized.
Finding pieces hasn't boosted my confidence though.
I cant see anything that looks broken though. Thats the weird part.
 
  • Sponsors (?)


Update to the above - I got the head off both sides and things dont look good.
Two of the pistons are at the same height, which with my basic knowledge of engines, seems very wrong.

Can anyone confirm?
 
Update to the above - I got the head off both sides and things dont look good.
Two of the pistons are at the same height, which with my basic knowledge of engines, seems very wrong.

Can anyone confirm?
In most engines, 2 pistons will be at or near TDC at the same time, one will be on the intake stroke, the other on the exhaust. It's why when doing valve adjustments on a "Vee" engine, you can do one valve each on two cylinders at a time if you know what you're doing, or just do it the slower, but easier to keep track of one-at-a-time like I do.
 
Firing order has a lot to do with it. Remember, each piston hits TDC twice in one complete combustion cycle, once on the compression stroke, and once on the exhaust stroke.

If the engine's locked up and won't turn over by hand, you'll need to remove the oil pan and look at the bottom of the engine for a broken crank or bent or broken connecting rod.

XF5Z-6009-AA.jpg


Totally different engine family (Ford/Nissan 3.3 from a Quest/Villager), but notice how it's similar?

156820633_brand-new-dart-shp-434ci-small-block-chevy-short-block.jpg


Same here on a Chevy small-block. (Kind of having to go with what I can find, have filtered internet here at work so Photobucket and a few other of my usual sources are ruled out.)
 
  • Like
Reactions: 1 user
I read that removing the oil pan is possible with the engine still in the car?
But if something is broken, which I think we can assume is the case... the engine would need to be lifted out to repair, right?

So really, I should probably just plan to pull the engine regardless?
or is there a chance this can be repaired without pulling the engine...
 
I read that removing the oil pan is possible with the engine still in the car?
But if something is broken, which I think we can assume is the case... the engine would need to be lifted out to repair, right?

So really, I should probably just plan to pull the engine regardless?
or is there a chance this can be repaired without pulling the engine...
You can pull the pan and get a look inside with it in the car, but any kind of bottom-end repair is going to be nearly impossible with it in the car.
 
Great, thanks,
I've pretty much resigned myself to having to pull the engine at this stage... just hadn't budgeted for it.! - and had thought that the car would come back to life without getting this deep in to it.
But hey, where would the fun be in that, right!? ;)
 
Well......

Since you have the heads off the car now, you could get yourself a valve spring compressor and disassemble the heads? I´m sure you would benefit from changing the valve seals at very least and hopefully confirm that your heads are good at the same time. Some of the work depends on how mechanical you are, but removing/replacing valves isn´t hard and I think most people could do it the first try if instructed.
 
Looks like crumbled up valve stem seal to me. Especially from where you found it.

Personally I've never seen an engine fail with a piston just sitting there, not without a connecting rod sticking out of the side of the pan. If you do pull the pan with the engine in-car, please let us know how that goes. I've got a few dents on mine and am reluctant to pull the whole engine if I don't have to.

If you're concerned about valvetrain binding, just remove the whole shaft on both sides. 3 bolts and it's out.

By the way, have you gotten around to checking the timing gears? That is absolutely the most common source of problems in these engines. Guaranteed to fail and very possibly locking up the engine when it does.
 
I've pulled both valve trains and they seemed fine... not locked up or anything.
And there was a semblance of oil around so that's probably a good sign.

timing-gear.jpg

Got the timing cover off on Friday and again, things seem ok in there.
I pulled the bolt from the top gear, and was able to jiggle the gear back and forth a small amount.
Seems like its the crank thats locking things up.

When you say fail? I guess you mean the teeth break and lock up the gears or something? All looked ok from what I can see.
 
Cool, that looks pretty aok to me. It also looks like it already got the aftermarket steel cam gear. The originals were plastic believe-it-or-not, and they'd frequently crumble and jam up the gears.

Brighter side you've got this thing most of the way apart for a rebuild. I agree that next up will be pulling the pan to see what you have going on down there. Before you do, with the heads off, you could try whacking each piston head with a soft mallet to see if you can get the problem child to free up. It's gotta move one way or another!
 
  • Like
Reactions: 1 user
If the motor is "locked up" I would plan on removing it to be gone through. It's likely that it won't last long or be in great running condition even after free'd up
 
If the motor is "locked up" I would plan on removing it to be gone through. It's likely that it won't last long or be in great running condition even after free'd up
I'd ordinarily agree with you, except that I have the same engine (2.8 v6) in my II, and it was locked up when I got it. Some persuasion with an impact wrench after some WD-40 soaking and it's been running like a top for two years. Something about those engines liking to seize while sitting, but they're pretty bullet-proof otherwise. If of course the Op doesn't have some mechanical damage, in my case it was just a bit of corrosion keeping things from moving.
 
I'd ordinarily agree with you, except that I have the same engine (2.8 v6) in my II, and it was locked up when I got it. Some persuasion with an impact wrench after some WD-40 soaking and it's been running like a top for two years. Something about those engines liking to seize while sitting, but they're pretty bullet-proof otherwise. If of course the Op doesn't have some mechanical damage, in my case it was just a bit of corrosion keeping things from moving.

What can happen, and could be happening here (and was likely what happened in your case) is a bit of light rust keeping the rings from moving in the bores, which keeps the piston from moving and so on. It happens at times when an engine is left sitting for long periods of time in a high humidity environment. In that case, the cure would be an oil change, and to soak all six bores in some form of penetrating oil (the aforementioned WD40 works well) for a day or so, allowing the oil to seep down into the rings, penetrate the surface of the metals involved, and loosen things up. After that, and attempt can be made at turning the engine over by hand. This is all IF pulling the oil pan doesn't reveal carnage, I'd still recommend that as a first step for a locked up engine simply to make sure you're not going to damage anything further if there is existing damage.
 
Any tips on pulling the engine?
I got a universal lift plate from autozone but it doesn't even remotely fit.
Can drill it out to match the carb bolts but was hoping you guys could provide some wisdom!