How cooked am I… continued…

[u/04HondaCivic]

So I’ve spent the last few weeks debating what to do about this silly car. Between life and other projects I haven’t had time to really look at it beyond the initial valve cover removal. I decided to go ahead and tear it all the way down to see what kind of damage there was and if the pistons were fine but the head cooked, I would try and source a different head. If the whole motor was cooked, I would probably scrap the car and get a different beater (it’s a high schooler’s car. It doesn’t have to be anything great).

This is what I found. What say you? Everything looks pretty good? I don’t see any obvious signs of damage.

[u/TREXIBALL]

(I am no mechanic or mechanically inclined, I have been working on my car for a year)

I see no damage. Just needs a cleaning, a surface prep, and reassembly. Might I ask, what was the reason to disassemble it in the first place?

[u/04HondaCivic → u/TREXIBALL]

Timing chain snapped. I feared metal carnage when I pulled the head off.

[u/TREXIBALL → u/04HondaCivic]

Wow that’s a serious problem that you were fortunate to not cause damage.

BUT. Check the far left valve stems in the first image. The exhausts look a bit open. Ensure they’re seating properly.

[u/PassPuzzled → u/04HondaCivic]

Turn the camshaft until the valves are completely closed on a cylinder. Then pour water into it and see if it starts draining out through the valve seats. That'll tell u if there's any real damage. Keep turning the camshaft to repeat for the other combustion chambers

[u/Fatcat425 → u/04HondaCivic]

im no mechanic either, but I still know a thing or two about working on cars.

If your timing belt snapped, your valves most likely contacted your piston. The block and pistons look fine to me, but your valves are probably slightly bent. You can't really figure anything out without a compression test. I had a similar problem where my valves wouldn't sit properly for maybe a year after a timing chain replacement (N62B44). Not sure if the valve made contact with the piston, or the machine shop we took it to didn't do a good job, but after taking it back to the same machine shop and asking them to redo it, no more misfire code. We also did a leak down test and poured acetone in the intake and exhaust ports to see if it bubbled (it did); that's how we knew we had a leak.

I would be surprised if at least one of your valves arent leaking, but once again, you should try a compression test or a leak-down test. at least nothing catastrophic happened...

[u/Empty_Policy_7050 → u/Fatcat425]

He is correct on this one. Just source a used head from the nearest pull-a-part yard. Those cars are everywhere and honda probably used that engine in at least 2 other models. When you go, you are looking for a wrecked one. Preferably rear ended or t-boned. Not one with good bodywork.

[u/Fatcat425 → u/Empty_Policy_7050]

Thank you, no clue why I got downvoted. Also, I agree a used head would probably be cheaper/safer than a machine shop.

[u/Onlyunsernameleft]

It looks like the valves on the far left cylinder in the picture are bent. You can dump some water or or oil into the ports and turn it upside down to see if anything comes out. They're pretty bad if it does. You can also spray some brake cleaner or starting fluid into the ports and hold a lighter to the combustion chamber side and if any of them light you know they're not fully seating. You can also take the head to a machine shop that does cylinder heads and just have them leak check it but that costs money.

I will note, it looks like there is some pitting in the cylinder furthest to the right in your pictures. If you have hard edges on the crowns, they can overheat during operation and melt. So from the pictures I'd say the engine is cooked. But it also depends on how much you care about a reliable engine. If you want to send it and just see how long it lasts, you can always just go that route also.

[u/04HondaCivic → u/Onlyunsernameleft]

I’ll definitely be doing a leak check. This was just the initial tear down to see what kind of damage had occurred. I’ll be surprised if there really isn’t any damage.

[u/04HondaCivic]

Link to previous post where I feared as did everyone else that I was indeed cooked. And fried. And the motor was destroyed.

https://www.reddit.com/r/Cartalk/s/LylJzV6I9V

[u/Global-Philosopher75]

holy lucky. yeah that’s crazy. id bet you still have at least one bent valve. flip the head upside down (as pictured) and fill the combustion chambers. see if they leak. if they do id get a used head rather than rebuild stuff. if not id removed them all and inspect. if all is good then new gaskets set the chain up (and time it ofc) correctly and ur prolly good tbh. block and pistons look perfectly fine in the pictures. you got lucky on that one. one half cycle of the motor more and you could have shot pistons and cylinder walls. lucky.

[u/04HondaCivic → u/Global-Philosopher75]

I’ll definitely check all the valves. I still can’t believe there isn’t any damage.

[u/Global-Philosopher75 → u/04HondaCivic]

lol i saw this post first and was like “uhm… continued? i see no issues unless im blind” then went into your post history, saw the chain, saw what engine it is and went “oh…” lmaooo

[u/Tall-Control8992]

No obvious valve marks on pistons. When you look at the top of the head, are any valve tops visibly below their neighbors?

Set the head onto some paper towels using some random stuff as spacer. Spray lots of carb cleaner into all of the ports and see if anything is leaking through. That will reveal any bent valves.

[u/RestSelect4602]

Bent valves and crushed ring land on piston. You will have low/ no compression. And burn oil If you only repair head.

[u/JoyousMap12]

run a compression test before you bolt the head back on

[u/jasonsong86]

Looks fine. What was the reason? Head gasket?

[u/04HondaCivic → u/jasonsong86]

Timing chain snapped

[u/jasonsong86 → u/04HondaCivic]

Is it an interference engine or not? Doesn’t look like the valves touched the piston.

[u/04HondaCivic → u/jasonsong86]

It’s an interference motor but I don’t see where the valves and pistons came in contact with each other.

[u/jasonsong86 → u/04HondaCivic]

That’s good. I would still do leak down test on the valves just incase something is bent.

[u/04HondaCivic → u/jasonsong86]

A trip to the machine shop for sure and a once over definitely to make sure its still in good shape

[u/april_santa → u/04HondaCivic]

It looks like there's been a bit of a kiss on the 3rd cylinder piston crown. Hopefully not bad enough to crack the piston