Learn me: Valve Replacement (alternate title: cheap hybrid, how bad can it be?)

So, I picked up a cheap Civic hybrid after reading an article about grid chargers restoring an IMA battery to working order.

It was way down on power, which I attributed to the IMA light being on. I went ahead and grid charged the battery:

After a test drive didn't show much improvement, I stopped and had the codes read, it was reporting a cylinder 3 missfire. No problem, we'll change the plugs and it'll be good as new, right?

Not. Good.

For the next step I crossed my fingers, went ahead and changed the plugs. Unfortunately that also didn't make any improvement. Finally, a compression test confirmed the worst, something was damaged in #3. So I parked it, as I still had the neon to drive. Lost my job, got a new one, took a few IT classes, and in between I'd wrench on it for an hour here and there. Which finally lead to a diagnosis of the problem:

So yeah, not sure if the valve failed and the chunk took out the spark plug, or the spark plug failed and took out the valve. Either way, it appears that the only significant damage was to the plug and the valve. The head and piston face have some minor pitting, but nothing significant.

Which leads me to, what are my options as far as repair goes? Once I remove the valve, if the seat looks OK, can I simply install another valve? Do I need to lap it or something? Haven't had to do anything like this, so advice would be appreciated. Thanks for looking!

MCarp22 wrote: Which leads me to, what are my options as far as repair goes? Once I remove the valve, if the seat looks OK, can I simply install another valve? Do I need to lap it or something?

If the seat is not nicked up you can just replace the valve. You will need to lap in the new valve. Just some vale lapping compound and one of those suction cup on a stick tools will do just fine.

If the seat shows no damage you can probably get away without lapping it, though lapping is pretty easy, just gotta clean up the compound well when done.

Make sure it has actual valve seats though, I know some newer Toyota engines have really thin ones put on with a laser or something nutty like that, you have cut the head for regular seats if rebuilding the head.

Not hijacking but is that hail damage on the hood?

Jerry From LA wrote: Not hijacking but is that hail damage on the hood?

Nah, dimpled like a golf ball - for aerodynamics.

Were it me, I'd hand the head over to my machinist and have a valve job done. It's an 8-valve head and you could save money by doing some of the disassembly / assembly work.

A valve broke first? On a Honda? Riiiiiight....

Cheapo spark plugs man.

I agree with Jerry. The head is off already. Just have a machine ship check everything out and do a valve job. Small amount of insurance to get the job done right.

Kenny_McCormic wrote: Make sure it has actual valve seats though, I know some newer Toyota engines have really thin ones put on with a laser or something nutty like that, you have cut the head for regular seats if rebuilding the head.

I think this engine is old-school enough to still have regular valve seats.

Jerry From LA wrote: Not hijacking but is that hail damage on the hood?

And the roof, and the trunk. I said it was cheap!

Trackmouse wrote: A valve broke first? On a Honda? Riiiiiight.... Cheapo spark plugs man.

NGK Iridiums are considered "cheapo" now?

jimbob_racing wrote: I agree with Jerry. The head is off already. Just have a machine ship check everything out and do a valve job. Small amount of insurance to get the job done right.

First of all, someone agrees with me. The apocalypse is upon us. Valve job, check the guide clearance, new valve seals, button it up, forget about the head for the rest of your life.

Jerry From LA wrote:

jimbob_racing wrote: I agree with Jerry. The head is off already. Just have a machine ship check everything out and do a valve job. Small amount of insurance to get the job done right.

First of all, someone agrees with me. The apocalypse is upon us. Valve job, check the guide clearance, new valve seals, button it up, forget about the head for the rest of your life.

Two people agree with you, so that must mean a meteorite is coming to wipe out the planet.. Had a similar issue where a friend asked me to reinstall a head her son "swore" was good, even missing a chunk from one of the exhaust valves like yours. Begged them both to send the head to a machine shop to have it checked out and serviced. Well, turns out the head was good, AFTER it was rebuilt by the machine shop and I installed it the second time. Lesson learned for them, more cash in my pocket (and one of the reasons i'm going to quit working on friend's cars)

Just dealt with this on SWMBO S10. Head looked great, just carboned up, figured it was just shy of 200k it was already off, cylinders all look good, lets go ahead and have the head gone through. Low and behold my mystery coolant leak was found. (been chasing it loosing coolant for 3 years) one of the water jackets was eroded and leaking. I blame it being a dexcool vehicle. Dunno, but I'm sure as hell glad I had it tested, etc. I would have been pissed had I put it all back together and it still leaked coolant. Quote for the machine shop to do it all was less than 200$, when they called about it being bad and asked if I wanted a price on a replacement. I told them I had priced them on Rock auto and that they were X amount, they called me back and got within 20$ of Rock auto and they handle all the shipping crap. Guess what I did?

What's the theme here? Is it: I want this fixed right and it to last as long as Honduh motors are supposed to last? Machine shop or new head. Is it: I want this thing running as cheap as possible so I can get groceries somewhat reliably? Get a valve, some lapping compound and slap it back together.

A brand new head for my 22R, loaded with everything except the rockers and cam, was cheaper than having the old one with 3 bent valves fixed.

I'm with Hess.

I had a core drop out of my Toyota 4x4 a long time ago. It pock-marked the heck out of the piston and cylinder head and eventually broke the #1 compression ring (I didn't have to replace the valve though). If the seat is good, then I see no reason why you shouldn't have to change one valve. In my experience you'll need to lap the valve, but you might as well lap all the valves while you're in there.

Never done it before? Neither did I. This video helped a lot: https://www.youtube.com/watch?v=7GEmuQa3dPY

my thread (valve issues are towards the beginning) http://grassrootsmotorsports.com/forum/build-projects-and-project-cars/my-old-truck-1987-toyota-4x4/101411/page1/

good luck!

In reply to Dr. Hess:

I don't know if I agree with that, is the machine shop going to use Honda OEM quality valves and guides installed to Honda OEM tolerances? On a "new" head, are we talking about a new Honda head, or some lowest bidder rebuild job? The head we have is presumably a factory Honda head that lasted this long without trouble aside from something that was likely no fault of it's own.

Unless it needs seat work, the guides are loose, or other valves have trouble, I think the best option is to just plop a valve in it, lap it, maybe change the valve seals out and put it back together. Should last "last as long as Honduh motors are supposed to last".

Upon further inspection, it looks like the block is dead too. The cylinder wall has a few gouges deep enough to catch a fingernail. For some reason these engines are really cheap, so I'm just going to go ahead and swap the motor.

MCarp22 wrote: Upon further inspection, it looks like the block is dead too. The cylinder wall has a few gouges deep enough to catch a fingernail. For some reason these engines are really cheap, so I'm just going to go ahead and swap the motor.

currently going through this as well..... Skippy

It's going to cost me close to $1300....

Update (5 months later!):

After all this discussion, I decided "berkeley it" and put it all back together with a new valve. Apparently things weren't as bad as I thought, as it ran so well that I decided to get a new hybrid pack, upstream cat, and tires. 6000 miles later, and I've averaged 41.5mpg!