Stock d16y8, 1999 Honda Civic ex/Si

Hey everyone, so I was on the highway headed home yesterday when all of a sudden I lost power, and the car started running rough. I pulled over, pulled the codes and got this

looked around, couldn’t see anything out of the ordinary so I lugged it home. This morning I went out and pulled the plugs and got this


far left spark plug(cylinder 4) was covered in oil on the threads and electrode. Figured that was strange so I went compression tested. Ended up with right around 150-165 but cylinder 4 wasn’t building compression and sounded quite different than the rest (see attached Video). I’ve read on here it could be chipped valve all the way too a bad head gasket. Would love some input and help as this is my daily and lost as to where to go from here. Thank you. (Car can still turn over and drive)

 

Leakdown test or sticking a bore scope down cylinder 4 would be my next step.

 

what would the leak down test do without any compression? And I tried a borescope that I have at home and it’s not wide enough of a lense to see the edges. Just looks like oil covering the head

 

Leak down test can help you pinpoint the leak. As you continually pump in air and the air loss goes through the leak location (exhaust means exhaust valve not sealing, intake means intake valve not sealing, bubbles in radiator means head gasket is not sealing). And the gauges of the leak down will show just how bad the leak is. And if it's coming out the oil dipstick tube then the rings/cylinder is what is leaking.

Leak down test is done with tested cylinder at TDC so all valves should be closed etc. Then you listen.

 

okay I think I understand now. I’ve got the tester coming from Amazon, should be here Friday. Anything else I could check while I’m waiting on it?

 

Burned exhaust valve is the most likely issue.

Did it sound like a Subaru?

 

sounded like a motorcycle 😂

 

Good luck man. Magic 8-Ball outlook says: Not Good

 

worst case, I have to pull the y7/y8 mini-me from my 97. Really don’t wanna do that though.
what’s the worst case if it burnt a valve and chipped?

 

So went ahead and cranked cylinder 4 to BDC and was able to get a photo of the piston with my boroscope. Still can’t work out a photo of the valves with the sh**y little mirror though.

 

so to tell where air is leaking from would I need to remove the intake and exaust, or is there some other sign I’ll need to look for?

 

Put your ear near the exhaust tip. You will hear it. Or air box, or oil fill cap.

 

so, finished up and did the compression leak down test. Only place I could hear air coming from was the third cylinder spark plug hole… would that mean it’s a head gasket. Doesn’t make a lot of sense though cause the compression and everything in cylinder 3 was the same as the rest (give or take a few psi).

 

Pull the head and you will have your answers.

 

figured I was going to have to. Is there a way to check rings without pulling the pistons? Like the cap and such. Thank you

 

if it was running fine before it pooped the bed, then chances are very good the rings are ok. It could be a number of things, but without taking the head off, you are making almost educated guesses.
I dont even bother having the heads serviced anymore. Its cheaper and quicker to just order one on line.
Good luck

 

where’s the best place to order a new head?

 

Using the valve lash trick, when #4 is TDC you do all of #4 and intake of #3 and exhaust of #2 if I recall correctly. So if for some reason your intake valves are not sealing in #4 (like it moved out of TDC when doing the test) it can pressurize the intake and come back out #3.

You have to lock it in TDC position each test or the piston tends to move which in turn moves the cam and valves.

 

UPDATE:

so, finally got it all apart (had some issues with snowstorms and finding decent enough weather) and it’s as everyone suspected. Burnt/chipped exaust valve


this is my first time going this deep into an engine so any help on where to go from here is greatly appreciated. Would love to keep this head and fix it up. ANY help is greatly appreciated. If there’s any more photos you guys need to get a better idea just let me know.

 

Toss in a new valve and go again. This time keep the valves adjusted.

 

Okay, so I should be able to just replace the one valve, so long as I clean the rest, and Lapp the new one into place?

as for keeping the valves adjusted I presume your referring to the valve lash which I did do about 2000km ago when I did the timing belt. Maybe I did it wrong though. I’ll have another look at them.

Also, would you recommend anything else while it’s apart such as replacing the valve guide seals etc…?

 

Take the head to a machine shop and have them straighten/flatten the head. when you put it back together use quality parts. DO NOT reuse your timing belt.
also I have always used Cylinder Head International when I need a rebuilt one. For $300 its complete and tested. something to think about

 

on average how much more would it cost for the shop to just install and inspect my old valves for me? Ask because I’m still searching for a decent shop around (seems I’ll have to go hours drive to get a good job done)

that place sounds convenient but they don’t ship to Canada(from small town Saskatchewan)

would love to try do the valves first but really just want my car back XD

 

Unless you were leaking oil/coolant from the head it's most likely still straight. Use a straight edge ruler if you want to try visually confirming, otherwise I agree with Ryan, you should be able to get away with just installing a new valve, cleaning the rest, and reassembling.

I'd recommend using lapping compound and a hand tool and just lightly lap the valve seat. Don't overdo it.

 

I mean I was leaking small bits of oil before but not sure exactly where from(been on the to-do list) but I was going to follow this guys video seems thorough and easy to understand. Would you recommend just getting a new valve from Honda or should I go the qftermarket route (if so which brand) thanks guys for all the help thus far!

also forgot to mention, I’m going to take photos of the piston heads as they had a bit of build up and not sure what from.