[Norcal_LX]

Proud owner of a manual 2008 Civic LX. Been my commuter for last 4-5 years. Has about 143k on the odometer. Owned since about 70k or so, don’t know of prior history. She burns less than 1 quart between changes. Doubt it’s ever had chain looked at.

I’ve done all the regular maintenance but over looked the timing chain problems. Had a 2004 Element for several years that needed a chain at around 140k, so I figure I’m probably due.

Anyways I was driving home yesterday and she started running rough, flashed the CEL and went to limp mode. It’s got a solid dead misfire for sure. Doesn’t sound terrible though, nothing banging, still have oil pressure. Had it towed home and scanned it with my basic iPhone app and Bluetooth dongle.

Got codes for cylinder 4 misfire and a catalyst inefficiency code. TBH I’ve had the p420 for about 1-2k miles, it would come and go, I had just gotten a new O2 sensor to replace this weekend.

So far I’ve throubleshot for spark and compression. Spark is good, compression was bad 60-70 psi on cylinder 4. #3 was 130-140 for reference.

I scoped the cylinder real quick and only had a chance to look at most of the piston and I think the intake valves. She’s looking pretty oily but in one piece, no signs of valve contact. I’ll try to get a better look at her tonight or later tomorrow.

Coolant seems clean and has not leaked.

The questions I have for you all:

Is there any chance that timing chain wear or skip could cause low compression misfire in only 1 cylinder?

Or am I looking at a new top and/or bottom end?

Can I tell if I bent a valve if a pull the valve cover?

Next step was to pull the valve cover and see if the timing skipped, but wanted to check with you all here before I got too involved in this thing. I’m somewhat mechanically inclined and plan to fix myself if I’m looking at a timing chain.

Thanks in advance for any help!

 

[Chaos Pilot]

I dont see how the timing chain would effect one cylinder only. Have you looked inside the intake manifold? If so was it really dirty?

Head gasket good around that cylinder, any oil seepage?

Otherwise...new motor time! Swap to k20 or 24 and have fun ripping, VTEC Yo!, high RPM naturally aspirated screaming shifts.

Do you know that the K motor in the S2000 was the record holder for most HP per liter from a NA motor for, I think, 10 years before Fe-fuckin-Ferrari beat it with a NA V8 pushing 120 HP per liter. Long live the mighty K..

 

[Norcal_LX]

Thanks for the reply. I don't see how it could be just a timing issue either but figured I'd ask before tearing into this thing. I have not looked in the intake manifold. No leaks anywhere that I can find, just an oily cylinder. My next step was to do a leakdown test this week and try to determine if the bottom-end is still good.

Cylinder head swap or head gaskets I'd take on myself in my garage. If it needs a new engine I'll probably look at offloading it. This is my practical commuter, my tuned and modded F150 3.5 Ecoboost is my fun/project vehicle.

Yes I have first hand knowledge of the S2000, my mom bought one in the 2000's, the generation with the glass in the rearview, and the circle tailpipes with the engine the reved to 9k.

I got a few tickets as a 17 year old in that car. She traded it in for a subaru 5-6 years ago.

 

[Chaos Pilot]

What a great car to be able to drive at 17. S2000 will one day be a collectable and highly sought after.

 

[Norcal_LX]

I did a leakdown test and was able to determine a very large leak through the exhaust valve(s). Pulled valve cover and as far as I can tell they aren't bent or broken. I'm in the processes of pulling my cylinder head now for replacement.

Crankshaft pulley bolt needed a 4' cheater bar, heat, PB blaster, and all my 180lbs to break free. Twisted my 1/2" extension like a twizzler.

Stripped hex key head on the tensioner pivot bolt, waiting for an EZ-out socket to finish that work now, then I can remove the timing cover. Also damaged my passenger side motor mount (probably due for replacement). Rest of the teardown has been pretty straightforward and easy so far.

Drained the oil and seemed normal, coolant was clean too.

Also planned is to replace my motor/trans mounts, timing chain, tensioner and guides, both O2 sensors, serpentine belt and tensioner, water pump, pcv valve, and timing cover seals.

Are there any other parts that should be replaced while I'm at it? Is the VVT solenoid something I should look at replacing?

Anything that I need to make sure is OEM?

Will also be replacing all 4 strut/shocks, and front control arms (bad bushings).

 

[Norcal_LX]

Got the head off, found the problem. Will be replacing.


Any ideas on what would cause this?

 

[Chaos Pilot]

Valve not adjusted correctly and caused a hot spot?

While you're replacing things check your intermediate shaft bearing. They go bad and make some hard to diagnose noises.

 

[Norcal_LX]

I’m sure the valves were adjusted correctly 140k ago, but they’ve never been touched since.

Learned this one the hard way I guess. So what’s a good interval for adjusting them? In the light reading I’ve done here on the topic I seem to recall 40k.

New head is on order, pistons all had 1/8” or more of carbon caked to them. Took it off with a wire wheel and some chem tool.

Checked the intermediate shaft bearing, seems ok.