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I'm looking for some help on a couple of issues with my Honda Civic. This is quite possibly my first post. I tried searching for this issue, but couldn't find anything with my symptoms. My apologies if this is a duplicate post that I missed.
I have a 2003 Honda Civic DX 5 speed with 208,xxx miles. It recently started overheating at idle and had milky coolant. The CEL came on as well (after the car started overheating) with code P0141, which I see is the O2 Bank1 Sensor 2 Heater Circuit Malfunction Bank. Due to the overheating and milky coolant, I decided to replace the head gasket, timing belt, and water pump. The head was taken to a machine shop where it was resurfaced and had a valve job. The car no longer overheats and seems to be running stronger, smoother, and no longer has milky coolant, but the CEL remains on. After approximately 250 miles, I was driving my daughter to school (about 15 minutes away on surface streets going < 40mph) and noticed that on acceleration there was a little bit of smoke coming from my exhaust. The smoke smells like a lawn mower and my eyes must be going bad because I couldn't tell if the smoke was white or blue. It's not dense like a fog machine, but not a thin layer either. Kind of in between. I got the car home and checked the CEL again. Now the P0141 code is gone, but I have P0420, Catalyst System Efficiency Below Threshold Bank 1. Also, there's a metallic rattling in the muffler, almost like there's a nut being thrown around in there. This seems to only happen after the car is at operating temperature. When the muffler cooled down, I shook it and can hear something in there!
Another thing is that when I replaced the oil after the head gasket, I put approximately 3 quarts in. After about 150 miles I added another 1.5-1.75 quarts (never listen to friends). When the car started smoking, I read that over filling may cause smoke to come out of the tailpipe, so last night I replaced the oil and filter, and filled to 3.4 quarts. I've ran it around the block maybe 2 miles and let it idle and light revving in my drive way for 10-15 minutes, but the problem persists.
At this point I'm not sure if the issues are related or not. Any suggestions as to where to start would be greatly appreciated. Thanks!
Oil consumption, probably needs a ring job (could have been related to severe overheating event, and could just be due to mileage as it's typical to have stuck oil rings at high mileage)
I assume machine shop did valve stem seals as part of their valve job, AND they were installed in the correct positions?
Cat code had to be present prior to the sensor code setting.
Pprobably needs both items BUT excessive oil consumption will dramatically shorten the life of a cat, so prioritize this group of repairs so as to not waste money.
If exhaust smells like a lawnmower, the cat is probably already hollow.
"I assume machine shop did valve stem seals as part of their valve job, AND they were installed in the correct positions?"
- I know they did valve stem seals, however I don't know for certain they were installed in the correct positions. Is that something the machinist would do or should I have done that when I re-installed the head?
"I assume machine shop did valve stem seals as part of their valve job, AND they were installed in the correct positions?"
- I know they did valve stem seals, however I don't know for certain they were installed in the correct positions. Is that something the machinist would do or should I have done that when I re-installed the head?
The machinist SHOULD get it right, but you won't know for certain.
Valve stem seals in a head gasket kit from Honda don't come with instructions in the kit.
IDK if aftermarket gasket set includes instructions or not.
Sounds like first order of business is a new cat.
NO!!!!
What he said:
Originally Posted by Colin42
No, you need to fix the oil consumption issue first unless you want to ruin your brand new expensive cat
Hello again! Just for grins I picked up a compression test kit and did a dry and wet test. The dry results came out to: Cyl #1 - 140, Cyl 2 - 140, Cyl 3 - 135, Cyl 4 - 140. The wet test came out to: Cyl 1 145, Cyl 2 - 150, Cyl 3 - 140, Cyl 4 - 160. Are these numbers acceptable? I'm trying to figure out a way to make sure the rings need to be replaced before I take everything apart. Any ideas? Thanks!
Had a hard time getting good light, but I took off the manifold and saw oil coming from the exhaust ports aligned with cylinders 1 and 2. Figured I'd pass this along as well. Hard to see but theres wet oil in ports 1 and 2. 3 and 4 are dry.
Using my own compression tester (known accurate) and my methods of doing the test, I expect to see 180-200 PSI on these engines.
Where did your tester come from?
Also you need to understand that a compression test cannot tell you anything about the oil control rings. The oil rings could be missing completely and you'd still have perfect compression numbers.
You JUST did a wet compression test and THEN took the header off? You found all the oil you just used for the wet test.
If it was consuming oil and you are already pulling the head off, just do the rings now. You'll kick yourself later if you don't.
Before you do......consider how cheap a low mileage used engine can be. Slap fresh gaskets and timing belt in and drop it in.
What’s your game plan, pull engine out and rebuild it?
Buy a likely much less mileage JDM engine and replace it?
Oil control rings on these engines can clog up with carbon to the point they become entrapped in the piston grove and allow excessive oil consumption.
Valve guide seals wear out and possibly split resulting in oil consumption as well.
once you start tak8ng it apart you might find other types of wear that can quickly escalate.
Using my own compression tester (known accurate) and my methods of doing the test, I expect to see 180-200 PSI on these engines.
Where did your tester come from?
I got it from Harbor Freight. It was only $25-$30 so I'm sure the quality isn't great.
Originally Posted by ezone
Also you need to understand that a compression test cannot tell you anything about the oil control rings. The oil rings could be missing completely and you'd still have perfect compression numbers.
Ohhh, I was under the assumption bad rings = low compression. So I've wasted a bit of time it sounds like
Originally Posted by ezone
You JUST did a wet compression test and THEN took the header off? You found all the oil you just used for the wet test.
Oops, poor wording. I took the header off a couple of days ago, but did the wet test a few hours ago.
I've been looking for some reading material or video that might have some tips/tricks to replacing the rings. Anything you recommend?
Last edited by ezone; 09-30-2018 at 11:48 PM.
Reason: fixed quotes
I got it from Harbor Freight. It was only $25-$30 so I'm sure the quality isn't great.
Method used has to be good too.
Connect battery charger so cranking speed will be consistent (slow cranking RPM results in low compression numbers, starter has to be good too)
Remove all spark plugs
prop throttle wide open
Install tester
crank until the needle no longer climbs, and keep on cranking just to make sure it's absolutely maxed out as far as it will go.
repeat for all cylinders
Ohhh, I was under the assumption bad rings = low compression. So I've wasted a bit of time it sounds like
There are many other possible causes of low compression too.
Oops, poor wording. I took the header off a couple of days ago, but did the wet test a few hours ago.
Ok then.
Not necessarily oil?
Soot + moisture is likely if the engine didn't get warmed up the last time it ran.
Warped head let coolant enter cylinders?
I've been looking for some reading material or video that might have some tips/tricks to replacing the rings. Anything you recommend?
Service manual and mechanical common sense?
There's a thread in this forum with links to service manual downloads.
Merry Christmas Everyone! I finally got around to replacing the piston rings over the past couple of weeks. Finally got everything back together, but when I started it up, there was white smoke coming from the muffler. It was 2am with temperatures in the 40s, and I only let it run for a few minutes before I headed to bed. I haven't touched it since. I haven't started the break in process yet, but wanted to find out if it's possible the white smoke is to be expected until I complete the break in process. I'm confident the rings were installed face up, with between .30 and .40 mm gaps, and that none of the gaps line up and are facing the way the service manual instructed. Any thoughts? Thanks in advance!
09-25-2018
