green01civic

Head gasket replacement happened, and now the car stumbles at 1000-1500 rpms. The mechanic is kinda stumped, he suggested to drive it around until it sets a code and then bring it back, otherwise he said bring it back early next week and he will look it over again.

Head was cleaned, milled, tested, lubed, and given back. Honda OEM gaskets used for exhaust, intake, and head gasket.

The car ran fine pre-HG replacement, with the exception of overheating. Car would accelerate immediately and smoothly.

Post-HG replacement, there's a 1k-2k rpm stumble. It also may exist at same spot upon deceleration (but less pronounced than during acceleration). (It seems that once it's going, it'll keep going fine, but from a stop it's very pronounced stumbling/hesitation).

Any advice of what I should check that could cause this?

I tried uploading it to youtube, but the audio would cut out after 1 second... I guess the 3gp video didn't convert, BUT, I uploaded the video here (1.5MB): http://www.multiupload.com/689JTATPM0

Thanks.

green01civic

More info: Mechanic said had checked timing and it was good, and he checked compression and that was good too (I think he said all cylinders were around 180, but I don't recall exactly if he said 180). He also said he tried new plugs and ordered new ignition coils, and nothing was changed (he returned those parts to his vendor and put my old plugs/coils back on).

I looked under the hood and don't see any loose connections, I went around and unclipped/reclipped a bunch of things to make sure. Drove the car around a little while and nothing has really changed, feels like the same stuttering/hesistation... no CEL still.

gearbox

iTrader: (95)

i guess check the obvious like pcv valve and throttle body sensors, make sure nothing got clogged. any engine codes? sometimes during the head swap a sensor or two gets damaged from coolant getting on them (cpk, cps, etc sensors by the timing belt).

green01civic

Oops, double post.

green01civic

Picked up a code scanner. No CEL, but codes are as follows:

P0301 (Cylinder 1 Misfire)
P0302 (Cylinder 2 Misfire)
P0303 (Cylinder 3 Misfire)
P0300 (Random Misfire)

The reader can also read "Enhanced DTC's". No Permanent Enhanced DTC's are set. One Temporary Enhanced DTC is set, "71-01", which a googling tells me may be an ABS code, possibly could mean "wrong size tire". No idea. I do think I need new front pads, cause I get a slight scrape noise and juddering stop, as if one pad is shot. I think it's the inside pad on the passenger front tire, cause the outside pad appears very low but not out.

The mechanic suggested possibly bad gas. There was a fresh fill up some days prior, but the day before the car was worked on there was no hesitation. Do I dare throw in a bottle of techron, or dry-gas, or both?

green01civic

CEL came on! While driving just now (between my last post and this one). Only new code is a Cylinder 4 misfire (P0304). I guess the car wants all four to be messing up before the CEL gets set.

All four misfiring, definitely when throttle applied cause it runs like garbage... any worse and I'd start to worry that it could stall out, lol.

gearbox

iTrader: (95)

yeah i figured a cel would come on eventually. new spark plugs?

green01civic

Mechanic said he tried new plugs and ignition coils and nothing changed (before I went to pick up the car he had already tried that), so he put my old parts back and returned the coils to his vendor (and I assume he tossed the testing plugs). He was hoping that me driving it around would produce a useful CEL, but that appears not to be the case.

The engine seems to vibrate a little more than I recall.

My wife wants me to bring the car to Honda tomorrow .

green01civic

Well the wife calmed down and is letting me poke around for a day or two before taking it to a mechanic .

Turns out there's a troubleshooting guide for the P0300/P0301/P0302/P0303/P0304 codes in the HELM manual. Look for page 11-79, "PGM-FI System, DTC Troubleshooting (cont'd)".


Here is the symptom chart to diagnose "P0300 with any or all of P0301/P0302/P0303/P0304":
Random misfire only at low RPM and under load
Procedure(s):
Check fuel pressure (see page 11-131).
Also check for:
Low compression.
Low quality fuel.

Random misfire only during acceleration
Procedure(s):
Check fuel pressure (see page 11-131).
Also check for:
Malfunction in the VTEC system (D16W7, D16V1 engine) (see page 6-9).

Random misfire at high RPM, under load, or under random conditions
Procedure(s):
Check fuel pressure (see page 11-131).
Also check for:
Correct valve clearance (see page 6-14).

So apparently the manual seems to think fuel pressure is the #1 problem (damn! I don't have anything to check that with!), and "low quality fuel" (aka bad gas) is a possibility listed... I'm down to 1/4 tank now.

I put a bottle of drygas (in case there was water) and a bottle of techron (clogged injector cleaner ) in the tank at 3/4 tank, and i've run it down to 1/4 tank with little to no change... I'm gonna get it to the gas light before I fill up again... and I'm gonna go to a brand name like exxon or BP this time, not the no-name station. That should eliminate the bad gas possibility.

I did get freeze-frame data from a P0301 and it may have shown acceleration taking place (I'll have to go read the codes again and see the exact details). It seems to happen most when accelerating from a dead stop, but the stumbling can happen by revving in Park/Neutral also, so it is not load-dependent.

ALSO: It does not seem to happen as bad (or sometimes at all) under light acceleration.

Matt_75

I had this happen to me years ago on my ranger. We (my dad and I) came to the conclusion that is was water in the gas. I ran it until the fuel light came on, filled it at a different station and all was good.

Engines usually don't like to compress water.

I hope, for your sake, that this is your problem as well.

Good luck.

green01civic

I ran to the gas light came on (finally), drove for a further 30 miles, then put a bottle of techron and $30 worth of Shell gasoline in the tank (about 3/4 full). Have driven maybe about 25 or 30 miles since then, and no change.

Did you notice a difference right away?

Matt_75

To be honest, I can't remember cause this was like 19 years ago. But if it's still rough, with a fresh tank, then it might not be your problem.

Matt_75

The more I re-read your posts, the more it sounds to me like it's miss timed. I mean all four cylinders have the same symptoms. There has to be something common for that to occur. If timing is off a couple of teeth the cars going to run real sluggish,especially when you go to accelerate. It's going to feel like it has no power.

I would seriously do an independent check of the timing. I believe the newer civic's 01 and up don't have tight tolerances and are non-interference engines meaning if timing is off, the valves won't smack the pistons, but the engine will vibrate and it'll run like garbage as you put it.

You can check the timing with the honda service tech manual. Link below.

http://downloads.hondatech.info/Auto...Civic01-05.zip

If you go to page 6-18, it shows you how you can check your timing.

I know your mechanic said it's good, and I hate to second guess him, but I would really have someone else check it. If your cam or crank sensors were off or disconnected I'm sure you'd be throwing a code for them, but your not, so I'm really thinking timing is off.

Oh and that 180 compression is about right. I did mine several months ago and they were all aroud 188 +/- 3 psi I think.

Just my .02.

Good luck.

green01civic

Thank you for your input . I still have such a hunch it's the timing, and I think you're right. But here's what I've done since... because it's simple for me to do these things, and it eliminates a bunch of possibilities:

- Cleaned out the EGR valve with throttle body cleaner (It was already pretty clean. Changed nothing).
- Switched Throttle Body with another '01 Civic EX. (Changed nothing, so that rules out the TPS and IAC).
- Switched Ignition Coils with another '01 Civic EX. (Changed nothing, so it's not the ignition coils).
- Switched out the entire Fuel Pump assembly with another '01 Civic EX. (Changed nothing, so that rules out the Fuel Pump and Fuel Pressure Regulator).

I'm pretty tired after doing all that today, lol. The other '01 Civic EX is my sisters, she was out doing things all day and let me use her car as a donor car to try parts off of... her car runs great. Her car has smooth acceleration, very smooth.

No codes since the last time I reset, but I bet the P0300 will pop up again soon, as it still runs rough and bogs/hesitates on acceleration.

I wonder though... the crank timing is controlled by the computer, right? So how would I ensure the cam timing is correct? (I'll look at the manual. I'm also concerned that it might be slightly off because of the head being milled... the mechanic swears it wasn't enough to make any difference, but hey, something is wrong still).

Matt_75

You're mechanic is right about machining the head. There is only so much metal that can be taken off before the head in considered bad and there are even marks on the bottom side of the head to indicate how much can be removed. And when I say too much, I'm talking several thousandths of an inch, which will make zero difference in timing.

The timing, as far as the crank and cam positions are concerned, is not controlled by the computer. It's controlled by the position of the timing belt relative to the crank pulley and its associated mark on the lower part of the block and the cam pulley markings relative to the top of the head.

Once again, I really recommend you, a friend, or another mechanic check your timing.

If you're timing is way off, which it sounds like yours is, your intake and exhaust valves are opening and closing at the wrong times along with your pistons being in the wrong positions, while your spark plugs are firing trying to burn fuel, thus causing a misfire in all cylinders resulting in poor acceleration and performance.

Just my .02. Take it or leave it.

Good luck.

green01civic

I replaced the upstream O2 sensor today... cross my fingers... it seems to have smoothed out the acceleration. I didn't get a chance to drive much but I didn't notice a problem. (Maybe a crappy but not failed sensor was causing a lean misfire during acceleration?)

I'm gonna reset the codes and see how it goes tomorrow.

I do think I have a vacuum leak now, though... I hear a weird vacuum-leak-like noise. I can't win! Lol.

stephenvdc

I am interested to know if that O-2 sensor was the fix for you, My '01 has been doing the same thing and the people I have been talking to are pointing to Timing or bad ECU just curious if you got it fixed?

green01civic

It helped a fair amount, actually, but didn't completely solve the issue. I'm thinking the O2 sensor was screwy but not bad and something else is still the cause of the problem and so replacing it made things better but not fixed.

I think there may be a vacuum leak between the base of the Throttle Body and the Intake. I've replaced the gasket (Honda OEM) and torqued down the TB, and the leak still seems to persist. (Spray brake cleaner at the base where the gasket is, and the engine bogs... and you can kind of hear it.)

Also, I found out that I'm burning crazy oil ever since this HG was changed... or it's going somewhere, but it ain't on the ground (if my rough estimate is correct, maybe 1qt per 300-400 miles. I have to monitor it more closely to make sure of the exact amount.) No clouds of smoke out of the tailpipe, so it's a little of a mystery. I believe it was burning it about 1qt per 5000 miles, previously.

I'm considering selling the car or trading it in. After the HG replacement I am kind of bitter.

green01civic

Also since the new O2 sensor, there is no CEL, and no codes present at all now, temporary or otherwise. So the O2 sensor change definitely helped, but the bogging/stutter still exists when hard throttle is applied from a stop.

So total problems:
- Massive oil consumption.
- Possible leak of vacuum between TB and Intake.
- Bogging/stuttering under hard acceleration from a stop. (Light acceleration and the stuttering is either less or non-existant).

sdaidoji

iTrader: (1)

how does the plugs look like? black?
maybe some seal left unchanged on the valves?

some oil in the chambers would mess the mixture and also the O2 sensor

SlimRisk

I dont know much about these types of things, but my best bet is that the head milling screwed it up. Every so much you take off you gotta compensate in timing (or so i read somewhere)

1993 Civic V X

While talking with my independent Honda ONLY mechanic, he told me about a later year Honda that had a stumble in acceleration. He said that various things were checked by him and finally changed the O2 sensor even though no change was indicated. IT WORKED.
.
WARNING !!
. I added Z-MAX total kit (corrected amount for oil and fuel capacity) to my oil and fuel at 120,000 miles. My oil immediately turned black and my gas mileage went from 48 MPG mixed driving to 32 MPG. It is slowly building to 38-40 MPG at 160,000 miles.
. When it was 2 years old, I was getting 54.967 MPG driving 2 lane in-town to 4 lane expressway to interstate then on a back 2 lane road that a road course track racer would love (I did). This was driven to and from work 4 days per week only. I drove my other vehicle the other 3 days.
. I took in to the dealer for plugs and valve adjustment. I drove out with 45 MPG on same trips to work. I took it back and found out that with my engine that the correct plugs (HOT not the standard heat range) were worth 5 MPG and the correct valve adjust was worth 5 MPG. Be careful the correct plug and correct valve adjustment are used.
. For a theft protection device, check with your mechanic about a wiring change that won't let the car start even though everything else will work.