K20A3 Misfiring (Compression Pics)

[theMan_ny]

Okay so since about the beginning of the Feb. of this year my car has been misfiring on startup. It only happens when starting the engine cold. It misfires for the first 3-4 seconds then goes away. After those first few seconds the car idles normal and doesn't have any problems on the road. Its not severe enough to throw a CEL every time but it has twice now. The codes were P300, 02,03,04. I never lose power on the freeway nor when I step on it.

I took the car to a get a compression test and the numbers were good IMO. Close to or dead on 160 all across the four cylinders. I was recommended that I change out the ignition coils since I recently changed the plugs 3 weeks ago and the problem persists. The engine has 216,000 miles if that helps.

I just need some input on what else I should look into getting fixed. I'm planning on changing the coils soon and having a valve lash adjustment. Am I going in the right direction?

http://img.tapatalk.com/d/13/04/24/ubyqebas.jpghttp://img.tapatalk.com/d/13/04/24/uvyja9av.jpghttp://img.tapatalk.com/d/13/04/24/eqadajyh.jpghttp://img.tapatalk.com/d/13/04/24/8yquryqe.jpg

[USAF EP3]

Yes, you are headed in the right direction!

I would look into possibly getting your fuel injectors serviced/cleaned. The stock fuel filter could also be on it's last leg due to how many miles you have. Honda deseigned them to be non-replaceable saying that it's service life is as long as the car/engine's. It's built into the cradle of the fuel pump and those can become clogged. They are NOT replaceable, Honda used to sell the upper half as a whole but not anymore. Now you gotta shell out $250+ for a whole new fuel pump assembly just to replace the fuel filter.

You might be running into a LEAN condition on cold start up since cold engines require more fuel and you might be starving the engine of fuel. That's why you're having lean misfires and they go away once the engine is warm. Warm engines require less fuel to idle.

[T_Virus]

I've had random misfires before and I replaced sparkplugs, swap coils, compression test, was going to do a leakdown test but after all the easy things taken care of, I finally decided to take my car into a shop and they found out it was my valve clearance. After they adjusted the valves and reset the ecu, it was fixed. I think I was the only member on here who had this random misfires and end it being a simple valve adjustment fix. Good luck, hope you find out what it is and have an easy fix too.

[theMan_ny]

Yes, you are headed in the right direction!

I would look into possibly getting your fuel injectors serviced/cleaned. The stock fuel filter could also be on it's last leg due to how many miles you have. Honda deseigned them to be non-replaceable saying that it's service life is as long as the car/engine's. It's built into the cradle of the fuel pump and those can become clogged. They are NOT replaceable, Honda used to sell the upper half as a whole but not anymore. Now you gotta shell out $250+ for a whole new fuel pump assembly just to replace the fuel filter.

You might be running into a LEAN condition on cold start up since cold engines require more fuel and you might be starving the engine of fuel. That's why you're having lean misfires and they go away once the engine is warm. Warm engines require less fuel to idle.

Makes sense. I would like to clean my injectors. How much does that normally cost? I swapped the coils with some low mileage ones yesterday and it hasn't had a rough start since. I'm assuming the coils were the main problem. My friend did mention that I was running rich or lean (I can't remember which) and he could smell it. This was before we swapped the coils. I once ran a test pipe and a gutted cat with a defouler. He said that I might need to clean/replace out my O2 sensor to see if that helps with the air/fuel problem? Is this true? I'm not throwing any sensor codes so I'm not sure if I should replace it and just clean it.


I've had random misfires before and I replaced sparkplugs, swap coils, compression test, was going to do a leakdown test but after all the easy things taken care of, I finally decided to take my car into a shop and they found out it was my valve clearance. After they adjusted the valves and reset the ecu, it was fixed. I think I was the only member on here who had this random misfires and end it being a simple valve adjustment fix. Good luck, hope you find out what it is and have an easy fix too.

You aren't only one :( Hopefully it was the ignition coils since it hasn't happend again. I did random start ups on red lights and it didn't hesitate to start anymore. :) I'm still going to do the valve lash adjustment since it's due for one anyways. I need this A3 to last just a bit more until I can swap it with an K24A1 or K20Z1.

PS Thanks for the replies guys.

[USAF EP3]

Please please please, do NOT fuck with the O2 sensor. The second you go to "clean" it you will fuck it up and find yourself paying $150+ for a new one. Our stock sensors are wideband and for that reason are sensitive. if you're not throwing a code for it then it's operating perfectly.

It sounds like you might have found your problem. Ignition coils don't have as long a lifespan as the engine so good on replacing them. Injector servicing usually runs between $80-$120 depending the on servicing company/shop. Just Google injector cleaning/servicing. RC Engineering is a large injector company that offers the service.

[theMan_ny]

Since my last post I've changed my ignition coils and also my injectors and the car still misfires. The last thing to do on my list is the valve lash adjustment. Other than that, what else do I need to start looking into? Like I've mentioned before the car runs fine after it warms up. It doesn't hesitate to start one bit. Sometimes the car won't misfire but that's rare.

[USAF EP3]

I don't think anyone ever asked this, even myself:

Do you still have the STOCK catalytic converter with 216,000 miles???

[theMan_ny]

I don't think anyone ever asked this, even myself:

Do you still have the STOCK catalytic converter with 216,000 miles???

No. I gutted that one a while back. I bought another used one though. It had around 100k I think, I don't remember. Why do you ask?

[USAF EP3]

No. I gutted that one a while back. I bought another used one though. It had around 100k I think, I don't remember. Why do you ask?

Clogged or semi-clogged catalytic converters can wreak all kinds of havoc on the engine and O2 sensors when cold. Once they heat up to operating temp and everything expands the flows evens out so the car feels normal again.

It's the only other thing I can come up with honestly. A valve lash adjustment seems way too far out there to cause misfiring. The ticktick taptap noise loose valve lash makes is SUPER audible and distinct, you would've known you needed one.

If it's not the catalytic converter, then I'm fresh out of ideas.

[theMan_ny]

I see what you are saying. I put on a defouler for the gutted cat but never took it off. I will take that off once I have a chance. Thanks for the advice.

[Powers]

So you have a defouler on a stock cat?

[theMan_ny]

So you have a defouler on a stock cat?

I did, yes. The car still misfires even after taking it off. I just feel like letting it die and swapping it instead of investing anymore into it. Unless someone has more input.

[USAF EP3]

Take the plugs out and take of pictures of them and line them left to right (cylinders 1-4) as you take them out of the engine.

Let's see what this bad boy is telling us is wrong.

[theMan_ny]

I hate that I don't get email's as this updates. :mcry:

USAF I will do that tomorrow morning since I'll be doing my oil change.

On another note, my car was overheating on me this morning while I was sitting outside of work with it on. To keep things short, I refilled my coolant after I swapped out the water pump and yes it was done properly about 2 months. I checked my coolant after work and it was missing a lot of coolant so to be safe I poured in some filtered water and made it home without the needle moving. I just checked it again and I was still missing a lot so I poured some 50/50 I had laying around for the time being. I burped the system and will be taking a 100 mile trip tonight. I want to see how much coolant I lose from now to tomorrow morning.
So here's my guess as to what is happening to my car. I don't notice any unusual stains on the floor, so I think it's not leaking to the outside of the car. My misfires are still there every now and then. I'm thinking I have head gasket leak or something else and is leaking into the spark plugs/ cylinders therefore when I start the car it's rough and shortly after burns off the coolant. I want to get a leak down test. What will that tell me? Weird since the compression test came out good.
Any input is greatly appreciated and sorry for the long post.

[USAF EP3]

The compression test won't tell you if you have a coolant into cylinder leak; it will only tell you if you have a leak going INTO the cooling system. In that case you would see bubbles or your coolant overflow if you did a cold start with the radiator cap off and watched the fluid.

You definitely have a blown headgasket. If you would've pulled your plugs earlier we would've seen the burnt remnants of coolant on the plugs (or 1 plug if its only affecting one cylinder).

You can pull the engine and replace the head gasket but there are some things to take note of if you decide to do this:

1)You need to pull the engine quickly so that you can prevent as much corrosion to the block sleeve lining, crank and rods as possible.
2)Depending on how bad the overheating was, you might not be able to use the block or head or BOTH. Warpage occurs rather quickly with all aluminum engines.
3)You might want to look into buying another engine entirely due to the headaches you might have from said above points. K24's are plentiful in the sub $1000/100k miles

Don't forget that when swapping an engine that is other than stock you'll require some form of engine management. Kpro is the easiest and cheapest solution at around $700 so at the very minimum you will be spending around $1800 to swap the engine, but the performance gains will be more than double for sure.

[theMan_ny]

I've already started looking into buying a K24 since this has started a couple of months back. with school starting next month, I need my car to be reliable. I do have a picture of the previous plugs and I think they are in order. Like I said I'm pulling them out tomorrow morning but even when I switched these out I knew something was leaking into there.
http://img.tapatalk.com/d/13/07/08/usaju7u7.jpg

[USAF EP3]

I've already started looking into buying a K24 since this has started a couple of months back. with school starting next month, I need my car to be reliable. I do have a picture of the previous plugs and I think they are in order. Like I said I'm pulling them out tomorrow morning but even when I switched these out I knew something was leaking into there.
http://img.tapatalk.com/d/13/07/08/usaju7u7.jpg

Do you think you can get of picture of them with the electrodes facing the camera?

From what I can tell 2 of the 4 look good (at least from this angle). The ones that looks iffy is the second one from the top but then again I can't see electrode from that angle and the second one from the bottom, there's what seems like a hot spot tarnish (brown) on the electrode from what I can see.

[theMan_ny]

I got good news!
Since my last post I'm pretty sure the problem has been fixed, temporarily at least. I knew the coolant was leaking but not a whole lot so I went to autozone and bought one of those Bar's bottles for a head gasket repair. I knew the risks it and decided to pour it in. It's been 5 days now and the car still has proper coolant level. Also it hasn't had a rough start or misfire.
Thanks everyone for the help. I'm still planning to swap when this A3 dies in a couple of months I hope haha.

[USAF EP3]

I got good news!
Since my last post I'm pretty sure the problem has been fixed, temporarily at least. I knew the coolant was leaking but not a whole lot so I went to autozone and bought one of those Bar's bottles for a head gasket repair. I knew the risks it and decided to pour it in. It's been 5 days now and the car still has proper coolant level. Also it hasn't had a rough start or misfire.
Thanks everyone for the help. I'm still planning to swap when this A3 dies in a couple of months I hope haha.

That stuff is literally a crutch.

I would buy a spare engine now and keep in bagged until you need it. No point in waiting for your A3 to go boom and then search frantically for an engine just to get your car going.

Search now to avoid headache later.

[theMan_ny]

That stuff is literally a crutch.

I would buy a spare engine now and keep in bagged until you need it. No point in waiting for your A3 to go boom and then search frantically for an engine just to get your car going.

Search now to avoid headache later.

Oh yeah of course. I've been going back and forth searching the best swap for my needs. I would like a K24A2 but they seem to be really high in price and a cheap one is high in mileage. An A1/A4 would not really be a big upgrade but definitely a noticeable upgrade. I'm thinking of a turbo build, and an A1 seems to the cheapest and would allow me to turbo with the extra money.. Also, with the extra money I want to do the TSX 6th gear since I commute a lot and would help my MPG. Decisions, decisions.. :mfrown: