[carbondave]

Ok I am new and this is my first post. I dont know if this is where I need to place this thread.
Let me first state the history of our van. This is our 2nd Odyssey. We bought it with 50k on it. I have changed the transmission fluid 3 times since then and now have 158,000 on it. At 125,000 miles I put a new timing belt, tensioner, serpentine belt tensioner, water pump, plugs, and belts on it. MYSELF!! 6 hours first time ever. Thanks to this website.

2 weeks ago it started missing going around 50-55 MPH RPM between 1500-1800. Threw codes P0303,P0305, P1399. Misfire #3 and #5 cylinders. So I bought 2 coils and put them in cleared codes. Four days later same thing, codes P0303,P0305, P1399. What is going on? It cant be the same coils again it has to be something else. Could I have been off a tooth on the timing belt and now the belt has stretched and is showing up. I have no idea.

BTW for the past few months I have been getting a noise from the back of the engine passenger side. Coming from the pulley area. The sound is like a A/C compressor with bad bearings. It is more pronounced when it is cold. I have no clue. I am going to tear it all apart but first wanted to ask for your help.

 

[William Wiles]

There are several things that can cause misfires. Plugs, valve adjustment, injector. It could be one of the other coils causing it. There are several good threads discussing diagnosing misfires.

 

[mjody]

Misfires at that speed are when the EGR is working. Possibly plugged EGR ports in the intake plenum. Pull the thin upper cover and see, 12 bolts/nuts iirc.

 

[carbondave]

Ok I am not following the last reference to 12 bolts/nuts. I see on the top of the intake there is 10 boost. Is that what you mean? If I take that off will I need to get a gasket or reaseal it? Also the egr when I take that off will I need a new gasket? I checked #4and 5 spark plugs and they look great. Maybe even on the lean side of things. Any help is appreciated tremendously. I will start with the eve and cleaning that up.

 

[carbondave]

I meant bolts not boost and EGR instead of eve. sorry using my phone. Now today it seems to stumble of the get go and even misses every now and again at idle.

 

[aaronm]

If you can change the timing belt, you can clean out the EGR ports:

This may not be the problem. Missing would probably occur at lower speeds when accelerating. Wouldn't hurt to see how much carbon is built up along those passages though.

 

[carbondave]

Yes that is where I will go next. I just got done watching that video. Tomorrow I will do the EGR ports. But I will also look into #1 coil. I checked the plug , which looked fine, but I did notice the boot had a brown stain or coating on it. Unlike the others. The porcelin on the spark plug also had a brown coating. Could it be # 1 that was bad initially and causing #3 & #5 to misfire?
I will keep you posted. Thanks for all your help.

 

[sontakke]

Don't go by the cylinder number as given by the P030x code. I do not believe Odyssey gives you the correct cylinder number even when you have a permanent coil failure.

 

[OdyinNH]

Did you put in an OEM coil or aftermarket? Another poster had an issue with an aftermarket one.

 

[carbondave]

Ok cleaned out the egr passages. They were dirty the actual ports were 50% closed. I seen worse in other posts. I pulled the egr valve and cleaned it and tested it. Works. Put everything back together and decided to look at #3 & 6 spark plugs. #3 looks to have a crack in the porcelain. I think that may be my problem. Tomorrow morning going to replace all plugs with NGK. The Bosch Platinum I have in there now only have 25,000 miles on them now. I will let you know.
I have one other question. Is it normal to have a little oil in the bottom of the intake? I pulled the plenum plate cover off only.

 

[carbondave]

Here are some pictures of the oil in the bottom of the intake and also the suspect spark plug. What do you think?

 

[OdyinNH]

A crack would be bad. The thing I suggest is like you mentioned, get the correct NGK plugs in there. My luck with Bosch has been bad and others have commented the same way. The correct NGK's are $10 or so a plug but are good for 100k so worth the money. Change all the plugs and your problem will probably go away. Sorry, I don't know about the oil question but it seems odd.

 

[aaronm]

I doubt it's oil from the crankcase. Mine looked similar, if I remember correctly.

Good luck with the NGK's, report back if that solves the problem.

$10 for a spark plug that lasts 100,000 miles is comparable to $1 per plug that lasted 10,000 miles in the old days.

 

[mjody]

Here are some pictures of the oil in the bottom of the intake and also the suspect spark plug. What do you think?

Those plugs are junk, suitable for lawnmowers at best. Get the proper NGK.
Also, keep scraping all the carbon and use a vacuum to suck it up. Make sure the black gasket is clean (it is re-usable, and make sure install it with the "tab" closer to the firewall than the radiator ). The upper plate you removed must be spotless, soak with carb cleaner and use a wire brush to clean.

 

[sontakke]

Stay with OEM NGK (or Denso) plugs for Honda and avoid Bosch unless you want to have mysterious problems. As a matter of fact, anytime a new person comes here complaining about engine related problems, the first recommendation is to make sure he has good OEM plugs in the engine *before* doing anything else. A cracked insulator definitely will cause missing.

 

[carbondave]

Ok so far so good. The problem seems to be gone. I replaced all of the plugs with NGK. Thanks all for your help. Truly appreciate it. I was starting to worry. On to the next issue: That mysterious noise coming from the back side passenger side of the motor. It sounds like a noisy bearing in a A/C compressor. The only thing is the A/C compressor is in the front. I pulled the rear top timing cover off and the noise got louder. Hmm. Any ideas? I will probably end up pulling it all apart and see.

 

[aaronm]

Best to make sure it's not a timing belt tensioner or pulley. If your timing belt goes, your valves go. Got a mechanic's stethescope?

 

[aaronm]

Or water pump.

 

[mjody]

The timing belt tensioner can fail, it collapses. With the cover off, set the motor to TDC, the belt should be tight everywhere you wiggle it. If the belt has slop on the firewall side, then the tensioner has collapsed. Do not drive it till you figure out the noise.