Hey Everyone,

So here is the backstory... I recently replaced the piston rings in my 2001 GSR (186,000km) as it was blowing lots of smoke and using oil by the boatload (1L every 500km). Along with that I changed the head gasket, intake mani gasket, exhaust mani gasket, spark plugs, intake valve seals(did not do exhaust as they were longer away and ran out of time as I was doing this as a project for college), and I did a valve adjustment.

Got the car started and let it run at idle for about 20 min, changed the oil and took the car to work. Only a few blocks away and the car drove fine.

Now the fun begins... On the way home from work it threw CEL at me and would idle rough (under 2000rpm) but beyond that the car is fine, pulls good, no smoke ect. This was friday. Read the codes from this on Sunday got P0301, P0303, P0304, P0300, and P1399.

Forward to sunday... started the car and lots of white smoke coming from the exhaust for about 15 minutes, car got to full temp then drove it and the smoke went away. Drove fine as we were trying to break in the rings (going to high rpm then letting the motor slow itself down, went to 4k then 5k then 6k ect.) Popped the heater core coolant hose off the head while driving and sprayed coolant all over (clamp wasnt on completely, my bad)

Drove the car yesterday after letting it idle for over an hour while bleeding/burping the coolant. No smoke. Ran great. BUT as soon as I let the car sit at idle for 30 seconds or so it will start to flash CEL and the revs drop to about 200-500 (used to idle around ~600 before teardown) and i can feel the motor shaking... It will not do this at all while the car is cold and will heat up normally, only once it is at full temp and been on for a while (20min+)

Topped off the coolant today... started the car... white smoke for about 3 min, definitely could smell coolant. Drove for about 30 minutes around town, then again the random idle misfire... Read the codes as the previous ones went away due to my battery ground being not completely connected. Got the same codes as the previous but it added P0302.

Now I am at a complete loss... I have looked for anything that may be out of place and I cant find anything... My brain cant find anything that would explain why this only happens at idle...

Anything you guys can think of please let me know! I will respond to any posts as soon as I can!

Thanks!
Robbie

 

Maybe put head gasket wrong way

 

I did that lost 70% of my oil in 2 minuts that's not his issue.

OP how's you cap,rotor and plugs ? new or old ?

 

p0301-04, first thing you want to check is ignition timing. next, vacuum leaks. then, recheck that valve lash. if you don't find the cause out of those three, report back and we'll dive deeper.

as for the white smoke on start up, it sounds like coolant in the combustion chamber. did you have the head pressure tested and resurfaced?

 

Plugs are brand new, rotor and cap looked good when i pulled them off, but i believe it is still the factory one.

 

Timing is fine, couldn't find any vacuum leaks all the connections are solid, Valve lash I haven't had a chance to check yet, hopefully in the next couple days, for that I set it to 0.006" for intake and 0.007" for exhaust as this is what the All Data program at school said the specs were.
Would this only happen at idle? Or may it be happening all the time it is just insignificant at higher rpm?

I did not have the head pressure tested, or resurfaced, with it being my school project I didn't have enough time/money to have that done, but that could be a possible issue... Could that explain why it will only white smoke for a short time then go away?

Thanks!

 

did u swap a coolant line into your manifold by accident....


Posted from Honda-tech.com App for Android

 

Hmm strange i had an issue where anything past 5.5k rpms would cause my #1 or #3 injectors to mess up. now i just have a slight miss at idle am still trying to solve it.

have a look at the last 7-8 posts https://honda-tech.com/forums/showth...4#post48715034

 

Lol no... If that were the case I think it would smoke all the time.

 

Sounds pretty similar... Haha let me know if you find a cure man!

 

how did you check for vacuum leaks? quick and dirty test is to pull the intake boot off, start the car, and cover the throttle body bore completely with your hand. if the engine does not stall immediately, there is likely a leak.

and the timing; you checked it with a timing light, yes? and you have checked it since the problem started occurring?
and the valve set, you did this stone cold, yes?
if so, a couple things you can try; disconnect the o2 sensor. see if the misfires persist.
fog in a shot of propane into the intake tract. if the misfires smooth out, you know the problem is a lack of fuel, which can include an excess of air (vacuum leak). if it doesn't, look towards ignition. use an HEI tester to stress test the ignition system. although, typically a weak coil or anything in the ignition system which effects all cylinders equally will be more evident under load, rather than idle only.
misfires at idle only are more likely to be vac leaks or timing

and yes, when the car is shut off, the cooling system is still pressurized. this can cause coolant to seep into the cyl(s) through the gasket, cracked/warped head, cracked sleeve, etc.

communication is key in problem solving. sometimes the smallest detail can help provide the answer

 

Thanks for the ideas!

I will do that vacuum test as soon as I can, I don't have my own garage so I need to wait for nicer weather haha. A friend said air may be sneaking by the intake manifold gasket, so I guess this test would show that as well...

As for the timing, when i took it all off everything was marked to make sure I wasn't off a tooth when putting it all back together, checked with a timing light as soon it was back together. Since the problem started I have not checked with a light as I do not have one. I will see if I can borrow one from a friend.

Yes valves were adjusted cold, the car was sitting on a hoist for a week prior to me doing it.

I appreciate your help and I will update back as soon as I can!

 

Alright so a little update... checked the oil the friday, was a little murky, went to change it yesterday, after burping the coolant system for an hour.

Long story short, the headgasket is done, oil was a cream color. Pulling the head off again to see if its the gasket or see whats going on...

I also did a little more research, and it seems like with these if there is air in the coolant system it can cause the misfire...

Will keep you guys updated!

Thanks again for the help thus far!

 

air in the cooling system won't cause a misfire. it COULD cause erratic idle. but not misfires. a bad head gasket could though

 

Here's something: said i'd comeback if I found it out....the fuel pump was starving the fuel sys at idle so no fuel no "bang" replaced pump with a new wally 255 hasn't done it since even in the cold. i'd say for 100$ why not give it a try

 

Thanks for the heads up! If the headgasket thing does not sort it out, ill look into it!

Thanks!

 

Alright... So its been a while, but i got the new headgasket and studs in, drove the car for about 30 min today and then the temperature started to rise. Parked it for a while, got in again, and we are back to the erratic idle and the misfire. Read the codes and it is P0300-P0304 and P1399.

Starting to get very frustrated with this.. any ideas for the overheat?

Or anything else for the idle besides fuel pump?

Thanks in advance guys!
Robbie

 

Head gasket could be bad but highly unlikely could you have put plug wires on wrong?

 

when does it misfire?