Changed the coil then checked the ICM in which os good and in specs. I also wanted to check the CKP (crank position sensor)and the camshaft sensor but dont know where they at and how to test it. Anyone knows how? Pls help...thanks

 

hey bud, not to be a dink, but this is my troubleshooting thread not yours, you should start your own, those sensors are down by the oil dipstick or something

After disassembling my ignition and confirming the ICM was good, closer inspection of the new aftermarket rotor showed that the thing had plastic in the wrong places making it cockeyed on the dizzy shaft causing a misfire. I put in the old OEM 200k mile rotor and all codes went away and the car purrs like a kitten.

Cept I overheated a little, bubbles in the overflow....

Compression tests and exhaust in coolant tests show no negative readings, I'm thinking its a leaky water pump gasket letting air into the line or a plugged up radiator trapping air or a hairline crack in it introducing air in the system, not sure, all I know is Ive done compression tests on the cylinders and they are fine, ive done the exhaust test on the coolant, there is no milky stuff in the oil, no white smoke, fan comes on...

Will be back with update after new radiator

 

Old radiator could just not flow when engine was max operating temp, put in a new radiator, flushed it with water and filled with 50/50 which is what honda recommends. Topped off the auto trans fluid since it dripped out a lil when changing over. Jacked up front end and burped the air out of it for about 20-30 minutes. So car runs like a dream now, no overheating, no bucking, radiator was just 13+ years old, time for a new radiator! 300k here I come

 

I am at a loss here. Installed new radiator, new thermostat.

I get tiny bubbles after burping the coolant for 20-30 minutes. People say its a bad head gasket, others say bleed it properly. I've done cylinder compression test and it checks out good, the exhaust block test checks out good, but I'm still losing coolant here somehow airs getting in there and making pockets, but now with the new radiator its barely noticeable until after 100+ miles the gauge only goes up 1/4 of the way from normal to hot but lost about 1 cup of coolant or more.

Also, the car bucks and gives me random misfire cylinders 1 + 3. Only when cold just starting up and under acceleration. Bucking goes away and smooth driving after 5-10 minutes or so. Happened before the overheating though on just cylinder 3 and went away next time I started the car. So it's been intermittent in the past 2 months. All Ignition components have been changed to new. This morning I floored the throttle when it was cold and got the 2 misfires. If I baby it until it warms up, no misfire codes thrown.

One website I read says that coolant is leaking into the cylinder and when it fires up cold its causing the misfire until the block heats up and seals the slow leak in the head gasket. My coolant had no oil in it, theres no indication of coolant in the oil, no white smoke, etc...

I've put over 2k miles on the car since it first overheated.

What do you guys think...

 

Do a leakdown test. This is where with the engine stopped you put compressed air into a cylinder and watch for bubbles in the radiator. If that test fails it's definitely head gasket.

Also if the spark plugs on some cylinder(s) are really perfect white and clean, that's because they're being steam cleaned by coolant leaking in.

 

I will try the leakdown test tomorrow, but upon closer inspection I saw the lower radiator hose clamp was like 5 inches above the bottom of the hose, it wasn't even on the spigot.. sure enough there was coolant all over the splash guard. I don't know how I could have been so careless, well I got the clamp on the hose, topped off the radiator and burped it, but now I'm getting bubbles coming out of the rad even after 1/2 hour of bleeding the system and faint faint traces of whitish smoke coming out the exhaust. I'm going to keep checking my levels every 20-40 miles and see what happens.

I need todo a leak down test , it's the only test I haven't tried.

 

Well looks like the loose clamp on the lower rad hose was it, the levels in my overflow tank are normal and everyday when I take the rad cap off the level is full and there are no bubbles for awhile until it starts boiling.

Now to fix those misfires, I had togo back to the OEM rotor with 200k on it, going to put a new OEM on there from the honda dealer and if that doesn't fix it, going to start looking at the injectors , fuel rail, etc.

Was wondering what sensor on the 98 civic controls fuel mixture when the car is cold because I only get bucking/jerking 5-10 minutes after starting cold and when under load then gradually goes away. I did clean out the IACV the other day, all kinda black stuff in there and going into the throttle body.
Also added a bottle of fuel injector cleaner and noticing some improvement.

 

I didn't even know it, somehow the plug wires got crossed so I straightened them and didn't let any of them touch cept at one point the 3&4 have to cross, it's like my car rolled off the factory floor...
No bucking/jerking, great pickup, takes right off. That must be it, or the injection cleaner did it's trick. All I know is after I played with the wires the car runs great. I'd like to get an original set, but cant find the info anywhere. Prolly have to call the Honda store for those. A rotor and a air filter cost me $60 can't wait to see what a new set of wires goes for.

And finally the leak rears it's ugly head, there is coolant gelled on the head from the upper radiator hose, must have been leaking out this whole time and evaporating, finally it got to the point where it built up enough to see. There's my slow leak causing air pockets. Cars are tricky machines.

 

8 bottles of 50/50 coolant later, there is finally some oil residue in the overflow tank, Im putting a bottle of steel seal in there tomorrow and saving up for a head gasket change over, Hopefully it's not too late to seal it. I can get 10psi off the cap before the fans kick on and bring it down to 6-7psi and that stays consistent. I lost about 1 psi over 2 minutes with the radiator pressure test kit, looks like I didn't know how to read it last time. Any drop in psi over the caps rated pressure means there is a leak in the cooling system, either externally or internally. I would pump that up to like 18-20 to see if its external, but if you don't see any leaks then its gotta be the gasket.

 

I passed on the Steel Seal, for about $300 I was able to do new head gasket, water pump, timing belt, belts, gaskets. The back side of the water pump gasket looked so nasty, all kinda silver gunk in there. The head gasket looked fine actually, but not ruling that out. Car runs smooth now, no bubbles in the coolant.
When I got the head off, there was massive amounts of gunk in the #3 intake on the head and the piston head was slimy black. What causes that?