Thank you very much for these bits of wisdom and knowledge, I have attached 3 pictures from different angles, as you can see this vehicle has been well cared for by the original owner from whom I purchased it.
You may also notice I replaced the IACV with a new Denso unit, but that really did not change anything and probably not the best 222.53 spent but it is on there now. I did easily find the bleed nipple right where you said it is, overflow is functional and fluid at proper level, checked hose and it is in excellent condition with no hardness or cracks and projects deep into the fluid. when I remove the radiator cap with the engine cold the coolant is level is up into the cap cavity.
So, should I bleed the air with the engine cold or hot or better please explain the procedure.
Again, thank you very much for all the help you provide those of us how are capable of doing the wrenching but lack certain specific knowledge to diagnose just where to look and/or how to resolve the problem.
Here is the bleed nipple.
Iām just gonna redirect you to Volvoās comment, OP ā heās right.
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Thanks everyone, and yes I did know that is the bleed nipple, question now is bleed engine cold just after starting or warmed up/hot ?
Thanks VOLVO_V70, nice car by the way. That was exactly my first thought but they swore up and down they wire Honda Civics this way all the time with out this problem. So I have been exhausting all other fixes and the problem appears to be solving its self so I am thinking a bubble in the coolant that has been slowly purging itself into the coolant res.
Still waiting for one of the Honda guys here to suggest doing it with engine running cold right after startup or hot after warm up.
Cheers
The heater control should be set on Hot when burping the Honda. That opens a valve on the firewall that controls the flow of fluid between the engine and the heater core.
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Warmed up a little is OK, no need to be fully hot. You just need the system under pressure.
Iāve had experience with '75 Civic, '81, '85 and '88 Accords.
Have the valves ever been adjusted? (not related to your problem)
Thanks, curcuitsmith, yes the valves were recently adjusted along with new plugs,cap,rotor and timing check. all good there.
curcuitsmith and shanonia, thanks for the bleed info will do that today.
Hi Iām new here but working on cars for many years, Iām working on a 98 Civic Dx 1.6L after changing the water pump and timing belt I started the engine to warm up and refill radiator the car shut off after checking found a bad coil changed restarted car now idle fluctuating between 1300 and 1600 check for vacuum leaks nothing found, still trying to determine if all the air is out of the cooling system, not throwing any codes
It might not have that bleed nipple. My 1999 Civic does not. To get air out: raise the front and take off the radiator cap. Set the heat control to Hot. Start it and let it idle and warm up. Add coolant as needed while air bubbles come out the open cap. Turn off engine and cap the rad. Fill overflow tank to its midway point. Open the rad again in the AM and top up if needed, also the overflow tank.
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From what I see the ECM controls idle rpm via the idle air control gadget (IAC). Perhaps it is reading the engine coolant temp sensor as fluctuating due to air pockets in the coolant, and adjusting the idle rpm for that. Generally the colder the coolant temp is the faster the idle rpm. You might try unplugging the coolant temp sensor (the one the ECM uses) and see if that has any effect on the idle rpm wandering.
The only time Iāve had wandering idle rpm on my Corolla, the problem was a faulty IAC device.
I would venture an educated guess that you still have air in the cooling system. When you get all the air pockets out and only when you get all the air out will the idle then be able to be controlled by the AIC valve.
Aside from burping the system with a bleed nippleā¦which you may or may not haveā¦ Several Hot and Cold cycles should do the trickā¦ That is assuming your overflow container and siphon tube are functional and you have coolant in the overflow ready to be sucked into the rad upon a full cool down of the engine.
Make sure your rad cap is fully functional and that it fits properly and makes proper seal to the rad neck. Fill your overflow container up to near the topā¦ Put the rad cap on tight and run the engine to get it fully warmed up. Then shut her down and let it cool down completelyā¦and I mean completely. this takes MANY hours to accomplish. Best to just let her cool down overnight. The next day you should notice the level of your overflow has changed. Hopefully you notice that it went down. āRinse and repeatā this processā¦ it takes a long time to heat up and fully cool down the system, many many hours, so again its best to do this sort of operation as an overnight thing do not sit around staring at it waiting until you think its coldā¦ it will be cold the next morning, Iām sure of it. In about 2 or 3 full hot and cold cycles your system should be fully purged of air and your AIC will again take control of your idle if that valve is healthy. If it functioned just prior to opening the cooling system as you haveā¦then you can pretty much bet that it is still functional.
If after the 3rd Hot / Cold cycle you still have an issue, you then need to go and find out why this is. It will either be an air pocket, a coolant leak, a non functional rad cap and or overflow systemā¦or your AIC valve.
Thatās about itā¦ Itās much easier when Honda provides you with a bleed nipple. With Hondaās its sort of a crap shoot of whether you get one or notā¦I donāt know if your year or model ever had one, but it sure is nice when you do have one. Aside from the bleed nipple, the hot cold cycling is the other mainstream way to purge your system. There are other ways sureā¦but lets start here for sake of keeping it simple.
Let us know how you make outski.
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Ok after two days I removed the AIC valve and cleaned it and yes it was stuck vehicle running good now thanks for your input it was very helpful
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Glad you got it sorted out. Keep in mind the AIC wont workā¦when its stuck and or there is air in the system.
ā¦or if its unplugged
ā¦or if someone cut the harness
ā¦orā¦ nevermind
Thanks for letting us know the outcome
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