Hey guys and girls, I recently bought a bone stock 1990 Acuta Integra GS, power interior with sunroof, b18a1, 5-speed manual, 120k (yes, thats a verified and accurate reading based off the ORIGINAL OWNER paperwork and mileage reportings to the dealership which he has taken the car to since he bought brand new. Im the 2nd owner), gray/silver exterior with blue interior.

Im having heater problems and cant quite get this figured out... When the car is warmed up to operating temperature, it seems to be blowing cold air when Im idling or at a stop, but once I step on the gas or go faster than 10 mph it warms up a bit. The thermostat and water pump are all brand new, hoses are replaced, and the coolant level has never changed... Any idea or something I missed? It gets cold around here in the north part of Seattle during this time of year and I like being warm in my car.... Thanks

 

Try flushing the coolant system. Make sure you have the heater turned on so that coolant circulates through the heater core.

 

Did that, twice now

 

Damn, it might just be your heater core going bad then.

 

I dealt with a 99 Durango at work a couple weeks ago with the same symptoms, turned out to be a clogged heater core. Fortunately, DA dashes are easy to remove if it is the heater core.

 

Any threads on how to diagnose if it is a clogged heater core or how to replace if that is the issue?

 

First thing to do is bleed the coolant system if you have not already, [you did not say you had].

Next is to make sure the heater valve is working, when valve is open, [heat turned up all the way] and engine temperature is up to "normal" both the heater hoses should be hot, if not, either the valve is not working or heater core is clogged, to check both you will need to remove the heater lines off the core, [return line off the core and input line off the valve], drain the coolant or pinch off the heater lines.

You will need to do some jerry rigging, connect a garden hose to the heater valve, [heater return outlet can stay unconnected or connect a line to it and run it into a bucket, open the valve, [turn heat all the way up] and turn on the tap a little, water should flow out of the cores return pipe, if it does turn the valve off, if it stops the valve is working, open valve again and open tap more, [increase water flow] and make sure flow increases out of return pipe, if it does core is good, reconnect the lines a properly bleed the system, there was an "airlock" in the heater core.

Again, make sure you bleed the system properly, it could save you a lot of unnecessary work, I can not count the number of times customers have come in with the same or similar symptoms as yours and think, [or have been told] they need one thing or another, [$$$] and it turns out all that was needed was a proper bleeding. 94

 

fcm this is off topic but what is ur picture for your profile of? looks like a communist peter griffin from family guy to me and i think its awesome and funny.

 

Thanks FCM, I actually did a coolant flush, but not a bleed. Not sure if thats the same or theres a difference hah. Will give that a try when I head to my parents later this week and figure out whats up.

 

Yes it is a pic of Peter Griffin as Che Guevara... http://en.wikipedia.org/wiki/Che_Guevara

From this "iconic" pic of Che...


Family guy cracks me up. 94

 

Yes "flushing" and bleeding are two completely diff. operations, flushing is used to "flush" out "particles/crap" out of the coolant system, bleeding is used to remove air from the system once system is filled with coolant, air will get trapped in the system and bleeding is needed to remove it, check your water outlet for a bleeding "nipple".

This is the correct way to bleed the system... http://www.wonderhowto.com/how-to-bl...ir-out-355092/ 94

 

My 90 Teg has the same problem. Tried flushing but that didn't work. Any hose diagrams available.
Thanks
Jim

 

Not to sure on that model. But, most vehicle the heater core is usually the highest part of the cooling system. Causing air to get trapped there. Then when off idle there is enough flow to push it out, but having it return when shut off again. Does the idle surge at all? Another sign of air in the system, as the air moves past the iac causing to heat and cool inconsistently. I know that's common in many hondas, with air in the system.

 

Another to stress is that when you bleed the cooling system that you have the heater valve open. This means you turn the climate control all the way to hot (the fan does not have to be on) and then bleed it.

 

Thanks for the info. This is driving me crazy...lol

 

there is a very simple way to diagnose a clogged heater core. takes 1 minute, but you'll need a thermogun. car at operating temp, heater on hot and fan on blast, take a temp reading of the heater core inlet. then take a reading of the outlet. since the job of the core is to transfer heat, the outlet should , in theory, be cooler. if it isn't, coolant is not circulating. either due to a clogged core, or inoperative heater valve. you can probably perform this by touch if you have a sensitive feel.
if it is clogged, a last ditch effort can be made to back flush the core. disconnect the inlet and outlet. run water, preferably somewhat pressurized, through the OUTLET and out the inlet. sometimes you'll get a lot of gunk out that way