I have an 88 crx hf b16 swap.
Havnt drove the car in 2 weeks due to replacing my clutch.
Now that I am driving it again the temp guage isnt working, and it didnt seem to be accurate half the time it was working.

It would take a long time for it to get all the way up to normal temperature.
and if i drove it on the highway from normal temp it would slowly fall the cold.

Anyone know how to diagnose this problem?

 

well i'd start off by checking my coolant level, then topping off and properly bleeding the coolant. if that doesn't fix it i'd spend the aprox fifteen bux or so on a new sensor to make sure everything's ok.

are u burning any coolant or leaking?

 

Wouldn't a stuck open thermostat cause this?

 

Got heat? Turning the heater on full hot when "bleeding" ? Bleeding correctly? I had the guy who bought my 88 crx calling me a month later asking after he installed a full length rad why no heat/acting like trying to overheat and after explaining how to bleed-come to find out he was trying to bleed with rad cap off,just saying...

 

@DCRB - Coolant level is fine, no leaks and It doesnt burn. Not sure how to bleed the coolant. It could possibly just be the sensor.

@Bigz - The car doesn't over heat, and it only seems to blow hot hair when the engine temp guage is at warm, and when it falls it seems to blow colder air. Sounds ridiculous i know. lol

 

@markolson - How would I check to see if the thermostat was stuck open and what would I need to do if it were stuck open? Ill get to researching i suppose.

 

After doing some research I find a guy who says "mine did this last summer, i thought it was the thermostat, so i replaced but still stayed on cold. so i replaced the "head senser" that tells the fan to kick on and it was fixed! try this out buddy!""

I definatley think That this is my problem because my radiator fan never comes on once the engine is warm, and once the engine is warm I eventually get a check engine light. But IF its cold at night I won't get a check engine light meaning that the fan never tried to turn on.

IS the head sensor the same sensor DCRB was talking about ^^^^. and if it is what sensor would I go ask for? A crx sensor? or a civic sensor? the engine is a b16 remember.

 

I have the same issue except my CEL light does not come on. Heater blows warm only after the needle registers warm temps. Fluid has been flushed and system has been bled. My fans work when the engine runs warm which is hardly ever. After reading this thread I'm going to change the thermostat out since it all amkes a little sense now.