So I get up and its a brisk 13*F outside. I goto start my car and the idle surges up to 2500rpm and just sits there. Normally (earlier this week, yesterday in fact) the car starts up at cold start with a 1800-2000RPM idle and in about a minute, it trickles in to about 900RPMs, and off to work I go.

Not the case today.... Car started fine, but idle shot up to 2500rpm and held steady. After about 30seconds.... the idle got weird. It started surging from 2500-3000-2500-3000 in a noticeable pattern. I found this strange as the car has been money up until this cold blast hit NYC. So without hesitation I moved the car aside in the backyard and used my other car to goto work. I did notice greenish coolant on the ground, but I didnt get a chance to investigate further as I didn't have the time this morning. Just needed to get to work.

Leading up to this... over the last few weeks I noticed that my Temp gauge was not reading as high as I would like, it was barely above the right part of the "C" on the temp gauge. I searched the forum and saw similar threads where sometimes it was the thermostat, and sometimes it was a lazy gauge. I also noticed my heat was not as hot as it should have been yesterday evening. (I just thought maybe it was "that" cold) but apparently when I got off the highway, the HVAC output began to get a bit hotter.

Has this happened to anyone else? I just find it suddenly strange, but not unbelievable though. I have not flushed the coolant system since I bought the car in April. God only knows what the previous owner had in there. Im betting the 50/50 coolant mix was not anywhere near that. Im thinking its more like a 80/20 where water is the 80%

I am leaning towards a coolant flush and thermostat test and replacement as soon as the weather gets warmer in the next few days.

Has this happened to anyone else recently? Any tips would be appreciated before I crack her open again.

- BDR

 

low on coolant i am sure, hence the bad idle. most likely you need a new radiator.

 

how does your coolant level look? ii would start with the coolant flush if you know it hasn't been done in a long time, and see if the low coolant/air in system, would have been the culprit.

 

I was never leaking any coolant until today (this morning). I need to see if that spillage came out of the overflow tank or a newly busted part. All fluid level were up to mark prior, since I drive this car 400miles a week as a commuter daily driver.

Hmmm how does low coolant affect the idle? I know I read a thread about coolant routed through the IACV, but blanket statements dont get much traction towards fixing the actual problem.

First thing I will do tonight is track down the source of that sudden coolant leak.

 

Probably have air in the system causing the surging. Find the leak, bleed your cooling system, probably won't hurt to clean your FITV and IACV.

https://honda-tech.com/forums/acura-integra-6/%2A%2A%2Ahow-clean%2A%2A%2A-your-iacv-k-idle-air-control-valve-1575913/

https://honda-tech.com/forums/acura-integra-6/%2A%2A%2A-how-%2A%2A%2A-clean-your-fitv-aka-fast-idle-thermo-valve-1564019/
https://honda-tech.com/forums/honda-civic-del-sol-1992-2000-1/95-civic-removing-oil-cooling-system-idle-issues-reward-2973163/

http://www.tegger.com/hondafaq/overheating/index.html

 

i had the same exact problem wit my 94 gs...change your thermostat. you'll still idle high when its below freezing but it shouldn't surge anymore. i got a stant thermostat from pepoboys costed me $9

 

Thermostat is definitely on the list. I have a feeling that its stuck open or doesnt even exist Either way I will be identifying and fixing the leak i saw this morning then doing a complete coolant flush with a new thermo, maybe if Im feeling ballsy, I even buy a new rad cap.

 

i just replaced my thermostat bc mine stuck and caused a hose to burst..gonna get all new hoses here soon since they are 2o years old

 

Was still in the 20's last night, so I will wait a few days till its in the 30-40's this Saturday. I have never taken off a Thermostat on this car yet. Can someone tell me if it is just the typical rubber O-ring gasket, or do I have to also buy a paper gasket to replace the housing? I know on most cars, I just use the Thermostat O-ring gasket and a little high temp silicone on the housing.

Thanks.

 

it is a rubber gasket, should come with the thermostat.

 

OK.... so its about 48*F outside now.... started up the car and its purring like a kitten. (as it was before this cold temp acting up) I let the car run (idle for 20min) No sign of any leakage. I did notice that (1) my temp gauge was on barely past the "C" again and (2) my coolant overflow bottle was bone dry so I filled it 1/3 of the way up with coolant to submerge the overflow hose.

Either way, I have the new thermo and gasket and a bottle of fresh coolant. I will flush, refill and bleed the system tomorrow during daylight hours. Hope fully that will help my lazy temp gauge.

 

if its a lazy needle, the thermo unit is going bad-sends info to tach i believe
http://www.acuraoemparts.com/delray/...All&vinsrch=no
i think its number 13. 15 is coolant temp sensor.

 

^^^that's completely wrong. there is a sending unit, a temp sensor and a fan switch.
the sending unit goes to the gauge. sensor to the pcm. fan switch to the fan relay.
sending unit does nothing but relay the temp to the gauge. the sensor effects drivability, as the pcm takes readings from it and adjusts fuel parameters accordingly. not sure what you're talking about with the tach, but it gets signal from the ignitor in the distributor.

to the op, change the t-stat, as it is the only thing that regulates minimum coolant temps. plus you said your cabin heat doesn't get very hot.
for the idle issue, try cleaning the iacv. if that doesn't do it, get back to us

 

what is function for part number 13? i been told this sends info the gauge for temp reading hence the "lazy needle"

 

ohhhhh. ok. sorry. i didn't look at the diagram and i read your post wrong i guess. yeah that's the sending unit. but it wouldn't be a "lazy needle", as you put it. since op says he has poor cabin heat as well. would be the t-stat

 

Update.... I installed the new thermostat and gasket. flushed out the coolant and added some new coolant. I jacked up the front of the car and ran it while massaging the hoses to purge the air from the system. Car runs pretty decent. The gauge is still only 1/4 of the way up ( 1/2 way between Cold and normal operating temp) The heat has significantly improved but its not blazing hot like how i remember it. I havent had a morning below freezing yet to try out the cold start. but this morning was 38*F and the car started up spiked to 2200rpm and then settled in to 1200-1500 after about 30 seconds and shortly after dropped to a regular standard idle around 900rpm or so.

Car drove great.... I would like to sort out the gauge inaccuracy, but that may be a long term solution.

 

the gauge may not actually be reading inaccurate. you can use a thermo-gun to see what the engine coolant temperature is and compare it to the gauge

 

my car idles at like 700 and it irritates the **** out of me bc it makes it shake, i cleaned my IACV, checked coolant, even adjusted idle screw on top of tb, got maybe 20rpms out of that..idk what to do lol

 

Update...

I noticed on the drive home last night from work that the temp gauge is now back to the middle of the gauge once fully warmed up. I gues it took a little bit of purging and driving for the new setup to kick in. Started up this morning and about 10min after starting the car, the temp gauge was at the correct normal operating temperature in the middle of the gauge. Heat also feels hot now, as it did before.

 

I have a spare Pro-Sport temp gauge I use during tuning, I was going to hook it up to validate the stock temp gauge, but things seemed to have corrected themselves.

 

check what you're getting for engine vacuum

 

umm, how do i check what im getting for vacuum?

 

with a vacuum gauge. install inline with a vacuum line off the manifold. at idle, should read steady, around 20 in/hg.

 

Final Update...... car is operating as it should. normal temps, normal idle, normal warmup time from cold start. Thanks for all the input!