ham

so i got my swap 2 months ago and put it in my 93 coupe in 0 degree detroit weather. it looked brand new, went in with no problems... everything went perfect. i noticed after the first time it warmed up that it was burning coolant out the tailpipe. it also took forever to warm up. (that really bummed me out, it was supposed to be a nearly new engine!)

so its been fine (driveable) until today, i occasionally added a tiny bit of coolant (i had to get to work, really didnt want to tear the motor apart when its 0 outside). yesterday the CEL came on and i didnt check it (no difference in driveability). today i started it and the code was gone and the motor was idling at 2krpm. I started driving and right away the temp was up but no heat. the engine started surging at idle from 1000 to 2500 rpm. i brought it back to my house and it was overheating. i opened the cap and the coolant started boiling (it was 9 degrees today, wind chill -4). i let it cool down and refilled the coolant and bled the air out and now it seems to be fine... idles at 700 and runs perfect

my current diagnosis: the headgasket is bad causing the coolant to burn in the combustion chamber and the coolant got low without me knowing and it got an air pocket, causing the loss of heat and overheating. i dont know why there was a code yesterday, i dont know why it was surging and now its not, and i dont know why there is no code now.

any other ideas or recommendations?

schardbody

my theory is you froze the water in your radiator and the coolant had nowhere to go when the thermostat opened so it caused the boil over. you are using 75/25 mix or something close to that in your radiator right. you do most likely have a blown head gasket also.

ham

im running 50/50, i really dont think my radiator was frozen, it would have to be -32 to freeze.

Probot

i cant remember the name of the test..i think it might be called a "leaktest"..but anyway, its a test involving the radiator..any local mechanic should know how to do it, but its a way to determine whether the head gasket is shot.

ham

youre thinking of a leakdown test. its where you pressurize the cylinder with air while its on the compresion stroke and see where the air is going. if you see air bubbles in the radiator, the head gasket is bad.

ham

update: car never gets heat and overheats (boils) after about 15 min. of running. radiator is FULL!

cdizzle

yes theres air in the system becuz u got a blown headgasket thats why u dont get any heat cus of the air in the system and it boils over becuz exhaust fumes are coming thru ur headgasket leak as well as it going into the combustion chamber. the reason it surged before becuz there was very little water i nthe rad, the car will surge when it gets to hot and theres nothing in the radiator.

ham

exhaust fumes arent coming through the headgasket, but most of the other things you say make sense, except the surging when its hot. it was surging the whole time, then it just stopped.

im gonna rip it apart tomorrow. its -1 outside

cdizzle

does the lowe rad hose get hot? you might have a problem with your thermostat not opening......is your overflow tank spitting coolant and bubbling over?????

cdizzle

i posted this in another thread "you need tocheck the cooling system in your car, something could be terribly wrong. first take off your rad cap andstart your car pour coolant in and let your car reach operating tempature (1/4 to 1/2 on the temp gauge)
take a feel of the lower rad hose make sure its nice and hot and pull the throttle cable to help your car reach operating tempature, once your sure your thermostat is open and the lower rad hose is warm keep adding coolant till its full air bubbles will rise jus do this for a good while, oh it also helps to have ur heater in the RED so u say and the fan on 4.

good luck and post your results"

it could also help u tommorow

ham

my lower hose is NOT geting hot

ham

OK its i got it:

the thermostat it stuck closed for sure, AND the headgasket has been had all along.

cdizzle

damn thats sucks...need any more help/

ham

https://honda-tech.com/zerothread?id=1532934