fluctuating temp gauge

ok so as many of you may know dan and i have had some problems with our new sir. about 3 weeks ago it over heated on the way to gympie. we concluded that the water pump needed to be changed. after 2 long weeks of trips up and down the north coast we finally finished changing the WATER PUMP, TIMING BELT AND THERMOSTAT all with new honda parts, except the water pump, i believe it was near new. anyway, after everything had been done we filled the car with water and let it run for half an hour. no overheating. so we closed the bonnet and left gympie, it ran fine for about 20 minutes, then the temp gauge started creeping up, i took my foot off the throttle and it went back to normal. this happened a few times before it went all the way up to hot and then in about 10 seconds dropped back down to normal temp, this happened the whole way home. does anyone have any ideas on what it could be?i think it may be a sensor or switch. any ideas would be helpful.

Blocked Radiator, get the radiator replace

radiator has been flushed out

i had the same problem on my civic and it was a blown headgasket not white smoke no oil coolant mixing or anything. drain the coolant out of the radiator and see if u can smell exhaust fumes

Quote:

---

Originally Posted by 1perfectday

radiator has been flushed out

---

in what way ?

running water through it ?

the only way to unblock a shagged radiator is to remove the top tank and poke a wire down each cappilarie.

it does sound like your radiator is blocked. or you fuel/ignition mixtures are way off ( lean mixtures can cause overheating as well )
is your ECU stock ? correct MAP for your engine ?

hmmm... we have already flushed out and checked for things like that. did it fluctuate rapidly?

well we just bought the car and the guy who sold it wasn't dodgey and said it was running fine before we bought it. I think the ecu is aftermarket not sure though. the cooling system also has a weird white thick calcified buildup through it

Quote:

---

Originally Posted by 1perfectday

well we just bought the car and the guy who sold it wasn't dodgey and said it was running fine before we bought it. I think the ecu is aftermarket not sure though. the cooling system also has a weird white thick calcified buildup through it

---

Should be blown head gasket then drain the radiator coolant and see if u can smell exhaust fumes or take it to a radiator shop they can do a few tests to tell u whats wrong

but if it was a blown headgasket it would be idleing weird and the water would be massivley boiling when you have the radiator cap off

mine would idle fine and didnt throw coolant anywhere for a while until it started getting worse. hopefully its not the same for u though.

cas our mate that helped us fix if turned on his crx with a blown head gasket and it was completely different. AND we left it for half an hour just idleing and it didn't overheat then?

if its really minor it wont overheat till u put ur pressed the accelerater but like i said after a while it started getting the problems u stated

:( i really hope its not a blown head gasket

my boyfriend has told me to add that he gave it 3 or 4 wot runs second to third with no effect on temp at all. which is why we think its not the head gasket

so i'm convinced its the radiator ... is there anything i can do to test that theory?

if u think its the radiator pull it off and take it to a radiator shop they can presure test it for u.

can anyone confirm for me that if the head gasket was blown would it get hot and stay hot or would it get hot and go back to normal then go hot again then back to normal or is this the behaviour of a blocked radiator

Quote:

---

Originally Posted by 1perfectday

can anyone confirm for me that if the head gasket was blown would it get hot and stay hot or would it get hot and go back to normal then go hot again then back to normal or is this the behaviour of a blocked radiator

---

Kirsty, I had this exact problem, I used to drive from syd to newcastle 2-4 times a week. Driving around town my integra never overheated, once on the highway for about 30 mins or more the temp gauge creeps up, til it got red hot, if I took off the accellorator and coasted down a hill it'd cool down

Its the radiator, 100%.. youd notice a massive loss of power if your head gasket was gone. It WILL go if you keep driving on a busted radiator. Just get a new one, I promise you the trouble will go away. It was really frustrating for me too as I just got that car and I thought the radiator was new, turned out if was 90% blocked so literally hardly any coolant was flowing through and was lucky I didnt blow up the engine.

New radiator, coolant flush and new coolant, your car wont be overheating for a very long time. Perfect time to do it now anyways as its getting hotter and people who care about their cars get a cooling system flush anyway as the old coolant isnt good for the hotter summer months.

before you do that check if ure ecu is correct one lol. never know

Kirsty, assuming its Kermit get the Radiator done anyway, its overdue.

IMO and experiences with the Civic, it does not sound like a head gasket, it sounds like the Radiator has had it.

If the old one is beyond repair, prepare to rage at pre-ED Honda, Sensors suck.

Quote:

---

Originally Posted by SHOGUNOVDDRK

Kirsty, assuming its Kermit get the Radiator done anyway, its overdue.

IMO and experiences with the Civic, it does not sound like a head gasket, it sounds like the Radiator has had it.

If the old one is beyond repair, prepare to rage at pre-ED Honda, Sensors suck.

---

no its not the green ar, she is sold to a guy in gympie :) its my new gen 2 SiR. but anyway that good to know everyone thinks its the radiator it means my $350 isn't going ot waste

Did you read what I wrote at the top? Its radiator for sure

Try a radiator from ebay, they got a few going for under $200 delivered..

ok so new development, i just started the car, let it warm up to normal operating temp drove it 5 kms to the shop and my boyfriend thrashed it on the way home to see what would happen, just short sharp bursts of vtec...... nothing.... only heated to mid way which is normal after a bit of a thrashing..... still the radiator??? or imagination?

Have you checked the wiring to the temp sensor, maybe its not over heating and the temp guage is just playing up giving a false reading?
Someone correct me if I'm wrong but if the temp wire looses ground or unplugged, it will cause the guage to give a false reason and sky rocket?

its definatly overheating, we were loosing coolant

this is starting to get really weird...

It will get hotter and hotter as you drive it more. My car would only overheat when I drove over 100km/hr even though technically more air is going into the engine at that speed
Just replace the radiator.

yeah its only ever overheated when we were on the highway.

Change the radiator!!

Seriously.
Just change the radiator.

Quote:

---

Originally Posted by wAYzoR

Change the radiator!!

---

i've got one on the way!!!!!!

Quote:

---

Originally Posted by 1perfectday

i've got one on the way!!!!!!

---

Good. Change it and it will be all good.

hopefully....

could be thermostat lol.

jsut replaced it

Cool did you drain your coolant system, refill it the proper way and bleed the system of air?
Now go for a drive for 15 min come back and check your coolant level again incase you got a leak somewhere
Then youll be good to hit some 9000 rpm vtec all summer without worrying

Hey just to let you know if your have change your radiator and this problem still occurs its definitely a blown head gasket. I have experience the same thing as you with two of my cars (r32) and have been in denial of the blown head gasket problem. When I actually took it to the mechanic he confirmed to was a blown head gasket. Luckily I sold both of them of quickly. So mate just a heads up

Quote:

---

Originally Posted by Chriskoss

It will get hotter and hotter as you drive it more. My car would only overheat when I drove over 100km/hr even though technically more air is going into the engine at that speed
Just replace the radiator.

---

My car does the exact same thing!!

Does that mean its the radiator??

^^^ if thats happening, its blocked or had a pin hole leak sum where

replaced the radiator and presto:)