jessamychelle

im at my wits end and stumped many mechanics as to the issue of my car. heres a list of all the things ive replaced on the cooling system. water pump and timing belt, relay sensors, temp sensors, thermostat, radiator and a majority of the hoses to the cooling system. everything has been replaced except the heater core. i dont have the tell tale damp floorboards. my car does not leak and is not going thru a huge amount of coolant. the car runs clean diagnostically and it has passed a hydrocarbon test. it is at a shop now and they said they cant find anything wrong with my car. here are the symptoms. it runs fine on cooler days and hot on warm days. i cant use the a/c cuz the temp gauge will go up if i turm it on for more than 10 minutes. when the temp goes up the cooling fan does come on and it takes the temp down somewhat. if i drive the temp will go down but idling it will tend to get hotter. i never let the car redline and i will turn the heat on to get the temp in check. maybe a faulty water pump??? please help i really love my civic and i want to keep it but i have dealt with this same problem for 2 yrs that i have had it, brought it to several different shops and no matter what we have done it still has the same problem!!!

Civic2Fast

this may sound dumb, but with everything you've done... are you sure it's overheating or does the gauge just indicate it???

ATLien6

Water pump, if that hasnt been replaced then go ahead and get it done... Have u had any head gasket issues by chance in the past? Or oil mixing in the coolant?

ATLien6

[
I didng even think to ask that lol but ive had a faulty gauge in my 96 sedan before myself

Civic2Fast

I've had it happen once... replaced every single part, then put an autometer water temp gauge on it and was like HOLY WASTE OF TIME AND MONEY!!! It was probably fine the whole time, just babied it because I thought the stock gauge was accurate.

05foresterxt

iTrader: (1)

Check with a known good gauge to see if it's actually overheating. If it is, it sounds like a headgasket issue. I could also be a thermostat issue. Did they replace the thermostat when they did the water pump?

Have you burped the entire cooling system? Have you tested your radiator cap?

strategy400

Check that thermostat was installed properly with the jiggle valve facing up. Open the radiator let it warm up til the fan comes on and check for coolant flow. Sounds like a possible coolant flow/blockage problem, maybe in the engine as the radiator was replaced. Also air could be getting into the system and causing cavitation in the water pump. Check clamps, orings etc.

jessamychelle

I have never had any headgasket issue & the car passed a hydrocarbon test which will tell you if it is.the headgasket. the thermostat was the 1st thing i replaced, didnt help so the water pump then replaced, then radiator then part after part after to try to solve the problem. a faulty gauge would make sense but the fact that turning the a/c up after temp goes up or driving will take the temp down & it will go back up at idling. theres obviously an issue

05foresterxt

iTrader: (1)

You should have found the issue before starting to replace parts. I've never heard of a hydrocarbon test, the test that would tell you if it's a head gasket would be a leak down test and compression test.

Have you properly burped the system? Check the cap.

strategy400

Radiator cap good? Pull the spark plugs and see if they have a nice tan color. Check your ignition timing.

motegicivic

Just to clarify, does it run hot when actually moving? or just at idle or both?

When you say fan comes on, you know there are 2 fans, are you sure the radiator fan will come on? if it comes on still fights to cool it down?

You said you had the water pump done, how long ago, was a honda one?

beecee18

You say it doesnt go through alot of coolant,
well does it go through coolant at all?, at the end of a week is the cooling system still topped off with coolant as it should?
Do you use water instead of coolant, or has the car been exposed to only running water instead of coolant?

Cause hondas that exibit these problems after all parts in the coolant system have been replaced can be from the cylinder sleeve rotting away, actually the outer part of the sleeve that is aluminum gets electrolosis and the head gasket loses its seal on that cylinder/cylinders.
I have personally troubleshoot this problem on 3 hondas in my past and the rot was too much that a deck to the block from a machine shop would have fixed. These cars were not going to lose their problems unless the engine was replaced.
The major cause of this is simply running pure water for long periods of time in the coolant system.
Just a suggestion

UrbanDiplomat

iTrader: (1)

It's either a faulty thermostat, intermittent cooling fan operation, or the head gasket (which can be a pesky bastard to diagnose sometimes). I think worst case scenario would be what beecee said about the rot.

motegicivic

The rot to the block is extreme, I am willing to bet the head is warped a little and or headgasket has some deterioration to it.

There is a good chance of a slow headgasket leak, sometimes it is not full on but slow and steady which causes idles issues, random overheating etc.

EGyoke

If all other components are replaced it has to be a faulty gauge or your headgasket. Any mixture in your coolant/ Coolant in oil?

Hybrid96EK

Screw your hydrocarbon test. Get a block tester and see if the fluid changes color AT ALL. I would want to rule the headgasket out for sure with the issues you are describing.

motegicivic

A block tester is a hydrocarbon test.

Block testing is not 100% esp if it is a small leak.

Hybrid96EK

Are we sure he used a block tester and not a tail pipe sniffer? I had assumed this was the test he did. With small leaks, keep sampling and it will change color.. Very light, but it changes.

beecee18

I simply give this suggestion when all parts from the coolant system have been thrown at the car including a headgasket job, The only thing that was not checked in my experience with this diagnosis was for true of the mating surfaces of the cylinder head and engine block.
But I was able too see the slight deterioration of the cylinder sleeve to confirm this diagnosis. So if you have the head off, all thats needed to rule this out is a good pair of peepers