Overheating but i dont think its the seals??

gear1275 · June 09, 2009, 08:10:33 PM

hey guys, since the weather has got warmer my car has been overheating. the stock guage has been reading about two thirds which i have been told is high. it used to be at about a half, i have tried the heater on full which has no effect. when running, the top rad hose doesnt go hard which is a good thing? i have just replaced the filler neck cap with a hks item and bought silicone rad hoses and a new larger rad which i am yet to fit. also, i have noticed that the fans never come on. no matter how hot the engine gets or even if i put the air con on?? maybe the thermostat isnt opening and letting water to the rad to be cooled?
im not sure really, all i know is that sorting this if possible will be cheaper than rebuilding so any help would be greatly recieved.
thanks, james

Grizzly · June 09, 2009, 09:05:03 PM

Check your thermostat

ro284 · June 09, 2009, 11:01:39 PM

James, it could be that the Thermoswitch has failed and not switching the fans on! or more likely as i had, the wire from the Thermoswitch had broken down, its a single wire from the switch to relay no 3
Certainly sounds as thogh it\'s getting far too hot if its reading high on the standard gauge! not good! best sort out asap. Good luck Bob

FDAsh · June 09, 2009, 11:17:43 PM

First off, you can\'t trust the stock temp gauge.

Have you tried connecting the fans to the battery directly, make sure the motor isn\'t goosed? If it\'s not coming on with A/C it sounds like a general wiring fault as it bypasses the thermostat to do so (unless I\'m mistaken)

rx7boy · June 09, 2009, 11:51:38 PM

Quote from: FDAsh;614848First off, you can\'t trust the stock temp gauge.

Have you tried connecting the fans to the battery directly, make sure the motor isn\'t goosed? If it\'s not coming on with A/C it sounds like a general wiring fault as it bypasses the thermostat to do so (unless I\'m mistaken)

Yeah your right, A/C button will turn both fans on !!!

nikp · June 10, 2009, 08:23:22 AM

Quote from: FDAsh;614848First off, you can\'t trust the stock temp gauge.

Have you tried connecting the fans to the battery directly, make sure the motor isn\'t goosed? If it\'s not coming on with A/C it sounds like a general wiring fault as it bypasses the thermostat to do so (unless I\'m mistaken)

You can trust it if it moves above the halfway point that it normally sits at. Means its overheating, and has got very, very hot!

I wouldn\'t use the car until you have identified and fixed the problem.

gear1275 · June 10, 2009, 03:37:31 PM

wow! thanks for all the feedback guys! so to check the wire from the thermoswitch to relay three i first need to know where they are. would i just replace the wire or could i check it for continuity first, also, if that was the problem how would i know if they were going to come on without getting the car up to dangeros temps again to check them?
are the realys referred to at the front left of the engine bay in a bank of four?
thanks for all replys, james

ro284 · June 10, 2009, 05:12:27 PM

James, im not much help just now, Had on op yesterday,Anyway the Thermoswitch is mounted on the back of the Stat housing under the Alternator, there are two sensors there, the one you want has a single wire only,(the other sensor has two wires) this wire is basically grounded to earth when the temp on the switch is reached, if you can do a continuity test on this wire, that would be good the other end goes to relay no 3, the lower one at the back of relay no 3, if there is no continuity you have a broken wire, you could prove the point by rewiring and by pass the existing wire, just to test for that fault, however the wire to the relay is the one that is shorted to earth if you did the fan switch mod in the cab, so in theory and as i did you can ground the wire relay no3 to check both the Thermoswitch and or wire failed, i cant go out to check wire colours today, not allowed out! sorry, if no one else comes up with any help ill see how i feel tomorow
Bob

gear1275 · June 10, 2009, 09:32:59 PM

cheers bob, well its raining at the moment so im not going out \'til tomorrow either. thanks for the help though. ill have to go out and familiarise myself!

nikp · June 10, 2009, 09:57:37 PM

i could pop round and see what i think if you like?

shaunwil · June 10, 2009, 10:44:24 PM

Also check that there is heat in the top pipe. If the thermostat isn\'t opening then it won\'t help at all ! Not an expensive swap to do either for safety sake.

Shaun

gear1275 · June 10, 2009, 10:44:38 PM

yes please!! that would be grand, just give me a call or text if your free, thanks nick

gear1275 · June 10, 2009, 10:46:06 PM

shaun, i have been told that in summer i can remove t/stat from housing? is this so?

shaunwil · June 10, 2009, 10:59:49 PM

I ran an electric water pump without the thermostat but it takes an absolute age to get warm and that isn\'t very good for the engine. It got put back in a while ago to speed the warm up cycle.

Most local auto factors should be able to source a replacement without too much hassle. It may even be on the shelf and in the guide in halfrauds.

Shaun

gear1275 · June 12, 2009, 08:32:36 PM

okay then, ill try the stat when i do the rad and hoses, then look into the thermoswitch and fan issue