Water Temp Guage

minh · Post by **minh** » Sat Oct 02, 2004 12:32 pm

What does your one show? Always below half? Does it ever creep to over half and both fans kick in and it goes back down?

Turning on aircon keeps it right down as both fans are one constantly.
Just curious.

TheSentry · Post by **TheSentry** » Sat Oct 02, 2004 1:46 pm

Mine actually creeps over half way coz I've got a problem with the water temp sensor, which causes the radiator fan to kick in late. To prevent that I do run the aircon for a bit, at least till I get a new sensor.

minh · Post by **minh** » Sat Oct 02, 2004 3:37 pm

does it always creep over or only sometime?

I know the Mivecs love to get sludgy in the cooling system.

Have you done a total flush of the coolant system? Sometimes the sludge does cause temps to kinda go up and stuff.

My friend had to flush his car like a total of 4 times in a 3 week period to make it perfectly green and the needle sits low as now constantly.

Boris · Post by **Boris** » Sat Oct 02, 2004 4:47 pm

Mine sits a little bit under half way. I'm going to completely flush out and clean my radiator and put Nulon Coolant in it. So let you know how my needle goes...

minh · Post by **minh** » Sat Oct 02, 2004 6:41 pm

Boris is there a correct procedure to totally flush out old coolant and gunk?

dannyboyau · Post by **dannyboyau** » Sat Oct 02, 2004 9:47 pm

there is actually a special tool for doing it that you use.

But you can use some type of can flush then according to the instructions on the can.

But when you do it you need to remove your thermostat so that you can flush the engine side of the cooling system, then you can get a hose in there and run the water through it.

Let the car cool down naturally before you flush the engine side with a garden hose and you should not try and flush the engine while it is at operating temperature as the sudden change in temperature as the cold water comes in contact with the hot engine can cause cracking of block or head and warping that will cause the head gasket to blow.

minh · Post by **minh** » Tue Oct 05, 2004 8:08 pm

I was reading the workshop manual and the diagram shows two engine coolant temperature sensors and one thermostat.

which one does what? if the sensor is faulty which one would I replaced?

I think the thermostat is the sender unit to the temp Gauge?

Boris · Post by **Boris** » Tue Oct 05, 2004 9:11 pm

minh wrote:I think the thermostat is the sender unit to the temp Gauge?

The thermostat is simply there to stop the coolant from circulating when the engine is cold. But once the engine reaches operation temperature the thermostat opens. It simply uses wax inside the thremostat so when the wax heats up it expands and so on... similar to a thermometer... blah blah blah....

This let's the engine warm up quicker & reduces engine wear...

It's not really a sender unit...

minh · Post by **minh** » Wed Oct 06, 2004 8:00 am

Thanks Boris.

very informative.

What about the water temp sensor? where does that sit?
As sentry mention his one if faulty and the fan kicks in too late. Is it possible to remove these and clean these items?
Maybe they get gunk on it too?

Boris · Post by **Boris** » Thu Oct 07, 2004 3:39 pm

I'm not exactly sure where each sensor is,

a) Sensor that relays temperature to the gauge
b) Sensor that relays to the ECU
c) thermostat.

Both of these are to the left of the thermostat, below where your radiator cap sits. Have to say can't help you any more then that... correct me if any of this is wrong ppl...

I think if you are concerned, do a cooling system flush, like Danny said, to do it properly you really need to take out your thermostat.

minh · Post by **minh** » Thu Oct 07, 2004 3:43 pm

Is the thermostat the big flat Black plug that is held with two screws?

Boris · Post by **Boris** » Thu Oct 07, 2004 4:02 pm

The thermostat can be easily found by following the intake radiator hose to the engine, in other words the bottom hose.

The thermostat is located inside the elbow fitting that is screwed with 2 screws (size 10 me thinks), this elbow fitting connects the bottom radiator hose to the side of the engine...

A very very important thing is to not overtighten the bolts when putting it back on, as the housing is very easy to crack... with my old car i had to buy a new housing cos i put to much force screwing it on. If you have a torque wrench then just follow the torque setting from the manual. Or just tighten semi-tight.

If you are finding your system overheating it may be worth replacing the thermostat, as they don't really cost an arm & a leg.

Picture:

minh · Post by **minh** » Thu Oct 07, 2004 4:07 pm

sweet! Thanks Boris.

Its my mates car. he flushed it and the gauge stays low but ocassionally it goes above the half mark and the fans kick in and it goes back down.

But he didnt flush it with the thermostat out.
Non mivec car should be the same? Cause thats what his got.

once again *thumbs up* Very helpful indeed

minh · Post by **minh** » Thu Oct 07, 2004 4:13 pm

The funny thing is I always had this assumption the thermostat was some sensor with electrical wires going to it.
from what I can see thats just a mechanical item operated by some valve?

Boris · Post by **Boris** » Thu Oct 07, 2004 4:26 pm

lol

Yeah, it's all mechanical, operated by wax inside, so when the wax heats up and melts, it expands opening the valve letting the water circulate through the engine block. Or something similar to that...

There are varius thermostats, like which open at different temperatures, depending on the designed operating temperature of the engine

By flushing the system without removing the thermostat wouldn't really do anything as your only flushing the radiator, you really have to remove the thermostat, put the elbow back on, and flush it, by running the car, filling up the radiator at the same time with the top hose off...

I'll stop rambling now

minh · Post by **minh** » Thu Oct 07, 2004 4:28 pm

No NO. continue your rambling. Its very informative!!! thats tops.
haha Thanks

Jono · Post by **Jono** » Thu Oct 07, 2004 5:57 pm

ive heard by installing Thermostats with lower temp ratings, that it can improve power output...

it might be minimal gains, but is it true?

minh · Post by **minh** » Thu Oct 07, 2004 8:44 pm

Hey boris sorry to be a pain but when filling up. I should

Have the heater on?
run the car?
Have the top hose off?

which top hose and why?

lol

Boris · Post by **Boris** » Thu Oct 07, 2004 9:11 pm

It's Cool, let's expand on what Danny said:

dannyboyau wrote:But when you do it you need to remove your thermostat so that you can flush the engine side of the cooling system, then you can get a hose in there and run the water through it.

First step is to remove the thermostat, it would make it easier if you remove the intake piping out of the way, you then need to put the elbow back, without the thermostat, making sure you don't over tighten the bolts due to previous messages.

dannyboyau wrote:Let the car cool down naturally before you flush the engine side with a garden hose and you should not try and flush the engine while it is at operating temperature as the sudden change in temperature as the cold water comes in contact with the hot engine can cause cracking of block or head and warping that will cause the head gasket to blow.

Like Danny said, don't even think about doing this with a warm engine, do you want your engine block to crack?

Do this when the engine has cooled down. You simply have to undo the top radiator hose from the radiator, and point it downwards so that when the water comes out of it goes sort of down.

You should have a garden hose ready, and stick it down into the radiator hole (from which you just took of the hose). This all works best if you have a nozzle that you can adjust the flow on.

Ok, now your set, turn the car on... what now happens is... basically water will start flowing from the top radiator hose that you just undid.

Before all the water out of the radiator flows out, go to the hose and turn it on and adjust the flow to suit the outcoming flow. Try not to dryout your radiator.

If your cooling system is dirty, trust me, you will know, if it's very very dirty there will be orange gunk coming out from the top hose that you just undid.

Make sure that you stop before the engine start to warm up... the water coming out of the top hose should be clear by the end of this.

To finish up, simply put back the thermostat, and the hose. To put coolant in, basically you can just undo the drain plug. to let some water out, put the consistency required by the manufacturer in you radiator.

dannyboyau wrote:But you can use some type of can flush then according to the instructions on the can.

Like Danny said, you can purchase flushing stuff that you can use that will help the flushing... from any auto shop... if you want...

that's about it... feel free to add/correct me ppl...

minh · Post by **minh** » Thu Oct 07, 2004 9:20 pm

hahah GIVE THAT MAN A NEW!!!!

Im gonna print that out.

We should archive stuff like this.

After I finish my friends Car I will do mine too.

Oh man I need a life. Its 8.20pm and I am yapping on a fto forum about flushing coolant