Unionised:
Help oooo!!!!

Just got a new tokunbo engine for my Rav4 2002 Model.

Well, my mechanic just removed the THERMOSTAT!!!

My engine is actually cooler now going by the METRE guage ON THE DASHBOARD.

But, my FAN is as noisy as its always been.

Always rolling at full blast.

Infact I can't sneak my car home, my children will always notice because of that noise.

Aside from this, no issues.

Abeg, who is in charge of the Fan Speed: the ECU or the THERMOSTAT.

Expert advice required.

Thanks.

Ikenna351:


Let me put it in a simple way you would understand, start planning buying another or replacing the newly purchased tokunbo engine you mounted, for this singular act of removing the thermostat, if you keep running that engine with that abuse.

The sooner you get that thermostat back in, the happier in future you become.

As for telling Toyota company that you knew better than all their engineers that ever existed in that company by bypassing the factory fan connections of that vehicle, you reap what you sow!

Ikenna

Unionised:
Help oooo!!!!

Just got a new tokunbo engine for my Rav4 2002 Model.

Well, my mechanic just removed the THERMOSTAT!!!

My engine is actually cooler now going by the METRE guage ON THE DASHBOARD.

But, my FAN is as noisy as its always been.

Always rolling at full blast.

Infact I can't sneak my car home, my children will always notice because of that noise.

Aside from this, no issues.

Abeg, who is in charge of the Fan Speed: the ECU or the THERMOSTAT.

Expert advice required.

Thanks.

Ikenna351:


Let me put it in a simple way you would understand, start planning buying another or replacing the newly purchased tokunbo engine you mounted, for this singular act of removing the thermostat, if you keep running that engine with that abuse.

The sooner you get that thermostat back in, the happier in future you become.

As for telling Toyota company that you knew better than all their engineers that ever existed in that company by bypassing the factory fan connections of that vehicle, you reap what you sow!

Ikenna

GAZZUZZ:


If in lagos come for a free thermostat and factory re-set of your cooling fan wiring.

Unionised:


Thanks for the offer sir.

How do I locate you?

Yes, I'm in Lagos, Alausa.

GAZZUZZ:
08033910382

GAZZUZZ:


If in lagos come for a free thermostat and factory re-set of your cooling fan wiring.

lomomike:


Lwkm Bwhaahahahahaha

Abeg you no go kill me with laugh. Although your statement is funny but I really admire your spirit man. Keep up the good works!

GAZZUZZ:


I have a soft spot for my NL cartalk peeps

Emperoh:


Export your services to Abuja. . . . . . my L needs attention.

Mike, stuff worsened this morning!

femi4:
A thermometer or temperature sensor picks temperature values depending on the state of the engine. The regional/enviroment temperature is inclusive.

For example, i noticed that the thermostat activate the fan quicker in the hot sun compared to early morning cold start.
The thermostat understand its work perfectly, at heavy traffic, the fan picks up immediately as if it was directly connected

Macmilla:

I'm not a mechanic and I probably don't know shii about cars, but simple physics will suffice here. All this talk about our temperature being too hot simply means that you guys don't know simple physics of thermostat function. Yes our temperature may be hotter, we have 32deg and they have 0deg, soo? The thermostat is designed to open at 82 degrees for instance, and whether you are heating from 32 or -3, everything eventually comes to 82 and voala!, the thermostat opens and maintains that temperature. The thermostat doesn't heat up ur engine nor does it cool it down, it only stops the cooling system to allow the engine get to 82deg or so. It's business is stopping you at 82deg, whether you are coming from 32 or -100 is not its business. Yanking it off simply means that the car can no longer maintain the engine temperature at 82 which is what the car needs to run efficiently. The implications of not running at that optimum temperature will be explained by the car gurus here.

I don't know how else to explain it.

Macmilla:

The fan control is similar in function but separate. At least for my car, it's very simple. It is installed on the thermostat housing so that it receives the same temperature that the thermostat receives. Once it's heated to 82* for instance, it closes the circuit and the fan blows and things start cooling. If it's cooled below 82*, it breaks the circuit and fan stops. Just like switching on and off the light in ur room.
I did a simple experiment to determine how the fan switch works and I was amazed at the result. I removed the switch on a battery powered torch light and connected the two wires to the wires on my fan switch which I brought out from the thermostat housing. I then placed the metalic tip of the switch in the flame from a gas cooker. After some seconds of heating, the torchlight came on. I removed the switch from the fire and after some seconds, it went off. I put it back in the fire and it came on again after several seconds, but this time, I didn't remove it. The light was on till I was scared I will spoil the switch and like b4, it went off after removing it from the fire.
The above experiment simply means that the fan will come on once a particular temperature is reached and will stay on to cool the engine until the temperature comes down. And like in the above post, it will switch on whether you are coming from 32* or -50*.
So it makes no sense keeping it on, running down ur battery and making the engine find it difficult to warm up.

lomomike:


Good morning chief, you mean the pulsating noise at high speed or the noise from the hub?

Emperoh:


The pulsation. . . . . i left it at Auto Genesis this morning. My front Stab linkages and suspension bushings are bad.
So I am changing those and then observe again. Dude is also suggesting my brake disc is 'burnt'. I am not sure how possible that could be. and if the linkage and bushing could be the fault.

Will do wheel balancing afterwards.

lomomike:


Auto genesis, where is it located?
Is it the auto shop in Dutse junction?

Macmilla:

The fan control is similar in function but separate. At least for my car, it's very simple. It is installed on the thermostat housing so that it receives the same temperature that the thermostat receives. Once it's heated to 82* for instance, it closes the circuit and the fan blows and things start cooling. If it's cooled below 82*, it breaks the circuit and fan stops. Just like switching on and off the light in ur room.
I did a simple experiment to determine how the fan switch works and I was amazed at the result. I removed the switch on a battery powered torch light and connected the two wires to the wires on my fan switch which I brought out from the thermostat housing. I then placed the metalic tip of the switch in the flame from a gas cooker. After some seconds of heating, the torchlight came on. I removed the switch from the fire and after some seconds, it went off. I put it back in the fire and it came on again after several seconds, but this time, I didn't remove it. The light was on till I was scared I will spoil the switch and like b4, it went off after removing it from the fire.
The above experiment simply means that the fan will come on once a particular temperature is reached and will stay on to cool the engine until the temperature comes down. And like in the above post, it will switch on whether you are coming from 32* or -50*.
So it makes no sense keeping it on, running down ur battery and making the engine find it difficult to warm up.

tonychristopher:
NOW I WILL HAVE A RETHINK MAYBE IF I PUSH A 6 CYLINDER ENGINE

9icetoo:

Tonychristopher, why don't you just want to learn? The thermostat is an electromechanical device. You are not paying me but I will teach you the physics behind it. Two metal strips with different rates of expansion are joined together to create a thermostat. When exposed to heat, the strip deflects or bends because the two metals are expanding at different rates. The thermostat in your car is purely mechanical because the heat source is from the water in the engine unlike the thermostat in an iron where the energy source is electrical. The principles of operation are the same though. The two dissimilar metals I talked about are in that spring you see on a thermostat. That is what opens and closes the thermostat. When functioning correctly, it does not impede the flow of water around your engine and radiator. It only causes overheat when it fails in the closed position.
Cars made since after the 90s have been tropicalised. It didn't cost car manufacturers an arm and a leg to do it.
Dubai is hotter than Nigeria. Some states in the USA are way hotter than Nigeria. Yet they all drive with their thermostats.
My fan spins once every three to five minutes or so in heavy traffic. My radiator is single cell and yet is efficient enough (engineers will appreciate this) to cool my coolant temperature from 96 degrees to 93 degree with just a fifteen second blast. (yes I have made a note of it). This is on a factory spec cooling system. So what do you need a double cell and a nonstop fan for? And I drive this car in ph so it is constantly in traffic. My car has never overheated. It has stood at a spot at ore for two hours with my engine running and ac chilling and the temp gauge didn't move an inch. Tropicalisation is an 80s topic. We are in 2015. Unless of course someone on this thread is driving a car made in the 70s, then they might just find this your stuff useful. I even doubt that.

Macmilla:
Please pals, i have a car that has been running without thermostat. The check engine keeps coming up indicating "cooling system malfunction". After some research, I understood that the code signifies that the car is taking too long to warm up. That makes sense as the car has no thermostat.
So I tried to put in a thermostat into the housing and drove the car. After less than 5min of driving, my temperature gauge hit the red zone. When I opened the hood, the coolant in the radiator was boiling. BUT I noticed the thermostat housing barely got warm. If the housing is cold, the thermostat won't open and the fan switch won't trigger the fan, that is fast overheating for me. I removed the thermo again and the overheating dissappeared. Fan still runs intermittently, being controlled by the temperature in the housing.

The question now is, why didn't the water in the thermostat heat up with the engine? What are the possible causes?
Thanks

lomomike:


A lot of things can cause overheating.
1. Bad thermostat, even if you've bought a faulty one will still over heat.
2. Bad water pump
3. blown head gasket, warped cylinder heads
4. Blocked pipes,
5. Bad heater core,
6. Leaking radiator and pipes,
7. Air bubbles in radiator
8. Bad radiator cover
9. Use of water only in collaboration with high temp opening thermostat
10. Improper cooling system bleed job.

Macmilla:
Please pals, i have a car that has been running without thermostat. The check engine keeps coming up indicating "cooling system malfunction". After some research, I understood that the code signifies that the car is taking too long to warm up. That makes sense as the car has no thermostat.
So I tried to put in a thermostat into the housing and drove the car. After less than 5min of driving, my temperature gauge hit the red zone. When I opened the hood, the coolant in the radiator was boiling. BUT I noticed the thermostat housing barely got warm. If the housing is cold, the thermostat won't open and the fan switch won't trigger the fan, that is fast overheating for me. I removed the thermo again and the overheating dissappeared. Fan still runs intermittently, being controlled by the temperature in the housing.

The question now is, why didn't the water in the thermostat heat up with the engine? What are the possible causes?
Thanks

adanny01:


How sure are you that the thermostat you installed is a good one? If it is bad and stuck in close position your car will definitely overheat.

Water pump may be another cause.

Macmilla:
Please pals, i have a car that has been running without thermostat. The check engine keeps coming up indicating "cooling system malfunction". After some research, I understood that the code signifies that the car is taking too long to warm up. That makes sense as the car has no thermostat.
So I tried to put in a thermostat into the housing and drove the car. After less than 5min of driving, my temperature gauge hit the red zone. When I opened the hood, the coolant in the radiator was boiling. BUT I noticed the thermostat housing barely got warm. If the housing is cold, the thermostat won't open and the fan switch won't trigger the fan, that is fast overheating for me. I removed the thermo again and the overheating dissappeared. Fan still runs intermittently, being controlled by the temperature in the housing.

The question now is, why didn't the water in the thermostat heat up with the engine? What are the possible causes?
Thanks

sultaan:


Model year and engine size of the car would help diagnose but with the information given we'll try using general diagnosis .
I will attach a web page for other too to learn how to diagnose.

You said thermostat housing was cold but that is attached to the upper radiator hose which goes to the upper part of radiator that was hot.

Try it again making sure thermostat is install properly in the right direction then run it till it gets hot while the car is os a nose up incline with radiator cap off so that bubbles can be purged if you don't know proper procedure.

http://garage.grumpysperformance.com/index.php?threads/how-the-cooling-system-works-basics.853/

Macmilla:

I tested the thermostat as described in the service manual by boiling it in water. It opened just before the water boiled and stayed open till the water cooled below about 82•
I don't know how to test the water pump in my car, but if it was the water pump, shouldn't the car still be overheating without the thermostat?

erico2k2:

Its easy one, take the v belt of and check if there is a play in the pulley system of teh water pump, also check for leaks, the major failure of the water pump is a broken impeller or leaks through seals or damaged bearing, there are no serviceable parts in most.