BlinkyBill

There is a temperature switch on the radiator which controls the fans which could be faulty. Or your main thermostat on the engine could be stuck which doesn't allow the engine coolant to circulate fully around the radiator, so the radiator coolant never gets hot enough to trigger the fans.

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Hey

It turns out my fan is working fine.

Its been around 2 weeks or so since my last post, I purchased another 6 Denso coils for cheap off somebody, and the car was working fine for the last 2 weeks, what I also noticed is that when the ignition coils are working well, the thermometer never goes over the halfway point, so it seems it may not be the heat that's degrading the coils, seems more like as the coils fail, the engine begins to run on less cylinders and this is what maybe creating the heat.

Any ideas as to what could be killing the coils if its not the heat?

Kind regards

I have taken two sets of ignition coils from my Is200.

I am wondering if there is anyway by looking at the coils to determine what the problem could be?

Perhaps they can be inspected with some electrical instrument?

I no longer need them so can send them off anywhere to be inspected before disposing if possible.

My garage doesnt know what the issue is, useless.

Regards

The fans operate at two speeds, slow when the AC is turned on and full speed when the water temperature reaches a certain temperature in the radiator. Therefore even though they work with the AC it doesn't mean they are functioning correctly.

They havnt entered that high speed mode for months, What broken components could stop the Fan from receiving the signal to turn on when the engine is too hot?

Underneth my IS200 automatic x reg I have noticed that there is quite a large board which is covering many parts of the bottom of the engine, from my research the coolant drain switch is under this - as I cannot remove it as I do not have a car lift to remove this cover, can I somehow drain the coolant from the top by opening the bonnet or some other way?

I have attached a picture of whats under my bonnet, can any of these pipes be disconnected perhaps?

Regards

I have a x reg petrol automatic is200.

I am planning to change the waterpump and thermostat.

I have never done this before, Have only been driving for 2 months and have not much experience with cars at all.

I would like some advice as I suspect from youtube videos its quite a long process.

Thanks in advance.

I have a is200 with an overheating problem.

When I turn my AC on, I see that the engine radiator fans come on, So I am wondering if its the waterpump or thermostat thats broken.

Here are some pics of my engine, I am not an expert but I have seen a part which looks similar to a water pump.

Can anybody confirm if this is the waterpump, Also, where would the thermostat be? and could I change these parts relativly easily or do I have to take all the timing belt parts off and so on?

Thanks

And here is that part from a different angle zoomed in.

And another

And another

When turning on my AC I can see that the Radiator Fans do turn on, I guess this rules out the possibility of broken relays and broken fans right?

However it still doesnt make sense that when the engine is overheating the fans do not come on at all. Shouldnt they be on during this time?

I had a look under the hood, I also noticed a fuse/relay type box which had fan 1, fan 2, and fan 3 written on the underside of the lid, each fan had a corresponding socket with a relay plug in it, is it possible that one/all of these are broken? If they are broke cud they cause the fan to not work?

Shame but there you go, re reading the posts I would have 1st checked the thermostat and then waterpump. Car is normal temperature for 10 minutes as engine warms up, if the stat pr wp are faulty the engine will then overheat which in turn due to the heat transfer will take out the coil packs.

I am going to try to check these myself(lost logbook so cant scrap yet).

Another thing I noticed is that many months ago the engine fans would come on, they havnt came on for months, I am assuming the fans are to cool the engine down, can this be the cause of the over heat problem?

Took it to the garage, apparently the tests shows ECU error numbers, coil pack numbers, air filter number and some others, Gona just scrap the car, had enough of it.

Thanks for the help guys.

Taking into account my most recent post above this, Does anybody know what the problem could be?

So I dissconnected the Battery for around 15 Minutes, unplugged one ignition coil.

The problem still exists.

The temp gauge is at the halfway point for around 10 minutes of general car usage, after this 10 minutes it goes right to the very top. At this point the engine becomes very bumpy and not much power when trying to accelerate after a brief stop.

I do think if I was to go and buy a 4th set of Ignition Coils this would completly get rid of this problem, but these coils would probably degrade pretty fast like the current ones have.

If it is getting that hot then you really shouldn't be using it, you could cause serious damage to the engine.

Difficult to tell remotely what is causing the overheating issue. Is it faulty coils causing the engine to run lean and getting hot, or is something else causing the engine to get hot (air lock, faulty thermostat, radiator fans, fuel injector issue causing lean running, restricted exhaust from cats breaking up) which then causes the coils to fail.

A Toyota engine will very rarely go above the middle on the temperature gauge if everything is working correctly, normally sits just below the mid point.

Going to d/c the Battery, will post back in 30 mins or so the outcome.

Regarding the heat, When I buy brand new coils and install, the engine doesnt get that hot, gradually as the coils degrade, the engine gets hotter, perhaps as the coils begin to not work, the engine gets hotter because only parts of it are working due to only some of the coils starting those cylinders?

A mechanic has suggested that perhaps it is an eletrical issue and the coils are being over powered which is causing them to break.

If the coils are truly being damaged then yes I would agree. The voltage regulator on the alternator could be faulty which is supplying too much voltage - easy to check with a voltmeter and if it is that then you are lucky the ECU and other electric components haven't been affected.

The only other way that the coils could be damaged that I can think of is if they are being overheated, but you would probably notice if the engine was running that hot.

Under the bonnet gets Extremly hot, So hot that the temperature gauge reaches the very top, then drops all the way to zero as it no longer registers the heat.

Once the car is this hot it will never start, I have to wait 2 hours or so for it to cool down.

Seems to me the heat gets worse when the coils degrade, better coils = no so hot, badder coils = hotter.

The coil packs are driven directly from the ECU so if they really are being damaged then maybe the ECU is at fault or an electrical issue. I'm not so sure the coil packs are failing though - worth getting the error code(s) as a first step and checking the battery voltage with and without the engine running.

When you are replacing the coils are you doing anything else that could explain the change - e.g. disconnecting the battery?

I do dissconnect the Battery when I change the ignition coils yes.

I still have all my old coils (Which I think are degraded).

Whenever I change coils the car does run very well, perhaps I should dissconnect the Battery for a while and see if it fixes the problem.

A mechanic has suggested that perhaps it is an eletrical issue and the coils are being over powered which is causing them to break.

Hello

I have an Is200 Automatic Petrol X reg(year 2000 or so)

Every two weeks now the engine begins to grumble and vibrate when the car is idle, along with losing power.

When I buy new Denso Ignition Coils and replace them, the car works fine, all power is back and the car runs smooth.

However over the period of 2 weeks, these begin to feel like they are degrading too fast, the car engine temperature begins to get hotter over the course of these 2 weeks as it begins to lose power and as they begin to feel they are degrading.

What could be the cause of this? I have now brought 3 sets of 6 Denso Ignition Coils, all are now pretty much dead.

Before replacing all of these Ignition Coils I replaced the Spark Plugs with a brand new set, so I dont think its the Spark Plugs.

Also the engine symbol is illuminated on the dash board along with the TRAC OFF flashing every 4 seconds.

I dont have any engine codes as I dont have a machine to check it.

seems to me somthing is destroying the ignition coils