Coolant Change

[angryengineer]

Dear Forum 🙂,

I am about to change the coolant on my 2005 Corolla 1.4 D4D saloon (Comma Xstream G30).

Is it advisable to replace the thermostat at the same time?

I do not know if or when the thermostat has ever been replaced.

[oldcodger]

Hi,

I did on mine at 100k miles, once under the alternator could see there had been a small leak from the thermostat seal., just make sure the little hole in the stat is uppermost.

Also used comma G30 after a good flush of the system and used De-Ionised water, ( in most large supermarkets/motor shops) , putting the concentrate in first then adding the water.

[angryengineer]

1 hour ago, oldcodger said:

Hi,

I did on mine at 100k miles, once under the alternator could see there had been a small leak from the thermostat seal., just make sure the little hole in the stat is uppermost.

Also used comma G30 after a good flush of the system and used De-Ionised water, ( in most large supermarkets/motor shops) , putting the concentrate in first then adding the water.

Can the thermostat seal be purchased independent of the thermostat?

[oldcodger]

Possibly,expect from a Toyota dealer, but they normally come with the new thermostat, if its from a reputable maker/supplier.

Would not go to the trouble of fitting one without replacing the stat.

[angryengineer]

On 2/28/2020 at 9:42 AM, oldcodger said:

Hi,

I did on mine at 100k miles, once under the alternator could see there had been a small leak from the thermostat seal., just make sure the little hole in the stat is uppermost.

Also used comma G30 after a good flush of the system and used De-Ionised water, ( in most large supermarkets/motor shops) , putting the concentrate in first then adding the water.

How many flushes did you carry out before finally adding the new coolant?

Is it advisable to change the water pump with the coolant?

Thanks for any information 🙂.

[oldcodger]

Hi,

You flush it until it comes out clear, think I did it twice, but your mechanic should know how to do such things.

Did think about replacing the water pump but seems there are two types and unable to indentify which one fitted my petrol, so did not bother, though no idea if its the same on yours.

Same with your other fuel tank post, surely a proper mechanic knows how to deal with that, no idea myself as never used diesel, though think a web search should provide the answer /methods.

[nginx]

Hi

Does it leak? You probably don't have to replace the thermostat if it works well and doesn't leak. Won't hurt if it's done right and if you replace it with a good quality one (and it seems like it's recommended at 10 years or 120K). The coolant change could be the perfect opportunity for that, but keep in mind that if needed you could replace it later, without the need to change the coolant (you'll be able to reuse the same one).

Regarding the water pump, the original one appears to be pretty good: many people never have to change theirs.