Coolant system flush

ParkRunner

Hi,
I have a 1996 Opel Corsa 1.2 litre and the engine tends to overheat if I get stuck in traffic. I have been told that I need to flush out the coolant system as there is rust inside.
Would anyone know any service centres that would do this..or anyone out there who would be able to do this? I was looking to do it myself but I cant get at the radiator hose clips so it will need someone with a bit more knowledge about this than I have. I live in Blanchardstown

Cheers!

Darragh29

EF wrote:

Hi,
I have a 1996 Opel Corsa 1.2 litre and the engine tends to overheat if I get stuck in traffic. I have been told that I need to flush out the coolant system as there is rust inside.
Would anyone know any service centres that would do this..or anyone out there who would be able to do this? I was looking to do it myself but I cant get at the radiator hose clips so it will need someone with a bit more knowledge about this than I have. I live in Blanchardstown

Cheers!

I'd just review the logic of what you've been told with regard to rust in the cooling system being the cause of the problem here.

Firstly, have you checked your coolant bottle and is there enough coolant in your engine?

Secondly, check to see if your radiator fan is turning on. Run your car and open the bonnet and let it heat up and run for a few minutes. If the engine is hot, the fan should cut in after a few minutes and then cut out again.

The most probable cause of your overheating, espcially if the engine is only overheating when you are stuck in traffic is that the cooling fan is not working. If this is not working, there is most likely a problem with the coolant temperature switch or the electric fan itself, assuming that there is no wiring problem in the circuit.

The problem could also be a thermostat which needs to be replaced, or it could be a water pump, but check the car for sufficient coolant and also check if the radiator fan is turning on and off intermittantly. If the answer to these two questions is yes, then you need to look at the possibility that the termostat needs to be replaced or the water pump. What I can tell you for certain is not the problem is "rust" in your cooling system, whoever told you this doesn't know what they are talking about! Problem is most likely the radiator fan is not working and this is due to coolant tempetarure switch or else a problem with the fan motor.

ParkRunner

The coolant level is spot on anyway, I got a better quality coolant today so hopefully that will help the situation.

The fan does come on alright before the temperature gauge goes into the red, the needle doesnt reach the red but I have to turn on the heaters full blast to help stop the temperature going too high. I bought a new thermostat as well today so ill try and get that put in and hopefully that will do the job!

Thanks for your help!

Darragh29

EF wrote:

The coolant level is spot on anyway, I got a better quality coolant today so hopefully that will help the situation.

The fan does come on alright before the temperature gauge goes into the red, the needle doesnt reach the red but I have to turn on the heaters full blast to help stop the temperature going too high. I bought a new thermostat as well today so ill try and get that put in and hopefully that will do the job!

Thanks for your help!

Also, check for any water/coolant leaks on your driveway. If you have, the problem is most likely your water pump is on the way out, although if this was the case, you'd have overheating all the time, not just when stuck in traffic. I'd say it could be your thermostat, if you are going at fitting this yourself, be sure you bleed all the air out of the system afterwards and make sure you seal up the thermostat housing site well. The quality of your coolant is not really important in the context of the problem you are having. The only difference a good quality coolant will make will be to lower the freezing point of the coolant solution depending on what ratio you mix it too, (coolant & water), it also acts as a corrosion/rust inhibitor. It won't do much if anything to assist or prevent overheating.

Also, for pig iron, open the oil filler cap on the top of the engine and see if there is a white-brown scum like substance in there. Also, try the same on the oil dip stick and also in the coolant bootle and check for a subsance that looks like peppered sauce! If you find any, you have a head gasket problem.

Be careful, as overheating problems tend to lead directly to head gasket problems if not sorted out.

BrianD3

A flush may help. The cooling system on your car is probably not as efficient as it was when new especially if coolant changes have been missed over the years (very likely) The result is corrosion and rusty crud restricting the flow of coolant through the rad, water jacket, heater matrix, any narrow rubber hoses etc. Generally doesn't cause a major overheating problem just hotter than normal running.

Also, something else that will contribute to a lack of cooling efficiency is the external condition of the rad. If it's the original one in the car it may well have loads of bent fins and be clogged with dead insects, leaves and other crud etc.