Mk 2 Losing Cooling Fluid

[Mike246]

I have a much-loved 1998 GS300SE owned for 16 years which has suddenly started losing cooling fluid.

It is losing maybe 1 -2 pints on a 100 mile run and I can't figure out where it is going.

No symptoms which could be associated with a head gasket failure and no loss while standing overnight. The top hose seems good as does the visible part of the radiator. No warning lights on, engine runs sweetly and has not overheated.

I have renewed the pressure cap and ordered a bottom hose, just in case.

Any ideas or experience would be appreciated. This car is my baby and I want to keep it going.

[steve2006]

If it's not dripping out anywhere and at the amount you are losing it would be fairly obvious it is either going into the engine or if I assume correctly it could be going into the transmission fluid due to a faulty intercooler.

No starnge sweet smells inside the cabin? usually caused by a leaky heater matrix.

You could have the cooling system pressure tested which may help find the cause.

[Mike246]

Hi. Thanks for your response.

I just checked the transmission fluid and have previously check the engine oil. So signs of fluids mixing nor emulsification.

[Guest]

I have a much-loved 1998 GS300SE owned for 16 years which has suddenly started losing cooling fluid.

It is losing maybe 1 -2 pints on a 100 mile run and I can't figure out where it is going.

No symptoms which could be associated with a head gasket failure and no loss while standing overnight. The top hose seems good as does the visible part of the radiator. No warning lights on, engine runs sweetly and has not overheated.

I have renewed the pressure cap and ordered a bottom hose, just in case.

Any ideas or experience would be appreciated. This car is my baby and I want to keep it going.

Hi,

Have you had a look for radiator leaks when hot? My 89 MR2 has no visible sign of leakage then I was advised to look closely at rad when hot and sure enough when under slight rev there was a fine mist blowing out of one of the radiator cores. look for a stone chip or a dent.

[Mike246]

Thanks for your advice.

I believe that I have found the source of the leak. It seems to be coming from the radiator header seam at the front. When up to running temperature and pressurised I can see water creeping across the seam and dropping on to the front fins.

First question: Eurocarparts do a radiator at £ 74 as compared to around £ 300 for the Lexus part. Local garage labour costs will be much cheaper as well. I know it's an old car but would you chance it?

Second question: I found today that the aircon is not blowing cold. Coincidence? I think it is. I have not let the car overheat and I can hear the relay kick-in when I operate the aircon override switch. I cannot think of any reason why loss of coolant with frequent top-ups would affect the aircon. The fact is that I cannot remember ever having the system repressurised in 16 years of ownership. Should I have the system repressurised and is the old type (now illegal) gas still available?

Mike