mull1986 Posted May 29, 2013 Share Posted May 29, 2013 My 94 n/a auto keeps loosing water from the expansion tank but the levels in the rad seem to be ok, can anybody shed some light on this please. Many thanks guys Quote Link to comment Share on other sites More sharing options...
Dnk Posted May 29, 2013 Share Posted May 29, 2013 First thing to try as its nice and cheap is fit a new o/e rad cap Quote Link to comment Share on other sites More sharing options...
mull1986 Posted May 30, 2013 Author Share Posted May 30, 2013 First thing to try as its nice and cheap is fit a new o/e rad cap Thanks I'll try that first. Quote Link to comment Share on other sites More sharing options...
Kaan W Posted May 30, 2013 Share Posted May 30, 2013 Is the expansion tank is full when the engine is hot then you check back once its cooled and the tank is empty? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted May 30, 2013 Share Posted May 30, 2013 New rad cap will 80% likely sort you out. Dnk gives good advice Very common problem, rad caps should be service items on cars this age. Quote Link to comment Share on other sites More sharing options...
mull1986 Posted May 31, 2013 Author Share Posted May 31, 2013 I've changed the rad cap and after two, 7 mile runs the levels seem to be ok but will keep an eye on it as I've just done the head gasket on it a month ago and this issue with the expansion tank was the first of many symptoms of a blown head gasket and I was worried that my engine was knackered!!! Best £30 I spent on this forum!! Thanks everyone Quote Link to comment Share on other sites More sharing options...
Dnk Posted May 31, 2013 Share Posted May 31, 2013 Hope its cured for you and glad to help, i always start with the cheap fix first, the mkiv engines aren't known for doing head gaskets. Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 2, 2013 Author Share Posted June 2, 2013 Just in case it happens again what are the other things to look at? Thanks Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 2, 2013 Share Posted June 2, 2013 Carbon monoxide in the coolant sniffer test, coolant system pressure test, remove and examine water pump, remove and change thermostat, remove and flow test rad, physically examine rad. In no particular oredr... Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 3, 2013 Author Share Posted June 3, 2013 Think I might have to do that cos I went on a 90 mile round trip and after the tank was empty and rad levels are down, even tho I put a new water pump and thermostat on about 8 months ago. Maybe time for a new rad but that got done 4 yrs ago by the previous owner Quote Link to comment Share on other sites More sharing options...
Josh42 Posted June 3, 2013 Share Posted June 3, 2013 Check the heater bypass hose that connects to the block right at the back by the bulkhead between the cam covers... Mine split and was causing a similar issue... Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 4, 2013 Author Share Posted June 4, 2013 Cheers kaan, I filled it the full line then went driving and the tank was empty when hot and cold later still? Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 4, 2013 Author Share Posted June 4, 2013 Carbon monoxide in the coolant sniffer test, coolant system pressure test, remove and examine water pump, remove and change thermostat, remove and flow test rad, physically examine rad. In no particular oredr... How do I check the coolant pressure, sorry if its a logical explanation Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 4, 2013 Author Share Posted June 4, 2013 Hope its cured for you and glad to help, i always start with the cheap fix first, the mkiv engines aren't known for doing head gaskets. Mine had gone cos when I took the head off I had water sitting where the pistons are and quite a lot of it, just unlucky I suppose :/ Quote Link to comment Share on other sites More sharing options...
Kaan W Posted June 4, 2013 Share Posted June 4, 2013 Cheers kaan, I filled it the full line then went driving and the tank was empty when hot and cold later still? Sorry but im having a hard time understanding this, what did you fill to the full line? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 4, 2013 Share Posted June 4, 2013 Cheers kaan, I filled it the full line then went driving and the tank was empty when hot and cold later still? Engine cold _ Fill rad to very top. Fill overflow bottle to line on the front of the tank "Full Level". Overflow bottle level should return to full level after use, and after the engine is stone cold again. Coolant system pressure holding test is done with special pump, by a garage. Checks whole system bar the rad cap holds pressure. Rad cap best just renewed with genuine Toyota one. DO NOT fit a higher pressure cap, they are for very special needs and NOT what you want. Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 4, 2013 Author Share Posted June 4, 2013 My mechanic friend says I should fill the expansion tank to the full line, is this right? Sorry but im having a hard time understanding this, what did you fill to the full line? Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 4, 2013 Author Share Posted June 4, 2013 Thanks, I have fitted a new one but not a Toyota one so will try that now. Engine cold _ Fill rad to very top. Fill overflow bottle to line on the front of the tank "Full Level". Overflow bottle level should return to full level after use, and after the engine is stone cold again. Coolant system pressure holding test is done with special pump, by a garage. Checks whole system bar the rad cap holds pressure. Rad cap best just renewed with genuine Toyota one. DO NOT fit a higher pressure cap, they are for very special needs and NOT what you want. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted June 4, 2013 Share Posted June 4, 2013 Don't just buy bits at random, if even a none genuine cap made no difference it's unlikely a genuine one will fix it. Sounds like it has a coolant leak, sometimes the hot water evaporates before a drip is found. Water pump bearing drain tube leaking? You need to take it to a garage and have a pressure test done!! Quote Link to comment Share on other sites More sharing options...
mull1986 Posted June 5, 2013 Author Share Posted June 5, 2013 Sorry but im having a hard time understanding this, what did you fill to the full line? I filled the expansion tank with coolant up to the full line and after my 90 mile trip it was completely empty?? Quote Link to comment Share on other sites More sharing options...
Kaan W Posted June 5, 2013 Share Posted June 5, 2013 I filled the expansion tank with coolant up to the full line and after my 90 mile trip it was completely empty?? Then you need a new radiator cap Quote Link to comment Share on other sites More sharing options...
Josh42 Posted June 5, 2013 Share Posted June 5, 2013 He's already fitted one Kaan:) Quote Link to comment Share on other sites More sharing options...
Kaan W Posted June 5, 2013 Share Posted June 5, 2013 He's already fitted one Kaan:) Then he needs to try some of the above Quote Link to comment Share on other sites More sharing options...
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