jara Posted January 5, 2012 Report Posted January 5, 2012 I had a thread for this but i wanted to start over from scratch cause it was all over the place. So when my car heats up it's putting all the coolant into the overflow bottle and not taking it back. If i just go on 30 minute drives it's fine, but if it get's hot enough it puts all the coolant into the overflow bottle and doesnt take it back. when the car is cold again, I empty the overflow back into the radiator myself. Then it is good again for a week. I've replaced the thermostat and it has a new water pump. I'm thinking it might be the radiator cap, even though it's brand new it's for a recovery system set-up, but my overflow bottle only has one pipe going in it and i thought a recovery was meant to have two... I'm hoping the guy at repco has just given me the wrong cap. and really hoping it's not the head gasket any thoughts? Quote
altezzaclub Posted January 5, 2012 Report Posted January 5, 2012 I wouldn't expect it to ahve two pipes, they usualy suck back down the same overflow pipe. So, its not sucking back.. how much?? Half the level of water above the radiator tubes?? or only a cupful?? How hot?? Can you put a thermometer in the rad and measure the temperature to check that the guage is reding correctly? Just take it for a quick wiz to have the gauge just move, then take the cap off carefully & dip a thermometer in there while it idles. I'd expect it to read 75-80deg when the gauge shows just under half, which is where it should normally run. Have you done the headgasket bubble check?? Before starting it one morning take the cap off, full it to just about overflowing into the overflow tube, then start it and lt it idle to warm. The test ends when the t'stat opens and the top hose gets warm, as does the water. A leaking head gasket will cause t to overflow before it gets warm, and bubbles should appear. This is not a very good test, so if it looks like it might be leaking you need a leakdown test done, where you pressurise a cylinder with a compressor and make sure it doesn't leak into the water. The option is the liquid from Repco that changes colour in the rad if combustion gases leak into the water system. How is the radiator top, where the cap goes?? What you might have is an air leak that allows air to be sucked back in instead of water as it cools. How about having a radiator repair shop check it out?? Quote
madKE35coupe Posted January 5, 2012 Report Posted January 5, 2012 Another thing mate check to make sure the bottom half of the radiator isn't blocked, which would only allow whatever water can flow from the top hose and whatever is in the motor to heat up......which when it starts getting hot and building up pressure would be spewing it straight out the overflow on the reservoir, if that makes sense? Try taking the bottom hose off the radiator and holding a garden hose in the top and make sure the water flows freely and clean. If not......new or 2nd hand radiator may be the way? Quote
jara Posted January 5, 2012 Author Report Posted January 5, 2012 It leaves the overflow bottle full, only when it get's really hot though. half hour drives only leave a little extra in there. I've done the head gasket check a couple times, and i usually get a few bubbles and sometimes it does build up and overflow after a while. I'll see if supercheap has any of that head gasket-leak test liquid today. if it is the head gasket, is it an expensive fix? cause i can barely afford fuel at the moment :/ Quote
jara Posted January 5, 2012 Author Report Posted January 5, 2012 and i don't think it's blocked. when i first had the problem we flushed the radiator out with a hose and it seemed alright. and the radiator doesnt look that old, it's been replaced at some point Quote
altezzaclub Posted January 6, 2012 Report Posted January 6, 2012 (edited) sometimes it does build up and overflow after a while. A leaking head gasket makes it overflow before the thermostat opens, so check it cold before driving it. The compression that leaks into the water jackets can't easily go up past the closed t'stat and as more bubbles leak in they push the water backwards up the radiator and it over flows. Once a cup or two has been pushed out it doesn't lose any more because the bubbles can escape without having to push water out. When the thermostat opens warm water flows upwards and any bubbles do the same and escape under the rad cap. The other thing that a blown headgasket does it make it a bit hard to start on all 4cyl first thing in the morning, but then its fine all day. During the night a trace of water weeps into the cylinder and condenses on the plug, then it doesn't like to fire up easily. Once it has been driven & is warmed up it will stay dry until the next night. The head job is not a biggy in itself, but once the head is off you think.. 'might as well do the valves too, and maybe a little porting out of the inlets and raise the compression a bit..'. and away goes the project. Phone an engineer and see what a head skim will cost, then ask him how much for valves/seats as well. Then get a price on a head gasket set from Repco or whoever. Should total around the $300-350 mark I think, so you would need to be sure the head is crook before you did it. If i just go on 30 minute drives it's fine, This would point to it not being a head gasket, so hit up a radiator shop and see what they reckon. Edited January 6, 2012 by altezzaclub Quote
jara Posted January 6, 2012 Author Report Posted January 6, 2012 Thanks heaps man, you've been really helpfull. when i get the money i'll be doing that. hopefully it's just sucking air from somewhere. and thanks again :) Quote
jara Posted January 8, 2012 Author Report Posted January 8, 2012 Well the car got hot today after just 30 minutes ... that's a first. I can't afford going to a radiator shop, does anyone here that knows radiators live near lowood or chermside? Quote
altezzaclub Posted January 8, 2012 Report Posted January 8, 2012 Did you top it up before you went?? So it started full of water and when it cooled down it was short of how much?? If its not short by at least a litre the overheating is not due to water shortage, its just not cooling correctly. It may be that it just can't cool enough so it is pumping more water into the overflow than it can suck back. I've replaced the thermostat and it has a new water pump. when i first had the problem we flushed the radiator out with a hose and it seemed alright. and the radiator doesnt look that old, it's been replaced at some point So, new water pump & thermostat, and a clean radiator with good fins. Have you tried with without a thermostat at all?? What sort of driving? Around town and idling at lights, or on the motorways at 100kph?? Ours cooled much better after i cleaned all the rust out of the block, but that was with the motor out and the head off! Quote
Evan G Posted January 8, 2012 Report Posted January 8, 2012 take the radiator out and get it professionally flushed. cheaper than a replacement. then run some radiator cleaner thru it (or do this before getting it flushed) Quote
Evan G Posted January 8, 2012 Report Posted January 8, 2012 take the radiator out and get it professionally flushed. cheaper than a replacement. then run some radiator cleaner thru it (or do this before getting it flushed) Quote
jara Posted January 8, 2012 Author Report Posted January 8, 2012 it was full before i left and when i got home it's short of just a little bit over the over-flow bottle's amount (the bottle overflowed a bit). havent tried without the thermostat. and it's mainly around 100km roads (i live in the country) but i usually sit at about 85 -90k's. and I'll take it to the pro's if i ever get money for it Quote
jara Posted January 8, 2012 Author Report Posted January 8, 2012 i've heard you can bleed the system to get air pockets out. firstly i don't know what bleeding is sorry, but does it sounds like something that could help? Quote
altezzaclub Posted January 8, 2012 Report Posted January 8, 2012 Take out the thermostat. Drive the car for a day or two and see if that solves it. Then park it on a hill facing upwards, turn the heater on full, take off the rad cap, idle the warm motor and rev it occasionally. Squeeze the rad hoses a couple of times. Its just to get out any bubbles that may be trapped in the lines. See if that helps it. Then put the t'stat back in. it was full before i left and when i got home it's short of just a little bit over the over-flow bottle's amount (the bottle overflowed a bit). That's a lot! Check the temp guage with a thermometer so you know if its reading OK (stick a thermometer in the rad when you're idling it with the cap off to bleed it) Either its getting to boiling point or something is forcing that water out. Quote
jara Posted January 8, 2012 Author Report Posted January 8, 2012 (edited) is it a must to take out the thermostat to do that? it's brand new. and i'll see if there is a thermometer laying around the place too. and is it really a lot? it's only a small overflow bottle that was already half full, so it would have only been half a litre that it spat out and didnt take back I'll come back with my results tomorrow Edited January 8, 2012 by jara Quote
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