Alex Posted June 14, 2002 Share Posted June 14, 2002 I've changed the fluid's today... I flushed every single bit of sh$t out of the block, matrix and radiator...the expansion tank had a thick layer of sediment in it which was cleaned out...lovely new coolant put in and what happens..................it over bl00dy heats! Grrrrrrr Well the symptoms are; No overheating at idle...constant temp - normal When it overheats is when I am cruising at 2,800rpm+ (80mph in 6th) Temperature lowers when I turn on the heater and the heater works faultlessly. Temp does not necessarily return to normal when turn on the heater. The expansion tank fills up but never seems to get drained...it sometimes over flows. I'm hoping its a shagged cap as its really easy to push the spring in....I think it works one way intead of two ways. Can it still be a blockage?? I cleaned it a thoroughly as I could. Has anyone else had these symptoms? Boost doesn't seem to affect it....running at speed is what raises the temp....though obviously by booting it I'll run high revs and raise temps pretty quickly. Cheers All Quote Link to comment Share on other sites More sharing options...
Keith C Posted June 14, 2002 Share Posted June 14, 2002 Have to whipped out the radiator and checked it's not blocked up or anything? This sounds exactly like what I had with my old 89T, and the rad was shot - a replacement sorted it no probs. Worth checking out - otherwise those symptoms sound very BHG Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted June 15, 2002 Share Posted June 15, 2002 Change the bloody rad cap!!!!!!!!!!!!!!!! Then after that start looking elsewhere Quote Link to comment Share on other sites More sharing options...
Nic Posted June 15, 2002 Share Posted June 15, 2002 Alex I've had similar problems with mine over the last couple of months. Chris W helped me out with advice and said to first change the thermostat, did that but no difference. Next he suggested it could be either the viscous coupling on the fan or the water pump. I took it to a HK TRD garage and they diagnosed that the pump and the fan weren't working properly. They replaced the pump and serviced the coupling on the fan and this seems to have sorted out most of the problems I was having. I did do a high speed run though at sustained boost in 4th and 5th and the gauge did rise to about 3/4. I think the problem with mine could be the temperatures here (39 degrees today!) and the fact that I have an FMIC fitted which is blocking the flow of air at speed to the radiator. I'm hoping the new front bumper and cover above the FMIC to force the air through the rad will help. Do you have a FMIC fitted? I think Paul W had similar overheating problem with his because of the IC. I would try changing the rad cap and thermostat first, if that doesn't sort the problem then it may be the pump and fan the same as mine. cheers Quote Link to comment Share on other sites More sharing options...
Alex Posted June 15, 2002 Author Share Posted June 15, 2002 Originally posted by Martin F Change the bloody rad cap!!!!!!!!!!!!!!!! Then after that start looking elsewhere Its on order along with a thermostat I'm going to have Gav's spare stock one or Terry's TRD rad cap...I'm hoping that Terry finds the TRD one as I think it would be prudent to use a higher grade one as I run high boost. I don't have an FMIC so that isn't blocking the rad...and if I did I have a rad deflection plate like the bruce nomura one to redirect the air flow... Cheers all Quote Link to comment Share on other sites More sharing options...
Branners Posted June 15, 2002 Share Posted June 15, 2002 Dont buy the uprated one just because it can take more pressure, the stock rap cap is more than capable of dealing with whatever you throw at it. JB Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted June 15, 2002 Share Posted June 15, 2002 There is another reason for having an uprated rad cap, if i remember correctly. A higher pressure in the cooling system will mean lower temperatures, lower temperatures means less timing gets pulled and hence slightly more power. Not sure if this is 100% correct, maybe CW can confirm. Quote Link to comment Share on other sites More sharing options...
Branners Posted June 15, 2002 Share Posted June 15, 2002 Not wishing to put down aftermarket rad caps, but I have heard people question whether the rating on the cap is actually what it can stand up to.... JB Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted June 15, 2002 Share Posted June 15, 2002 Yes but you forgot the important bit. They look pretty! Quote Link to comment Share on other sites More sharing options...
Branners Posted June 15, 2002 Share Posted June 15, 2002 Its a Bloody Rad Cap Quote Link to comment Share on other sites More sharing options...
Gordon F Posted June 15, 2002 Share Posted June 15, 2002 Originally posted by Martin F There is another reason for having an uprated rad cap, if i remember correctly. A higher pressure in the cooling system will mean lower temperatures, lower temperatures means less timing gets pulled and hence slightly more power. Not sure if this is 100% correct, maybe CW can confirm. A higher pressure in the cooling system only raises the boiling point of the coolant. It also puts more strain on the radiator, hoses, heater matrix etc as they are all running under higher pressure, therefore more likely to leak or fail. A better way of raising coolant boiling point is to use an additive such as Red Line Water Wetter. Quote Link to comment Share on other sites More sharing options...
Alex Posted June 15, 2002 Author Share Posted June 15, 2002 I'm with martin they look pretty and have TRD written on them...what more could I ask for!! I didn't think about that water wetter stuff...I'll look into it. Quote Link to comment Share on other sites More sharing options...
Myles Posted June 15, 2002 Share Posted June 15, 2002 Myles trying to get in on the act: I'd recommend trying to sort the problem , rather than treat the symptoms , with standard Toyota parts (where available) ...I wouldn't have thought water wetter & the likes would cure your problem . Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted June 15, 2002 Share Posted June 15, 2002 Whats with all this big colourful text ??? I might be late in on this one but, Alex, have you had the system pressure tested? Quote Link to comment Share on other sites More sharing options...
Alex Posted June 15, 2002 Author Share Posted June 15, 2002 Originally posted by Matt Harwood I might be late in on this one but, Alex, have you had the system pressure tested? Is that when you take the cap off whilst the system is still pressurised and see how high the water/cap fires into the air??? If so we did that yesturday...my mate severly burnt his hand... Feckin' mechanics you'd think they'd know better!! The water fired up over the bonnet and made a right old mess!!! Well I guess that wasn't what you meant so please explain. Myles, I wouldn't use it to "fix" the issue but I would like to know if it can give me room to manouvre say on track days etc... Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted June 15, 2002 Share Posted June 15, 2002 Originally posted by Gordon Flynn A higher pressure in the cooling system only raises the boiling point of the coolant. It also puts more strain on the radiator, hoses, heater matrix etc as they are all running under higher pressure, therefore more likely to leak or fail. A better way of raising coolant boiling point is to use an additive such as Red Line Water Wetter. Yep quite right. As soon as i replaced a knackered rad cap on our MKIII one of the hoses gave up, just due to the increased pressure. Redline water wetter does have another great property, that of better conduction which would mean improved cooling. Defenitely a worthwhile product. But in Alex's case you need to get the std system working properly first before altering it. Alex, Did you try Halfrauds for a rad cap? I have a feeling they do have the right size. Quote Link to comment Share on other sites More sharing options...
Alex Posted June 15, 2002 Author Share Posted June 15, 2002 Nope, can't get there at the mo I'm at work I'll see if I can get out early enough to get down there. Quote Link to comment Share on other sites More sharing options...
Myles Posted June 15, 2002 Share Posted June 15, 2002 There is an american product , I can't remember the name right now (I think it's made by Evans cooling systems?), that can be used successfully on a non pressurised system .... Evans is marketed in the States , but I don't know of any distributers over here . Neither do I know if it's Toyota gasket friendly ...... ie. it may/may not be better to stick with the red For-life stuff??? Quote Link to comment Share on other sites More sharing options...
Gordon F Posted June 15, 2002 Share Posted June 15, 2002 -------------------------------------------------------------------------------- Originally posted by Matt Harwood I might be late in on this one but, Alex, have you had the system pressure tested? -------------------------------------------------------------------------------- Originally posted by Alex Holdroyd Is that when you take the cap off whilst the system is still pressurised and see how high the water/cap fires into the air??? Not exactly!! To pressure check your system You fit a dummy radiator cap connected to a hand air pump with a pressure gauge in line. (Sykes Pickavant make an excellent one) You then pressurise the system slightly over the rad cap pressure and check for leaks. You can also run the engine and any spikes in coolant pressure normally indicates a BHG:( Quote Link to comment Share on other sites More sharing options...
Alex Posted June 15, 2002 Author Share Posted June 15, 2002 Went to halfords...no joy Quote Link to comment Share on other sites More sharing options...
Matt Harwood Posted June 15, 2002 Share Posted June 15, 2002 I know the car is no comparison but I had a 3 litre Capri that kept overheating and my local friendly Ford dealer did a pressure test on the cooling system. I don't know exactly what they did because I left the car with them, but apparently it did show up fault. If I remember correctly, (bear in mind this was 10 years ago), it was a leaking inlet manifold gasket. I'm not sure if the pressure test showed this up or they were just lucky by removing this bit first! Quote Link to comment Share on other sites More sharing options...
Alex Posted June 16, 2002 Author Share Posted June 16, 2002 New cap didn't help...though much appreciated Gavin's help in this respect. Just found this on the SONIC site.... #3 (hard to tell what is wrong) You are cruising down the highway on a long trip and two hours have passed with no problems whatsoever. Then you look down and notice that your temperature gauge has started to climb and there are signs of coolant coming out of the overflow bottle. There has been no change in the speed you were travelling and the ambient temperature is the same. In this example it is safe to assume that your engine has a very small leak in the head gasket. When there is a slow leak in the head gasket allowing compression gases into the coolant system it takes time for the compression gases to force enough coolant out of the radiator into the overflow bottle and cause this condition. Driving this car in the city for a short 30 to 40 minute trip, where you stop the car and let it cool down, completely when you get to your destination will mask this condition. When the car cools down the engine will suck back in most of the coolant that it started to push out. Balls!...say it isn't true! Full doc here http://www.supras.com/~riemer/sonictech/cooling/cooling.html My car hates cruising at speed....starts to gain temp...the expansion bottle fills with 2cm's worth of fluid. I don't get the issue with idling OR running a 1/4 of a mile. If I rev the engine whilst I have my foot on the clutch..I can reduce the temp...I just blip the throttle and the neddle moves down a bit. If I drive it hard then kill the power completely the neddle goes mad, and want's to point due north!! Could that mean is a knackered waterpump or is it looking likely that it's a BHG on its way? If it's the later that'll just make my day!! F&*^%&^^&%^$&%^^%&$&*&!!!!!!!!! Just praying for some sort of miricle. Still she ran a 13.6...and kicked a higher spec supra's bum.. Quote Link to comment Share on other sites More sharing options...
Guest Martin F Posted June 16, 2002 Share Posted June 16, 2002 I guess the next step is to look at the water pump and viscous fan. Then if it's not these then it could be BHG.... Are you still spewing fluid into the expansion tank even with the new cap ? Quote Link to comment Share on other sites More sharing options...
Alex Posted June 16, 2002 Author Share Posted June 16, 2002 yes the flow of water either way is still happening. I maybe making this up but I think its faster to suck it back into the rad!... My old rad cap was rated at .9bar Gav's old stocker is 1.1bar...is that a J-spec to UK-spec difference or did someone put a cr@ppy cap on my rad. Anyone know how much a twin leccy fan conversion is??? I could then wire it up to the ignition and keep the fans on when the engine is off! The water pump is £110 - ouch! Has anyone by some fluke got a spare going cheap? Cheers Quote Link to comment Share on other sites More sharing options...
Alex Posted June 17, 2002 Author Share Posted June 17, 2002 OH MY GOD!!!!!!! You'd think they'd have a feckin waterpump in the country.... "you'll have to wait 3 weeks" 3 WEEKS are you INSANE! Quote Link to comment Share on other sites More sharing options...
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