msmile Posted December 15, 2012 Share Posted December 15, 2012 Hi! My tt is overheating in higher speeds, so I'm thinking to start solving problem by changing 19y.o. oem radiator. Have anyone tried those cheap non branded aluminium 'performance' radiators (140-180 on ebay)? They look exactly the same as some good branded ones, and as far as I know they are the same in some cases, they just put a branded logo and double the price. Please, share your experience Thanx! Quote Link to comment Share on other sites More sharing options...
SteveC Posted December 15, 2012 Share Posted December 15, 2012 It was a little out of character for me (I usually only buy Toyota parts), but a few years back I took a chance on an aluminum radiator off eBay. I can't remember the exact price, but it wasn't much over £100 and I was surprised how well made it was when it arrived. It came quite quickly from China and, if I recall correctly, it is branded 'ASI' - or something similar. Fitting was straight-forward and I haven't had any problems at all with it over the few thousand miles since it's been fitted. Quote Link to comment Share on other sites More sharing options...
SPG Posted December 15, 2012 Share Posted December 15, 2012 OEM all the way, Copper core if i remember correctly and if it has managed to perform for 19 years then im sure its worth the initial outlay. Quote Link to comment Share on other sites More sharing options...
Dim Sum Posted December 15, 2012 Share Posted December 15, 2012 A lot of people will and agree that stock is the best because of the copper core, for me to change the OEM radiator will be purely for cosmetic reason. Quote Link to comment Share on other sites More sharing options...
msmile Posted December 15, 2012 Author Share Posted December 15, 2012 what im thinking is, tuned engine needs more cooling, so im not sure how many horses OEM radiator can cool down to Stevec: how many Bhp have you got in yours? Quote Link to comment Share on other sites More sharing options...
SteveC Posted December 15, 2012 Share Posted December 15, 2012 to Stevec: how many Bhp have you got in yours? It's at BPU level, so I guess somewhere in the region of 400ish. Quote Link to comment Share on other sites More sharing options...
listy Posted December 15, 2012 Share Posted December 15, 2012 People like Add Heywood iirc still have an oem rad pushing 700hp Quote Link to comment Share on other sites More sharing options...
Guigsy Posted December 15, 2012 Share Posted December 15, 2012 OEM all the way, Copper core if i remember correctly and if it has managed to perform for 19 years then im sure its worth the initial outlay. i agree, and iv been told by trader on here the same. oem is copper and more densely packed. why you would want a less conductive rad with less fins i dont know :S the oem one was cheeper too, Quote Link to comment Share on other sites More sharing options...
Dnk Posted December 15, 2012 Share Posted December 15, 2012 (edited) OE rad is over £300 i think plus its not bling, there's your answer to why people by aluminium ones Edited December 18, 2012 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
ripped_fear Posted December 15, 2012 Share Posted December 15, 2012 Go back into one of my old threads mate! Do not buy one, had no end of trouble with the piece of rubbish, Ring Chris Wilson and pay an extra £10 for an OEM one and have no trouble at all. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 17, 2012 Share Posted December 17, 2012 I paid for some flow and heat rejection tests on a new stock TT thick core rad and a couple of the at the time popular aluminium "performance" rads. I did used to sell an uprated rad, but the cost was fearsome and I only sold two. The people who do my intercoolers reckoned the "performance" ali rads were 20% less efficient than the stock rad. My properly uprated ones were about double the price of a stock one. They also made the comment that the stock rad was in the top 5% of road car rads they had ever tested, and up there with medium size truck rads Very efficient cores, good flowing header tank design, and you KNOW the pressure drop and flow rate across the cooling system is as designed. And it IS designed, critical, and takes a LOT of getting right. Fiddle and you may well have a bright and shiny rad, that's actually about as efficient as, or even less so, than a knackered stock one. Bear in mind the stock rad has to cope with Death Valley, steep hills fully loaded in tropical temps, and meet all OE specs for longevity and efficiency. Quote Link to comment Share on other sites More sharing options...
msmile Posted December 18, 2012 Author Share Posted December 18, 2012 Thanks guys! You made up my mind so maybe its not even worth to change my old oem as it looks fine from outside... Why is it overheating then...? Quote Link to comment Share on other sites More sharing options...
Dnk Posted December 18, 2012 Share Posted December 18, 2012 (edited) Whats the coolant look like ? is the expansion tank approx half full when its cold. Is the rad full to the filler neck when its cold ? Pop the bottom hose off the rad and run a hose pipe into the top and see how well it flows out the bottom, probably a little bunged up inside seeing as its very old. I'd personally buy a new o/e rad with o/e cap and at the same time pop a new o/e thermostat in it then re fill with fresh coolant. You'll need just under 10 litres for a full re fill and use Ethylene Glycol pre mixed, Toyota sell Cool Red and its approx £20 for 5 litres Edited December 18, 2012 by Dnk (see edit history) Quote Link to comment Share on other sites More sharing options...
Stevo Posted December 18, 2012 Share Posted December 18, 2012 If it's overheating, maybe its your waterpump on its way out too? Quote Link to comment Share on other sites More sharing options...
Ian C Posted December 18, 2012 Share Posted December 18, 2012 Something else you can do is pull the rad out of the engine bay and jetwash the fins. They clog up with a lot of road grime, which stops airflow - especially near the bottom of the rad. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 18, 2012 Share Posted December 18, 2012 Overheating checks: Rad cap, the rubber sealing disc, and the little one way valve that controls the overflow bottle. The little valve often falls off, letting water out, but not syphoning it back in as the coolant drops in temperature, and thus in volume. ANY doubts fit a new GENUINE cap. Pattern ones are often very poor. Thermostat not opening properly. Only real test is removal, and if you remove it it you might as well renew it. Like rad caps, in my (considerable) experience, genuine `stats are far more reliable than pattern ones. You will need a new outer sealing ring for the new `stat. I don't THINK they come with them. Blocked rad. This is very unusual unless someone has "repaired" a leak with Radweld, used in excess. More common is crumbling fins at the front of the rad, at the bottom, where wet leaves and dog ends gather. The damage would need to be extensive to compromise cooling to the point the car overheated in normal use. Weeping head gasket, usually a fracture in the shims around a rear cylinder. You need the right gear to check this. I use a two pronged approach. A chemical that changes colour if combustion gasses are exiting the water level just below the top of the rad cap. A gas analyser to also "sniff" for combustion gasses exiting the rad. Very rarely the gas level present is too low to trigger a response, but over time the coolant is pressurised sufficiently to blow the cap spring. You would probably see a rising level of coolant in the overflow bottle as the overheating occurred. If the head casting is warped due to overheating it's nearly always scrap. You can machine the head face flat where it contacts the head gasket, but the WHOLE head will be banana shaped, meaning the cam bearing journals are no longer in line. The cams will try and wear them straight. If one doesn't snap in the process you will get low oil pressure due to excess bearing clearances, possible valve train noise, and alloy debris in the lubrication system, wearing all other moving parts out prematurely. If it were an ultra rare casting this can be remedied, but the remedy is about 3 times the price of even a brand new casting from Toyota, let alone a good used one. The head casting is also likely to be soft after a serious overheat, and prone to subsequent gasket failures, as instead of sealing, the gasket beads will dig in and no longer maintain enough contact pressure to seal reliably in future. Most of the above applies to any OHC ally headed petrol engine with the cam(s) running directly in the head casting. Quote Link to comment Share on other sites More sharing options...
msmile Posted December 18, 2012 Author Share Posted December 18, 2012 Thats lots of information, thanks! I couldnt find this problem on forum, because its not very usual overheating. As far as i know, my car just had engine bottom cracked and replaced, so cylinder head is skimmed, cambelt, water pump and all the gaskets are new, but not sure if genuine. The cooling system is full with no air and non genuine new radiator cap looks like working fine, so i consider there may only be three things causing overheating - coolant, thermostat or radiator. Even with temperature reading on the dashboard just above the normal i can hear the coolant boiling at the top of the radiator... As far as i know the propper coolant shouldnt boil to at least 130 degrees by celcius, so maybe thats the problem Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 18, 2012 Share Posted December 18, 2012 Don't waste money on fancy coolant, plain water is fine for test purposes, apart from the fact it may freeze!!! Coolant "bumping" in top of rad may be because you have air in the system. Is this problem straight after the rebuild? If so, do this: Top up to the very brim at rad neck. Run at fast ideal, with cap off, when water drops, add more water, if it blows some out, ignore it, keep it running. All of a sudden it will probably drop a lot, keep topping up until things stabilize. If it goes berserk and blows huge amounts of water and steam aout you have a serious issue. If it ran fine after the rebuild, but suddenly started overheating I would suspect head gasket, cracked head, or faulty `stat. Or lousy rebuild Quote Link to comment Share on other sites More sharing options...
msmile Posted December 18, 2012 Author Share Posted December 18, 2012 Im pritty sure theres no air in the system... Nobody knows when this problem started, but as the engine block was cracked, i believe it was because of overheating before. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 18, 2012 Share Posted December 18, 2012 Blocks crack through detonation or freezing, I have NEVER, EVER come across a cast iron block that's cracked through overheating. How hot has this engine got? Given the history I'd say get it to a pro for proper evaluation. Personally I'd have found another engine rather than fiddled with the damaged one. Good luck. Quote Link to comment Share on other sites More sharing options...
msmile Posted December 19, 2012 Author Share Posted December 19, 2012 Well i have seen few cracked blocks in my life from overheating, but thats a very rare case of course. Rebuilding engines is my hobby, i have done arround 20 of them, so i got a clue, and this engine looks fine after all the tests i've done, sadly it wasnt me who did the repair before i got it. And the overheating problem doesnt seem so common, because usualy cars overheat on idle or low speeds if theres an air jam, or thermostat problem, but this one doesnt. I'll do the tests and i'll let you know what was the problem. Firstly i need to change the igniter which died today thank you all for the advices anyway Quote Link to comment Share on other sites More sharing options...
msmile Posted December 21, 2012 Author Share Posted December 21, 2012 If it's overheating, maybe its your waterpump on its way out too? Pump is brand new. Quote Link to comment Share on other sites More sharing options...
Kaan W Posted December 21, 2012 Share Posted December 21, 2012 Go back into one of my old threads mate! Do not buy one, had no end of trouble with the piece of rubbish, Ring Chris Wilson and pay an extra £10 for an OEM one and have no trouble at all. I bought one too and sent it straight back! I went to fit putting the 2 legs in the rubber holes at the bottom, immediately looked at the top of the rad and the left side of it was 1" away from the frame while the other side was touching! The damn thing was twisted. I went straight to SRD and bought one of there radiators and the quality and price makes it one of the best imo. Quote Link to comment Share on other sites More sharing options...
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