so i installed my new koyo radiator (all by my self to ) and i trpple checked to see if ihad done everything right. well i cranked it and car runs fine dosent over heat but sits at the same temp as my shity stock radiator. now im confused and dont know jack about radiators so could some please explain to me what might be wrong ?

 

There's no reason it should sit at a lower temperature now than before, unless you mean it was running too hot before. It just has more capacity to cool your coolant now. You might notice that it takes longer to heat up to operating temperature now, but it sounds like you have it installed right.

 

its no good! take it out and give it to me!

 

You just take longer to overheat, that's all.

 

Unless you have too little cooling capacity, the coolant temperature is controlled by the thermostat. The only time the radiator capacity will affect coolant temperatures is when you are generating enough heat that the thermostat is already open a significant amount.

 

i was allways asumed that bigger radiators always held temp at lower temps. see what i dont understand is my old radiator never actually heated up and always sat at about 95c untill you got on it the it would go up to about 110c and my new one sits at the same temp and basically does the same thing as the old one did. i was sitting at idle one day and it temps went pass 104 at idle so im very confused. im starting to think my motors going but that just me being parinoid i hope.

 

Are you ducted properly so all the air coming in the nose goes thru the radiator and not around it?

 

Are you sure your temp gauge is accurate? Those temps are very high as I'm sure you know. Your radiator will do next to nothing at idle with no airflow on it, but your water temp still shouldn't get that high. Did you properly burp the system? What are the air temps in your area?

 

You have another problem with your cooling system. Either there is air in the system, your fans aren't coming on, or your thermostat is bad. Given that your old radiator did the same thing, I would vote on your thermostat being bad.

I don't understand why people just start buying expensive parts when they don't even understand the nature of the problem. In this case, it's not much of a problem, because your stock rad probably needed to be replaced anyway.

Properly troubleshoot the problem or get mechanical help before just buying new parts. It will save you money and a whole ton of aggravation and wasted time.

Step 1. Get a Factory Service Manual if you don't have one. You can download one for free from the stickied thread at the top.

Step 2. Follow troubleshooting steps in cooling section, especially verifying proper fan operation. Follow through on any problems you find.

Step 3. Replace thermostat, which you should have done when you were doing the radiator. Don't use a parts store one, get an OEM Mazda t-stat.

Good luck.