New cap
 

I installed a new cap with the first radiator. Nothing bubbles in the over flow. Just seams to be leaking at a few parts of the seam. Where the plastic meets the aluminum. Is it possible I got 2 bad radiators. If so. What brand do you think I should buy? Also what is the correct way to blled the system. No bleeder on the thermostat housing. I also changed the thermostat. I ran the car after I but the new radiators in with the cap off and let it bubble out the air. For about 20 min's. Then burped it a few times. The Temp Gauge also reads ok. About 1/4 of the way up is all. Sometimes lower. The fans do work. It does see like it takes a while for them to kick on tho...Guess thats normal? Both kick on at the same time. Thanks again. I always wanted a Honda V6. But am getting kinda down with this problem. The car runs and looks great. Only 89555 miles on it. Shifts good,air works great. Tight steering and suspension. Just changed the oil. Mobil 1 and Mobile 1 Filter. I just hope it is just another bad radiator...Although it is a pain to change. The plastic shield ect. But I am almost a pro at it..HAHA. Thanks again. Have a good night. Tom

I don't think the V-6 has a bleed bolt on the thermostat. It's needed on the F-series 4-cyl because that's a high point where air bubbles will collect.

So the procedure for getting air out is real simple. Pretty much just what you did, except you should turn the heater to full-hot setting, so it circulates through the heater core. The air "should" collect at the radiator cap (assuming it's on a level parking spot).

In my experience, the fans don't switch on until the temperature gets higher than normal, above 1/2 on the gauge. Depending on the weather, it can be difficult to get them to come on without blocking air-flow from the radiator.

I haven't had one fail on me, so I can't say firsthand about different brands of aftermarket radiators.

Well...guess I am going to buy a OEM Factory Honda Radiator andkeep my fingers crossed. They say 3 times is a charm. Wish me luck and thanks again.

Question.
 

If you follow my thread you will see what I have done so far. Now before I install the OEM Brand new radiator and OEM themostat is there something other that can be wrong other than 2 bad aftermarket radiators ar not bleeding them right that caused them to fail? New thermostat,2 radiators,new cap (not oem). And both radiators leak at the bottom seam of the radiator. Seem to leak more when the car is cool. Also the fans dont kick on for a while..Then (both) come on and run for about 10 sec. if that then turn back of. The temp gauge never goes high...only about 1/4 to mid way at the most. Never bubbles into the over flo tank. Is this possible I got 2 bad radiators. And maybe did not bleed the system right that caused them to go bad. Or a Sensor? Head Gasket? Like I said no coolant in the oil, no smoke out the exhaust and the car runs great. Thanks again. I just want to make sure before I install the new oem radiator and cap that it may be another problem. Like a Coolant sensor not telling me the car is hotter than the gauge reads,air in the system ect. Thanks Again.

If the gauge operates normally (starts at the bottom left, and goes up to almost halfway as the engine warms up) the gauge is probably working fine. Even if there was air trapped in the system, I don't think that would cause the radiator to leak.

Ok.
 

So I should not panic and think it is a blown head gasket. Just 2 Bad Radiators made by Ready Rad. I pray thats all it is. The old cap and the new stant one never let antifreeze blow in to the over flo tank. Just a leak at the seams of the radiator on both new ones is where it was leaking. No hoses blew..no coolant in oil, no white exhaust smoke. The car runs great,idles smooth ect. Thank you very much for the info. Any tips or things after I install the new OEM Radiator and cap that I shold do? Have a good night. Please Honda Gods make this great car stop bleeding the greeen stuff. Only 89000 miles on her and garage kept.

I think it's been explained before, but after you fill the new radiator, turn the heater on full heat, then put the radiator cap on loosely (one notch, not all the way), and run the engine until the cooling fans come on twice. Some coolant may overflow through the cap while you do this, but it shouldn't be much. Check the level in the radiator again, and add some if necessary. That should be all you have to do. This procedure should be in the owner's manual. If you don't have one, you should get one.

PS: Are you sure the leak is coming from the radiators, and not a hose etc.?

Ok.. I got in the mail today the New OEM Denso Radiator and and OEM Cap. I also have coming 2 coolant temp sensors A and B.and another new lower rad hose. I am on vacation starting Sunday. The one thing I noticed is the on the new oem radiator the oem cap twists on pretty easy. The fist click it is very loose and can tell it will let air out...and the 2nd click seems much pretty smooth and easy. Question? On the after market radiator with either the old oem cap or the stant cap the first click seems real tight and the 2nd even tighter. Can it be the aftermarket radiator locks the caps down too tight and cause problems? If I run the car with the aftermarket rad and cap with one click it seems as tight as the 2nd click on the oem radiator. Wish me luck. This is going to be my 3rd attemp. Go Honda! Thanks Mothership for the answers or possible solutions.

Well, the way you describe the fit of the radiator cap, it might have allowed the system to reach too high pressure.

The fully-on position of the radiator cap has the little ears of the cap oriented side-to-side, square with the car. Not diagonal.

The cap
 

Well...The old rad is still in. I bent the tabs on the cap so it would fit loose. Took it for a ride and no leak, The hoses also were not hard like a rock. They had a little pressure...but after a few minutes the became soft. Like the cap let out the pressure. I am going to be darn mad if it was only the design of the after market radiators that caused the cap to go on too tight. I still have the new oem rad and cap hoses and sensors to install. Spent a ton. And it looks like it was a cap issue..What the heck. I bought 2 caps and it was the radiator that was the fault. Too thick where the cap twists on. Boy oh boy. Thanks again. p.s. I am going to install the new parts too be safe. What a ordeal. Thanks again for all your help. Wish me kuck mothership. ;)