Pressure tested cylinders - 190, 180, 190, 190

Replaced head gasket, radiator, Honda water pump, new screw-down type clamps on all hoses. RTV on heater hose inlet, temp sensor gauge, ect sensor and upper radiator hose inlet. New fan switch, relay works, Honda thermostat, Honda radiator cap, clamped off overflow hose and overflow tank does not leak.

First the cooling system would cause overflow tank to fill up and leave radiator empty. After doing the RTV on side sensors on head and upper rad hose, system gained pressure and radiator is now taking coolant from overflow when engine cools.

System reads and holds 16psi when cold. After heating up and bleeding the system, turn off car and 16 dips to 13psi over a couple minutes time. Stays at 13 psi. Cannot find a leak anywhere. The head was machined when I did the gasket, did the gasket good, all torqued to spec with new head bolts. Top of block is level and square, and for 200k miles, the pistons all still show metal, no buildup or burnt oil on them. The engine is strong and has good compression over the whole block.

Every time I burp the system, looks like its totally burped, no bubbles, then depress throttle and get about 3-6 small to mid-sized bubbles pop up. Also the intake has a new gasket.

Also, the temperature gauge on the dash stays at the wavy line of the thermostat icon on the gauge. I thought it was supposed to be lower, but maybe the dash is different on a 99-2000 than a 96-98.

I am at a loss here and been going crazy trying to get this Honda to stop losing coolant. I thought I had all bases covered, apparently there are still issues. Any advice is greatly appreciated!

 

60 views and no one has touched this one!

Well I found out about the special Ultraviolet Dye you can buy. I got a 1oz. bottle at Advance Auto Parts for $7.99 and an UV Rayovac flashlight at Walmart for $9.97. Used some napkins to suck out a enough coolant from the top of the radiator where the cap is and dumped in the dye. Drove around for a bit and when it got dark I shined the light all over the engine compartment. Sure enough, the smallest hose going into the overflow tank was bright green! Got a 1/4" hose clamp at the hardware store, clamped it off and it appears that no more coolant is being lost from the overflow tank, and the radiator is full of coolant right to the top when I take off the cap. I also discovered a leaking transmission gasket which was shooting trans fluid inside the engine bay all over the evap canister, so now that's another issue. I recommend the UV method for any 6th gen Honda's 96-00' because this stuff will definitely show you where the coolant is going! Couldn't even tell there was a leak on that hose and it was in the most obvious spot. I did actually think the radiator I bought was garbage cause it cost $50 and I kept finding fluid all over the top of the fan shroud. So it had a lifetime warranty I brought it back and replaced it. If only I had gotten that dye sooner I would have saved the trouble. Oh also, the temp gauge has gone down a tad from staying at the wavy line, to a needles worth below the wavy line.

On another note, I did a PCV valve on it tonight, from the top. It's doable if you take the wire harness for fuel injectors off, throttle cable bracket, and another sensor with some type of magnetic bar inside it off. It was a pain in the *** but I got it done. Good thing I did it too cause the old PCV valve was 15 years worth of oil and sludge built up in there. Since doing that the engine has a lot of pep and I'm getting better gas mileage. Over 200 miles and still over 1/2 tank of gas.

 

sorry i only check this site once a week its usually dead here.