Ryleeryno

I replaced my engine 3 weeks ago and I've since noticed that I am loosing antifreeze from my Heater core line. I think it may be an air pocket in the coolant system and may be pressurizing the system. I replaced the radiator cap but it still hasn't bled air properly. I already tried relieving air through the bleed valve near the thermostat housing to no avail. I noticed when I open up the heat valve and allow flow to the heater core that it will stop leaking for a bit.

Any suggestions? I am loosing antifreeze more and more!!!

MrChad

did you bleed the system with the heater controls set to max heat? Do that so that the core will be open when you drain and add fluids.

Else you could have a head gasket failure.

Ryleeryno

The installed engine is a 99 2.3L VTEC with 28,000 miles. The car itself has 182,000 miles. The coolant is leaking from the upper heater core hose (weakest clamp in the coolant system??) I strongly believe there is a lot of pressure built up in the engine for it to be forced out of the heater line.

MrChad

My front radiator hose leaked at the block fitting for some time (it would get dry sitting idle all winter), I have to have the hose on just right--it's fine once I run the engine for a day or so after getting out of storage. I'll look at my helm later I don't know what to tell ya. Replace the entire hose and clean off the fitting, use a T-clamp?

JimBlake

Pressure in the entire system is gonna be about the same, controlled by the radiator cap. If it leaks out only one place, I'd blame the hose nipple or the clamp. Take the hose off, clean off the nipple really good, inspect the hose really good for cracking or ???. Maybe use a new clamp.

Is it leaking at the heater valve? Check to see whether the valve itself is what's leaking. It might not be the hoses.

Ryleeryno

It is leaking from the upper hose. Return hose I assume. The valve itself isn't leaking which is the lower hose. I'll try replacing the clamp and see what happens.

Also... How can I test the radiator fans? Is there a bypass or a plug that I can disconnect to see if the fans turn on? I've never seen them turn on yet even after 20 minute idle.

MrChad

I had this happen once when I didn't bleed the system properly, you must have air in there, if the upper hose isn't hot the thermostat isn't opening up and the fans won't come on. Open the bleeder, get some more coolant out, be sure the heater is on too. Make sure fluid is in the res. bottle too.

As long as the temp gauge doesn't go past normal you should be ok, it took some time for my fans to come on too.

JimBlake

The fan switch is in the thermostat housing (lower radiator hose @ engine).

Unplug the wire from the fan switch, jumper those together with a paperclip. Key on, that should make the fan run. If so, your fan fuses, relays, motors, and circuits are all OK.

This time of year, the fans hardly ever run. If they don't turn on after 20 minutes idling, what's your temperature gauge reading?