Losing coolant but not sure where
 

Hi all,
I replaced the radiator myself a few months back during the heat of summer. Replaced the upper hoses and t-stat as well. Flushed and bled the system and the truck was fine the last 3 months. Suddenly over the last month, we've had to refill the reservoir about once a week, as the truck starts to overheat. I top off the empty reservoir tank and then about a week later have to do it again. My wife only drives the truck to and from work which is about 5 miles each way - so 10 miles a day max.

I put the truck on the ramps, got underneath, used a flash light, looked, listed and could find no sign of a leak. I checked all around the engine, and as much of the new radiator as I could see.

She was told to pressure test the system, but I wanted to ask if ya'll could advise on how to locate the source of the leak.

Thanks!

You can try to use a dye and blacklight to find coolant. They have kits at the local autoparts for this. What was the reason for changing the radiator? Were you losing coolant before? Check the throttle body hoses. They get hard from the heat and are prone to crack and leak. Also check the coolant reservoir. The return nipples will crack especially if its overheating. The usual suspect with these engines when they overheat is a blown head gasket. Good luck

I replaced the original radiator after breaking the nipple on the return hose that had become brittle.

I would have figured that with a blown head gasket, fluid would get into the exhaust and be seen as white smoke.

Is there any remedy even as far as a temporary solution or how to test for sure?

throttle body heater connections or gasket are pretty common as well

Typically these engines have the head gaskets fail at the ends of the heads so coolant pours down the block instead of into the cylinders. You would usually get a pressurized cooling system if that were the case. Check the throttle body plate. You may also have a bad reservoir cap which could allow the coolant to escape through the vent tube, or it could be leaking out of the heater core into the passenger compartment but if you don't smell it in the car that probably isn't the case.

Pull the spark plugs and compare them to each other is an easy way. Mark them to remember which cylinder if you have one that looks cleaner or greyish than the others. You can do cylinder compression test also. Check the 5/16 coolant hoses going to intake and radiator. I had to replace every couple years due to becoming hard and brittle. Finally gave in and bought 5/16 silicone coolant hose. See how long they last.

I just had a coolant leak fixed that sounds about the same as what you are dealing with. I couldn't figure it out for the life of me. Turned out to be one of the hard, plastic coolant lines that ran under the intake. My mechanic replaced that line with a rubber hose and all should be good. I'll have to see how my coolant levels are in the next few days. We just got the truck back from him last night.

She was told to pressure test the system, DO IT.

I had replaced the brittle hose from the radiator to the reservoir a couple months ago. The throttle body does have a leak, but it looks wet, but not dripping. It does not seem to be more than just a seep. I want to replace that gasket though. I put a flashlight on the engine and on the passenger side, to the rear of the engine, just behind the exhaust manifold, i see wetness, and i can see some green coolant. I don't see any dripping or leaking to hit the ground, just traces of green liquid on top the bolts. That is about as far as I could see any external signs.

I had that exact same issue.. blown head gasket is most likely your problem.. get it checked ASAP! I did not because I was new to Rovers and ended up having to replace a blown motor...
Romove your oil filler cap and drag a finger inside it to see if you get a yellowish colored oil.. that means antifreeze is in there...