I have been pumping coolant by the gallon into the reservoir of my truck now for a couple of months. It seems to be losing fluid slowly. I have done the cardboard under the running truck test with no spots. The other day however after stopping to fill up the gas tank I noticed a puddle under the truck. further inspection showed me fluid everywhere under there probably being blown around by the fan I'm guessing. The temperature guage in the truck will randomly shoot up to off the charts heat and then will settle itself back down into normal range! Can anyone tell me what the heck is going on here please?

 

Get under there and thoroughly clean everything. Then use a pressure tester and look for leaks.

 

Thanks and I would if I had a pressure testing device. Any other suggestions?

 

Head gasket leak...had the same problem...or hope that your thermostat is stuck. Smell your coolant and see if it smells like exhaust fumes. The fact that your gauge goes way up and then down again means two things either a stuck thermostat or an integrity problem with the gasket. Perhaps a water pump but dont keep letting ur truck overheat...GL
P.S. Do a hydrocarbon test on the coolant to test for exhaust.

 

So after doing a check I found Water leaking directly under the center of the truck? Somewhere around the waterpump I think. Any ideas? Bad Pump?

 

They usually don't leak up there, BUT! - There's a weep hole on top of the pump. Pumps bad if coolant is spewing from that. Grab the fan while it's not running, check for bearing play. If the bearing decides to go out totally, could leave you stranded.

 

Thats a lot of coolant to be leaking from the waterpump but could be possible I guess. If its the pump there should be a track running down the front cover from coolant that has evaporated. Look in the valley (area directly under the intake manifold).There is a bypass tube that passes through that area that can develop a leak capable of losing a few gallons of coolant. The coolant can run out the rear of the engine and depending on how you park a nose down position for your truck will allow the coolant to run forward at the oil pan area. Also turbulance from driving can blow liquid round in all different directions under the truck. Check all hose connections and around the front and rear of the intake gaskets as well for coolant. Check the radiator hoses and radiator itself. The fan could blowing coolant backward from a leaking radiator or hose. Also as suggested above I would have a hydrocarbon test performed on the coolant. The symptoms you discribe regarding temperature spikes do have characteristics of a head gasket leak. Good luck.

 

Right. I was surprised to hear it was coming from the front. I agree, could be the radiator as well. I thought about that.

I think Dynotech has it - Leaking at the WP stem O-Rings for the heater core hard-line. Filling the valley, then leaching out back of the engine/ starter side (passenger).

Or the coolant hoses back by the firewall.

chaddarou, - your going to have to narrow it down a bit lol.