Just taking a look under the truck today and I spotted coolant on the front end of my drive shaft and crossbar. The rear part of the engine and transmission look a little wet as a whole.

I religiously check my coolant and I have it marked. I haven't lost much coolant if at all since I topped it off. I have my reservior marked where I have determined the sweet spot for the coolant, the point where excess coolant stops spilling from the overfill tube.

However I do need to replace my t-housing on the coolant system(in front of the radiator) as I have a stop gap screw in place of the original factory part. It holds well but seeps a little bit. I think I am getting air in the system some how because when I check the coolant I need to loosen cap some to depressurize and have some of the coolant return to the reservoir.

Where should I start looking? I have checked my oil and it is not milky. I haven't experienced any overheating or fluctuations in the temp gauge. Power seems normal and the engine runs fine.

 

1. The D2 ECU is programmed to make the temp gauge read 9:00 for a wide variety of temps. If over 9:00, that is the sign that beginning overheat has been reached, not very fair in my opinion. If you have a scanner or Ultra Gauge you can digitally see the temp from the coolant sensor and make up your own mind.

2. An auto parts store will rent or loan a coolant pressure tester, will take some adaptation to fit, but once attached you pump up the system and wait, it will show up as pressure gauge drop, or that with the external leak.

3. Rear of engine area could be head gaskets, but could also be the far cheaper to deal with valley pan gasket. Some members doing HG work have reported intake manifold bolts quite loose, wondering if that contributed to HG fail. See attached page from RAVE on the valley pan.

 

Okay will do. However if it's anything deep I'm guessing it's the passenger side head gasket. We replaced the drivers side one as it failed last year. With that came a new valley pan gasket as well. Valve cover gaskets were replaced as of a month and a half ago.

 

I don't know if you know this already but if you tighten your valve cover bolts at every oil change interval they will not leak and last a lot longer.

 

Okay thanks for the responses guys I'm finally trying to get to the bottom of this, this weekend. I just had one theory to run by just in case it was possible.

I am really not losing much coolant at all, but I am obviously losing some as it gets on my driveshaft. Is it possible that the heater core is leaking? My floor board is not soaked but I wanted to ask.

When the other head gasket failed I was losing loads of coolant. I do not currently have the water fall noise but I can hear a slight "trickling" on occasion.

Is it really common for valley pan gaskets to fail after a year of use? AB will be hearing from me.

My buddies got a pressure test kit so he will be helping me.

 

See attached, all the places that a hose can leak. The heater core has several joints from core to coolant source and return, any could be the one. D2 heater has coolant flow 100% of the time engine is running, no matter position of HVAC controls. So I would say no wet floor boards is a good thing. Unless the heater core is leaking inside the unit, and dribbling out the AC drain, don't know if that is possible, and you would think you would smell coolant inside the cab.