Ok guys, I'm in need of some advice. I have an intermittent coolant leak. I can see the results on my tie rod and the ground below. I haven't yet had a chance to crawl underneath to see where the leak may be orginating from. Looking from the topside, every now and then, I have seen fluid on top of the thermostat housing where the upper radiator hose goes.

I've been topping of the fluid about twice a week with what it leaks out. The leak doesn't always happen tho. Take today for example. I drove 30 minutes to work and then the truck sat for about 5 hours and had a decent sized puddle underneath. I moved the truck around the lot and let it sit for about 3 hours and when I came outside it was completely dry underneath. After work I went shopping after driving for about 45 minutes. On my way there I did briefly smell coolant with the AC going but that went away. When I came out from shopping it was again dry underneath. I'm pretty sure however when I get up in the morning I will have another puddle to wake up to.

Before I go firing up the Buckzooka I wanted to ask what I should look at when I get to crawl underneath. I know from hunting around on the net the lower elbow can be a leak point. Or is it just the beginning signs that my water pump is going bad.

I'm the 3rd owner I believe for this 2002 Excursion. Couldn't find many service records for it and the toad behind the desk was less than helpful when I went to inquire As far as I can tell it's still the original pump. I just rolled over 146k earlier this week. I did also last week install my sinister diesel coolant filter. All those connections are solid. I did attempt to replace the upper hose that runs through the serpentine belt but ran out of time and just left the old one in place and tried to make sure that the clamp went back in place.

So where should I look first to try and diagnose where the coolant is leaking from? Or is the water pump toast?

 

Most of the time is the t'stat housing, but you might want to check the water pump if its seeping, also check you oil cooler

 

Good point about the oil cooler....I forgot about that. I'll added it to my check list.

If I pull the T-Stat housing I would plan on changing the T-Stat itself too. What would Yall recommend? I've read somewhere that International had designed the 7.3 to operate at like 205 vs the 195 Motorcraft one. Is it woth it going with the high temp or would the stock be the better option. I live in Houston Texas so I don't see crazy cold winters here....if you can even call November thru February here cold

 

Your going to open a can of worms when you get into thermostats just look what happen in the obs section

 

Oh Lord was gonna give the higher temp one a try just for kicks an giggles

 

I chose to stick with the 195* thermostat. I like it better for when I am towing in the south. Heat kills.

I agree with the T-stat housing for starters. You can replace it for about $10. Until you get it figured out, you may want to slowly release some of the pressure after driving it to save on anti-freeze cost.

When you replace the top hose, are you going with the hose that routes around the serpentine belt?

 

Definitely going with the around the belt hose.....still boggles my mind the way it comes setup....I remember looking at the first engine and going

 

Look hard at the degas bottle.

 

I will.....it's not clear like a brand new one.....probably the original.....I do have plans on replacing that one too

 

If you find it is leaking around the housing, you can get a billet one to replace it and I would highly recommend some sealant on the base of the housing or top of the pump. I used some of this recently after my International water pump started leaking between the billet housing and the pump after a year of running.

No more leaks...

 

Finally got time to take some pictures this morning. Had a busy busy weekend thus far. I've already ordered a new T-Stat and billet housing. Hopefully they get here this week. With the wetness I felt above the pulley I think the pump maybe on its way out....just couldn't figure a good way to get myself positioned to see it.




Passenger side





Looking up from driver's side





Was trying to find the weep hole....phone is too big....stuck hand up there and its very very wet





Coolant level was full Friday morning heading to work. Its sat since I got home around 1430. Coolant level is now down to where my finger points





View from the top

 

Release the tension of the serpentine belt and wiggle the water pump pulley. Betcha a PBR the water pump is the problem. The coolant coming out the weep hole underneath gets flung hither and yon, tracking it gets impossible.

You have choices on the pump, either Ford style aluminum or iron International style. (IH iron link is for complete kit, just pump here.) To me the style you choose depends on what coolant you plan on running. Your X came off the lot with Ford Gold, and it looks like the same is in the degas bottle now. Running Ford gold or the top dog $$ ELC variety, you can stick with Ford Al waterpump and skip the coolant filter. If you want to run traditional green an iron pump with built in filter would be good, or the Ford Al with that Dieselsite coolant filter. I ran gold with the coolant filter for the last 4 years, used two filters and found zip nada zilch in the filter media when I cut them open. I removed the coolant filter setup in October. Filtering the coolant is well known to be unnecessary with the ELC, and equally so with the gold, in my experience. Use your google-fu wisely to research your choices.

Definitely a billet thermostat housing and a thermostat with integral rubber gasket. I've seen persuasive arguments both ways on thermostat temp, but I settled on stock in case I need replacement out on the road. Tempted to try a 203* just for kicks for local use.

 

So I got in my dieselsite 203 thermostat in the other day and I have a question. There is an o-ring that comes with the billet housing and one also with the thermostat. Do I need to fool with the thermostat o-ring or should I just use RTV to seal the thing up?