First of all, I'm glad to have found this forum. Looks like a lot of info and experience here.

Secondly and importantly, I have a 2006 TRX4 with the 4.7L engine (not the flex fuel). I noticed the other night that my temp gauge was almost tapped out. I tried to turn on my heater to get some heat off of the engine and noticed that I had no heat coming into the truck. I babied it the rest of the way home. I noticed a smell of antifreeze when I turned the truck off. I popped the hood and saw that the reservoir was pretty much empty. First thing that came to mind was a stuck thermostat.

I replaced the thermostat today and refilled with a 50/50 mix. I turned the truck on and attempted to "burp" the cooling system using the hex screw on the upper radiator hose. Not sure if I was successful (never did that before) but I left that nut unscrewed for about a minute until there was steam coming out.

The truck is still running extrememly hot and the heat is not working at all. Now the depressing part.. I hear a ratteling coming from SOMEWHERE under the hood. It's hard to pinpoint though. A buddy told me this sounds like a water pump that went out. Any thoughts on this? The truck has 20k miles on it and has had no problems at all until now.

My echelon of treatment was thermostat, burp system, fan clutch?, water pump, heater core. Does this sound like a good way to go about diagnosing this problem?

If anyone has any input at all, it would be appreciated. My google searches have run dry for the most part. I have read that it seems to be a pretty common problem on the 4.7 but i have yet to read what the problem/fix was.

Thanks
Sam

 

sounds like you have a good start on it by knowing what your doing so thats good . i would say water pump , but again i know nothing about the 4.7. but you will get r done ..sounds like you know a thing ot two .
and welcome to DF stick around we are a good group

 

Not sure if this helps, but I thought I would add that there is no CEL on or "check gauges". It's cold as heck here and there is no steam coming from the engine bay while driving. Looks like I'll be taking the wife's Jeep to work until I figure this out. Hoping to figure out a way to diagnose the water pump and the fan shroud (anyone know about this?). Then I guess a radiator flush? If you think that might help, can you tell me exactly how? I'd hate to pay those aholes $80-$100 to do it for me.

 

man with only 20k on it doesent it have a warrenty??? i would love to help ya out but like i said i no little about the 4.7 ...hears a free bump for ya

 

I'd guess water pump, too. Sure is early for that to fail, though. The 3/36 warranty has likely expired. I've not looked at the 4.7, but it looks like the Hemi version would be easy to change. If you grip the fan blades, can you wiggle the fan side-to-side? If so, the pump bearings are gone. Any leaking from the weep hole?

 

Sounds like a water pump failure to me too. You haven't noticed any fluid under the truck? Like mike said if the seals in the pump are gone you will have a drip or something coming out of the weep hole. Do you have any fluid on the passenger's side floorboard? It's surprising that you've lost that much fluid and didn't mention seeing any fluid anywhere. It wouldn't be your thermostat because it wouldn't cause you to lose fluid. The truck would redline on the heat.

 

Just to throw this out there, even though we havent seen any guys come in with it in a while, there was one time not too long back when guys with 4.7s were over heating left and right and blowing head gaskets like crazy.

 

I heard about the fan wiggle so I tried that a little while ago. I can wiggle it to the drivers side about a 1/2" it seems but once back centered, it will not wiggle to the driver's side. Not sure if that helps. No leeking that I can tell but we have about 3' of snow on the ground and a lot of melting snow coming off of the truck and it's hard to tell at the moment. Also, I live in a community and don't have a private drive or garage to help me tell.

Dumb question.. where exactly is the water pump on the 4.7? I hate these newer vehicles. I'm used to working on much older trucks. Nowadays there is no room to work and too many electrical sensors and vaccuum lines to tell where anything is. I miss the days of sitting on the fender with your legs in the engine bay. You could hold your beer while you spun your ratchet Now you have to take off about 549398 pieces just to see where your spark plugs are.

I always thought the water pump was inline with the fan clutch. Not the case it seems, unless I looked at it wrong. Hell, there are about 6-8 pulleys on that one serp belt.

 

Don't you put that evil on me, Ricky Bobby!

 

Yeah, the water pump is still behind the fan/clutch. No worries there, you can still have your beer. It's not that hard. lol