Searching for the Elusive Coolant Leak

I've been noticing some coolant spilled on the garage floor where I park. I took a look under the truck and see that it seems to be pooling on the front brush plate and coming from where the lower radiator hose hard line connects to the engine block. Or behind it or above it.
I guess it could be the connection of the small hose that T's off from there. It's not leaking very fast and doesn't dump it every time I leave it parked. This is the 3400 V6 engine with 197k miles.

I'll post a picture of that I'm seeing.

 

Wondering on the age of that hose? Is this a newly replaced radiator hose or an older one? Is the hose soft or brittle? Suggest if older, that it may have a crack in it that seeps fluid?

Location is near the thermostat, could that be the source?

What is your temperature gauge reading? Is the fluid{antifreeze} clean looking?

Just tossing out some thoughts.Good luck, Woodcutter

 

that picture is pointless if your trying to get our help in isolating a leak for you....
waterpump, timing cover, etc....
that pic is worthless from how im seeing it...

if you think its coming from where the large rad hose connects to the pipe, youre not showing us that view, youre showing us the top & the leak would be seen from bottom view...
this pic is totally inconclusive.

 

Pressure test it,,, sitting in the driveway, cold or hot.

 

The hose is pretty old, don't remember if I have ever changed it. Leak location seems to be behind the lower hose hard line where it connects to the engine. In the near future I'll remove the black guard from the front of the engine and look around with mirror and such. Supposed to rain tomorrow, so might be a few days.
Not near the thermostat, which is at the upper hose connection. Temp gauge reads 180 ish, not high. Antifreeze is clean looking, and it's not leaking much, but it is leaking.
Thanks for the input.

 

You're right about the picture. I was trying to show the lower area where the leaked coolant had gathered before dripping below, thought someone else might have experienced the same thing. I'm unsure exactly where it's coming from, cannot access it to see it. As said above I'll give it a closer look in the near future.

 

some auto part stores may have a pressure tester you can rent or borrow, that will expose the leak for sure....
pump system up to 15-20psi max & eventually you will see the smoking gun.

or...

$36 HZAUTOS 14PCS Pressure Leak Tester Tool Kit, Radiator Pump Pressure Tester Kit for Automotive Cooling System Water Tank Leakage Detection

https://www.amazon.com/HZAUTOS-Pres...ure+tester,aps,136&sr=8-83&xpid=MH_wFbxSuQ-cV

 

That’s good to know. Tomorrow I’ll see if our local Carquest has one to borrow.

 

Above and to the left of the thermostat housing is the water pump. I can almost guarantee you that's what is leaking

 

Could be. What is the degree of difficulty to replace the water pump?

 

You have to be comfortable removing and installing a timing belt. And the harmonic balancer (crank pulley) needs a puller tool to remove. Other than that it's just a bunch of 10/12/14mm nuts and bolts. As far as timing belt jobs go, the 3.4 is pretty easy

 

Clean and dry everything really well. Let it sit with a paper towel under the water pump. If it turns pink that's where the leak is coming from.

Not sure how the 3.4 leaks, but this is where the 4cly leaks from when the pump is failing.

 

Today I borrowed from Advance Auto a pressure tester for the radiator. We're expecting rain tomorrow, so it'll be mid-week before I perform the test. I too am suspecting the water pump.
Nov 2014 with 116k miles I replaced the timing belt and water pump. Now at 197k miles I have 81k and 10+ years on that timing belt. If it is the water pump, I might change the timing belt while I'm in there.

 

There really isn't anything else on the front of the motor that could leak other than the pump

 

Come on, midweek!!!
Could have had it done in less time than responding to us....
Get your big boy pants on & go do some work!!!!
Will just take 5 minutes or less, could take 30 seconds if its a good leak...

 

I'd say go ahead & do the timing belt while you're in there. You've gotta remove & reinstall it anyhow, and a timing belt kit with a water pump, belt, & new idlers isn't going to be much more than a standalone water pump.

Plus, do you really wanna reinstall a belt you're just going to have to replace in 9000 miles?

 

You guys are a tough crowd! Yesterday I had stuff to do and today it's cold and raining. Much better weather is forecasted as the week progresses.
As SpencerTacoSC suggested, if I have to replace the water pump, I might as well do the timing belt replacement.

 

So today is the day to apply the pressure test. First, I needed to remove the black plastic guard that covers the timing belt, water pump and other stuff on the front of the engine so I can see what's going on. But I couldn't slide the guard forward past the upper radiator hose clamp. So, I drained enough coolant to allow me to remove the clamp and slide the hose off to remove the guard. To access the radiator drain I had to remove the brush pans below the engine. So, I did that too and then reinstalled the upper radiator hose and poured the coolant back in. By that time, I had spilled some coolant on front of the engine, which might make it difficult to spot a leak. So, I rinsed it off with water and then ran some errands, driving it without the front engine cover.
Upon my return home, as the engine cooled off, I watched for a leak. Didn't spot anything.
After everything cooled off, I applied the pressure tester thingy. I pumped it to 15 psi and watched. Nothing is leaking. In 30 minutes, the pressure had dropped to 12 psi with no noticeable leaks. The only thing wet is the front of the block near the oil filter. I added a picture.
Hmmmmmm.... What to do?
I guess for now I'll use the truck with the front guard off and check it after each drive. I suspect the bearing seal in the water pump is allowing some seepage that accumulates on my under-truck guard that dumped when I parked in my garage. Any other ideas?

 

Get all that grime out of there using degreaser & water...
Get an eye on the waterpump, stains?
pressure test 20psi overnight, look at it in the morning....
Some scenarios they only leak under certain conditions & you need time....

Coolant can be absorbed by all that dirt & grime...
I dont even see the wp in that pic...

pic from bottom of engine showing evidence of coolant stains?

once again, you have a leak if youre getting drips on your floor...
Park it in a clean place & leave it under pressure till you get the puddle...
Follow the puddle & trail till you find the source.

 

You lost 3 psi over what period of time,,,? You have some sort of leak I'd bet.