2006 2.5T coolant leak question

[AnotherPassword]

Hi All,
Strange thing. I replaced radiator a few days ago because it had a pinhole leak. Wife drove it a few days, and I started getting a pretty good amount of coolant coming from the cover on bottom of engine. My thinking is that since it was not fully perssurizing, maybe the radiator fix fully pressurized the system and now a new leak? Not leaking around radiator or any of the hoses I worked on, and did not undo any hoses on engine side. Did not replace thermostat housing etc.
Took cover off bottom of engine, it seems to be dripping down oil filter area and drops on bottom of cover at bottom of balancer. Thought maybe water pump, pulled plastic cover. Pic of water pump, seems a little dirty but not leaking. Leak seems to be dripping around the bracket that holds the a/c compressor, so probably from above it? Would that be the thermostat housing? I don't see any coolatd, kinda hard to see in there, and it has been really humid here so not sure.
Am thinking that while I have it torn down might as well do the timing belt and water pump kit. When I bought it Carfax said it had been replace, but I have 130k miles on it and no sticker under hood showing timing belt service.
I am not positive it is the water pump given where the drips are, so had to just do water pump and still have a leak.
Thoughts?
thanks,
ds

[Rattnalle]

Isn't the oil filter pretty much right under the thermostat and it's hoses? Including hoses for coolant through the pcv if you have that kind.

[AnotherPassword]

Yeah, I am kinda leaning that way and going to do the thermostat housing. Any thoughts on the timing belt? It does not look real worn.

[Rattnalle]

I replaced mine this autumn at 150 000 km and 7-8 years and it didn't look worn either. The pulleys do look very clean though compared to mine. The red bearing seal in one of your pictures for example.

In Sweden the practice is for Volvo to replace the water pump only every second timing belt unless it feels bad in some way. Yours doesn't look like it's been changed but it also looks dry and not leaky.

Stuff some paper or rags around the thermostat hoses and see if they get wet.

[blandis]

No leak prior to work on the radiator... I would retrace my steps. Start up high with paper towels and work your way down until they are wet would be my approach. Any chance you pulled a bolt from block that requires a bit of sealant? Not even sure if this is a possibility and if so which bolt require sealant. Just a guess as I am unsure of what all was taken off to get radiator in and out.

I have same setup. I did water pump, tensioner, belt and all while I had it apart at 100K. Belt looked fine as did water pump. I knew I would not keep the car until 210K when next belt change was required. My approach is do it all while it was apart and not have to worry about tearing into it again for another 100K plus for any reason. Never had a WP leak on any of the various 5 cyl cars I have owned. Ran my T5 s70 225K before I changed the WP and it was fine.

[AnotherPassword]

Dang, good idea on the paper towels in and around tstat, I will give that a shot. Also, on the tstat housing, the other suspect is the hose that comes off of the tstat housing an goes under the intake. Looks like it connects to a metal tube and that and a wire are in a sleeve that I can't see where it goes. Is there a diagram that shows where all the coolant hoses go? I have not seen that one coming off the tstat in any pics.
On tstat housing assembly, I see everything from OEM to Dorman, is there one that is more recommended than others?
Thanks again for all the input.

[oragex]

Careful with the paper towels not to get trapped into the spinning belt. I woukd guess the hose to the thermostat is not tight or doesn't seal properly. The water pump seems to be stamped Volvo so should be good up to 200k miles. The belt looks recent but double check for cracks on the other face of the belt. Thermostat don't touch dorman, use Beck & Arnley or Volvo

[Roger_850T]

If you can, it's sometimes helpful to pressurize the system cold to help track down leaks. I have a little hose section that has a Schrader valve and a gauge, and I put it in the line by the coolant reservoir, then pressurize to ~10psi or so with compressed air. When it's hot, the coolant can come out as vapor and be tough to find, but when it's cold you can see it dripping easier. Plus, you're doing it when the engine is not running, which means you don't have to worry about getting caught in moving parts...

Roger

[rakesh4404]

I have the same problem, after recent radiator job the leak from the radiator stopped but right under the Engine/oil filter the Coolant is leaking. Not sure if I snapped something during my work.
Any guidance will be helpful.

[leatherntextilec70]

I recently noticed the EXACT same leak on my 5 cylinder after taking care of all the other leaks. From below it looks like its coming from between the ac bracket and oil pan and leaks down the filter and pan the same way as your pictures. I have been looking at the car for days trying to find the source, looking with a flashlight at all angles and even breaking out the digital inspection camera. On the second try with the inspection camera I finally saw a drip of coolant forming on the under side of the thermostat housing. Looking from above I can see the side of the thermostat housing (aluminum piece that goes from thermostat cover to cylinder head) is wet and coming from the thermostat cover. Very difficult to see at first since its all shades of grey with little visibility but I am certain this is the source, at least on my car. Likely the o ring for the thermostat is bad, or the thermostat cover is warped.