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Not Another Coolant Leak Thread?!

2007GrandPrixGT

New member
So here's the deal,

I have a 2007 Grand Prix 3.8L SC with 117000kms. I knew I had a leaking water pump, discovered also leaking tensioner elbows.

I took the day and replaced the tensioner elbows with aluminum elbows, installed a new bosch water pump, replaced the thermostat 180F. Mixed 70% Coolant/ 30% water. Ran the car for about 45 minutes with the funnel set from Napa to rid air locks.

For about 3 days to follow I didn't notice a leak per say but I went from a constantly fluctuating temp gauge to a gauge that didn't come passed the 3/8's mark once, except the one time passed half a little when I was bleeding the air locks on first start-up.

So now 2 weeks later I have a medium leek that seems to worsen when the vehicle is started/pressurized. I thought for sure it could be the lower hose I didn't check prior or when I was doing the water pump. I cleaned up the areas stained by leaks when I changed up the parts mentioned above to make sure everything is ok later on.

The water pump, the elbows, the thermostat, rad, hoses, heater core hoses, none of it are leaking. I can faintly see a pool of coolant somewhere down on the subframe. It leaks down off the subframe in the mid to far back side on the passenger side.

I don't have heavy grey exhaust, only for a few seconds on start up on a cold day. No oil in the coolant as far as I can tell and the oil level seems to be fine. There wasn't milk in the oil when I changed it in Dec. I have periods of heat loss in the cabin, temp gauge has gone back to jumping around.

where the funk can I find the leak? Cant really lift up the car enough to fit under to look.
 


Use a mirror and check the back side of the heater hose fittings on the tensioner assembly.

I had a 07 or 08 in at work that was leaking from there last week. The rubber o-ring failed.

Just something to check.
 
Well i discovered the timing cover is pissing coolant. I'm loosely familiar with how to go about changing the gasket out and replacing the timing chain, anyone know of a video out there i can use as a guide? Preferably a 3.8L application.
 
I don't know if there is a thead about it, but it's kinda straight forward.

Pretty much remove everthing for doing a water pump but going 2 steps further and removing the balancer and timing cover.

Not sure if what you said meant that you were going to replace the timing chain, but I wouldnt even bother as they can last well past 200k miles and further before they might be considered worn.
 


Ya i only have 117,000 kms on the motor but it just something id ratherdo, replacing the timing chain prematurely instead of screwing around with it later, i think its worth the 80 bucks extra.

I found pictures of the 3.8L block, all angles, it shows everthing so thats good enough.

Heres the link if anyone else wants to download the pictures. http://www.rockauto.com/catalog/moreinfo.php?pk=3637944&cc=1433703&jnid=483&jpid=0
 
is the coolant coming from a bolt? or out the side of the gasket?

if its leaking at the bolt, take that bolt out, and clean the threads and put thread sealant on the threads and put it back in.

your 100% sure its not a plastic elbow? you got two, one you can see, and a lower on under the alt near the p/s pump. that one leaks down the fire wall side of the engine.
 
Well i discovered the timing cover is pissing coolant. I'm loosely familiar with how to go about changing the gasket out and replacing the timing chain, anyone know of a video out there i can use as a guide? Preferably a 3.8L application.


I have this same issue but i am trying to figure out if it is coming from the bolts or the actual gasket. How do you discover it was coming the cover?
 
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