Need help with a coolant leak

[Chubbs]

here in dallas, the air temp changes 40-50 degrees. it was 70 deg on Fri and snowing Sat morning. whenever this happens, something leaks on at least 1 of our vehicles. the major temp swings are ******* seals with 200k miles and/or a good 15-years on them.

her 2008 the belt was squeaking on super cold mornings. i correlated that with a weeping water pump. it leaked when the temp changed so much so i went & replaced that even though the bearing was still tight. hated to do it only bc of the PIA coolant refill & air pockets that gave me hell.

i will remove the plastic guard and get a better look at the WP tomw if it warms up some. i’ve been under there 2-3 times looking for the leak. it’s all wet on the oil pan but i think it was dry up at the front.
FYI the oil pan was bone dry up until 2 weeks ago but both oil & coolant loss had occurred. i’ve never had to add oil bw changes and the coolant i’ve topped off with about 1/2 cup distilled water 2x in 1.5 years and neither was recent. it hasn’t lost any oil at all since i added 2 weeks ago (i checked yesterday) but i’m @ 5% on engine oil life and replacing it this week. i will be sure to check the level before i drain it to see if anything leaked after this cold front today.

will update tmw of anything found on further inspection. somebody asked about pics. pics are posted above in my last post

 

[Chubbs]

The highest point on the front of the engine that would have coolant is the throttle body. Check the small hoses going to each side of it. Next highest would be the coolant crossover ("steam vent") tubes. Pop off the intake duct so you can see and check these items.

the info i was waiting for. thank you sir!

 

[HiHoeSilver]

here in dallas, the air temp changes 40-50 degrees. it was 70 deg on Fri and snowing Sat morning. whenever this happens, something leaks on at least 1 of our vehicles. the major temp swings are ******* seals with 200k miles and/or a good 15-years on them.

her 2008 the belt was squeaking on super cold mornings. i correlated that with a weeping water pump. it leaked when the temp changed so much so i went & replaced that even though the bearing was still tight. hated to do it only bc of the PIA coolant refill & air pockets that gave me hell.

i will remove the plastic guard and get a better look at the WP tomw if it warms up some. i’ve been under there 2-3 times looking for the leak. it’s all wet on the oil pan but i think it was dry up at the front.
FYI the oil pan was bone dry up until 2 weeks ago but both oil & coolant loss had occurred. i’ve never had to add oil bw changes and the coolant i’ve topped off with about 1/2 cup distilled water 2x in 1.5 years and neither was recent. it hasn’t lost any oil at all since i added 2 weeks ago (i checked yesterday) but i’m @ 5% on engine oil life and replacing it this week. i will be sure to check the level before i drain it to see if anything leaked after this cold front today.

will update tmw of anything found on further inspection. somebody asked about pics. pics are posted above in my last post

I would definitely send a sample of the oil to Blackstone for analysis, especially since you're so close to changing it. On top of all of the other reasons, you will know for sure if there's coolant in it.

Over the years, I have had various coolant leaks on my Tahoes. It usually starts with me smelling it when I get out after a drive. If it's a slow leak (and no signs in the oil), I simply keep an eye and fill as needed until it reveals itself. Most often, it's while idling. I just let it idle in the driveway while I'm doing something else, watch it for a bit every few minutes, and eventually I see a puddle or a drip.

 

[Chubbs]

I would definitely send a sample of the oil to Blackstone for analysis, especially since you're so close to changing it. On top of all of the other reasons, you will know for sure if there's coolant in it.

dang! this why i hardly ever post on forums. get people to thinking the worst.

for SURE coolant is not mixing with engine oil.

i just wanted to know what all can leak coolant up on top of the engine. and if anybody mixes Zerex orange with OEM dex cool.

 

[HiHoeSilver]

dang! this why i hardly ever post on forums. get people to thinking the worst.

for SURE coolant is not mixing with engine oil.

i just wanted to know what all can leak coolant up on top of the engine. and if anybody mixes Zerex orange with OEM dex cool.

Not thinking the worst, just saying it's a perfect time to send a sample. Not only will you confirm what you know about your heads (or gasket), but you'll get a little insight to some other aspects of your engine. Well worth the $28, imo.

@iamdub is right on with the crossover hoses.

Otherwise, I stand by my "let it idle" method. You will find it eventually, even if it's got to get worse first.

 

[Chubbs]

here’s what i’m talking about.



this is supposed to be dex cool. zerex has a bottle, when you google it, actually says “DEX COOL” where this 1 has ‘american vehicle’

it was throwing me off. i compared the industry/engine spec codes and they all match up. so, zerex took the name dex cool off of their dex-cool antifreeze. at least where they sell it down here. i searched google and could not find a picture where ‘dex cool’ is removed from the label

 

[wjburken]

here’s what i’m talking about.

View attachment 238412

this is supposed to be dex cool. zerex has a bottle, when you google it, actually says “DEX COOL” where this 1 has ‘american vehicle’

it was throwing me off. i compared the industry/engine spec codes and they all match up. so, zerex took the name dex cool off of their dex-cool antifreeze. at least where they sell it down here. i searched google and could not find a picture where ‘dex cool’ is removed from the label

I would imagine it is fine as they it is for GM vehicles.

On a side note, I would save that jug when it’s empty and then next time by the concentrated coolant and mix it with your own water in that jug. The jug cost about the same but your not paying for water. Some folks say use distilled water. I use tap water and have never had an issue myself, but either way, you will save money.

 

[retiredsparky]

If you have rear heat, the most common leaks on older tahoes, yukons, etc are at the heater hose tee connections at the fire wall above the engine. O-rings are the way that the factory seals these connections. O-rings should not be considered a permanent connection as they shrink over time and will result in leaks, whether coolant, fuel, freon or transmission fluid. Replace all of the parts, including the tees themselves, if it is leaking.

On another note, auto parts stores have kits that contain ultraviolet die and a small ultraviolet flashlight for detecting coolant and other types of leaks. The kits work very well and are relatively cheap.
Larry