Air bubbles in the coolant reservoir

[Doubeleive]

so the wifes 04 has a mysterious coolant loss, no leaks and passes a pressure test, also passes the test for gasses in the coolant, I see bubbles in the reservoir??, i'm stumped. looses about a quart every 2-weeks. water pump was replaced and replaced the crossover pipe because both were leaking. oil looks fine and nothing under the fill cap.

 

[Scottydoggs]

have you filled the rad via its cap? id idle it open cap till up to temp, then top it off and cap it.

the heater hoses at the fire wall connections can drip ever so slightly you wont notice unless you touch it and feel the little drip.

 

[Doubeleive]

have you filled the rad via its cap? id idle it open cap till up to temp, then top it off and cap it.

the heater hoses at the fire wall connections can drip ever so slightly you wont notice unless you touch it and feel the little drip.

i've filled this thing up I don't even know how many times, found a leak at the water pump bearing seal, replaced that, then I found the crossover pipe seal was leaking, fixed that, everything is bone dry and still loosing coolant. heater hose T's and connections front & rear are dry and I have checked them multiple times to verify, radiator is new, no coolant under it or on the sides. no drips on the ground, no traces of coolant under the engine area.

 

[Scottydoggs]

my old regal used to eat a qt or so every week. dumped blue devil in the rad and it stopped eating it. i also never found a leak, later blew the engine up, pulled the heads to see if it was a hg and they looked good. so real mystery. but the BD stopped it from disappearing.

 

[Doubeleive]

my old regal used to eat a qt or so every week. dumped blue devil in the rad and it stopped eating it. i also never found a leak, later blew the engine up, pulled the heads to see if it was a hg and they looked good. so real mystery. but the BD stopped it from disappearing.

I was thinking of putting something in it just to see what happens, not sure what's tried and true so much snake oil out there.

 

[Tonyrodz]

so the wifes 04 has a mysterious coolant loss, no leaks and passes a pressure test, also passes the test for gasses in the coolant, I see bubbles in the reservoir??, i'm stumped. looses about a quart every 2-weeks. water pump was replaced and replaced the crossover pipe because both were leaking. oil looks fine and nothing under the fill cap.

Didn't @iamdub's brother's truck have a very similar issue? His was such a slow leak it wasn't even noticeable til it was too late. Think his was due to the 706 heads.

 

[Doubeleive]

Didn't @iamdub's brother's truck have a very similar issue? His was such a slow leak it wasn't even noticeable til it was too late. Think his was due to the 706 heads.

this is a 2004 5.3l vin t I don't know if it has those heads or not, I will take another close look under it and check again but i'm stumped on the air bubbles

 

[Tonyrodz]

this is a 2004 5.3l vin t I don't know if it has those heads or not, I will take another close look under it and check again but i'm stumped on the air bubbles

I was just putting it out there and tagging him. Hopefully he might have a good idea what direction to point you in.

 

[Scottydoggs]

i can attest to the blue devil working. its thin clear liquid, no tar pellets to clog stuff up or leave a slime behind.

only thing is, if you flush your coolant you need to add more or the old missing coolant act starts up again.

 

[Rocket Man]

Never heard of Blue Devil...where did you hear about it @Scottydoggs ?

 

[Tonyrodz]

Never heard of Blue Devil...where did you hear about it @Scottydoggs ?

It's good stuff, not cheap tho. They sell it in parts stores around here.

I even found it on Walmart's site.
https://www.walmart.com/ip/Blue-Dev...pFwJ58OOoYnHeEOcEQCnQxreOyQzbDuxoCzYIQAvD_BwE

 

[swathdiver]

...radiator is new

Is it OE or aftermarket? Remember those aftermarket ones are lacking the restrictor for the system to function properly? If it's not that, then I would suspect the heads or head gasket.

 

[Doubeleive]

Is it OE or aftermarket? Remember those aftermarket ones are lacking the restrictor for the system to function properly? If it's not that, then I would suspect the heads or head gasket.

it's a new oem from the dealer, no exhaust gasses in the reservoir I was checking it for a few minutes even before I made the video fluid stayed nice and bluish color

 

[Scottydoggs]

its sold all over the place. all i can tell ya is it works, unlike all other snake oil bs tar pellets junk.

 

[Rocket Man]

Head gasket sealant or coolant stop leak?

 

[Fless]

have you filled the rad via its cap? id idle it open cap till up to temp, then top it off and cap it.

The OEM radiators don't have caps in these.

 

[iamdub]

Didn't @iamdub's brother's truck have a very similar issue? His was such a slow leak it wasn't even noticeable til it was too late. Think his was due to the 706 heads.

Affirmative. I never got to witness anything (bubbles in the tank, etc.) prior to it's failure and he's not one to know to look for anything to report to me. He told me after the fact that he had been adding coolant since he bought the truck and that the oil pressure had been gradually decreasing over the week or two prior to it losing all pressure. Yes, it was a Castech 706 head failure. '05 LM7.

 

[iamdub]

Unless it's just still working out air from when you replaced the pump and rad, it's gotta be compression gases. You could run it with the accessory belt off to rule out pump cavitation. The common Castech head failure let coolant leak into the top of the head where it would run down the drain holes and into the crankcase. It wouldn't leak into the cylinder or be pressurized by the cylinder pressures. Castech head or not, there's still a chance the head is cracked or the head gasket has failed.

 

[exp500]

I've seen the rear heat plastic fittings leaking a very tiny amount, until it got big enough to shoot onto exhaust manifold and stain it I could not find it. Now I wrap the suspect in TP and if it gets wet it stains or falls apart. Works pretty good if away from fan. Another likely spot is lower radiator hose at water pump, look for stains.

 

[Doubeleive]

I'm going to check it all over again, I just ordered a blackstone test kit because I suspect it's a head but it's not showing any signs other than the bubbles, oil level stays the same and looks normal, no problem other than slow coolant loss.