Causes other than HG for bubbles in overflow (1 Viewer)

[jfz80]

Looking at a truck with the tale tale symptom.

200k. Under oil cap clean. Well aged and yellowed rad had 6” weeping crack at backside with minimal wetness. Fluid was full and clean. Temps while idling were 185. Did not drive and put under load

Any other likely culprits for blowing bubbles in the overflow tank?

Realize the most likely culprit but making sure I didn’t overlook other possible causes of pressurizing coolant system.

 

[LandLocked93]

Other possible cause in the interest of hope upon hope:
Recent work on the cooling system, bubbles are just remnants of the air purge process.

 

[LongDuck]

Is the crack in the back of the top (plastic) tank? When you say "yellowing" of the tanks, that's a sure indicator that it's end of life, and if it's cracking, it's done.

When you say it's a weeping crack, but minimal wetness,...??? Is it leaking or not?

IF it's leaking, coolant comes out when air goes in. That air makes its way to the top tank, to the Radiator Cap, and out the Cap to the overflow bottle. That radiator is going to be low on coolant every time you open it.

 

[jfz80]

Yes. Top tank is plastic and well past service life. First thing I noted. Same as blend valve.

There is a slight wetness at the crack but not puddling on the crimps. Assumed that if pressurized below cap then coolant coming out made sense but perhaps as it cools it could also draw in air?

Radiator was full. Overflow was low. I added water to overflow and ran it at 2k rpm and witnessed the bubbles.

 

[LongDuck]

Once it's hot, steam comes out of that crack, so you're not likely to see any pudding of coolant or the pink residue which is a tell-tale sign of Toyota Red leakage. I wouldn't run that motor knowing it has this radiator problem going on. At least not if you care about it.

Replace the Radiator and Heater Valve, look closely at all of the other "while you're in there" stuff (*water pump, hoses, thermostat, radiator cap), and then watch for other problems down the road - knowing your coolant system is overhauled.

Until then, the most likely cause of bubbles in your overflow tank is as stated - an unsealed radiator.

 

[Kernal]

@jfz80 : "Looking at a truck with the tale tale symptom."
Is that your current 80 or something else you're looking to purchase?

Buy (or rent) a head gasket leak detector kit from a local autoparts store.

Combustion Leak Detector

Amazing deals on this Combustion Leak Detector at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Amazon product ASIN B0007ZDRUI

 

[jfz80]

@jfz80 : "Looking at a truck with the tale tale symptom."
Is that your current 80 or something else you're looking to purchase?

Buy (or rent) a head gasket leak detector kit from a local autoparts store.

Combustion Leak Detector

Amazing deals on this Combustion Leak Detector at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

Amazon product ASIN B0007ZDRUI

One I was looking to purchase. None of the local stores has a test kit and it’s not particularly near to anything. Knew I was gonna be on road last two days before getting back so quizzing the brain trust here. Have my suspicions. Should have purchased or rented one while in bigger town today :/

Unfortunately another guy having PPI done so I’ll know by end of day if he purchased or back in my court.

Thanks.

 

[Kernal]

Appears to be in stock (if your in NC):

https://www.oreillyauto.com/detail/c/lisle/lisle-combustion-leak-detector/lis0/75500?q=head+gasket+block+detector&pos=8

 

[bj70bc]

could be both too......hg pressurizing stuff and cracked the almost caput rad

 

[beatle_bayly]

If possible, you could also pull the plugs and compare them. Often, with a leaking HG, coolant seeps into a cylinder and that plug/piston gets a steam clean and looks cleaner than the rest. And the coolant may also colour the sparkplug insulator. Sniff the plugs for the telltale coolant smell