Help coolant leak issue

[Indo93]

Ok back at this again. My 05 ls v8 is leaking coolant ( same spot drivers side tire) from the over flow (not tank new tank) , if i idle or put a/c on the car the coolant starts to boil & spill out the over flow an cause alot of steam, i put heater on and coolant goes back down
. I try to open bleeder valve but i get no stream at all. after hours of trying no stream of coolant lets out. Got a check engine light on,checked it got codes p1299 over head cylinder?.


Its really got hete in texas i have kids so much help as possible if any1 unsderstands what im saying kind of hard putting a todler to sleep an writing a thread.

In process of buy new cooling systen components o replace at the same time as i been reading in this forum.
I have new thermostat/housing,degas bottle,water pump, dccv. Any specific hoses i need to get ? Much ppreciated

 

[joegr]

GenII LS8 Cooling System Overhaul

 

[Indo93]

Thanks joe was looking for that thread. So this could cause my bleeder valve not to let no stream out? No matter how long i have my heater on n idle it, still no stream of coolant.
If i turn off the heater n let it sit. It'll boil & come out over flow. I been buying parts for a week now & its too dang hot to be riding with this heater on. Thanks

 

[Indo93]

Oh and is there an auxiliary coolant pump in the 05 or is it just the 1st gens? Or both. And would that cause my bleeder hose not to stream coolant?

 

[Firebrian]

Radiator is not blocked or obstructed with anything? Radiator fans are coming on? Drive belt tightened properly to spin water pump correctly? No signs of head gasket leakage into the coolant system? Some things that can lead to overheating at idle besides all the plastic parts failing.

 

[joegr]

Yes, failure to pressurize will keep the heater bleed from working.
Yes, all V8s (both generations) have aux pumps.
This is only one engine/radiator fan.
Head gasket leaks on the 3.9 V8 are incredibly rare. Degraded plastic parts are incredibly common.