ace32x

iTrader: (10)

Recently swapped springs out in my wastegates since the 8 psi ones were not holding, after that we have been having cooling issues. keeps pushing coolant out like it has air pockets. We pressurized the cooling system and scoped the cylinders, theres no leaks out of the headgaskets. the old radiator blew up around the seams and was leaking (replaced that now have a koyo one peice aluminum one). repressurized the cooling system after the new radiator was in and it held pressure fine. but still having the issues when driving. any thoughts on what this could be? its not down on power and theres no coolant in the oil. my only thought is maybe the seal on the turbo has let go already? garret 2871 water cooled unit

jerryd87

iTrader: (4)

wheres it pushing it out? the radiator? overflow? i would imagine if it was the turbo seal it would leak down the same as if anything else was leaking. im thinking this is a dumb question considering who i am asking but did you use one of the coolant bleeder funnels when you filled it?

ace32x

iTrader: (10)

its pushing out the overflow like theres pressure in the system. but thats where im stumped because we pressurized the cooling system to 28 psi and there were no leaks and it held pressure everywhere. and yea i bled it 3 times each time it pushes coolant out with the funnel bleeder

str8dum1

iTrader: (11)

hope its not, but thats how a dropped sleeve starts....

but you sure your overflow tank isnt just too small. my coolant rises an inch or so in the overflow between cold and hot.

jerryd87

iTrader: (4)

both rad hoses hot? if its holding pressure, not burning anything, nothing in the oil, and properly bled the only other thing i can think of is a stuck closed thermostat or some other obstruction in the lines somewhere. it might suck but mayby flush the coolant system to be sure its flowing properly, much sure the water pump isnt shot(ive had instances where it wasnt leaking but it dint work because the impeller busted loose from the shaft, happened on my 93 cavalier matter of fact.) and also check the thermostat in some boiling water on the stove to make sure its opening.

or if you really think its the turbo mayby pull that apart see if you can find coolant some place it shouldnt be.

actually thinking about it more if there was an obstruction or stuck thermostat it wouldnt go back down the funnel when you bled it................... im actually a bit stumped i would think there would be a leak somewhere. no high temps showing on the guage?

ace32x

iTrader: (10)

its the stock overflow, and its raising like 4 inches : /. ive thought about the sleeve. it would loose compression if that was the case and make less power wouldnt it? thats what gets me is it hasnt lost any : / and its not overheating

ace32x

iTrader: (10)

No high temps and the gauge is working properly. Thermostat is opening and closing. No oil or coolant mixing anywhere either, I'm left scratching my head

Blackbird CPV35

iTrader: (19)

I had an issue like this and it was a faulty Cometic headgasket. It would keep pushing coolant into the reservoir at higher boost and the coolant would never get sucked back down. This was on a brand new engine too, had to tear it apart and put a HKS headgasket in it and it was fine

rcdash

iTrader: (18)

^ agree - sounds like a headgasket. It might hold pressure fine at 28 psi, but cylinder pressures are much higher.

Alberto

iTrader: (14)

Motor is done.

I have experienced this issue myself. Ended up being the HG, past 8-9psi it got so bad it would spew coolant onto the windshield. Started with the overflow.

Good luck

ace32x

iTrader: (10)

it takes the coolant back in out of the overflow though, its acting as if its just like a bubble like its not being properly bled. im getting a powerbleeder and am going to try that tonight. i suspect it wont be as simple as that though.

And it did it driving home from my shop last night when it never got out of vaccum is the thing. -42hg as as much as it saw and the temp gauge started cycling up and down as the buble circulated through the cooling system

ace32x

iTrader: (10)

but wouldnt it smoke and have a loss of power if that was the case? and also there would be oil in the coolant or vice versa?

ace32x

iTrader: (10)

and if it is really done and has to come out, its getting an ls2 with a maggy on top

rcdash

iTrader: (18)

Well sleeve may have dropped just a fraction, headgasket may be losing partial integrity. Sounds like it's on its way out - sorry man. I would have a chat with your engine builder if it's a new motor.

ace32x

iTrader: (10)

that sounds like it could be the culprit. but even then wouldnt there still be oil in the coolant or vice versa? i dont see how it could leak out and have no mix in either of them. it is a new motor has 1700 miles now. i was there when he assembled it they were put on correctly and torqued down properly. darton west did the sleeving, so if thats the case and it did drop i'm SoL xD

ace32x

iTrader: (10)

reading through an old post and came across this, that describes my issue to a T. except i have a koyo rad and a new koy radiator cap that we just put in. Do i need a larger overflow maybe?

because it doesnt do it the first pull, usually the second or third after the overflow is already full.

Cux350z

iTrader: (162)

would your 28psi test be adequate:

1. Cylinder pressures are nearly 7-8 times that pressure
2. Will the cylinders be pressurized if the thermostat is closed and the pressure is being induced at the radiator cap?

rcdash

iTrader: (18)

I would definitely try a large overflow container and when cool just have it barely filled with any coolant in it. Get the funnel bleeder thing and bleed it with that - just revving under high vacuum. With the car hot it should only go so high in the overflow tank. With no boost in the motor there is still high cylinder pressure on spark ignition and burn so it can be hard to diagnose. You sure you are not just overheating due to fans not kicking on, t-stat not working etc?

Coolant pressure should hold steady state to whatever is listed on the radiator cap.

ace32x

iTrader: (10)

Yea the tstat is opening and fans are coming on. And the temp is staying fine it hasn't been going over normal operating temps it just pukes out coolant after the overflow gets full, its good for 2 runs on the dyno before it fills and then it just pukes out. It goes back down though after it idles for a bit but during the process air is getting in somewhere

midz350

iTrader: (4)

The VQ35HR uses a larger overflow tank than the DE.