zapp109

iTrader: (13)

I have a 93 mustang with 408 lq4 block and 317 heads with a valve job. Ls9 head gaskets. All arp bolts and studs. New 3 core radiator with 16 psi cap I believe that's what comes on mustangs. Trick flow steam tube kit on all 4 corners going to upper radiator hose. Turbo is s480r. Car has about 300 miles on it now. Car made 825 hp at 18 psi through unlocked 4l80e. On the dyno we never had any signs such as coolant smell or haze out of the exhaust. And I've never noticed any thing cruising around. However I keep having to add coolant.

Example is on dyno day it was running a little warm and I haven't checked it in weeks. It was like 6 inches low in the radiator. So topped it off, been driving a bit more and had to add to it 2 more times. About 3 inches low yesterday after driving 60 miles. And doing 2 pulls at 10 psi.

I've checked oil and spark plugs no signs of coolant. I'm thinking next maybe pull off my manifolds and see if I see any signs off coolant. Anyone have any thoughts?

Ryans99ls1

iTrader: (16)

Unless there is a leak in the system you dont know about, its drinking coolant. If it wouldnt have been for my old *** cap, i wouldnt have known mine was until the coolant light came on. Turns out i was lifting the driver side head. Never had a problem on the dyno but as soon as i hit the highway it would lift.

The Alchemist

iTrader: (19)

Isn't there a dye you can put in the coolant then use a UV light to check for leaks? With that much leaking, I would suspect a system leak vs. a lifted head, but you never know till you check.

zapp109

iTrader: (13)

Forgot to mention I also had a buddy do a hydro carbon test and it was good. So I'm sorta running out of ideas. That's why I wanted some other opinions.

Sarg

iTrader: (6)

Been dealing with this same crap. I did spot a tiny area by the radiator drain, but it does not seem it would leak out that much from there. Not even a visible puddle. Thinking of pulling manifolds on mine too but I would think with that much it would show as steam in the exhaust.

zapp109

iTrader: (13)

Damn sarg you losing as much as me? Yea I have absolutely no puddles or drips of any kind. No smell or steam from exhaust.

Forcefed86

iTrader: (4)

Do a pressure test on the cooling system.

Sarg

iTrader: (6)

Zapp, not that much, but after sitting for 2 weeks it was down like 2" in the rad. I have yet to pressure test.

zapp109

iTrader: (13)

Yea pressure test is next. I don't lose any sitting or anything I've noticed anyway.

SmartOJ

iTrader: (44)

loosing coolant here as well. constantly having to add but I dont have any visible leaks. i lightly copper coated my ls9 headgaskets and torqued them down once the the spray was tacky...wondering if i should have installed the heads dry...smh...

The Alchemist

iTrader: (19)

There was a guy on here who put a gopro in his engine bay and found a huge leak when he hit a certain psi of boost. I think it was near his radiator overflow. Normal driving it didn't leak, but when he hit full boost it was like a gusher.

So you could always toss a camera in there and see if you see anything.

SM105K

iTrader: (3)

At least it didnt lift the head and shoot the freeze plug out of the head........

yenkomike

iTrader: (2)

if you dont have a good working overflow tank it is going to go down and stay it needs to be able to push out coolant when its getting hot then as it cools it needs to be able to suck the coolant back it from the overflow . or else it will stay down 3-4 inches.

Ron_Stoppable

iTrader: (1)

Is the level in the overflow increasing. I was damn near about to pull my 5.3 out of my s10 because i kept losing coolant and i forsure thought it was something serious. I had replaced my rrservoir with a smaller one from summit and it would push while running. Got rid of that ****** and went back to my stock overflow and i havent had a problem. Collant has stayed the same level in the radiator and overflow for 2 weeks now. Id do a leakdown test personally if the cap isnt bad

zapp109

iTrader: (13)

Yes I've thought of the overflow but I guess never really understand how it should work. So here is what I got. It's a sorta cheap summit brand with a valve at the bottom to empty it. Never had more than 2 drops come out.

Blown06

iTrader: (32)

That would be me

Wicked69

I bet that can is the issue. How does it vent? Also are you absolutely sure that you had it full to begin with. When we first got mine running I filled it and same ****. Finally realized that it just hadn't been completely full yet. If I was to bet pull that over flow tank off and just let the hose hang (no overflow) drive around a few days and see if the problem still exists. I bet it won't

Ron_Stoppable

iTrader: (1)

Dude thats the same reservoir i had. Take that bullshit of your car lol. Something about those reservoirs are flawed because i havent had a problem since i removed it. For one the grommett on top always had air escaping out of it which prevented vacuum from building to pull the coolant back in.

yenkomike

iTrader: (2)

if that tank does not have a tube in it you need to turn it upside down so the hose can pull coolant back in.

zapp109

iTrader: (13)

Okay I'll give that a shot and unhook it. I've noticed hearing sir leaking from the top grommet as well. What are you running now that's working?