mike13

iTrader: (27)

After I make a pass my water level drops about 1 quart, just low enough for the low water symbol to light on the dash. Doesn't seem to drop any lower when making further passes. The water is going into the overflow but doesn't siphon back. no other signs like water in the cylinders or around the heads.

Car doesn't run any hotter or show any signs of having issues. Using MLS gaskets on a iron block 390, 83mm turbo on 14lbs making 800-820rwhp.

Is this common or do I have a problem or overlooking something?

Thank You

Forcefed86

iTrader: (4)

Do you have any sort of catch can or evac system? Anytime I was pushing coolant I'd see it there first. Could just be your coolant system finding it's "happy place" .

mike13

iTrader: (27)

yes catch can, nothing unusual. Hope it's the " happy place" for the coolant level.

Forcefed86

iTrader: (4)

You'll probably be fine. Usually if you push coolant into the cyls you get a smoke show as well.

Pocket

iTrader: (22)

^ And the O2 sensor for that bank flips out

Ryans99ls1

iTrader: (16)

You are probably lifting the heads very slightly. Mine did it and did exactly what yours did. When the headgaskets got bad enough, it was pushing enough coolant into the overflow to blow the cap off at WOT. No smoke either. Swapped to ls9 gaskets/arp headstuds, problem gone.

mike13

iTrader: (27)

[QUOTE=Ryans99ls1;17392634]You are probably lifting the heads very slightly. Mine did it and did exactly what yours did. When the headgaskets got bad enough, it was pushing enough coolant into the overflow to blow the cap off at WOT. No smoke either. Swapped to ls9 gaskets/arp headstuds, problem gone.[/QUOTE

Thanks, I have a set of LS9 headgaskets on the shelf. I'll pull it apart if it gets worse.

Vetal

iTrader: (3)

I have similar problem. After few passes at 14-15psi coolant level in my radiator drops by 3-4 inches. And I don't see it coming back from overflow tank. In fact I don't see this ~quart anythere. What the hell is happening?? Where does the coolant go?

Ryans99ls1

iTrader: (16)

Like i said above, you are probably lifting the heads ever so slightly and consuming the coolant. Its what happened to mine. It started just eating coolant and eventually it began pressurizing the coolant system and blowing the overflow cap off. It starts off as a very small headgasket breach and normally gets worse over time (i had stock 50k mile graphite gaskets, stock headbolts and stock heads).

The engine suffered no damage but driver side pistons were clean as whistle when i pulled the heads off lol

Vetal

iTrader: (3)

OK but where does the coolant go? It can't be "consumed" in cylinders because pressure is blowing it away from cylinders. But where?

Twin turbo c5

Your probably good. I've had that happen.

vwdave

iTrader: (3)

Just keep adding boost till you smell coolant, then back off.

offaxis

iTrader: (19)

Out of the exhaust .

Twin turbo c5

I've been losing water for awhile on my 6.0 I turned it up to 20psi last weekend at the track and a finally blew the gaskets but my motor was bone stock with factory head gaskets and 182,000 miles.

Ryans99ls1

iTrader: (16)

This.

25thhawk

iTrader: (3)

Try a new radiator cap first. Mine would heat up, fill up the overflow and the cap was just loose enough that it wouldn't make a seal and suck it back into the radiator. I just bent the tabs on the cap so that it tightened up a little and that solved the problem.

dmaxvaz

iTrader: (1)

Is this a AES 390? Also what fuel are you running on 14psi boost?

408GT

iTrader: (2)

This made me lol

mike13

iTrader: (27)

yes, pump gas mixed with 114

dmaxvaz

iTrader: (1)

What kind of timing are you running and what ratio of 93 and 114 octane are you mixing?