Coolant boiling over...NOT overheating...

[vr2jetta]

I posted this in the g60 forum too considering this is a g60, but I figured this is a regular problem not specific to g60 so here go's.

So I have removed the bottle and replaced it with an inline filler from summit. I am running a 20lb cap and as I drive it is still building pressure over 20psi and blowing off into the overflow tank. It doesn't get hot until enough coolant spills out to cause it to. I have no idea. I'm getting very irritated and about to say ef it and put the bottle back in. Any ideas?

Here is the setup. Its in a caddy.

[vr2jetta]

Ive put the factory coolant bottle back in and its still doing the same thing. Not even hot and the cap is opening and spewing coolant everywhere.

[ps2375]

will it idle and not over heat? Have you replaced the thermostat? My car has never had a bottle on it and I don't have any issues. Sounds like you have a cooling issue or maybe a HG problem.

[vr2jetta]

I have not checked the thermostat, that was my next step. Pull it, flush the system, possibly gut the thermostat to delete that possibility. What kind of HG issue are you thinking? I had tossed the idea that the compression was building the pressure up causing the blow off, but wouldnt I smoke? Or at least have coolant pour into the combustion chamber after driving it? You got any pics of your bay? Just for fun...

[ps2375]

Pushing water out when not overheated is a symptom of a possibly bad HG. And that may be the only symptom you get. But you said this bottom-end is "new", what HG did you install and is the head good (flat and no cracks)?

Does the system blow bubbles in the tank when cold and running?

The motor is NA on MS.

[vr2jetta]

No, the bottom end is not new. Not sure where you saw that but this motor has never been apart as far as I know. It does have 158k on it though. I will have to let it idle today and see if it gurgles when cold. HG is not an issue if that is the problem, they are easy enough to do, just finding the loot to do it. I have contemplated doing it before but the truck runs so damn good especially when driving it hard.

[ps2375]

Sorry, I got that confused with another thread....

[vr2jetta]

Sorry, I got that confused with another thread....

Its ok...


Well, I pulled the truck up 20 feet in my driveway and when I pulled the rad cap it all ready had pressure. It couldn't have ran for more than 30 seconds. I started the truck with the rad cap off and I kept seeing air bubbles rise up. Coolant wasn't overflowing or going down so I'm thinking HG time.... Shouldnt be more than $100 so I may be ok. I have an extra set of head bolts here so just the HG, intake and exhaust should be all I need.

[ps2375]

I would clean that bay real good before tearing it down. You must travel many miles on dirt roads...

[vr2jetta]

You must travel many miles on dirt roads...

No, I had a honda rad in the truck and it blew off many times also, with just water in it and it rust stained the engine bay. It def sucks but at least the engine looks as aged as the truck does. lol

[WaterWheels]

The motor is NA on MS.

Could you run down real quick just what you have there. OK, I don't see the fuel distributor so maybe it's off for some reason or you have some setup I'd be interested in hearing about. CIS with MegaSquirt? Running it on ignition only? Is this some kind of "grafted" mix of CIS and EFI? Would be interested in a quick run down.

[ps2375]

Could you run down real quick just what you have there. OK, I don't see the fuel distributor so maybe it's off for some reason or you have some setup I'd be interested in hearing about. CIS with MegaSquirt? Running it on ignition only? Is this some kind of "grafted" mix of CIS and EFI? Would be interested in a quick run down.

MS doing fuel and spark. Since I already had a drop in K&N filter for the CIS, I just kept the CIS airbox and removed the fuel distributor. I opened up the metering hole some and called it good. I know it looks deceiving with some of the CIS parts there.

[Glegor]

Could you run down real quick just what you have there. OK, I don't see the fuel distributor so maybe it's off for some reason or you have some setup I'd be interested in hearing about. CIS with MegaSquirt? Running it on ignition only? Is this some kind of "grafted" mix of CIS and EFI? Would be interested in a quick run down.

you can see the high pressure fuel lines around the front of the bay, clamped to the fan shroud.

you can also see the fuel rail, with the fuel lines connected to it.

you can also see the TPS on the bottom of the throttle body.

you can see the CIS fuel dizzy and lines are gone, as well as the cold start valve

and you can see there is no WUR or lines for it..

definitely NOT a CIS/MS mix.. only thing left there thats CIS is the air box, and i think thats a GREAT idea to gut the CIS box, and use it.. makes it appear more stock(ish)

very nice swap, if you ask me.. especially for such a rust bucket!

back to the original question at hand tho.. as for your car puking coolant before its warm, that means that the cooling system is getting OVER PRESSURIZED before it comes up to temp.. theres basically only one way to accomplish that, by combustion gasses getting into the cooling system..

im willing to bet that you have a cracked head, or more likely, a blown head gasket..

my buddy used to have a CRX that would start pressurizing the coolant the second you started the car.

it would bubble soo good out the radiator cap, that the radiator would sound like the wet exhaust of a boat.. im sure you could have heard the exhaust leak/crack had the engine been dry of coolant..

[vr2jetta]

Head gasket done....problem solved. Fu*k coolant bottles.

[Glegor]

Head gasket done....problem solved. Fu*k coolant bottles.

no dude, coolant reservoirs are your friend.. VW cooling systems function soo good because of them!

they act as a BUFFER of types, so that when your coolant gets low, the radiator and engine are still full of coolant, the only thing that ever gets low, is the reservoir, if you check your coolant frequent enough..

VW used coolant reservoirs on almost all their cars for a reason.. its the highest point in the cooling system, and it makes them VERY EASY to bleed the air from the coolant..