no pressure when removing rad cap
05-22-2008, 08:51 AM
#16
Nordschleife Master
05-22-2008, 09:07 AM
#17
Drifting
on my car there is still pressure, but with this test, we saw that the cap was leaking, my actaul tank can still hold pressure, but needs to be replaced as well
atleast your fan's are coming on; mine aren't; I have to get a new fan relay and probably a new thermo switch, then I should be golden and ready for an oil change, new rear bearings, and a t-belt kit
05-22-2008, 12:59 PM
#18
Track Day
Well system holds pressure. Set it to 10psi last night (it looked steady) and it was 5psi this morning. Sounds quite tight to me. I vented the system a few times under pressure just to make sure all air was vented. The kicker is the cap when tested held no pressure and after looking at it, it is definitely useless. I'm going to replace the cap today and hopefully the cooling system will work as it was supposed to (pressurized). It makes complete sense now and based on Wallace's experience which was similar to mine (thanks Wallace), if the car's cooling system is not under pressure, once it is turned off the heat in the hot areas of the engine (well above the 86deg C of the coolant) will heat the coolant up to 100 deg C since there is no flow to the radiator, and then any other heat to get dissipated will cause the coolant to flash to steam. The resulting growing steam bubble will push the coolant out the expansion tank overflow line (kind of like a burp), and since the cap is not sealing, it will not keep the pressure and coolant contained in the cooling system.
So if all is well later with the new cap, I'm done here and will come back soon with the all the other things on my list I have to unravel (but this was priority one!!). The car is getting aligned today at CT Automotive in Campbell. I replaced control arms and tie rods last week. Next is interior update/repair (seats and dash).
Can anybody here recommend good seat covers or a inexpensive way to repair/replace 2 torn up burgundy seats?
So if all is well later with the new cap, I'm done here and will come back soon with the all the other things on my list I have to unravel (but this was priority one!!). The car is getting aligned today at CT Automotive in Campbell. I replaced control arms and tie rods last week. Next is interior update/repair (seats and dash).
Can anybody here recommend good seat covers or a inexpensive way to repair/replace 2 torn up burgundy seats?
05-22-2008, 05:40 PM
#19
Instructor
Join Date: Mar 2007
Location: Raleigh, NC
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Well, I drove the car today and the tank level was hanging in there when i checked periodically during the day. I let it sit and cool down and when I checked the tank it was low again with the level down near the bottom.
where is the coolant going?? no smoke, the oil level is constant and clean, compression check was good.
any thoughts or ideas?
where is the coolant going?? no smoke, the oil level is constant and clean, compression check was good.
any thoughts or ideas?
Beginnings of a blown head gasket. Mine did the same thing.....with no real OBVIOUS symptoms like smoke, etc. right before it blew.
Sorry.
05-22-2008, 06:13 PM
#20
Drifting
Thread Starter
no idea, just went to the local parts store (lordco) and asked for a pressure cap for a 944 and they had one in stock like 10 bucks. I thought it was cheap so might as well replace it.
