Radiator Cap?

[Uber_Matt]

Evening gents!

Recently my car has been spitting coolant out from around the radiator cap, i know this becasue all the surrounding parts, CAI, top or radiator etc, all have the tell tale white residue on them.

I replaced the cap before Christmas, and it stopped doing it for about a month and a half, however now it is doing it again!

I read the owners manual and it specifies for the 5.0l VR, a cooling system pressure of 120 to 150KPA, however the CPC cap is only rated to 100kpa!!

To remedy this I ordered the genuine Holden cap instead (which incidentally is $5.46 fro Holden, or the same parts was $16! from Repco), however it turns out to be the exact same part that Holden supplied me with.

So my question is, what does your cap say it is rated for? And would this be wh the coolant is leaking out? I know it isnt a cracked neck on the radiator, as I have checked that and its not cracked at all.

I also noticed that around my coolant overflow, there is white coolant residue all over the bottle, the ABS and the drivers side wheel well part. Why would my coolant be spraying out here for?????


Any help would be appreciated guys.

 

[accentstencil]

Is the area where the radiator cap goes on clean and smooth? It may not be sealing properly if it isn't.

 

[hako]

I'd be screwing each spark plug out (8) and checking them as one of the prime suspects for your problem is a warped head or blown head-gasket. Eyeball each plug and if one is covered with crap then its probably the headgasket gone. Another way to check is to go to a radiator shop and get them to check the coolant for exhaust gas leakage....this will tell you yes/no.
Coolant should only be spraying out of the coolant overflow bottle for one reason - excessive pressure.....caused by overheating or head gasket failure or the radiator cap leaking (though 100Kpa should be OK).
The neck on the radiator can also appear OK when cold, but the crack can open up when hot so thats something also to check if you haven't already.
Hope it turns out OK.

 

[Uber_Matt]

Pluds didnt look too bad, I took them out yesterday and had a look. Since putting the new cap on it doesnt seem to be spitting as much out the overflow anymore. I have whiped the area down so its clean so ill keep an eye out for more residue. I still think its bit stupid that they sell and recommend a 100kpa cap for a 12 - 150 kpa system but anyway...

One of the blokes at work reckons could be a blockage, or partial blockage, in the cooling system, or thermostat faulty, although the car doesnt get overly hot , (no more than half on a 30+ day with A/C on), so I dont really suspect this but it cant hurt to check!

I am going to remove thermostat and take a look and make sure its working properly, and also take this opportunity to flush the system to check for blocks.

Only problem is, the wingnut that holds the cover on over the throttle body (and hence thermostat cover) has broken off wings!!! so I have been attacking it with a hacksaw trying to remove the body of the nut, but I havent had much luck! Anyone know any tricks for removing this cover/a broken wingnut?

 

[kopper69]

Just replace the thermostat mate if your going to pull it out. There is a gasket too. These can be purchase from supercheap etc for almost nothing. Have a look here:

http://forums.justcommodores.com.au/holden-commodore-how-s/28762-how-flush-v6-cooling-system.html

 

[Uber_Matt]

yeah I was going to do that tomorrow, provided supercheap is open.

Finally removed the plate covering the throttle body, in the end I just cut into the wingnut howixontally down to the threads with a hacksaw, then lifted the edge of the plate as much as I could and used my tyre iron to prise it up and break what was left of the wingnut. Worked a charm.

 

[RVN 355]

change the rad cap,thermostat and top up the coolant see how it goe's dont go cnc there crap caps had one on the vn and it leaked also.

 

[Uber_Matt]

change the rad cap,thermostat and top up the coolant see how it goe's dont go cnc there crap caps had one on the vn and it leaked also.

Yep ive come to that conclusion as well! Holden sells them as the genuine part too! Mind you, Repco was asking $16.50! and I got the same part from Holden for $5.48 lol. It s**ts me of that Holden would sell a cap that is rated for a lower pressure than the system is rated for as well.

What other brand would you suggest, and where would I get one from? Supercheap, Repco, Autopro in my area seem to only have the CPC branded caps.

 

[VS_Pete]

My v6 vs is starting to leak under the radiator cap I replaced it about 6mts ago.
Mybe CPC have gone to crap???????


The VS is 135kpa

 

[vlv8vic]

yeah do the thermostat. Is the car running hot at all?