coolant overfill tank emptying?`

[nichwan]

Hi,
My vr's overill coolant tank is filling up on long trips and then the overflow reservoir is then emptying via the out hose onto the street... I fill it up, and it empties if i drive it. I have checked the oil and the coolant, no bubbles and no thickness... just seems strange that it tries to empty the overflow reservoir...

any advice guys?

[accentstencil]

A new radiator cap might fix the problem.

[hako]

If it's flowing out of the overflow reservoir hose onto the road that could point to a head gasket leak or a crack in one of the heads which is worst case scenario.
However, as you say that it happens on long trips then its more probable that the engine is boiling and this can be due to a number of factors but the first one that I'd check is the suggestion by accenstencil to replace the radiator cap which may not be holding pressure which in turn lowers the boiling point of the coolant.
Hope it's just the cap.

[social]

better yet man PRAY its the cap, you dont want headgasket problems

[nichwan]

thanks guys,
is a 100kpa radiator cap too low in pressure for a v6 vr? that's what the mechanic put on

[VT-565]

Not sure about the pressure, thought the V6's cooling system ran higher than that though.


Ah, another thing, you got a mechanic to change your radiator cap?

[Not_An_Abba_Fan]

136kpa I thought the cap should be. But yeah, it is probably the cap causing your problem.

[nichwan]

Not sure about the pressure, thought the V6's cooling system ran higher than that though.


Ah, another thing, you got a mechanic to change your radiator cap?

lol.. i was on my way up to uni and there were no mechanics. i had bought a cap from autobarn the other day, however, it leaked, so i only found this when i was about 50k's either side of my destination, so i stopped in the nearest mechanic to get it replaced. He only did it as it was the only place i could find one. hahaha...

anyway, took it to the mechanics, they conducted a block and compression test, both read normal.. then the found that the radiator was a little dirty.. lol so maybe gunge was cloging the backflow on the radiator... eitherway, it's not the head luckily

[michaelw]

Tell me at speed can wind pass over the drain line. For example did you poke the pipe down a hole in the engine bay to stop it draining on the paintwork inside the engine?

In my old car (VN) the drain was in a hole in the engine bay so that the end of it was in the wheel well. The windage sucked the overflow dry. When I stuck it in the engine bay out of the wind all was well.

Hope this helps.

Mike

[BlackVXGTS]

V6's need a 135kpa cap.
V8's use a 100kpa cap.

[vsl67]

Classic sign you need to bleed the air out of the system

[delcowizzid]

and make sure the outlet hose for overflow isnt right in the bottom of the overflow tank or it will pump the water out reguardless

[kopper69]

Could also be a split in a hose. I had the same thing not too long ago. Took me ages to find a tiny hole that only opened up when the system was hot and came up to pressure. The tiny hole would appear and start spraying out my coolant, which was hot and would evaporate, so was very hard to find. Yours is leaking on the ground though, so its not getting up to pressure. Im with the guys above, start with the cap. If you havent done it for a while do a full cooling system service. Instructions in the how-to section. Its fairly comprehensive and will give it a good clean out too.