Water pressure problem > radiator cap ?

[Nico]

Hello there !

I know there have been several threads about radiator caps and more especially about performance radiator caps but none of them really answered my question...
My 1992 Camry (4 cyl) has had a reconditionned engine recently (again ...) and it seems like there is a very high pressure in water hoses although the overflow reservoir remains totaly cold. I had the impression it was just a problem a radiator cap but my dealer is telling me this is normal and water should only go into the overflow reservoir in case of a dead head gasket. This seems a bit weird to me but I am getting a bit paranoid because of all the engine problems I have had 'till now so I just want to make sure it is nothing serious...
The car is not losing water, has got a new radiator and is able to suck water from the overflow reservoir but not the other way round (unless it needs a LOT of pressure then) but water keeps cold in the reservoir. What do you think it can be ? Don't you think it is just a malfunctionning radiator cap ?
Thanks for your comments !

Nicolas

[2wickedtoyz]

your cool man as long as it's not bubleing over you need not worry

[canadiancelica]

Get some garage to do a pressure test to calm our nerves, but I think you are fine if it isnt boiling over.

John

[Nico]

Thanks for your replies ? BTW how is it "normaly" supposed to work ? Is water in overflow reservoir getting hot when engine is running or is it just staying cold ?

[Pineapple]

Rad suppose to hold pressure. Pressurize coolant absorb more heat without boiling. Rad will dump to overflow only when pressure is too high. Check upper hose after you drive the car for 30min and see if its hard. If its soft, you don't have pressure and you got a leak somewhere. If its hard, you're ok.
Coolant will get into rad when rad got vaccum due to coolant cooling off and reduce in volume.

[Nico]

Pipes are hard indeed but I have the impression that before the last engine rebuilt and repairs they didn't use to be that hard and I am just curious to know at what stage the water is supposed to leave the system to the reservoir because they are REAL hard...

[canadiancelica]

well your rad cap should read 13lb.....Im using a 16lb, doesnt hurt, but I wouldnt go any higher. Also, if the pressure is too high and the rad cap isnt working, one of your hoses will blow off, that'll let you know theres a problem. So get the car pressure tested to calm your nerves.

John

[5Sfte]

The overflow tank is there for 2 reasons.

1. If the system overheats it provides a way to relieve pressure so that you don't blow hoses.

2. Heat makes the coolant expand therefore it needs a place to go. That is why there is a hot and cold line on the overflow tank. Coolant cold--> more coolant is in the radiator/hoses/block. Coolant hot--> some coolant overflows to the tank but will be sucked back into the system when it need it as to prevent air lock.

[CrawlingEye]

I think the reason I've been considering a new 'radiator cap' is due to the fact that mine seems to be garbage (my coolant boils on a 15 minute highway drive), so I'm just going ahead and not only replacing but upgrading.

Something you might want to consider, 'cause my assumption is, you were talking about the thread that I had posted.

[Nico]

Thanks for your comments guys ! Yep I'll make a compression test just to make sure. My impression was that the cap was not able to relieve any liquid because even when I squeeze the upper hose very hard just nothing leaves to the reservoir...prhaps it just needs more than that...

Originally posted by CrawlingEye
I think the reason I've been considering a new 'radiator cap' is due to the fact that mine seems to be garbage (my coolant boils on a 15 minute highway drive), so I'm just going ahead and not only replacing but upgrading.

Something you might want to consider, 'cause my assumption is, you were talking about the thread that I had posted.

BTW is your current one broken or it just can't handle the right pressure?