johninar

Well for the second time I've popped the upper radiator hose off the radiator. Sunday I was out on the 6th lap and water was pushing close to 230. I had checked my guages not 20 seconds before it blew so I know I was not overheating. Car was running okay. So after this happened last month I swapped the OEM spring clamps for stainless worm clamps. I thought it was plenty tight. I ran 5 sessions on Saturday without issue.
At least this time the track workers were happy I was running straight water.

Has this happened to others and what do I need to be looking at? My other C5 never had this problem with 4 years on the track.

TIA John

c4cruiser

Bad thermostat? Could be closing and creating excess pressure. Maybe an air pocket? The OEM clamps should hold the hose to the radiator "unless" there is a crack or a portion that is out of round.

Is there any material on the inside of the hose or on the radiator fitting that is slippery?

davidfarmer

stock radiator???? I had an aftermarket radiator that had a top fitting that was just a wee bit smaller, and it would blow off under extreme conditions. If not............put more clamps on!

meldog21

I had an upper radiator hose blow off my stock radiator once. Like you, everything else was fairly normal, however I hadn't checked my water temps so I can't be sure. I just replaced the hose, refilled the water, and went back out. After that incident I kept track of my water and oil temps. The temps were usually very high so maybe that was the cause. Unfortunately I did not find a problem area so I can't offer a specific fix. I took the easy route and replaced my radiator with an aftermarket radiator and integrated oil cooler. Not a lick of problems since and it runs at 192 unless it's really hot ambient and I'm pushing it hard.

Now I'm only limited by high trans temps.

Ultimately, you're not alone in having your hose blow off and not knowing what it is that needs to be fixed. At least you have the $1200 option for solving the problem, whether or not that fix is the 100% the correct thing to do.

Dog

johninar

It's a stock radiator (maybe not for long though) I'm going to pull the radiator to do some serious cleaning so I'll look at the neck real close. Hose does not appear to be deformed or damaged, and appears to be in good condition.

MySR71

My upper radiator hose came off once. I was at an autocross test and tune. I'm not sure of the water temp when it came off. A few weeks before I had the radiator flushed so I thought maybe the shop that did the work got it fouled up. Who knows. After the hose came off at the test and tune, I replaced the clamp with a worm drive clamp and didn't have any more problems. Several years later, I put in a larger radiator.....

UstaB-GS549

It's been a few years, but I had a friend with 04 Z06 that blew the upper hose off several times in one day. It happened when launching car from the pit lane at high RPM. We could not see much of anything wrong. He had a stainless screw type clamp. I think the problem was with the raised bead on the radiator.

froggy47

I have seen a couple blow off. Not designed for the wp pressure at high rpm. Use more clamps.

johninar

Thanks for the replies. I'm going to double clamp them. Strange that it would be late in the weekend of a two day event for this to happen. It sure was not hot outside this weekend. Oh well live and learn.
I agree about the hose retention bead on the radiator. It does seem a tad minimal.


Thanks!