rkdc5z06

my car is c5 z06 w 121k miles. bought it 3 weeks ago.


last sunday, I took my z to the mountain and drove kind of hard for 8~10 minutes. temp was rising but I was expecting that since I was pushing. all of sudden around 230 degree, my upper radiator hose busts open and spilled alot of rad fluid all over. temp was rising past 245, so I shut it off.

called a towing company and brought it home.

when I replaced a upper rad hose and filled about 5 qrts of dex cool, and idle for 10 min, it gets past 230 but Both upper rad hose and lower hoses are cold and no pressure. when I squeeze the lower one, I feel the liquid, but not so much on the top one.

Since the burst incident, my water pump area makes squikky noise when car is runing. can't tell if it's just a belt or something else, but It didn't make any noise before this.

what do you thing its the problem?

here is the problem..



p.s. Im going to replace the thermostat when it arrives here on Thursday from LGM.

striper

Possibly stuck thermostat not allowing coolant flow. Easy enough to check and change. Or maybe the water pump is bad.

racebum

thermostat is my guess

pull the stat, seal it back up and start the car. should get up to at least 150-160deg with no stat. if all goes well you know your problem

ZigZag

+1 on this.

runner140*

I agree with the above....the thermostat "might" be stuck.
Would also make sure you don't have an air bubble trapped in your closed system. Do an additional bleed/burp system and make sure there is no air trapped in there.

JetMechZ16

After you change the thermostat make sure you burp the cooling system to ensure you get all the air out.

According to the service manual:

1. Fill the system through the surge tank opening.
2. Fill half the capacity of the system with 100 percent DEX-COOL® coolant.
3. Slowly add clean drinkable water to the system until the level reaches to the base of the neck.
4. Start the engine.
5. Idle engine for 1 minute.
6. Install surge tank cap.
7. Cycle the RPM, idle to 3000 in 30 second intervals until engine coolant reaches 99°C (210°F).
9.Shut off the engine.
10. Refer to step 3 above to remove the surge tank cap.
11. Start the engine.
12. Idle engine for 1 minute and fill surge tank to 1/2 inch above COLD FULL mark on the radiator surge tank.
13. Install the surge tank cap.
14. Cycle the RPM, idle to 3000 in 30 second intervals until engine coolant reaches 99°C (210°F).
15. Shut off the engine.
16. Top off coolant as necessary, 1/2 inch above FULL COLD mark on the radiator surge tank.
17. Rinse away any excess coolant from the engine and the compartment.
18. Inspect the concentration of the coolant.

Martinh5621

Your water pump is squeaking now because of all of the fluid you lost when it all burst out the first time, I'm pretty sure you got some on the belt and its causing the squeaking.

I'd go with the t-stat first and then try the water pump.

rkdc5z06

Thanks alot guys!
I'll do the T-stat first. I've already ordered the water pump just in case.

Hope I can just get away with the t-stat..

Thanks guys and I'll update as soon as I check the t stat!

Cheers!

Martinh5621

Honestly, since you have the t-stat and water pump both coming in, I'd just change it all at once even if its just the t-stat. Your hoses are gonna be disconnected and since your right there I'd just go ahead and do it. That way if it isn't the t-stat and you try the pump, you have to re unplug everything and do a lot of the stuff twice.

I changed mine about a month ago (w-pump) and I didn't lift the car or anything all I did was drain the fluid. It'll be a bit of a pain without jacking it up but it can be done, and I changed it all out in about 30 minutes.

After draining the fluid, seperate the air filter tunnel and move that to the side so you can reach your hand in through there to undo the bolts on the driver side of the pump, there's only 6 total, 3 on each side. Make sure you have some extensions and patience lol. You'll probably have to do quarter turns because of how cramped it'll be.

When you bolt it back up MAKE SURE you run the car in idle and keep filling her up with water or coolant till she fills completely back up!!!

Hope this helps and hopefully 1 of these is the solution!

racebum

water pumps often leak on many cars right about 10 years of age.

since you have it on the way and the coolant will be drained, swap it all. in fact, come to think of it, you have to swap it all. the new style thermostat and outlet housing don't fit the old pumps

if you ordered water pump ac delco 251-744 you have to use the stat and outlet part number 15-11057

striper

I hate doing jobs twice. You got it apart, change the pump!

Martinh5621

Exactly^^^ and unplugging the hoses and draining it all out means you have to buy coolant all over again and that can get pretty expensive quick lol trust me on that.

Do your car a huge favor and treat it to a new water pump even if its just the t-stat, at least you'll know you have a new w-pump under the hood and its something you won't have to worry about in the long run.

rkdc5z06

I got a "1997-2004 C5 & Z06 Corvette Water Pump GM Replacement"

from Corvettemods.com

and hearing opinion from y'all, I should do water pump and t stat together. I was thinking the same about wasting coolant which is $ 17~19 a jug.

And I'll make sure my cooling system burps and no "air" in the system.

Thank you all for many inputs! Happy Friday Corvetteforum!

rkdc5z06

Changed water pump & T stat and 2 gal of dexcool + more water, it is back on the road!!!!

ideling @ 190 and traffic @ 210~225 and driving hard up the mountain never got past 225

I was going over 235 and blew the upper rad hose 2 weeks ago.

BUT now, It's better than ever!!!!

pic of NEW vs OLD water pump (took like 3 hrs no rushing, chilling with beers)



and I also did serpentine belt, Tranny fluid, Diff Fluid.



I should be good for a while!

thank you all your help & support!

Happy hump day Corvetteforum!!

Martinh5621

Awesome glad we helped! And that's what it's about here, we learn from each others mistakes

whydallas

two bottles of water-wtter and a 160 thermstat, fixed my overheating this summer in dalls, 172 hwy and 185 city