Hey guys, hope you can help with this, the problem is after driveing for about 10 or 15 min my overflow resivor fills up, the cap blows off and gets antifreeze everywhere. I have been haveing heat problems and have changed the thermastat twice flushed and refilled twice installed a new water pump(the fins on the waterpump were almost completly gone)and am now going to try a new rad-cap. at start up i get heat after about 15min withe the temp gauge at C, 5min later the gauge reads half way and i get nothing but cold air, after about another 10min it drops back to C and i get hot air again then the gauge goes back to mid way and the heat works fine,any ideas would help.

Thanks

 

You can borrow a cooling system pressure gauge from Autozone. It will test the cooling system & the cap. Just screw it on in place of the cap.

Does it puke coolant when you let it idle/cap off to get the air out of it?

 

If the pressure check, or new radiator cap doesn't prove out, kinda sounds like you didn't get the cooling system burped real good.

When refilling the cooling system, I like to leave the heater return hose loose until coolant begns to drip out, then reconnect it & "milk" the lower radiator hose, to help burp the block & remainder of the system, before starting it up.

If you'll use a OEM thermostat with the built in air bleed valve, or one like it, it'll make burping the system of entrapped air, much easier.

Or if the new thermostat doesn't have the air bleed valve. you could try raising the front end on ramps, stands, or pointing it front end uphill & letting it idle long enough for the thermostat to open & that should help it burp any entrapped air, as it'll want to migrate to the highest point, the uphill radiator.

As the water pump vanes were nearly gone, what kind of coolant were you using & what kind of shape was the coolant in???? Lots of rust & dedris????

If so, did you run any kind of cooling system cleaner upper through it, to tidy things up inside, then do a reverse cooling system flush, before adding the new coolant???? If not, debris could mess with the new thermostats operation, or coolant fow.

In any case, make sure your using the proper coolant, mixed at the proper ratio in distilled water & get the system burped well, as the engine doesn't like air around the cylinder walls, or in the cylinder heads.
Hot spots can then form, the coolant will boil & the resultant cavitation from those bubbles bursting, can eat away at things & cause all sorts of mischief, the least of which is it spitting up it's coolant.

Let us know how it goes.

 

This all started with a pinhole in a fitting near the thermastat houseing, i changed that and drained the rad flushed it out with clean water, drained that and put in a cleaner from prestone ran that for about 20 min, drained and flushed with clean water again and then put in another cleaner from prestone that you drive on for 2 days. I did that, drained the system again and filled with a 50/50 mix of prestone antifreeze and water (no i didnt use the premixed stuff, and by the way.. why does the premixed cost as much as the regular??arent you getting half the amount of antifreeze???) I did not know about burping the system so i'll try that next as i put in a new rad cap without any change. I had the truck running for about half an hour and the upper rad hose never got hot , i know its possible but what are the chances of getting 2 defective thermastats?? thanks for the help guys

 

pawpaw is right....bleed system of air

 

When you discovered the pinhole leak & bad water pump vanes, what did the coolant look like, that was drained out?????

Had you been using the specified coolant/antifreeze????

The wrong specification/recipe of antifreze can cause cavitation erosion of the water pump vanes & may not be kind to other things in our cooling system.

We should NOT use tap water to cut the antifreeze, as the minerals, chlorene & other putrids in it, aren't good for the antifreeze, nor the cooling system componens.
ONLY use Distilled, DI (De-Ionized) or Demineralized water to mix the coolant to it's 50/50 mix ratio.

The pre-mixed coolant, has already been cut to the the proper ratio, with the proper kind or water, for those of us that are too lazy to do it, so your right, we get half the amount of antifreeze, for about the same money.
If we choose to the premix coolant, we have to pay someone else to do the pre-mixing, botteling, truck it to us, stock it on the store shelf & then sell it to us & the folks that do all that, don't work for miimum wage!!!! lol All that mixing, bottling, shipping & stocking, costs the same as a straight uncut bottle of antifreeze!!!!

Bad thermostats right out of the box, aren't that uncommon & if your following any of the forums cooling system problem threads for the last few days, your about the third or fourth person to have gotten a faulty new thermostat, right out of the box. Might be interesting to know the brand, maybe they have a big production lot quality problem & folks could steer clear of that brand.

 

The water that came out of the pinhole was kinda brown, i had only had the truck for about 6 months and not checked on the coolant as i should have, i had planned to have it flushed before winter but then all this happened, any way both thermastats were bought here in Chicago from Advance Auto and are made by Stant, i did notice that they did not have a bleed hole like the one that was replaced so i'm now off to burp the system, i'll let ya know how it goes ... thank again

 

is there any chance a egr could have anything to do with it?just a thought.because mine is doing the same thing.and thats the only code i have is for something to do with the egr valve.maybe I'm wrong though wouldn't be the first time.

 

smokn03, no i dont think so, i had mine replaced over the summer due to a code from a check engine light but i didnt start haveing thid problem untill a week ago

 

ya i didn't think so either but thought i would throw it out there.let us know if you find a fix.seems to be a few of us with this problem.