Hello im new here and looking for help.. very stressed with my car!

Pretty much my ford mustang 2005 v6 started to overheat and leaked all my coolant out.. was pouring out under my car somewhere alot till none was left in radiator! we thought it was the thermostat housing.. since it looked like it was coming from there and there was coolant on top of engine behind it.. i put new thermostat housing.. didnt start car untill i i checked the pressure for leaks.. after some playing around and checking.. the pressure was holding at 15psi without leaking any coolant.. looked like problem was fixed yay.. next day no leak.. drove car to store and back in area.. no leak.. next day no leak.. so drove again back np.. saturday didnt use car.. when i went to drive sunday there was no coolant in coolant reservoir ..( btw i put in water as coolant was supposed to go.. didnt want to keep spending if kept leaking.. untill problem fixed 100% ) so i refilled it back up with water.. kept car running till preheated.. no leaks.. couple mins after water pouring out of radiator cap like crazy.. all gone again.. this time left cap off and filled to max line .. turned car on to see bubbles.. some came then it went down a bit.. no leak.. then out of no where started to raise and powered out like a fountain of the radiator hole... what do i need to fix.. i bought new radiator cap couple days ago too though it was leaking.. i just need some help. idk what to do! thanks !

update: before i left to write here.. there was 50% water in coolant reservoir left.. came back to close up car.. now its all gone.. disappears when im gone ! empty

 

Maybe an air lock in the system or maybe the fan isn't kicking on when it gets hot building up pressure to blow anti-freeze out your tank. I've seen those air pumps to blow out any extra locks in the system.

 

so today i refilled coolant tank with water again.. this time my boss gave me his radiator cap from his ford econoline truck.. preheated car up nothing.. drove around block.. water held strong.. a very minor leak from cap..opened it up wasnt really any pressure right away.. then i put on my old orginal radiator cap and drove around the block .. nothing happened at first then stored to pour out the side of the cap.. not sure if my radiator cap is messed up .. the aftermarket one i got from advanced auto parts was bad too.. or if there is another problem thats making this happen.. my boss told me when pouring coolant into a acura car ... there is a bolt you got to unscrew to let the air out.. something like that.. i know all cars are different but might there be something like that in my ford mustang 2005?? thanks again

 

There's no special procedure for the 2005 Mustang coolant system. they 'fixed' that problem on these cars, seems. You just fill it at the degas bottle (The little tank on the right side of the radiator) until it's at max level for hot or cold, whichever, start the car, turn the heater on full blast, leave the cap off and wait for the coolant to circulate. You'll see it, it comes from the thermostat when it's hot, the coolant will be movin' about in the degas bottle. If it drops below the max hot line, then add more. When it's done dropping and you see the coolant movin' in the degas, that's it, cap on, drive on.

I just did this for my GT, by the way. It works exactly as it should. If you overfill the system, it *will* puke coolant out. It's overpressured at that point, and it must be released. The problem is that if you overfill it, and it blows coolant, it'll probably push out way more than it should.

THAT said... it may be that you have a bad thermostat. 15 years old might be time to swap it. It could also be a bad water pump. Maybe your belt is slipping, the water pump pulley is not grooved, so it's possible it's not turning like it should. Outside chance, but I throw it out there. Maybe your tensioner is not good, causing said slippage. Although you'd probably hear that, still.

It could also be a bad fan or fans, or their relays. It could be a plugged radiator. It could be you have the car tilted downhill, which *will* keep bubbles in the engine, and the fix for that is raise the front of the car while you fill the system. Squeeze the hoses connected to the radiator, that'll help get some of the air out, as you pour in coolant. Just a couple of them here and there, you'll see the burping happen in the degas bottle. Use a 50/50 mix of Motorcraft Gold concentrate and *distilled* water. Recommended by Ford, of course, and after 181,000 miles, I can attest that the coolant is amazing, don't not get exact OEM. If you're using just water, that's a problem. You need that mix. You can buy it premixed, or get the concentrate and mix it yourself, your call.

It could be a bad cap, sure, but you should get an OEM replacement. If it's not Ford/Motorcraft, then it's not the one to get.

And finally... could be a bad head gasket, or warped head, but *just* enough so that when it's cold it won't do the coolant spit. But when it warms up, the engine is spitting hot gas into the coolant system as things expand, the warp/bad gasket opens up, and Norene is my nephew's mother's father's daughter's friend from Toledo, there's a volcano of coolant happening. Not that Norene has anything to do with it, but I thought I'd tell ya about it anyway. You kind of hope it's not that. I mean, Norene's ok and all, but a bad head gasket/warped head is just not... um... cool.

Hope that helps! And belated welcome to the forums!

 

wow alot of info .. helps a bunch.. i did install a new thermostat housing.. car was fixed for 2 days .. didnt leak from the bottom but started leaking from radiator cap! but update on today again.. i tilted car up on ramps and turned car on with heat up.. i also took the cap off like said. after some time my temperature raised in the middle like supposed to be , but this time the fan didnt turn on.. fan worked when ac turn on accident but it didnt turn on for the radiator.. car was preheated, hoses were hot.. well everything was hot like supposed to be but fan didnt turn on then my water came out again of radiator.. maybe bad relay in my CCRM? do i take a look there to find maybe my solution?

 

Ok, so the fan running while A/C is on is correct. It should always come on with the A/C. And that also means the fan itself is good, and it's getting power from something.

http://iihs.net/fsm/?d=40&f=Fuse%20a...nformation.pdf

That's the two relays. A low speed and a high speed relay are in the diagram left as you look at it without rotating. One or both of those may be the issue. Probably the low one. The low one is supposed to come on first. Then the high one kicks in if the temps keep going up. The high one is used directly when the A/C is turned on, so it's probably good. I'd therefore conclude that the high certainty is either the low speed relay is not kicking on, as it's bad, the wiring thereto is not working, or the temperature sender is not working correctly/not being listened to. Kind of hard to think the temp sensor isn't working/being listened to when you have a temp on the dash, which gets its info from the engine computer, so, I'm thinking the low speed fan relay's the one. By the time the temps get up, it's too late, the fan hasn't been running at all, so it's all hot and bothered.

Maybe. This is gettin' close to 'take it somewhere' territory, to be honest, but keep tryin', maybe ya get it figured!

You might can try swapping those two relays and see if that changes things. First, the A/C should probably not get the fan running, second, the low speed should kick in, and that should prove it out all the way 'round: New relay should fix it.

Again... maybe. So... find out?

 

update again... i went to the fuses..I swapped the low speed fan fuse with a different one .. first horn then rear defroster.. the fan still didnt turn on when the car preheated and everything was hot.. i turned ac on and the fan kicked in automaticly.. the fuses seem to be working i guess.. maybe its some sensor? would it be the sensor on the thermostat housing?

just used a code scanner to see if anything wrong in my car that could be hidden and not showing up on dash.. and nothing clean..

 

Yes, it could be. It will say it can see something, but it could be lying. The easiest thing to do is to short the wires at the sensor, which should tell the computer the car is *hot*, and turn on the fans. Well, these computers these days... go get a 3000 ohm resistor and put in across the two leads. That should be 'hot' to the computer... I think. Maybe 2000, or 1000... I dunno what 180, 190, 200, 210 degrees would be in the resistance value of the sensor... *Oooh*... get a potentiometer! Get it from, oh, 1000 ohm to 20,000 ohm? If you can get such a thing... hang on...

Yeah, you can: https://www.mouser.com/ProductDetail...2FAKkqOuk9c%3D
Should do the trick...

Probably a bit more trouble than it's worth, but funtimes and shenanigans on my end... Anyway, if the shorting or the low resistor value causes fan to happen.... the sensor could be reading cold... and staying that way. Possibly. Stranger things...

There's also a possibility I've read where the connector at the shroud itself could be a factor, and/or any resistors in the fan shroud for the low/high setup.

And then... After all that... assuming you've done everything else right, including a new thermostat and a new sensor and the already new housing and ensured air isn't in the system (which I'm guessing it isn't at this point...) There's a more sinister wiring issue somewhere, which would be fun to trace out... or the ECM is not happy.

I'd throw the parts cannon of sensor and thermostat at it. I'd also do a complete drain and refill if you've accidentally used different types of coolant. Motorcraft gold 50/50, or similar, only, please. You mix them, they might gel, and that'll be fun.

After that... It's getting weird in that engine bay...

Also, check this out. You could test your sensor and see what it's doing...