Mad Hatter

So where i live the temp usually stays on average in the high 90's with 60% or more humidity, and my mustang has been running hotter than it should. It gets hot sometimes just driving normally, but most nights the temp holds great even when on the throttle. So my question is would my mustang benefit from switching my coolant out for straight water with an additive such a water wetter or purple ice? Obviously only during the warm temps and I'd switch back to regular coolant in the winter months. I also have another issue with my stang and i went into great detail specificly about both my issues and what ive done so far to try and fix it but as soon as i clicked post the page redirected and said sorry couldnt post new thread so I'll address the other issue tomorrow i can't type all that again tonight. Thanks any info or advice is greatly appreciated.

houtex

If you're having cooling problems at those temps/humidity, there's something wrong with the cooling system, and you need to fix it, and it's likely not the coolant... with one exception...

For a baseline, Awesome is a 2006 Mustang GT, stock drivetrain, 163000 miles currently, and not babied, daily driver. And in the Houston area heat and humidity, she runs as normal as she's ever run. Right in the middle of the temp gauge. And that standing at idle on an uncovered by anything parking lot, middle of the day, 100 degrees (and the parking lot is hotter than that!) for easily 20-30 minutes, or more. Not an issue. Regular manufacturer's recommended coolant. Flushed once before.

So, if you've not flushed the system and replaced the coolant at least once before, that could be all that's needed. And I wouldn't ever recommend not using the regular correct coolant for the car. It'll work just fine, no need to play tricks with the system, and take a chance at making things worse. The coolant is not only in there to cool, but protect the innards. Running straight water is not a good idea. And running coolant for too long is not good either, as it loses it's properties of cooling/protecting the system over time. You don't say how many miles, but if the coolant is original from day one, yeah, it's way past time to change it...

Other items it could be beyond the flushing/coolant swap are:

The the water pump is going out, but seems to me there'd be a leak in the weep hole... unless rust ate the impeller...? *dunno*

But if it did rust away, it'd explain why possibly the radiator could be plugged up internally and will have to be replaced outright because ain't no flushin' gonna get it cleared up...

Radiator fan isn't working.

Radiator/condenser is plugged up with debris causing air to not flow through.

Thermostat is bad.

You have an air bubble in the system, need to burp it.

Temperature sender is bad.

Temperature gauge is bad.

Chasing down the problem might be fun (he says sarcastically, mind) but that's the rundown I got. Keep in mind that the other issues, if engine related, could also affect the cooling system in some way, but you'd have to list those issues to help figure that out maybe. But just going with the cooling alone, these are pretty much the list... Guys/gals, got anything to add?

Hope that helps. Welcome to the forums!

wanted33

I agree with my brother houtex in all things stated above. I would start with a radiator flush, and go from there.

Mad Hatter

I'm sorry i forgot to mention that i have a 2005 mustang GT stock except for exhaust with a litle over 154,000 miles. Thanks for the list of things to chase down i will look into all of this, but i did a complete radiator flush about 6 months ago and i also put a brand new failsafe thermostat. So i dont think its anything related to the thermostat or anything a radiator flush would fix unless i somehow didnt flush it right but i know i did. As far as the other things im not sure. What confuses me is that most nights the temp holds strong right in the middle even when im flooring it, and if it was something wrong with the cooling system wouldnt it still run hot regardless of the temp wihtin reason? Like most nights its about 10 degrees cooler than during the day so not much of a difference. Or am i wrong? I also changed the oil, oil filter, oil filter adapter gasket, and coolant about a month ago due to a leak and all seems good as far leaks. Also when i mentioned just using staright water i meant to say use straight water with an additive like purple ice or water wetter that helps prevent corrosion and what not like coolant minus the freezing prevention. As far as the other issue I'll try to keep it s short as possible. Basically sometimes not every time my car has trouble starting and staying on. What i mean is it turns over fine but sometimes it just wont start or if i get it to start under this condition it runs really rough and eventually dies to what seems to me of fuel starvation. When its acting like this so far the longest ive been able to keep it runnig is a minute but it usually dies within seconds. As i said this doesnt alwyas happen sometimes it will fire right up with no issue. When i cant get it to i just spray some starting fluid and it usaully starts and with a few revs everything is back to normal. Now i've added seafoam to the gas tank, ive used the sea foam spray to clean the upper engine, and i added some to the crank case to try and quite the cursed tick most 2005-2009 mustang GT's are plagued with sadly it hasnt helped the tick, but i have noticed an increase in performance nothing crazy though. When it first had this no start issue i thought it was the fuel pump or something in the fuel system. So the first time i got it started with this issue it ran really rough and died a few seconds later. I tried a few more times then i decided to hook the battery up to a trickle charger just to see if it would help although i highly doubted it would. So i came back an hour later and tried it again and no luck so i thought maybe i got some bad gas and i threw some fuel cleaner and stabilzer in the tank and let it sit and mix for 30 minutes then i added some gas i new was good to help mix everything. Then it stared fine and thats when i added all the sea foam. Now ive isolated to when it wont start on its own, because i wont hear the fuel pump prime. The weird thing is once i get it started and let it get up to temp everything seems to work like it should even when im on the throttle (except the whole running hot sometimes). Now where im at with this issue ive checked all the fuel pump fuses and relays and everything seems to work fine until the fuel pump decides to not prime. Its just random and im stumped. Thanks for all the info thus far and i hope you guys can help point me in the right direction. Once again thank you and have a good day/night.

wanted33

Ummmm, as far as the rough start you may want to try cleaning the throttle body, and mass air flow sensor if you haven't already. And if it hasn't been changed do get you a new gas line filter. I bought my '06 with 89K miles, and when I changed the gas filter I wondered how it was running at all, and the throttle body entrance along with the MAF sensor were absolutely filthy. It ran even better with all that done. Mind you unhook the battery when doing any of this, and if you change the gas filter be sure to let the system prime before trying to start the engine.

As far as the engine heating I suggest trying some of the things already stated, especially the cooling fan.

I wish you luck. Little things like you have can be quite aggravating.

houtex

Goodness. A bit of advice, and I know it's going to sound like I'm being a jerk, but truly... better formatting will help us help you. Wall'o'text is not good. That's just tough on my eyes, man...

Trudging forward: For the non-start issue: I don't see in here where you've replaced the fuel filter, so if not, do that. If you have, disregard, but now the guess is you're having either the fuel pump, the fuel pressure sensor, and/or the fuel pressure regulator going out. Maybe the fuel cutoff switch (located in the driver kick panel) is unhappy. Or the socks in the tanks are plugged up. Might need a shop, or you can just throw parts at it... Your call.

Regarding the temps at night... sure it'll run fine there. 10 degrees ambient is quite a bit different to people, so a car definitely. I mean would you rather an 80 degree day or 90 in the sun? (With a hat and some sunscreen, maybe some sunglasses, of course, I'm not a savage.) Bet you'd be more comfy with 80, right? Same thing with the car. The lower air temp means it can cool better. Which leads me to believe it's the radiator or water pump now for sure.

As far as the straight water with stuff in it... Yeah, no. Coolant as specified is what you need, don't play with the system, you could damage it or the engine worse than where you're at. The car is not happy, and it needs fixing, not bandaids, lest it bite you in the buttocks and make you regret things, yeah?

I might suggest a shop at this point, to be honest. Sometimes it's better to bite the bullet and pay now rather than pay and pay and pay over the course of weeks/months and then boom it's dead Jim, and you still spent a lot of money to get there, y'know?

Good luck and all!