Well I tried to post this on the mustang corral website and wasn't getting any quick responses. I know some of you like myself, own mustangs and may be able to help me out. Well last night my 89 5.0 overheated/leaked on me. Fortunately I was right around the corner from home. I kept noticing my temp gauge stayed a notch from the red at idle and cruising around town but on the HWY it would drop midway. Well when I got home I smelled antifreeze and noticed it leaking under the front of my car but it was too dark to see actually where it was coming from. All I could hear was a boiling sound, saw smoke and heard the leak dripping. This morning I got up, checked under the car and it had to be about a half gallon of antifreeze on the ground. I fired it up and the only sign of anything I saw was condensation leak in between my Hpipe/catback. (I had the catback and two converters installed yesterday). Also I noticed water spitting out of the tail pipes but I figure that was normal for a cold start in 25 degree weather here in Ga. Well I took it for a spin after warming for about 8 min and as soon as got halfway down the road the temp needle was a notch under 270degrees again. On the way home I WOT just to up the pressure some more and it still pulled hard like normal. When I pulled in the driveway I smelled the antifreeze in the car. So I got out, left engine running to see where the leak was coming from. It seems like it's dripping from the bottom of the lower pulley. Antifreeze is all over the hoses mainly on the driver side. I looked in the overflow reservoir and saw no bubbling. I popped the hood and noticed smoke coming from where the water pump is located and heard the same boiling sound. There was no sign of antifreeze anywhere around the upper or lower intake or coming from the block/head area. I had a heater core bypass done a couple a weeks ago so I don't know if that could effect anything. Also didn't notice any oil mixing with the antifreeze. Anyone have any clues?

BTW..I also did a head/intake swap a couple weeks ago using felpro gaskets through a reputable shop..I hope I didn't blow a head gasket..I'd rather it be the water pump..Car has 138K miles on it and the water pump was changed back in 98
Need some suggestions fast being this is my daily driver and don't want to wake the L outta Hibernation.
Thanks guys!

 

From what I have read from your post, it sounds like you have a water pump leaking. The antifreeze is comimg from the weep hole on the underside of the pump. Replace the water pump and your problem may go away. I hope you didn't run it too long after it got hot.

Hope this helps,

 

It deffinatly sounds like you have a bad water pump.

Larry.

 

nope..didn't run it too long..I was only 4 mins from home when I first noticed the leak and the smoking and I drove slowly...Thanks..I'm hoping thats all it could be..I'll check it out again tommorrow

Anyone else with anymore ideas?

 

Im not a mustang guy but if it has electric fans make sure you check/replace the fan temp sensor . It may have gotten smoked if you were up to 270 like you said.

I made the mistake of changing the radiator, thermostat, cap etc on my 92 rs but forgot to change the fan sensor.... if it is electric fans ..ground the fan sensor wire to the block with the ignition on. Fans on ?? sensor ok.

I doubt if this is the reason you are loosing coolant .. but if it got hot and its electric.. this is something that can be easily overlooked when you put it back together.

P.S If you need a 302 let me know. I can find one easy.

ARTY

 

Thermostat?

 

Wish I could help, but its hard to diagnose a water leak over the internet...LOL. But seriously, can you pressure test it at home? Look for the highest wet spot..gravity will help coat everything from there down! Wish ya luck...those 5.0's can take a beating though.

 

Cant remember if 89's had electric fans or not but over the time the connectors degrade and sometimes cause the fan to work intermittently. If you do have an electric fan make sure its running when the car is overheating, start it up and play with the wires around the connector on the fan and see if it cuts on and off...

 

I was a mustang guy and have worked on 5.0L for a long time. Sounds like the water pump, but you want to make sure it is not a head gasket. The FIRST thing to do is to check the oil. If it looks like there is too much oil in there, the chances are that there is antifreeze mixed in there. Check it closely. There should also be no oil mixed with the antifreeze. If you want to check it then try this...with the car cooled down, open the radiator cap and top off with water. Leave the cap off and run the car. After the thermostat opens, then water level in the radiator should go down. If you can't see the water level then top off again. Now watch the antifreeze flow in the radiator and look to see that there is no oil mixed in there. If there is oil in the radiator or water in the oil then it is most likely a head gasket.

Another thing you could do is put a white sheet of paper behind the tailpipe that is spraying water (Have a few sheets of paper). Don't plug the tail pipe, just tape the paper on the ground or hold it in where the liwuid is spraying out. Once all of the condensation has evaporated, there should not be too much liquid coming out of the tail pipe. Analyze the paper, if there is oil or antifreeze on the paper, then it MAY be a head or intake gasket.

But if you are hearing boiling sounds and there is actually antifreeze on the ground, then I wouldn't suspect a head gasket. They prolly didn't seal the back plate in the water pump or something stupid like that. Good Luck

 

first step (and easiest) is to replace the waterpump and thermostat. With coolant leaking out of the waterpump, it has to be replaced. If you change both and the problem persists, they may have installed your head gaskets incorrectly. If you install the head gaskets backwards, you will block off two vital cooling passages that will cause overheating.

Depending on the type of felpro gasket you used, you can actually tell if it's installed correctly just by looking at the lower front corner of both cylinder heads. You should be able to see the tip of the head gasket. Felpro makes the gasket end square on the front side and round on the backside for this reason. Obviously the round end will be hidden under the cylinder head while the square end will be exposed.

Let's hope that it's just a waterpump and thermostat.

Good luck

 

THanks a lot my fellow L owners! No oil mixing with the antifreeze and it is in fact leaking from the weep hole..Its the water pump..Now I don't know which water pump to buy now..Just wanted to thank all of you guys for the help with my stang

Take care!

P.S..I AM GLAD IT WASN'T A HEAD GASKET

 

get yourself one from the dealer or at least make sure it's an original Ford one. The ones from the autoparts stores (Autozone, etc) don't have a good track record.

Good luck!

 

Also make sure to match the pump you get to your current one. Ford used some with slightly different castings... real close in design, but with slightly different gasket flange shapes. Trust me... I blew a water pump gasket 3 times before I noticed the Autozone rebuild one curved up a bit more along the base, covering the gasket on the block by less than 1/16th of an inch... where it would push out no matter how much silicone was used.

 

I would suggest using Weiand (all I would ever use on mine)... but if you like changing out pumps every few months then Autozone ones work too


What every you buy MAKE SURE they get you the one for your stang. The rotation is backwards on older style but will bolt right up (and wont work of course), just look at the impeller on your old one and compair to the new one.