2003 Overheating on short trips

[JBond007]

Hi everyone, I recently had an issue with my car pegging HOT and temp light coming on after a very small trip. Have 40,300 miles on it. 5 min drive to store, inside for an hour and 5 min drive home (happened after 2 min) and was going to pull over but I quickly shut the a/c off to reduce the load and temp started dropping right away, light went out and got home with gauge showing smack in the middle as always.

I raised the hood and looked around. Saw that the upper radiator hose has a dry white corrosion and a wet leak on the top of the plastic tee connector. After car cooled checked fluid level and it was down about 20 oz. I have Gold in mine so added the premix gold to get it to the cold level. I took it to mechanic and they changed the hose out to a Dorman with metal tee connector for future protection from cracking. They said they bled the air out. Got home with it and all seemed good. In the morning saw like a 3" puddle under overflow tank directly down to floor so thought they put lil too much fluid in. Went for 5 min ride, reached normal temp, car sat for about 1.5 hrs, drove 5 min more and car sat for 2 hrs and saw 2 spots about 2" big in friends driveway. 5 min to home after, temp gauge still good thru all this. Parked in garage, went in for 10 min, came out and saw this giant puddle under the car ( clay litter on some but couldn't get to the other part). Again dripping down from the overflow tank only. Called mechanic, sent them pics, owner came to my house and said still has air in system so he filled it and I drove it to them. They bled it again and manager wanted to change the thermostat but I declined since owner said it was just air. He said fan and thermostat was working fine. Manager changed the cap on the overflow tank saying the spring was weak and they ran it for an hour and all good. Car sat for 3 days with no issues. 4th day drove it 5 min, sat for 1.5 hr, 5 min home - all good no leaks. Sat for a day, no leaks. Next day, 5 min drive, sat for 3 hrs, 5 min drive home. In morning had about a cup of fluid on the floor again. What the heck is going on?????

I saw an old post but it didn't have any replies to it about possible "Bad PCM" (title of it, they had 03 with coolant leak too)?

Look forward to your thoughts.

***Pics: 2 with old upper, leak after

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[bmac1060]

Possibly an intermittently sticking thermostat. There is No way to rule out the thermostat without removing it from the car so may as well change it.

 

[Chopt34]

I went through the same thing on my 2004 last year. The white residue is the coolant leaking through the micro cracks from your injection molded plastic coolant components. My recommendation is to change all of the coolant system components including the rubber hoses including the degas reservoir as shown in the attached diagram while you have it apart. I serviced my serpentine belt while I was at it, One important thing to note, change the coolant tube that runs underneath the intake plenum. I missed that line when I had my intake off. It goes together faster the second time! (ha ha). This molded line is not available, but that is not a problem. I inserted tubing inside the rubber line to hold the shape to avoid kinking the line. There are some You Tube videos that show how to change some of the components without removing the intake manifold. It is your call, but I recommend just do it right and lift the intake manifold since that is the only way to access the tube that is under the plenum. after you have that lifted up, it is easy to access the bolts to replace the injection molded parts. If you work on cars, you will find it is not hard, there are some very tight access areas, it just takes time. I also recommend replacing all of the clamps while you are at it. Some viewers may have been fortunate to successfully reuse the factory clamps, but several of mine lost the clamping force and started leaking, so I ended up changing all of them. I added a couple of additional photos, I found the photo of the line under the plenum, I also label all of the lines and electrical connections to make it easier during assembly.

 

[biddle]

The most common crack is in the thermostat housing which should be inspected carefully. Also, this cooling system is much harder to bleed air from than a typical car.

This thread has all the common parts-

Thread '2002 2003 2004 2005 Ford Thunderbird Thermostat Housing Water Pumps'

Jun 16, 2020

If you are having trouble with your cooling system on your 2002, 2003, 2004 or 2005 Ford Thunderbird here are some useful parts used in the repairs. Note, a 2002 Thunderbird has a different thermostat housing than 2003-2004-2005. The water pump & thermostat are the same. You can upgrade the thermostat in a 2002 Thunderbird to aluminum. I believe only plastic is available for 2003-2005 Thunderbirds. The plastic thermostat housings often need to be replaced every 5 - 7 years.
Several people have reported issues with the paper gaskets on the aftermarket water pumps. The water pump itself is...

• biddle
• @tbirdbob coolant thermostat cooling system overheating paper gasket thermostat thermostat housing
• Replies: 27
• Forum: 1955 - 2005 Parts Discussion & for Sale/Wanted

• 

Here's a video with some coolant system burping / bleeding tips on the "cousin car' Lincoln LS. Would be great for a member to make a Thunderbird specific video and send to us to add to our YouTube channel!

 

[wiggy]

I would check degas bottle (overflow tank) for leaks. I replaced mine with an aluminum one which are available on ebay. Position of leak suggests this is possible. Make sure bleeder valve wasn't left open.

 

[biddle]

I would check degas bottle (overflow tank) for leaks. I replaced mine with an aluminum one which are available on ebay. Position of leak suggests this is possible. Make sure bleeder valve wasn't left open.

One issue on these, Inferior or budget aluminum brands can suffer from pinhole leaks along the seams or improperly sealed bungs. These overflow tanks made from automotive plastics last 20++ years.

 

[JBond007]

Thank you all for the replies. I decided to try the bleeding first. I have done it 3 times via the bleed tube release near overflow cap. I put a white towel under tube to catch anything. I got air out first time and 1/4 cup drip on floor (not sure when it spit out). The heater is working fine. 2nd time, after letting car cool off for several hours, before starting it I heard what sounded like a teeny bird chirp and it was coming for the bleed tube. I released it and heard air come out. Went thru the startup/running/pressurizing procedure and got just some little bubbles from bleed tube then flowed and only 3 small spots on floor. 3rd time, same chirps after cooled off, released air, same procedure and only 1 very small spot no color. Should I keep doing this? Is there any other reason that the air builds up with the chirps? Or just still more air in there to get out? I'm going to do a 4th time today and see. Note: When I saw the leak in the first place it was running behind the wheel well black cover liner.

 

[Chopt34]

Thank you all for the replies. I decided to try the bleeding first. I have done it 3 times via the bleed tube release near overflow cap. I put a white towel under tube to catch anything. I got air out first time and 1/4 cup drip on floor (not sure when it spit out). The heater is working fine. 2nd time, after letting car cool off for several hours, before starting it I heard what sounded like a teeny bird chirp and it was coming for the bleed tube. I released it and heard air come out. Went thru the startup/running/pressurizing procedure and got just some little bubbles from bleed tube then flowed and only 3 small spots on floor. 3rd time, same chirps after cooled off, released air, same procedure and only 1 very small spot no color. Should I keep doing this? Is there any other reason that the air builds up with the chirps? Or just still more air in there to get out? I'm going to do a 4th time today and see. Note: When I saw the leak in the first place it was running behind the wheel well black cover liner.

You can keep trying bleeding, but the fact is, air is getting in your cooling system. This a common maintenance item for this vehicle, it is not if the injection molded components and hoses start to fail, it is when they fail because it is a 20+ year old car. The coolant dripping by the front tires, is your coolant leaking and traveling though the valley pan under the intake down the back of the engine. I build hot rods and restore cars as a hobby, so I do all of my own maintenance on all of my cars. This one had me stumped since this was my first 2004 T bird, until I figured it out. Sorry to sound negative, I really doubt the bleeding will help you out since you mentioned you have coolant dripping by the bellhousing, that is the key tell-tale sign you need to replace the coolant lines. The reason the dripping is intermittent, is because the rubber & injection molded components heat cycle and will expand and contract. Since you have to pull the cowl screen to service the degas bottle and serpentine belt to service the thermostat housing and hoses, pull the intake and replace everything at the same time. If you do it piece meal, every component will require removing other components to access it. It will save you time, or save you $$$ if you have a technician do the work you pay for. That way you only cry once, but you will be happy you did. I am sharing this from personal experience, after I replaced hoses and thermostat housing, etc. I overheated again and had to call a flatbed since I did not change the rubber line under the intake manifold when I was servicing my T Bird because I ignored my better judgement and did not want to go to the trouble to pull the intake manifold. I ended up having to drain the coolant, pull the intake manifold and other related components to replace that little hose I should have done the first time. That project that should have only been a weekend project ended up stretching out over 3 weekends because the tension of the original clamps lost temper and I ended up changing clamps too, as I mentioned in my original response.
If you have tools and experience with PM work, it is not hard, it just takes time because you need to be very careful in removing components to allow access to items you need to service and be very careful separating the electrical connections because heat can make the clips brittle. If I recall, I think it cost me around $600 in parts (last year), plus coolant. You can save a little in parts if you choose, since I changed my water pump, serpentine belt and tensioner while I had access to these components. I figured the cars is over 20 years old, approximately 80K miles, it is cheap insurance to avoid calling triple A for a flatbed again.