2003 coolant and thermostat change

[jgoedd99]

Ready to embark on additional deferred maintenance by doing coolant and thermostat change. I have the service manual and have read it and also searched this forum and got a lot of good information to figure both these out. I have two questions that perhaps someone can help me with that i have not seen addressed/can't figure out. The Motorcraft thermostat (2W9Z-8575-AB) appears to be no longer available. RockAuto shows a Stant 49499, but that is the only one i see anywhere on the internet. Most parts houses (Advance, AutoZone, OReily) don't even show a TStat and instead want to sell you the complete housing. Anyone have any insight into the proper replacement TStat?

Second question, when i pull the TStat housing to change the TStat it looks like there is an O-ring that seals the housing and probably would be good to replace at the same time. Ford Parts does not show a part number for this part. The service manual shows it as #8A571, which Ford Parts says does not fit my vehicle. Does anyone have a source and a part number for this O-ring that seals the TStat housing?

Thanks
JohnG

This page contains affiliate links for which I may be compensated. As an eBay Partner, and Amazon Associate I may be compensated if you make a purchase at no cost to you.

 

[JoseG]

There is one here.

Engine Coolant Thermostat-Therm 190 Motorcraft RT-1163 | eBay

Engine Coolant Thermostat. The engine types may include 3.9L 242Cu. V8 GAS DOHC Naturally Aspirated. This part fits vehicle s made in the following years 2002,2003,2004,2005,2006. To confirm that this part fits your vehicle, enter your vehicle's Year, Make, Model, Trim and Engine in...

www.ebay.com

 

[Merk]

Ready to embark on additional deferred maintenance by doing coolant and thermostat change. I have the service manual and have read it and also searched this forum and got a lot of good information to figure both these out. I have two questions that perhaps someone can help me with that i have not seen addressed/can't figure out. The Motorcraft thermostat (2W9Z-8575-AB) appears to be no longer available. RockAuto shows a Stant 49499, but that is the only one i see anywhere on the internet. Most parts houses (Advance, AutoZone, OReily) don't even show a TStat and instead want to sell you the complete housing. Anyone have any insight into the proper replacement TStat?
Second question, when i pull the TStat housing to change the TStat it looks like there is an O-ring that seals the housing and probably would be good to replace at the same time. Ford Parts does not show a part number for this part. The service manual shows it as #8A571, which Ford Parts says does not fit my vehicle. Does anyone have a source and a part number for this O-ring that seals the TStat housing?
Thanks
JohnG

 

[BruceBlueStang]

Last December, I replaced the thermostat housing on our 2002 Thunderbird with a Dorman 902-215. It came with the Thermostat & O-ring already installed. I believe the 2003-2005 uses a different thermostat housing

 

[cochon]

Before you tear into the system on your '03, you might give careful consideration to the age/condition of the black plastic parts, including the t'stat housing, the crossover, and the 45 degree tube that mounts to the top of the block (a real bear to replace). Unlike the 'rubber' portions, that seem to last forever, the black plastic components on this particular engine design are notorious for deterioration with heat, miles, and age, often leading to hairline cracks and issues that go with brittleness. Google it on the lincoln LS sites and you'll get a better idea. Unfortunately, Ford has been discontinuing the motorcraft replacements and the jury is still out as to the quality and longevity of the aftermarket alternatives. If it were me, I wouldn't dream of touching a functioning thermostat on a retro bird, unless and until I was ready to do a proactive replacement of all the black plastic parts and already had all of the replacement parts and seals in hand.

 

[jgoedd99]

Before you tear into the system on your '03, you might give careful consideration to the age/condition of the black plastic parts, including the t'stat housing, the crossover, and the 45 degree tube that mounts to the top of the block (a real bear to replace). Unlike the 'rubber' portions, that seem to last forever, the black plastic components on this particular engine design are notorious for deterioration with heat, miles, and age, often leading to hairline cracks and issues that go with brittleness. Google it on the lincoln LS sites and you'll get a better idea. Unfortunately, Ford has been discontinuing the motorcraft replacements and the jury is still out as to the quality and longevity of the aftermarket alternatives. If it were me, I wouldn't dream of touching a functioning thermostat on a retro bird, unless and until I was ready to do a proactive replacement of all the black plastic parts and already had all of the replacement parts and seals in hand.

Thanks for insight. Everything is working (no overheating) except i don't get as cold on the passenger side AC as the driver side. Was intending to do heater control valve and as long as i am opening up the system was going to do coolant flush and fill at the same time seeing as the coolant is likely 21 years old. So if i leave the TStat as is, what's your take on doing heater control valve and coolant flush with VC-1 and fill?

I am thinking the heater control valve may be gummed up with dirt and that was why i was thinking i should do a flush before i change out the valve.

 

[cochon]

Thanks for insight. Everything is working (no overheating) except i don't get as cold on the passenger side AC as the driver side. Was intending to do heater control valve and as long as i am opening up the system was going to do coolant flush and fill at the same time seeing as the coolant is likely 21 years old. So if i leave the TStat as is, what's your take on doing heater control valve and coolant flush with VC-1 and fill?

I am thinking the heater control valve may be gummed up with dirt and that was why i was thinking i should do a flush before i change out the valve.

My experience doesn't extend much to the DCCV, but your suspicions sound reasonable. Have you tried doing a simple bleed per the shop manual, with or without a radiator drain and new coolant? Due to the design you won't get all of the old coolant out at single session but it's not so bad if you start changing it on a regular basis, and not a bad move even if you end up doing it again as part of a further repair.

 

[wiggy]

Recently replaced thermostat housing with a Dorman which includes thermostat. After doing so car was overheating. Apparently new tstat was defective as cooling was restored after replacement with a Motorcraft .I got lucky as they had one and only one on Rockauto. Noticed it was made in Great Britain not China !!

 

[Liquidlounge]

The Motorcraft parts are getting really hard to find. I did see where Gates offers a complete integrated thermostat housing for the '03 up Thunderbirds. A lot higher $$ than the Dorman, but I would bet it may be the best option left.

 

[jgoedd99]

Well I did it. Flushed coolant system, and changed coolant, thermostat and heater control valve (DCCV). It all went well, no issues, and coolant temperature is running right where it was before i started. Even got it full without having to do a whole lot, just followed fill and bleed procedure in service manual. FWIW - here's what i did, it may be helpful to others with 20 year old cars with original coolant. For reference i have service manual, scoured this website which is always helpful, and looked at a couple videos available on internet. Ford tech Makuloco has a great video on flushing Ford coolant systems that i have used in the past on my other Ford vehicles. I followed his recommendations for the VC-1 flush part of the process.

Remove front of engine cowling, top of engine cowling, and front bottom of engine cowling. Loosened clamps holding air intake tubes and air filter hold down. Run engine up to temperature. Turn engine off. Open degas bottle top (carefully and slowly as pressure will be present), open radiator drain, once it drains a bit, open coolant fill (top of engine). Remove air intake tube from air filter box and engine and swing out of the way to allow access to the TStat housing. Remove large hose from Tstat housing and remove Tstat housing. Open heater core vent tube (straight screwdriver and turn CCW to remove vent plug. Using Shop vac and varying sucking or blowing at degas bottle, vent tube, and top of engine i was able to get ~ 2.5 gallons of old coolant out. Capacity is 3 gal. Coolant was quite dark compared to new VC-7A/7B but not too bad (no debris or rust).

Run garden hose in degas bottle to flush bottle and run that out the bottom of radiator. Again suck/blow at available locations to get all this water out. Close radiator bottom drain. Put Tstat housing back on (TStat still in place). There is an Oring on the housing that i reused as i could not determine the P/N for a new one. Lubed ORing with silicone grease. Leave cap off the top of the engine fill. Add Motorcraft VC-1 flush (1 quart to degas bottle). Put hose in degas bottle and add slowly till it starts coming out the top of engine fill cap. Squeeze hoses to help burp. Put cap on top of engine fill, continue filling at degas bottle with hose until bottle is at full cold level. Start and run engine up to temp with heaters set to 90oF (full hot). Add water if necessary to degas bottle to keep in full hot range. Close heater core vent tube when steady water stream is coming out. Reassemble air intake hose (do not run engine without the air intake fully assembled and filter in place). Run engine for 15 minutes or so varying RPMs up to 1500 - 2000 every couple minutes. Monitor engine temperature, monitor heater output (should be blowing warm). Do this for about 15 minutes to flush the VC-1 coolant flush throughout the system. After 15 minutes, with engine still running, open radiator drain plug and turn hose on in degas bottle. Add water at about the same rate that the water is coming out the drain, i.e. the water level in degas bottle stays the same. Keep engine at idle. Do this for 15 or 20 minutes until water coming out is clean and no more "bubbling" (due to VC-1 flush). Monitor engine temperatures while doing this.

Once water runs clean and you have rinsed all the VC-1 out of the system, turn engine off and drain everything once again (through radiator bottom drain, remove TStat housing, open heater core vent tube, suck/blow with Shop Vac, etc as was done the first time). Again i got about 2.5 gallons out. Put Tsat housing back on, close radiator drain and fill system with distilled water at the degas bottle, using same fill and vent as described before. Run engine up to temperature and add distilled water to degas bottle if necessary to keep at full cold level, put cap on degas bottle and run for about 5 minutes at idle with heaters on and blowing hot. At this point you should have a very clean system flushed of all VC-1. Drain everything one more time.

Reassemble TStat housing with new Tstat (STANT 49499). Remove old DCCV and install new DCCV (Motorcraft YG-378 / 2R8Z-18495-AA). Once DCCV is out you have access to 3 more hoses to/from heater cores, so i sucked/blowed the water out of these heater hoses with Shopvac. Reassemble everything and fill with 1.6 gallons Motorcraft VC-7B (MC gold antifreeze). Capacity is 3 gallons, so i am a little over 50%. Top off with distilled water. Fill as described before. Run to temp and if level goes down top off with distilled water. Check coolant for freeze protection and monitor next couple times out and top off with distilled water if the level drops below the full cold level on the degas bottle.

No issues. Temp guage at same position as before. No air locks, no overheating, etc.

Hop this helps anyone inclined to do this themselves.

JohnG

 

[jneuenburg]

Well I did it. Flushed coolant system, and changed coolant, thermostat and heater control valve (DCCV). It all went well, no issues, and coolant temperature is running right where it was before i started. Even got it full without having to do a whole lot, just followed fill and bleed procedure in service manual. FWIW - here's what i did, it may be helpful to others with 20 year old cars with original coolant. For reference i have service manual, scoured this website which is always helpful, and looked at a couple videos available on internet. Ford tech Makuloco has a great video on flushing Ford coolant systems that i have used in the past on my other Ford vehicles. I followed his recommendations for the VC-1 flush part of the process.

Remove front of engine cowling, top of engine cowling, and front bottom of engine cowling. Loosened clamps holding air intake tubes and air filter hold down. Run engine up to temperature. Turn engine off. Open degas bottle top (carefully and slowly as pressure will be present), open radiator drain, once it drains a bit, open coolant fill (top of engine). Remove air intake tube from air filter box and engine and swing out of the way to allow access to the TStat housing. Remove large hose from Tstat housing and remove Tstat housing. Open heater core vent tube (straight screwdriver and turn CCW to remove vent plug. Using Shop vac and varying sucking or blowing at degas bottle, vent tube, and top of engine i was able to get ~ 2.5 gallons of old coolant out. Capacity is 3 gal. Coolant was quite dark compared to new VC-7A/7B but not too bad (no debris or rust).

Run garden hose in degas bottle to flush bottle and run that out the bottom of radiator. Again suck/blow at available locations to get all this water out. Close radiator bottom drain. Put Tstat housing back on (TStat still in place). There is an Oring on the housing that i reused as i could not determine the P/N for a new one. Lubed ORing with silicone grease. Leave cap off the top of the engine fill. Add Motorcraft VC-1 flush (1 quart to degas bottle). Put hose in degas bottle and add slowly till it starts coming out the top of engine fill cap. Squeeze hoses to help burp. Put cap on top of engine fill, continue filling at degas bottle with hose until bottle is at full cold level. Start and run engine up to temp with heaters set to 90oF (full hot). Add water if necessary to degas bottle to keep in full hot range. Close heater core vent tube when steady water stream is coming out. Reassemble air intake hose (do not run engine without the air intake fully assembled and filter in place). Run engine for 15 minutes or so varying RPMs up to 1500 - 2000 every couple minutes. Monitor engine temperature, monitor heater output (should be blowing warm). Do this for about 15 minutes to flush the VC-1 coolant flush throughout the system. After 15 minutes, with engine still running, open radiator drain plug and turn hose on in degas bottle. Add water at about the same rate that the water is coming out the drain, i.e. the water level in degas bottle stays the same. Keep engine at idle. Do this for 15 or 20 minutes until water coming out is clean and no more "bubbling" (due to VC-1 flush). Monitor engine temperatures while doing this.

Once water runs clean and you have rinsed all the VC-1 out of the system, turn engine off and drain everything once again (through radiator bottom drain, remove TStat housing, open heater core vent tube, suck/blow with Shop Vac, etc as was done the first time). Again i got about 2.5 gallons out. Put Tsat housing back on, close radiator drain and fill system with distilled water at the degas bottle, using same fill and vent as described before. Run engine up to temperature and add distilled water to degas bottle if necessary to keep at full cold level, put cap on degas bottle and run for about 5 minutes at idle with heaters on and blowing hot. At this point you should have a very clean system flushed of all VC-1. Drain everything one more time.

Reassemble TStat housing with new Tstat (STANT 49499). Remove old DCCV and install new DCCV (Motorcraft YG-378 / 2R8Z-18495-AA). Once DCCV is out you have access to 3 more hoses to/from heater cores, so i sucked/blowed the water out of these heater hoses with Shopvac. Reassemble everything and fill with 1.6 gallons Motorcraft VC-7B (MC gold antifreeze). Capacity is 3 gallons, so i am a little over 50%. Top off with distilled water. Fill as described before. Run to temp and if level goes down top off with distilled water. Check coolant for freeze protection and monitor next couple times out and top off with distilled water if the level drops below the full cold level on the degas bottle.

No issues. Temp guage at same position as before. No air locks, no overheating, etc.

Hop this helps anyone inclined to do this themselves.

JohnG

Nice write up. I wonder if there is a simpler, tool-free method to do a coolant change (not talking about going to a shop that has a coolant exchange machine)? Drain radiator, suck out the bottle, fill system with hose water, run it, drain and fill a couple more times, then drain and fill with distilled water a couple times, running for a while each time, then drain and put antifreeze in, top with distilled water?

When I was in the automotive chemical business as a rep for BG Products, and later with a big diesel engine parts distributor, I learned that it was not good to assume 5 year coolant would be good for 5 years. My latter company sold turbochargers, fuel injectors, EGR coolers for the Ford 6.0L diesel, the first one with an EGR system, and that system could be victimized by old coolant. After some years, one of the additives would come out of solution and form a fine powder. This would clog the small passages in the OEM oil cooler, thus restricting the coolant side of it, which shrunk the coolant flow to the EGR cooler which was downstream. That would end up cracking internally due to excess heat, coolant gets into the intake and combustion chambers, then the wet soot would clog the variable geometry turbine in the turbo. The lost coolant led to a hotter engine which was/is not always spotted, engine would stretch, and the head gasket would blow. Big expenses. My point is those failures can normally be eliminated with regular coolant changes. Like sticking with green coolant and changing in two years. Our T-bird motors are not the problem child the 6.0L Ford diesel is but going too long on fluids is not smart.