$750 to replace thermostat housing?!?!?

[LVTrixie]

My '05 Sport Trac Adenalin suddenly started overheating recently (the first time was right after a mobile mechanic replaced my AC blower motor, and the hose to the coolant reservoir "popped off" while driving (I believe he did a crappy job of putting it back in after the job, but he said/she said). He put a zip tie on it, refilled the reservoir, ran the engine for about 10 min (in triple digit Vegas heat) and though there was visible crusties around the thermostat housing, we could not see or hear any coolant coming out. I decided to wait til a bit on replacement. I started back to work the next day (after a 4 month Covid furlough) and it made it about 2 miles before overheating again. Murphy's law! Had it towed to a "real" mechanic who has quoted me $750 to replace housing and do a coolant flush with 3 hours of labor! Seems at least a couple hundred too high from everything I've read. Can anyone confirm my suspicion?!?

 

[koda2000]

My '05 Sport Trac Adenalin suddenly started overheating recently (the first time was right after a mobile mechanic replaced my AC blower motor, and the hose to the coolant reservoir "popped off" while driving (I believe he did a crappy job of putting it back in after the job, but he said/she said). He put a zip tie on it, refilled the reservoir, ran the engine for about 10 min (in triple digit Vegas heat) and though there was visible crusties around the thermostat housing, we could not see or hear any coolant coming out. I decided to wait til a bit on replacement. I started back to work the next day (after a 4 month Covid furlough) and it made it about 2 miles before overheating again. Murphy's law! Had it towed to a "real" mechanic who has quoted me $750 to replace housing and do a coolant flush with 3 hours of labor! Seems at least a couple hundred too high from everything I've read. Can anyone confirm my suspicion?!?

I assume you have the 4.0L SOHC V6 engine. It's possible you're over heating because there was an air pocket in the cooling system after the mobile mechanic worked his magic. These engines are notoriously difficult to get air out of cooling system due to the location of the thermostat housing. The only way to get the air out is to refill the system with the front of the vehicle high in the air. Even then it can be tricky. Due to the location of the T-stat housing (high point on the engine) air tends to get trapped in the housing right under the thermostat and temp sensor/sender. This doesn't allow the thermostat to open as the coolant is heated causing it to overheat.

IDK why your new mechanic believes you need a new t-stat housing, unless yours is cracked and leaking (which is a common problem with the OE plastic housings). I recently replaced my plastic housing with the best quality aluminum housing on the market (Simmons Autosportz) and even with the extra replacement parts it only cost me around $187. I would never use a plastic housing again. The labor involved in replacing the t-stat housing is a bit of a PITA, but no way it should cost you $750.

Questions:
Why is your original housing being replaced? What make of new housing does the mechanic plan to install (if you must go with a plastic housing Ford OE is probably your best choice, but plastic is still a bad choice). Dorman/Napa are terrible choices. Does the mechanic also plan to replace the thermostat and water pump bypass hose? He should.

 

[LVTrixie]

I assume you have the 4.0L SOHC V6 engine. It's possible you're over heating because there was an air pocket in the cooling system after the mobile mechanic worked his magic. These engines are notoriously difficult to get air out of cooling system due to the location of the thermostat housing. The only way to get the air out is to refill the system with the front of the vehicle high in the air. Even then it can be tricky. Due to the location of the T-stat housing (high point on the engine) air tends to get trapped in the housing right under the thermostat and temp sensor/sender. This doesn't allow the thermostat to open as the coolant is heated causing it to overheat.

IDK why your new mechanic believes you need a new t-stat housing, unless yours is cracked and leaking (which is a common problem with the OE plastic housings). I recently replaced my plastic housing with the best quality aluminum housing on the market (Simmons Autosportz) and even with the extra replacement parts it only cost me around $187. I would never use a plastic housing again. The labor involved in replacing the t-stat housing is a bit of a PITA, but no way it should cost you $750.

Questions:
Why is your original housing being replaced? What make of new housing does the mechanic plan to install (if you must go with a plastic housing Ford OE is probably your best choice, but plastic is still a bad choice). Dorman/Napa are terrible choices. Does the mechanic also plan to replace the thermostat and water pump bypass hose? He should.

Thank you for your expert insight. Makes total sense about the air in the system. . Mobile mechanic was definitely not knowledgeable and didn't even mention that as a potential issue after driving all the coolant out of the vehicle thanks to his carelessness. (BTW I was only using a mobile mechanic to avoid taking Uber/Lyft during the pandemic, and now thanks to him, I have had to take 5 rides so far.)

I told the shop what happened, but do not know if they attempted to bleed the air out of the aystem He the housing was spewing coolant and needed replacing. Using Napa parts at double the online retail price: $168 for part S1602AT "thermostat and water output assembly"and $55 for MS96123 "manifold gasket set" (plus $69 for system flush and $45 for 3 gallons of coolant). No hose listed on work order. Oh, and BTW I'm female....so I'm always concerned about being ripped off, so thought going to a woman-owned shop would be safer. Apparently not.

Unfortunately the work has been done, but I've already put them on notice that when I pick it up today I will be expecting some give on the price of the parts. I have worked in retail/buying so I know they are getting their parts at wholesale. So mad I could spit fire! Before this all.started, I watched several YouTube vids in how to clean out and replace the blower motor if needed (which was making a lot of noise). I know I could have done the blower motor myself, but I didn't want to do in 110 degree heat. I deeply regret that decision now. Lesson learned.

 

[koda2000]

Thank you for your expert insight. Makes total sense about the air in the system. . Mobile mechanic was definitely not knowledgeable and didn't even mention that as a potential issue after driving all the coolant out of the vehicle thanks to his carelessness. (BTW I was only using a mobile mechanic to avoid taking Uber/Lyft during the pandemic, and now thanks to him, I have had to take 5 rides so far.)

I told the shop what happened, but do not know if they attempted to bleed the air out of the aystem He the housing was spewing coolant and needed replacing. Using Napa parts at double the online retail price: $168 for part S1602AT "thermostat and water output assembly"and $55 for MS96123 "manifold gasket set" (plus $69 for system flush and $45 for 3 gallons of coolant). No hose listed on work order. Oh, and BTW I'm female....so I'm always concerned about being ripped off, so thought going to a woman-owned shop would be safer. Apparently not.

Unfortunately the work has been done, but I've already put them on notice that when I pick it up today I will be expecting some give on the price of the parts. I have worked in retail/buying so I know they are getting their parts at wholesale. So mad I could spit fire! Before this all.started, I watched several YouTube vids in how to clean out and replace the blower motor if needed (which was making a lot of noise). I know I could have done the blower motor myself, but I didn't want to do in 110 degree heat. I deeply regret that decision now. Lesson learned.

Well, I wish you good luck with the Napa T-stat housing. I'm pretty sure it's made by Dorman (re-boxed as Napa) and Dorman stuff is usually crap. Their plastic T-stat housings have a really bad reputation. Keep a close eye on our coolant level for any sign of coolant loss. The problem with the plastic T-stat housing is the tops are sonic welded to the lower part. With the hot coolant the plastic becomes brittle and the sonic weld splits.

As far as your mechanic ripping you off... unfortunately this is what many mechanics/shops do to people (and not only just to women). This is why I do my own repairs. I don't trust anyone and over the years the very few experiences that I've had with shops and dealerships has almost without exception been bad, but I didn't let them get away with it because I knew better.

 

[LorenzoGarbanzo]

I did the thermostat housing on my '07 4.0 which is fairly similar about a month ago. It cracked open and puked coolant everywhere. 2 beers, 3 bolts, 2 hose clamps, and a jug of coolant had it back on the road. The entire assembly made by Dorman with lifetime warranty was about $80.

Based on this video, you might have a few extra steps, it looks like the throttle body, belt, & intake hose may be in the way from pictures. The creator was able to get it without removing the intake plenum. I'd shop around, don't think I'd pay over $350ish for that job if I was in a pinch.

 

[LVTrixie]

Well, I wish you good luck with the Napa T-stat housing. I'm pretty sure it's made by Dorman (re-boxed as Napa) and Dorman stuff is usually crap. Their plastic T-stat housings have a really bad reputation. Keep a close eye on our coolant level for any sign of coolant loss. The problem with the plastic T-stat housing is the tops are sonic welded to the lower part. With the hot coolant the plastic becomes brittle and the sonic weld splits.

As far as your mechanic ripping you off... unfortunately this is what many mechanics/shops do to people (and not only just to women). This is why I do my own repairs. I don't trust anyone and over the years the very few experiences that I've had with shops and dealerships has almost without exception been bad, but I didn't let them get away with it because I knew better.

Thanks Koda...Everytime I have to deal with another big repair, I wish I'd gone to auto tech school and become a mechanic, instead of a retail slave.

 

[donalds]

Buying a plastic thermostat housing is like using a $50 Bill too light a hot water tank works for a while

 

[LVTrixie]

I did the thermostat housing on my '07 4.0 which is fairly similar about a month ago. It cracked open and puked coolant everywhere. 2 beers, 3 bolts, 2 hose clamps, and a jug of coolant had it back on the road. The entire assembly made by Dorman with lifetime warranty was about $80.

Based on this video, you might have a few extra steps, it looks like the throttle body, belt, & intake hose may be in the way from pictures. The creator was able to get it without removing the intake plenum. I'd shop around, don't think I'd pay over $350ish for that job if I was in a pinch.

I wish I could have done it myself...because I'm paying twice that, and it makes ME want to puke all over. Unfortunately I had to have it done ASAP as I don't have the luxury of time or back-up transportation to work (which I just started back to this week after a 4 month+ furlough). I couldn't even get a Lyft or an Uber today to pick up my truck and had to pre-schedule for tomorrow! (Covid cases are spiking bad here in Vegas so I think drivers are getting scared). The mechanic said he HAD to take off the intake manifold and replace the gaskets on it (also paid double for those), so obviously he found everyway possible to add to the cost. I had it out with him today and got nowhere...aside from my AAA 15% discount which saved all of $40. He tried to claim that Napa charged him $115 for the housing assembly. I told him that was pretty hard to believe when it was $83.50 retail on their website, and that I was pretty sure he was getting either a wholesale or discounted dealer price. I'm sure he won't be willing to show me his invoice. I honestly don't know how these people sleep at night.

 

[LVTrixie]

Buying a plastic thermostat housing is like using a $50 Bill too light a hot water tank works for a while

I agree. As they say: They sure don't make 'em like they used to! Too bad If it takes a crap again, I will definitely be replacing it with the aluminum option.
Honestly, I love my truck, but hate the dread I feel everytime something needs fixing. If it weren't so unsafe to drive them and so damn hot where I live I'd still be driving a vintage VW and fixing all but the big stuff myself.

 

[MrQ]

The engine and transmission properly maintained can last up to 200k miles. I've seen it on multiple vehicles. There are some defects out of the box due to the general cost cutting around manufacturing and some poor design choices (what company hasn't?), but overall, after 2002, the SOHC engines got a lot more reliable.

After my first repair bill to replace the master cylinder in my first Explorer, I said "never again." That was over a decade ago and I knew absolutely nothing about car repair. But since I am a ********* and continue to own and collect these 20 year old vehicles, I seem doomed to the inevitable cycle of breakage, cursing, repair, and repeat.

It can definitely be a daunting task to do the work yourself for the first time, but I've done a lot of it in parking lots in 90+ degree heat and 80% humidity and in below freezing temps (I didn't get an actual garage until this year). However, I have saved thousands of dollars in repair work. If you choose to do the work, this forum is a great resource to get you started.

 

[koda2000]

I agree. As they say: They sure don't make 'em like they used to! Too bad If it takes a crap again, I will definitely be replacing it with the aluminum option.
Honestly, I love my truck, but hate the dread I feel everytime something needs fixing. If it weren't so unsafe to drive them and so damn hot where I live I'd still be driving a vintage VW and fixing all but the big stuff myself.

YouTube is also a great source for visualizing how to make specific repairs. IDK about you, but I'm a visual learner. Search the repair you need to make and find a video that is well done and easy to understand. Two of my favorite go-to posters are fordtechmakuloco and South Main Auto Repair. Some YouTube poster video's are horrible and their camera stills make me nauseous. Fortunately there are usually multiple videos to chose from.

 

[donalds]

Details of my tribulations with this issue at Engine Coolant ThermoStat
Also best learn to work on your own vehicle; even the most conscientious commercial mechanics\shops are driven by profit, not quality.

Great post