spewing coolant below thermostat

Anyone know what part is directly under the thermostat? Its spewing coolant from here. I figured maybe the therm was stuck so i replaced it and it is still spewing from the same area. Looks like maybe a gasket against the block or something. I can't find an engine diagram to determine the part. it looks like like a gasket may have been there and got blown out by closed thermostat. or is it the waterpump?? Thanks so much. Anywhere with pics or engine diagram so i can see or order the part?

2002 4.0 explorer

Picture?

Could it be the o-ring gasket that goes around the thermostat that is leaking?


If its the waterpump, it will leak from the area under where the fan attaches to the waterpump. There is a small hole on the bottom side to allow the coolant to come out when the waterpump shaft seal is gone.

well

its definetely not the o ring around the thermostat. That doesn't leak at all. its another area down along the therm neck close to the engine. It looks like you can unbolt just beneath the thermastat housing. About 5more bolts. It literally just spoits coolant out. I'll try and get a pic.

Thanks for such quick responses.

Ok. Lower thermostat housing i believe

I think thats what its called. A dealer part i'm sure. I got it off pretty easy and on the back of it a leak had sprung out through the gasket i guess. Probably because the thermastat closed shut????

any advice. Napa can't find it. Dealer said to bring it in. Can the therm cause this problem? Hate to replace it and have it happen again.

I doubt that the thermostat would cause anything to leak, but if you have it all apart anyway, thermostats are pretty cheap to replace. You can test the thermostat with a pot of boiling water and a thermometer, but it isn't worth the effort IMO when you can buy a new one for less than $25.

BTW, fastpartsnetwork.com has the thermostat for $23 and the housing for $39.

thunder i have the same exact problem...i noticed it a couple of days ago went and looked in my chilton book and couldnt find the part itself...let me know what you turn up at the dealer...my ex is a 4.0 also...its the housing that holds the ect sensor and has the thermostat housing attached to it...

yep

well the dealer calls it the lower thermostat housing. Contains the sensor on top of it and an inlet house also. Around $60 for just he lower housing. I don't know how to get the top off to attach but we'll see when i get part tomorrow. I know mine is bad i just hope it was the therm causing it to leak. I think so.

how many miles you got on your ex? mine has almost 81,000 and my guess is that the seal just gets old? maybe ford cheaped out on this part also...let me know how it goes for you thanks

installed new one and runs good

No problems so far. $60.00 for whole thermostat housing. Explorer has 100k on it. No leaks at all as of yet. Still waiting for the thermostat to open completely once car is hot though. The hose above it didn't seen totally full just yet. Driven 15miles so far.

Make sure to recheck coolant level after the thermostat opens. You can tell because the upper radiator hose will get warm. I usually just let it idle until that happens.

update. working well

went fine man. just cleaned off lower housing area and put a little gasket glue. i had to reuse the therm gasket and worked just fine. Just make sure the upper house is getting hot. That way you know its opening up the thermostat. the coolant i had said i could mix with either red or green coolant. good luck. its pretty easy and i'm no pro. Oh and theirs a little seaper on the top of the therm where the wire plugs in. it will leak a little at times. Its supposed to. Mine just did in beginning.

$60 for the whole thing?! I just paid $200 for one for a '98 SOHC!!!!

Is there an air bleed procedure for these after doing this job? Im getting ready to replace my thermostat for the second time in 88K miles, and the dealer did it the first time when they replaced this lower housing due to a leak. Thanks!

no air bleed procedure...just gotta make sure the top hose gets hot...

Be careful with the lower thermostat, don't remove the sensors in it. Those will break the housing when removed, and most of those are over $200 as an assembly, $60 sounds odd.

I think the newer intakes have a very small lower thermostat housing compared to what im told is an integrated one on the older SOHC's. I think 60 is high for that little "neck" of plastic. I would expect 200 for an entire lower intake.

Ah, that is good for them, the older parts are too sensitive and expensive.

Agreed. When you put plastic through that many heat cycles and then try to move/adjust/re torque it, its just asking for problems. I remember everyone complaining about the weak aluminum parts in engines, and now its all plastic.

I did cringe when torquing the thermostat housing on.

CDW6212R said:

Be careful with the lower thermostat, don't remove the sensors in it. Those will break the housing when removed, and most of those are over $200 as an assembly, $60 sounds odd.

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its actually 60-70 bucks and the ect sensor has a clip that holds it to the housing....its easy to unclip and put it on the new housing