Wesley1995

My mustang keeps blowing the (lower thermostat housing), also it has recently started blowing the (heater hose) on top of the thermostat housing. I've had several (shade tree) mechanics look at it an they can't find anything. I've also replaced the radiator.
Now I have some upgrades to my car
1. Cold air intake
2. Throttle body spacer
3. Bosch plug wires 8MM
4. Bosch platinum +4 plugs

Can someone please help me find this issue with my mustang? It's costing a lot of money to keep replacing these parts. Ie replaced the lower thermostat housing (5) times and the heater hose (2) times now all in less than a year.

jimkaray

Sounds like the system is being over pressurized. The worse case scenario would be headgasket is failing. When you lost the coolant in the past issues did you drive it and over heat? How many miles on the car? Did you replace the thermostat with the housing? Could simply be a sticking thermostat.

Wesley1995

The mustang never over heated, the temp needle moved a little but never past the 3/4 zone. Has 145,897 miles on it. I've replaced the thermostat every time I replaced the housing also replaced the temperature sensor on the housing too. How could I tell if the head gasket was felling? The oil is clean now water in it

jimkaray

If you haven't pushed it when hot then at least you can't be blamed if it is a head gasket issue. The 4.0 is not known for head gasket issues but the miles are up there and they do fail. One way to check is to look for bubbles in the radiator but with our setup I don't think you would see anything in the overflow tank. How often is it blowing the hose off and is it only after extended driving?, is it ok on short trips? My guess is that if it is the head gasket it takes a while for it to get hot enough for a gap to open up and start pressurizing the system. A leak from the combustion chamber to the cooling system in this case isn't mixing oil with the coolant. There is a neat tool known as a Block Tester that will detect the presence of hydrocarbon's in the cooling system. If you can idle the car with out issue for a long time then it may not detect anything. You may have to wait for the issue to occur then do the check which is hard to do while its overheating. You may want to research it though for a reasonably priced do it yourself check. A leak down test is probably the best bet if the issue is random and you want a more conclusive answer. This test puts each cylinder under pressure and checks how fast the pressure leaks out. Look for a reputable mechanic for their opinion and advice on running a leak down test as a lot of shops have the mini camera's now that they can use to inspect inside the combustion chamber.

Wesley1995

It blows the hose in half like ever 3 months. It blows the thermostat housing just about every month.
An it blows the hose in half only under stress. Last night when it blowed I was doing a 30 mph pull an at about 65mph it made a pop an then smoke. The car had only been running for maybe a hour just cruising around town. It only blows the housing and that hose when I get into the pedal an at higher rpm. There is bubbles in the resivor tank

jimkaray

Get a professional's opinion giving him that information but I see no other explanation than head gasket. Given the labor involved to pull these heads I'd say a motor swap is going to be your cheapest solution. Sorry for the bad diagnosis.
I'm going to guess you bought it used and someone overheated it possibly after the housing failed the first time. Just a guess.

Wesley1995

I have the shop and the tools to do a head gasket job but I've never pulled the heads on my mustang before and I've heard you have to pull the engine out to pull the passenger side head

jimkaray

right, so with that many miles I'd lean toward putting in low mileage motor from a wreck. Especially if you don't know the maintenance history of this motor. Once you go down the gasket replacement path then you should replace the timing chain & tensioners while it out of the car so it adds up fast. If you've maintained it from new than that would be big plus towards keeping it.

jimkaray

FYI
Head Set: http://www.rockauto.com/catalog/x,ca...,parttype,5412
Head Bolts: http://www.rockauto.com/catalog/x,ca...,parttype,5308
Intake gaskets: http://www.rockauto.com/catalog/x,ca...,parttype,5424
Timing Set: http://www.rockauto.com/catalog/x,ca...,parttype,5756
+Valve cover & Exhaust Gaskets...