Thermostat housing leaking, replaced thermostat and resealed with black rtv, however it is still leaking?

you also need to be certain that the mating surfaces of the head and thermostat housing are absolutely clean and flat. I use denatured alcohol after gasket removal to make sure there are no oil or coolant residuals on the surfaces.

drain coolant until its below the thermostat.then remove two thermostat housing bolts.remove thermostat housing and thermostat.make note position of thermostat before removing it.then carefully clean all old gasket material from thermostat housing and cylinder block you can buy can gasket remover at any auto parts stores.buy new thermostat gasket.if you have the paper type you need to buy RTV SILICONE to help seal gasket if you have rubber type gasket you dont need RTV SILICONE.make sure both surfaces are clean.then install new thermostat and new gasket.if you have paper type gasket apply thin 1/16 coat RTV SILICONE both sides thermostat gasket.then install gasket to thermostat housing then install housing to cylinder block first make sure new thermostat in place before installing thermostat housing. let RTV silicone sit up about hour before adding coolant.IF THERMOSTAT HAS THE O RING SEAL DONT NEED RTV SILICONE AND THE PAPER GASKET.

drain coolant system half way until coolant below thermostat.to locate thermostat follow upper radiator hose to engine.just remove both thermostat housing two bolts then clean all traces of old gasket material. be sure to have new thermostat gasket and gasket sealer on hand.make sure both thermostat housing and engine block clean dont have any traces of old gasket material if so you will have coolant leak.but besure to put gasket sealer both sides thermostat gasket just need thin layer RTV silicone.you can buy can of gasket remove to help remove old gasket material. try not to damage thermostat housing surface or engine surface with scraper deep scratches cuts in either surfaces will cause coolant leak be careful.

Locate upper radiator hose.

It will attach to the top or front of your engine block via thermostat housing.

Remove hose from thermostat housing,catch coolent accordingly. Then remove thermostat housing, usually two or three bolts. If housing does not come off easy you may try an jiggle it loose, if no luck get a flathead and pry it off, there may be a thermostat housing gasket, or possibly simple RTV silicone gasket maker. Once housing is off pull thermostat out. Noting it's position, mostthermostats have a small dimple of hole indicating upwards position.

Once removed use razor blade to remove old gasket and or RTV.

If it's a paper gasket, buy a new gasket with your new thermostat. (some thermostats come with gaskets, others dont). Also while at the parts store pick up a tube of silicone RTV black gasket maker.

Now! Once everything is cleaned, mock up the gasket with the housing so you know proper placement. open gasket maker, lay a 2mm bead (read packaging to confirm bead) along the gasket on bock sides leaving no open parts, leave the bead, don't spread it around with your finger.

Ok now put thermostat in block, then gasket and housing. Try and install it one swift motion without making a mess. You do not want that RTV to leak out the sides and be all messy!

Torque both housing bolts to factory spec. I you don't know spec call autozone, or just tighten them to your liking. Not to tight.

Crack open a miller light and wait for RTV to set up. When set up( again read packaging) then install radiator hose. And clamp it down, not to tight, the clamp may puncture the hose if swollen or old.

Now, tour good to go, but you may need to bleed air out the system, I suggest taking it to a jiffy lube or shop n asking them to do it real quick, or just ask another question on here and I'll explain!

Good luck.

Hi, It is actually called an engine thermostat, as it regulates coolant flow through the engine. If you follow the top large hose coming off the radiator to where it connects onto the engine, you will find a housing there connected to the engine with 2 bolts. There may be another hose connected to this housing also. You will lose a bit of coolant when doing this, so use a bunch of rags under the work area and a catch pan beneath the vehicle.
Parts needed: Thermostat, gasket, tube of black RTV sealant, new clamps for hoses if they look rusty or do not have good resistance on removal. (for factory spring type clamps)

Procedure:
Remove hoses from housing and bend back and tape back out of the way (use some cable ties if you wish) to keep coolant from running everywhere and so they are out of your work area. Remove 2 bolts holding the thermostat housing to engine. Gently tap housing with rubber hammer to break the gasket seal on housing. Once housing is off, you will find the thermostat underneath. Remove thermostat from engine. Clean the housing and engine mating sufaces of all traces of gasket material. Surfaces must be clean and dry before re-assembly. Use a rag to soak some coolant out of engine side hole to facilitate cleanup. Scrape off gasket material and use brake cleaner to wipe off residue and dry with clean shop rag. There are 2 types of thermostats for the jeeps, one has a rubber seal around the thermostat, and requires no other gasket, the other has no seal and requires a separate paper type gasket to be sealed to the mating surfaces. I believe the straight 6 has the paper type. Install thermostat with spring end into engine cavity. Put a thin even coating of black RTV sealant on the engine mating surface. Place gasket on RTV coated surface, aligning the bolts holes to holes in gasket. Apply thin even coat of black RTV sealant to thermostat housing mating surface. Put a small amount of RTV sealant on threads of bolts (clean them first) coating the entire thread. Put housing onto engine and install bolts finger tight - firmly seated. Allow RTV to cure for 5 minutes. Some RTV will squish out, thats OK, but use the RTV as a THIN EVEN coat, as you dont want a bunch of excess sealant in the thermostat cavity. Torque bolts to 16-20 ft. lbs. or a good wrist tightening. DO NOT overtorque, as you will either crack the housing, or cause warpage making your gasket leak. Re-install hoses and tighten clamps. If spring type clamps were on the hoses, replace the small clamp with a band type clamp. If large clamp installs tightly, it can be reused. If it was rusty and goes on rather easily/weakly - replace with a band type clamp. Refill - check coolant level, add as needed. Start engine, allow to reach operating temperature and check for leaks. Done!
Please rate this answer! Thanks, Mike

Most common overheating problems are: 1) incorrect coolant or degraded coolant mixture (check specific gravity), 2) bad thermostat (replacement it simple and part is cheap) , 3) bad water pump (will usually see a leak at pump or hear gurgling coming from heater core area when warming up engine) 4) bad radiator (will be leaking / steaming from radiator area) 5) cooling fan not coming on after engine has reached operating temperature). First, deternine the specific gravity of your coolant. You can buy a cheap tester for this, or some auto parts stores will check it for you. If your coolant looks discolored or rusty, a flush and coolant change would be first line of action. Second, determine if your cooling fan at radiator is coming on. Start engine and allow it to idle until you have reached operating temperature, about 3-10 minutes. With hood open, you can visually and audibly notice the fan kick on after that point within the next 10 minutes. If not, could be bad temperature sensor or fan relay. To test temp. sensor, remove wiring clip on the sensor usually located on or near thermostat housing (follow large hose from top of radiator to where it connects to engine, that is the thermostat housing). Using a multimeter set to OHMS @ 200 , should get a reading of about 81 ohms resistance. If bad, replace, test warm up procedure as before. If still not kicking on, better to take to a mechanic to check relay system if you are not very mechanically savy ;) If fan kicks on primary stage and engine overheats, replace thermostat. Do this by tracing to the housing, remove bolts on housing retainer to expose thermostat,replace, reseal with gasket and RTV sealant (use sparingly) or if o-ring type, no sealant used. Spring end toward engine block, then put housing back on tighten bolts a good hand tight, do not overtighten, as you can crack the aluminum housing. Use warm up procedure as before and check to see if still overheating. If so, could be clogged radiator. If you have leaks, trace to origin, that is most likely the cause. Let us know what you find.
Mike

YEP YOU HAVE LEAK AT THERMOSTAT HOUSING.YOU NEED REMOVE THERMOSTAT HOUSING OUTLET AND CLEAN THE MATING SURFACE THOROUGHLYTHEN APPLY RTV SEALANT IN THE GROOVE OF THE WATER OUT LET HOUSING.INSTALL THERMOSTAT WITH SPRING TOWARD THE ENGINE TORQUE THERMOSTAT OUTLET HOUSING BOLTS 89 INCH LBS.IF STILL LEAKS OUTLET HOUSING COULD HAVE CRACK IN IT CAUSING LEAKING.

BUY SOME GASKET SEALER LIKE RTV SILICONE BLUE TYPE RESIST ANTIFREEZE.

Yes rear cam plug leaks are common. no need to replace, just remove & apply rtv to sealing surface. Also check cam housing on right bank rear. This can be removed & resealed with rtv silicone.

Follow the upper radiator hose back to the engine block. There will be a cover plate with bolts holding it to a housing. This housing contains the thermostat. It has to be taken apart with the 2 possibly 3 bolts and a gasket. A LOT of fluid will pour out when you break the seal and open it. It maybe very difficult to get out without special tools to get to the bolts. You will then need to reseal it with rtv or supplied gaskets.