4.0

Ok, I did some maintence on my 2000 XJ and replaced the thermostate along with a bad heater hose and the radiator, serpintine belt and the idler pully also. Everything looks fine but I have a leak on the housing for the thermostate where it meets the engine intake. I am frustrated. I took it apart cleaned it and got a new gasket just like the first time and again it is still leaking. Am I over tighting the two 14mm bolts on the ears or not putting some sealant on the housing or something else wrong ? Is there a trick that I dont know of ? Thank you in advance with any help or suggestions.

P.S. yes, i did a search first but only got 12 responses that didnt tell me anything. Matty

tjwalker

1. Be sure BOTH mating surfaces are perfectly clean. No leftover gasket debris, etc. After scraping them, I wipe down the surfaces with carb cleaner, brake kleen, etc. until it is shiny clean.

2. I use a tiny bit of the appropriate type of RTV on both surfaces. Not much needed. It helps if there are any imperfections in the metal on either of the mating surfaces.

3. It is easy to overtighten these bolts and crack the housing. Not uncommon at all. That is why there is a "torque spec" for these bolts. Often you can't see the crack. If you are doing #1 and #2 above, then get a new housing and start over; they aren't that expensive. Use a torque wrench the next time.

peep

To insure flange face of the thermo housing is flat, place a piece of emmery cloth on a flat surface, glass, or a ceramic tile are excellent flat surfaces, or a steel place, last resource when the wife is away, the kitchen counter. Stroke the face of the housing back and forth with even downward pressure. Check the face, any irregularities or warp will show. Continue till all abrasion is even across the sealing face. Check you housing and the engine block for scratchs (deep scratches) can sometimes occur when scraping off old gaskets. Really deep can be filled by wiping the surface super clean with solvent and smearing lightly some JB weld epoxy into a deep scratch. To be ABSOLUTELY sure, when I use a gasket goo product, the product called "the right stuff" is absolutly excellent gasket goo. U can use it with or without a cloth gasket. Surfaces really clean! Let is set up before placing into service. Only 13 ft lb torque needed on your thermo housing bolts. Best of luck on your results.

4.0

this is what I was looking for. I know that I have done this before with other vehicles and hell I just did the wifes blazer radiator and themostate with no problems the week before.
I will start from scratch again. Waiting for daylight and a warmer day tomorow to do this. Thank you again. Matt

Xj7piggy

Yep super clean just did mine I did mine with fine wire brush wheel on a drill and window scaper I would also get a fail safe thermo ther Awsome

Howler_GT

EXACTLY like PEEP said.

IF it still leaks afterward, might need to replace the housing.
They arent very expensive.

4.0

He was correct. I took everything apart this am cleaned it and reinspected it. Seemd I did miss a microscopic piece of gasket material. The only thing I can suggest is if taking the rad out like I did to clean the surface mating while the rad is out because it gives you alot more room to work with. Cleaning the thermostat housing was no problem as it just picks up out of the way. The intake was a headache while the rad was in and the fan shroud was in place also. I should have done this when the rad was out as stated before. Everything went well and I used gasket cinch to coat both surfaces after I cleaned them and made sure they were planed level. New gasket and only torquing them to 13 ft lbs was the right thing to do. I was over tighting them also. NO leaks No drips No errors. Everything is fine right now. I have to check the fluid level and top it off later after it cools. Again, thank you guys for the help. Matty

Xj7piggy

That's cool u just don't have to do all that work