speedyp

Hi searched but could not find and answer....

92 XJ 4.0 Auto

How hard is it to do ?
How long does it take ?

its very cold here and the jeep is rusty... Just want to make sure it does not end up taking 4 hours to do hehe

BowtieGuy3

It's about a 1/1.5 on a scale of 1 - 5, 5 being difficult.

Takes about 10 to 25 mins if you put your mind to it, and provided the bolts come off and don't strip/break.
Could take 4 hours depending how many beers you have while changing it.

luckylewk

Go get a manual at the parts store...Ive never had a vehicle that I didnt have one in the trunk or back seat or in the tool box...

120mm

The big thing to remember is to get both mating surfaces good and clean. Remember which direction the t-stat goes, and be careful that the t-stat is in the recess.

If you pinch the gasket with the edge of the t-stat, you won't get a good seal.

Torque values are important, too, as there's only two bolts.

When you finish, make sure you keep a close eye on it for green stripes showing leaks.

It's easy, but there's ways to screw it up.

Desertfox1023

1) Un do 2 bolts
2) remove t-stat
3) clean area
4) replace t-stat
5) apply gasket
6) Reinstall 2 bolts
7) Refill the Radiator
8) Check for leaks

Can be done in less than 10 minutes...

speedyp

Nice not to hard of a job .

I just went to the part store and they asked me do you need the thermostat with the jiggy valve or no jiggy valve !

WHAT the hell is a jiggy valve ??

Which one do I need to get hehe

BowtieGuy3

Which store did you go to?
Tell them you need a Stant #13009 or #29309. (The 13009 has a 1yr warranty, the 29309 is heavier duty)
The gasket you need is Stant #25160 or Fel-Pro #35630

91 Laredo

Quick question -

Is RTV necessary on the gasket?

BuckB91XJ

Just take the old T-stat into the parts store when you go. Even a totally brain dead counter guy like what works at Autozone should be able to match. Most of us learned matching in Pre-School or Kindergarten. Get some of the special T-stat housing RTV. Autozone sells little packets of it at the register. Costs like $.30. This stuff has held my T-stat housing and water pump (without gaskets), so far. Good stuff in my opinion.
Be sure after you thoroughly clean the gasket surfaces, that you rub your T-stat housing on a piece of sandpaper on a flat surface until you have shiney metal all the way around, before putting it all together. Aluminum pieces always warp. This will ensure a perfectly flat surface.

91 Laredo

Okay. I already have the gasket and some RTV somewhere..... The parts guy told me to use it so I wasnt sure. My BMW does not use any (yes, just did a cooling system overhaul in that one too.) but it has an O-ring as opposed to a gasket.

Is that generally the rule of thumb? Gasket = RTV, O-ring = no RTV?

BuckB91XJ

In my deaqlings, yes, any waterneck with a rubber "O" ring doesn't require a gasket or RTV. Rubber on metal makes a good seal.

fivendime

X2 they are worth there weight in gold. Plus they give you torque specs for it, and all the other little goodies you need to know. I have a Chilton manual. The change should only take around 30 min for an unseasoned wrencher. X2 on the clean surfaces for gaskets as well as quality gaskets.