what can i do to find out if i have a cracked head? i have a 98 xj that i just bought and finally got on the road. find out the hard way that i dont have heat and only works on 4 to blow out air. can i pick everyone's brains on how to diagnose a cylinder head.

list of related issues
1) no heat slightly warmish
2) not sure if its a 0331 head (crack prone)
3) dont know where to start

help please

 

Umm.. Blower motor resistor is bad, heater core is clogged- flush or replace.. Wondering if troll.. :/
0331 wasn't made in 98.. Not till late 99 models.

 

a troll was my first guess

 

I got the same problem in my 98 xj. I just bought mine a few weeks ago also and mine also only works on 4 lol. Im gonna do a full system flush and change the thermostat once it gets above freezing outside. Check ur radiator and see if there is any gunky build up. Check ur upper and lower hoses. Should be pretty warm. If not then theres a clog. Let the truck run for about 15 mins or so untill the motor gets upto temp and then check.

 

Do you have good reason to believe your head is cracked, or are you just assuming that no heat = cracked head?

 

A cracked head isn't the first thing you should assume if you don't have any heat. Start with the heater core, it's probably clogged.

Your blower only working on '4' could mean the blower motor and/or blower motor resistor. Search this site, there are plenty of examples of all of these things.

 

Warmish air could also be caused by a vacuum leak

 

I didnt think the heater controls were controlled by a vacuum system

 

well be for i just jump to a cracked head i might as well fix the all coolant related leaks and replace the stat and hoses possible water pump. i do smell coolant burning but im thinking its from little leaks here and there getting hot on the engine. ill keep you guys posted on new updates. and thanks for the help guys.