trezz101

My Jeep is overheating like crazy and there is a ton of smoke coming out of the radiator. What do you guys think the problem could be? clogged rad? or could it be a failed water pump. Any suggestions would be helpful.

Thanks

gully369

Where is the smoke coming from? Is it leaking any antifreeze?...Check the weep hole on the water pump, the radiator cap, gaskets on pump and thermostat housing, hoses for cracks.

trezz101

The smoke is comming from the rad. I changed the thermostat and that didnt do anything. The rad does look like it might be leaking a little. Also I hear a loud hissing comming from the rad. The hoses look fine. What should I be looking for when checking the rad cap?

thanks

gully369

The rad cap is similar to your thermostat in that it opens when the temperature hits a specific temp or is it pressure. Can't remember for sure which. Try to find out where the hissing is coming from. If you pull the grill off, 4 screws, you will be able to look at the front half of the rad. You can also check for temperature differences to see if you have any clogged areas on the rad why you have the grill off. Be careful it is hot .

You could try to get one of those leak stop additives. I am not a fan of them but you may be nearing the end of options and looking at repair or replacement depending on what is going on and where your leak is.

EvilBlackXJ

Let's get this defined a little better.... are you talking about "smoke" or "steam"??? There is a tremendous difference!!!

trezz101

Your right, its actually steam

ol"blue

Do a pressure test of the system. If the rad has a small leak, like a pinhole in a tank seam, it will show itself. Check the hose where the over-flow leaves the rad cap. Sometimes they weep there causing occasional steam. JMO

fantic238

In addition to what ol"blue already stated i would check the conition of the cap rubber gasket too.
If you hear the hissing you have a big leak somewhere.

bishop letov

you can use a bycycle tube that has been cut to test the rad. cut the tube equal distances from the tube valve and connect each end to the inlet and outlet. leave the rad cap on. Fill it with about 12-13 psi and if theres a leak itll show if you have refilled the rad or you will hear air . Usually I do this with the rad out laying on the table or ground. if its been leaking a bit you should also notice green or yellowish residue from where it was leaking. Sometimes it just looks whitish and or oily if you use the orange antifreeze.

water pump seal failure would be seen at the bottom of the water pump where the fluid tends to leak out of after the motor is shut off. it wouldnt be hissing normally unless the center shaft was ready to fall off.

you may not be able to see the from of the rad due to the factory ac core or a trans cooler so you may need to add leak detector to it if your not willing to pull it out.

Stop leak makes a great product but alot of times unless it was a physical object that damaged it from the exterior it means its time for a new rad. if it leaks due to normal pressure then its a problem you will be dealing with in the future again.

Brass rads can be soldered or brazed to fix them but aluminum is hard to fix properly especially if the endcaps of the rad are plastic. they dont like to be messed with.

lastly check the hoses for pinhole leaks that could spry up onto the rad and have you looking in the worng place.I had a heater hose that looked like it was swiss cheese and it was brand new. it was spraying all over when it was hot but it would evaporate pretty quickly making it a little difficult to see if you werent looking for it.