BryceAZ

Alright well i just purchased a 93 cherokee sport with the 4.0.
I drove it for a couple days before i started getting some overheating problems....

it would go to the line right before red, and then cool as i started going slower through trails. This was with no a/c windows down in az. probably mid 90s.

well i got home fine and i did a check on the radiator fluids, and they were nasty, i mean like rust red, i did a home flush......3 times just to be sure and it started to come out a bit cleaner. i bought a new radiator cap just to be sure.

Sure enough problem is still there. I buy a new thermostat and put it in and i overtightened the housing and snap.....30 dollars and a new housing later i get it all back together. For good measures i checked the oil even though the guy i bought it from said he changed it.

Yeah right.....this stuff came out black. So a quick oil change and filter later i start up my jeep.

Well its better, it will start at just above 210, when i come to a stop the temp will rise just below the 3rd line, sometimes hitting it, but then slowly creeps down to between the 210 and 3rd line. and will go down a little more when i get going. All this is with the a/c blasting.
And yes the aux fan comes on.

now i just want to know what you guys think before i go and buy a new water pump and/or radiator.
Any ideas?
Something simple im missing?

Also what is this piece? The rubber that connects the little tube to the top of the motor keeps breaking and im wondering if it can have bad effects on the motor





im new to jeeps so dont laugh at my lack of knowledge any input is very appreciated

Veeb0rg

Check the fan clutch on the manual fan. It sounds like its a bit worn out. You might also want to flush it again now that its been a few days.

BryceAZ

Is there a way to actually check it rather than replace it?

dyte2004

get the jeepp nice and hot pop the hood and give it gas it should sound like a plane

ruglyot

The piece on the valve cover is just a connection for your crankcase breather, not cooling related. Chrysler changed the replacement part to look different and the new design is available from NAPA - @$13.00. It does have a necked down orifice at the elbow that needs to be there.

Russ

fishtaconc

I agree, if this is done run a 50/50 mix of water and vinegar through itll clean the rust out really good

BryceAZ

Wait, so put a 50/50 water/vinegar mix and should i actually run the motor? For how long?

fishtaconc

just be sure its full then run till it gets to normal temp, I forgot to add turn heater on to get the core clean as well. then drain and flush refill with 50/50 water/antifreeze. also to check the fan clutch run till it warms up and shut off the engine the fan should be harder to turn than when cold

spittinimage

You can mess with the 50/50 mix to make it run cooler also (less antifreeze more water) but be carefull you dont get it to light on anitfreeze if it can still get cold where you are. I run about 70% water 30% antifreeze with a 180 t-stat and it never gets over 200 when am playing.

fonman25

I agree, the "vinegar douche" should clean out the rust pretty effectively, just don't go TOO light on the antifreeze, as it is needed to prevent rust/corrosion.

Tophog

When we got ours, with about 123k on it, it overheated going up long grades. Going slow on trails, etc. was no problem.
Turned out to be the catalytic converter was pretty well clogged.

(Just something else to think about.)

BryceAZ

well, the damn radiator started to leak now so im starting to thing thats what my problem is.....
lucky for me my local jeep graveyard had a 2 month old 3 layer radiator that i got for 90 dollars

im going to run the vinegar thing through all the old stuff and then install the new radiator.

however i was thinking about the cat as mine has quite the rattle when i take off or kill the truck. is there a way to clean it or do i just buy a new one?

cdeal28078

Going slow over trails uses the mechanical fan for cooling unless it gets hot enough for the electric fan to come on. Do you have a fan shroud on the mechanical fan? A shroud works when the speed of the truck is slow to help channel the air. Going down the road enough air comes through it doesn't even need the fan.
I changed my radiator from the 90 model closed loop to the open loop and didn't get a radiator that had the sensor for the electric fan. I just wired it up where the electric fan is on when the key is and it stays just below the 210 marks even after running in the driveway for an hour in 90 degree heat.
clint

spahr69

The picture is the Crank Case Ventilation system. You can replace the whole hose with a breather filter if you wish.

BryceAZ

thanks everyone
the radiator seems to have done the trick, now runs just below the 210 line and sometimes goes over just a hair when im coming to a stop.
but then it cools back down. Nothing i see worrying about.

Gonna make the final test tomorrow offroad. see how it does on the trails.

:fingers crossed: