Here is a real tricky one
So I bought a 2005 Jeep Grand Cherokee from my brothers girlfriend. I obviously know
where the jeep came from, and know it was very well taken care of. When she had it, it
did not have any problems at all, and as soon as I bought it, it started to have issues.
My engine light came on, so I headed over to have the code read. On my way there my
heat stopped working and was blowing cold air and by the time I got to my dads, he
said he was overheated. He automatically thought it was the thermostat and the code
read a misfire in the cylinder. I took it to my cousin who works on cars, and there was
some miss communication so he thought it was losing antifreeze and assumed it was
the head gasket. We then took it to a mechanic to have the head gasket changed, but
soon found out about the miss communication and told them it was not losing any
antifreeze. The mechanic did a test on the head gasket and said it was okay, and he at
first thought the engine was junk, but ran a test on that and it came back that the
engine was okay. He was completely stumped he said he ran it all morning and it didn't
over heat and it seemed okay, so my dad had him put a thermostat in it, and I started
driving it again. It has been totally fine on the temp, and is not losing any coolant. The
engine light keeps coming on, and shows a misfire in cylinder 8, however the Jeep has
135,000 miles and hasn't had new spark plugs so I am sure that is why that cylinder
keeps misfiring. However today my heat stopped working, and my jeep overheated
again. We cannot for the life of us figure this one out. If the thermostat was changed,
the head gasket is okay, and the engine is fine, what is it!?
Check your radiator hoses. With age I have seen them collapse on the inside of the hose (look good on outside)causing reduced coolant flow and over heating. Also check radiator cap. If not sealing properly or wrong psi it can cause overheating issues. Also what color is the coolant? Could the previous owner have added some fix in a can(stop leak) to it for some reason? If so you could be having a coolant flow issue due to this.
www.youtube.com/watch?v=Xw89mL2jNk8 -- check this out it will show you where the bleeder is so you can make sure radiator is full of coolant.
I am also seeing where a lot of owners with the 4.7L engine are having head gasket issues. Keep an Eye on your oil color and level. If oil level starts rising or it starts to look like a milkshake color you have a head gasket issue.
I am having the same issue, it overheats sometimes. I replaced the fan, then figured out that it wasn't the fan. I know it isn't the fuse, and likely not the thermostat, but however I am cleaning the relay right now to see if it will help. I called the dealership, and they said it is a common problem with jeeps ,and it is likely either the relay or wire harness
I don't know if you're still having this issue, but check your passenger floorboard. If there is coolant there, your heater core is bad. I had the same problem and eventually the coolant started leaking into the floor. Hope this helps.
For a 3.7 it was the radiator. Replaced it. Fixed. BOOM.
I have the same problem with 2005 jeep grand Cherokee Rocky Mountain 3.7. I got the engine light i checked it and they say it is the O2 sensor for in the right so i changed it but still i have the same problem. It do control the temperature and other things. What will happen next is i will get all sensors checked in the jeep so i can know which one is making the problem. I don't know if this is the right thing to do?
Rocker arm has fallen off on #8 exhaust valve I can guarantee it !
i have an 05 jeep grand cherokee laredo and i recently discovered the heat not working. i bought the vehicle back in march in california i did not need the heat up until recently and the heater wasnt working. i put it on blast and tried to use the defroster as well and that wasnt working then i started smelling antifreeze smell maybe like burning plastic or melting plastic and a few days later noticed wisps of smoke coming in to the cabin from the vents my jeep started getting hot when it was sitting in traffic. im taking it in to get diagnosed hopefully its an easy fix ive never had any problems with it for almost a year and now its acting up in the winter which is odd. because it was a hot summer and it never overheated and i commute thru the bay area a lot and i never had issues.
Chances are your heater core is leaking if you have smoke-like wisps coming into the cabin. Check fo moisture on your passenger side floor mat.
If you di
If you didint find the right thing for the Jeep change
Water pump in water cap
It happened to me to in i change the water pump and the cap
Might I suggest you check your fan clutch...if free wheeling..it won't move air through.the radiator if idling in traffic or at low speed..Ac on makes it worse...highway speeds would be enough to cool
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