It's not really overheating until it reaches 260 degrees.

 

Basically I had the same issue except that I didn't replace the head. However, I replaced everything else and the system still ran hot. I noticed that the hoses were cold, too. So, I replaced the water pump. The pump turned fine and did not leak at all...BUT, the paddles were totally gone and I could've used the worn down blades to cut steak. Now, the thing runs under 210 without a problem. On my 98 XJ I had to remove the power steering pump to replace the water pump...keep in mind that there are holes in the pulley so that you can get at the PS pump screws with a socket. That fact alone will save you a lot of time. Total time to replace water pump was less than 2.5 hours and could've been less but it took a long time to get the RTV off of the mounting surface. Another thing: did you check the cap? I bought a new cap and it tested bad right out of the box, but that would usually have you hitting the red mark temperature-wise. Water pump is worth the effort.

 

you have a vacuum leak or the toilet plunger is bad and get a good t-stat

 

I am thinking the same thing. I have the water pump and will be changing it out today. I should have done that before going into the whole head thing. Thanks.

 

I already fixed the vent issue, as mentioned earlier, as well as replaced the t-stat, mentioned in the OP.

 

I replaced the water pump this afternoon. I verified the t-stat worked, via boiling water, and since the water outlet (t-stat housing) looked quite used and pitted, I bought a new one as well. It was off already, so why not.

I stay around 210, until I put it into gear, then the temp gauge starts rising. I don't go anywhere, just put my foot on the brake, put it into gear (D or R doesn't matter), and rev it to about 15-1600 RPMs. The temp rises at that point. I put it into Park, keep it idled at the same temp, and it drops backs down to 210.

There is nothing left to the cooling system, as far as I know. I replaced the trans cooler lines and services the trans, when I replaced the head. I also had the radiator checked while I had it out.

Anyone heard of this little issue. Come to think of it, it has only gotten hotter, prior to the head replacement, when it was in gear. Even just sitting at the end of my drive, in Drive, with the brakes applied, which is why I called the mechanic in the first place, who told me it was the head.

 

run it until it gets hot and feel for any cold spots on the radiator you keep saying you had it checked and it is the only thing you have not changed as far as I know. All of the symptoms have to do with flow through the radiator. How are you adjusting the fan belt you want it tite to where you can only get 1/2 to 3/4 inch with firm pressure. Pull the radiator if you have a cold spot/spots plug the lower outlet fill it with 1/2 bleach 1/2 water and let it sit overnight the backflush it real good using the hose at full pressure no nozzle I bet it is the radiator not able to keep up with the demand or just as simple as a loose belt I give mine about 1/4 to 1/2 inch playa loose belt will wear your bearings out faster than a tite one especially a dry bearing like a alternator.

 

Well, I just cancelled the order for the replacement radiator. I ordered the CFS dual core from a lovely company I have seen others here use, called Auto Parts Warehouse. After talking with two different people that cannot speak english, I finally talked with someone that kind of spoke english, who took offense that I wanted someone in the US.

I ordered the radiator on 1 May. I received an email stating that they would not charge my account until they processed the order for shipment. That was a lie. They processed it immediately.

It is Wednesday, 5 May. The email said it would be processed and shipped in 1-2 business days. It has not been. I was informed that it would be another 48 hours before that happened, and I received a tracking number. That makes 5 days, not 1 - 2. Furthermore, it will be 10 to 14 before I receive the product.

I told her I wanted a refund, and then she had to put me on hold and talk to a supervisor, etc. I am really ticked, but I did not lose my cool, just spoke firmly to help them understand. I want my money back...NOW! It will be 2 to 7 days.

This is a lying sack of crap company, with no customer service, and I will not do business with them again. I reckon I will try the more expensive Radiator Barn.

 

Air pocket is my guess. You had the head off and the whole system opened up. Sometimes it is a pain to get all the air out.
I did a flush and thermostat swap on my father in laws dodge pickup last month. I couldn't get it to take more than a gallon of water after idling for an hour. Thought maybe that is all we lost. He left. Couple days later he called to say it was overheating. I got there and the radiator was cool as well as both hoses and the cap.
I added some coolant and it finally started burping all the air out of it. Took 3 more gallons. If you ever notice the temp. gauge moving pretty erratically that to me means an air pocket, especially if the system has been opened up recently
clint

 

I have had radiators tested before and later found to be restricted by as much as 50%.

 

I put in the new radiator last night. I am concerned about something, and wonder if this is logical reasoning on my part.

When I disconnected the trans cooler lines, I removed the bottom one first. When I did so, there was NO trans fluid that came out...from the line itself, nor the radiator. When I loosened the top line, I started getting drips in just a few turns of the wrench, and subsequent drainage after removal of the connection.

Would it be logical to assume that with the temperature sending unit on the BACK of the head, near the transmission, that if the trans cooler part of the radiator was plugged up, the transmission could significantly heat the rear of the engine, to raise the temperature gauge towards overheating? I ask this with the added knowledge that sitting at idle for however long, the temp stayed around 210 on the gauge, but it would get hot when I put it into gear, even if I sat at idle with my foot on the brake. I would guess, with the temp sensing coming from the engine coolant sensor on the FRONT of the engine, for the auxillary fan, they could be at two different temperatures, and hence the fan would not come on, due to the sensor on the front, while the gauge would show overheating, with the sending unit on the rear?

 

I had the same problem, after finding that my aux fan came disconnected it was still doing it. I think that is why the guy sold the jeep to me for so cheap so I started up the engine and noticed the fan was barely moving. I replaced the clutch and never looked back since.

 

Its better, but having a specific problem now.

While getting to operating temperature, it will go past 210*, a little over halfway to the 3/4 mark, then drops back down below 210* really quick. I am guessing that is the thermostat opening up. It will come back up to the 210* mark and stay there until I run the AC, then it will head towards the 3/4 mark. I always cut it off before the 3/4 mark, so I don't know how hot it goes. It gradually works back down to the 210* mark.

I never noticed the temp spike, then quick drop when the t-stat opens, prior to doing all the work on it. I can idle with the AC on, and it will not go up, just when I drive highway speeds.

Ideas?

Replaced items (all items new):
-head
-water pump
-fan clutch
-radiator
-radiator cap (16#)
-PCV valves
-oil cap
-heater valve control
-new heater hoses
-new radiator hoses (took spring from old lower hose and put in new one - no rust)
-thermostat (x2 - current is fail safe, previous was regular, both 195*)
-water outlet
-coolant temp sensor
-temp sending unit
-tune-up: plugs, wires, distributor cap & rotor
-new trans cooling lines
-trans filter and fluid

 

hows your motor oil?

 

This may sound VERY stupid, but is your electric fan working and pulling air inside instead of pushing it outside?