Why does my 95 Grand Cherokee run hot sitting in a drive thru or driving real slow?

Question

It only does it in the hot weather.It done it last summer but did not during the winter and has started back this summer. It never gets to the red but gets more than half way and spews out anifreeze onto the ground .

The fan is run by the belts .

Answer 1

You lose antifreeze because it expands when it gets hot, and therefore overflows.

It is almost impossible for any engine to overheat in the winter. If they overheat it is in summer. There are a number of faults that can cause overheating.
1. Low coolant. (doesn't sound like your problem, but check the level after the engine's warm and make sure)
2. Bad Water Pump. Either a loose, noisy, or constantly weaping (leaking) water pump won't circulate water and cause overheating. (doesn't sound like your problem, but worth double checking)
3. Failing Fan. If your fan is electric (not bolted to the motor) it may not be coming on to cool the water through the radiator. If your fan is mechanical (bolted on the front of the motor) this is not your problem.
4. Thermostat. Located in the tube between your radiator and water pump, this opens letting fresh, cool water from the radiator in to your engine. They are set for specific degrees, the higher the number the warmer your heater in winter, but the warmer your engine in the summer (especially when it's really hot, or not getting fresh air through the radiator to cool the water). When these fail it's really obvious, major overheating, or no warmth in winter (depending on how they fail). Otherwise it's a judgement call. If you want it to stay cooler in the summer, then swap out for a lower degree thermostat, but if you need a warm heater in the winter it's better to keep the higher thermostat.
5. Finally, if the fins on your radiator are mashed flat (from bugs and rocks and little kids fingers smashing them down) then little or no air can get through your radiator to cool the water, and therefore your engine. Use a butter knife, or "Radiator Fork" (tool sold at auto stores) to straighten the fins back out. Be careful not to punch a hole in your radiator as that's very expensive to fix. (It's almost impossible to do with a "Radiator Fork" but very possible with the butter knife)

Lots to look at, but that's the whole system.

Good Luck!

Answer 2

If one or both your electric powered followers at the prompt are not operating, verify that the ballast resistors at the prompt are not blown. regrettably they're typically complicated to locate, yet would appear as if a coil of thick cord round a porcelain insulator, each and every each and every now and then interior a perforated metallic field. those commonly have a low resistance, yet in the journey that they burn out the fan received't paintings. The thermostat is often positioned in a bulbous setting up on the engine end of the thick hose that effects interior the authentic of the radiator. you could merely have it replaced with a clean sealing gasket, or you could verify it through eliminating it and putting on a pan of water on a range with a thermometer beside it. warmth slowly to boiling. The t'stat has a disk about a million.5 to 2 inches for the period of on a crucial stalk which seats adversarial to the body. The stalk sits in a wax pellet interior somewhat metallic holder.. even as the wax melts, it expands and pushes the disk remote from the body of the t'stat, allowing water to move with the help of. In maximum autos it will be open at 80C, it really is 176F. some open at 90C, it really is 194F. in case you're taking it out, you'll likely ought to change the gasket or the gadget will probable leak even as warm. Low oil can truly reason your engine to overheat, even if it would should be especially drastic to get the point precise down quickly once you've crowned it up.

Answer 3

It stays cool while you're driving because the rad is getting "force fed" cool air. Your best bet is to get a pressurized flush of the coolant. After that, make sure the thermostat works properly as well as the water pump. Your car shouldn't spew anti-freeze. That's why they have an overflow. It sounds like you have a lot of sludge in your coolant.

Answer 4

most likely its the thermostat. i have had 2 grand Cherokees and had the same problem with both. they go bad easily. some are bad right out of the box. the good thing is, that for that model there only about 5 dollars and they are very easy to install yourself. you might also want to squeeze all of your hoses while your at it. if they feel hard and wont squeeze then they need to be replaced also. go to auto zone and buy a Haynes manual. they make them for every automobile. it will tell you everything you could ever want to know about a automobile.

Answer 5

the coolent in the car is under pressure and it sounds like the cap is loose, you should make sure its really tight and that the level is adaquate.
if that doesnt solve it then you may need to flush the coolent system to get rid of all the crap in it, do this either once a year or every other year.

Answer 6

check the radiator cap, make sure the radiator is not full of leaves,bugs, paper make sure its clean . Maybe the thermostat, loose belt on the pulleys to the fan

Answer 7

make sure the electric fan is working properly , radiator may need cleaning.Jeeps have a history of running on the hot side

Answer 8

im thinking theres a problem w/ the fan that allows air to blow through which helps to cool it down get it checked for sure

Answer 9

the fan clutch is most likely the culprit.

Answer 10

check the timing