1998 Dodge Durango V8 Four Wheel Drive Automatic 147000 miles
I bought my Durango just over a week ago, and everything was fine initially. A few days ago, I started it up and the heater would not blow even warm air, let alone hot. After I started driving, I noticed that the temperature gauge would gradually move up to the red, causing the " Check Gauges" light to come on. After a minute or two, the needle would drop back down to mid-range (approx. 190 or so), and gradually cycle through the process again. I put a new thermostat and gasket on it, and the problem still persists. I've added plenty of water and anti-freeze, and am gradually losing it. I have found that it is leaking coolant, but that it only drips once every three seconds or so when the engine is running and warmed up. I have a Haynes manual, and I've checked the radiator and hoses--no problems there. The leak seems to be on the low back of the engine block, down near the oil pan. I've heard it could be a freeze plug, a water pump, or something else. Any thoughts?
The new thermostat could be bad-retest it-continues to overheat bleed the cooling system - see below that don't work have the tests done.
Always bleed air from cooling system after replacing coolant. Set heater for maximum heat. Remove radiator cap. Loosen drain plug and remove drain bolt (if equipped) from engine block. Drain coolant reservoir. Fill coolant reservoir to MAX mark with 50/50 water-coolant mixture. Loosen bleed bolt and fill radiator up to base of filler neck. Close bleed bolt when coolant flows out without bubbles. Tighten bleed bolt. With radiator cap removed, start and operate engine to normal operating temperature. Add coolant if necessary and check for leaks.
Block and Pressure tests
Have it block and pressure tested-do the block first to pinpoint a combustion leaking into the cooling system or a gas analyzer to sniff for hydrocarbons at the radiator fill neck.
Pressure test: do not do a pressure test if there's leakage at the headgasket this might cause coolant into the cylinders and lock it up or bend a connecting rod if cranked thereafter. The headgasket should be repaired before doing the pressure test.
If the block and pressure test passes check the following: Thermostat, Pressure test the Rad. Cap, Clogged radiator, Fan clutch, Radiator electrical fan, collaspe hoses, water pump.
December, 27, 2007 AT 1:12 PM
I've already bled the system, and it actually started blowing hot air from the vents, while maintaining constant temps in the middle of the gauge. However, once I started driving it, it was right back to the same routine of up and down readings and cold air. I have a mechanic (trusted family friend) that is going to block and pressure test the engine in an effort to locate the problem. He's said that the freeze plug problem will cost a lot to fix (cheap part, just lots of labor with dropping the transmission and all), but that it could be any number of other things. I'm in a money crunch, so I'm hoping it's not too bad. If you have any ideas on pricing or what things " should" cost, be sure and pass them along.
THANKS FOR YOUR HELP. What a great website!
January, 4, 2009 AT 10:25 PM
I am at witts end like you, cant fig this out, but as far as freeze plugs my husband is no mechanic and he was able to do 2 freeze plugs, all you have to do is jack up front of truck, if you still have them keep them, unlike us they dissapeared and it was hard to find a match, what the computer at parts store said was not the real ones,
still having problem with overheating tooo.