I just picked up a 2000 Grand Cherokee Limited 4.7 Power Tech V8, with appx 171,000 miles today for $800.
Previous owner had it listed on Craigslist saying it possibly had a bad head gasket but he didn't seem too sure about it. The vehicle started right up, ran great, and was running at 230 degrees on the temp gauge after it warmed up for a few mins. I had checked the dipstick, oil looked fine, no bubbles or discoloration, smelled normal.
While it was sitting idling, there was no smoke from the exhaust, but whenever I would rev the engine there would be some bluish smoke coming out, but it didn't smell like coolant, more like oil. Took it on a test drive, and everything seemed fine aside from the occasional smoke when I was taking off from a stop.
I bought the jeep and drove it home, only about a 4 mile drive. Still only running at 230. A few hours later I took it out for a quick drive to the gas station when the temp gauge jumped up to max, and within a mile I had steam coming from under the hood and coolant everywhere and on the windshield. I pulled right off the road and shut it off, let it sit and cool with the hood open for about 20 mins. I drove about a quarter mile back to my house and found that the radiator had broken off on the top drivers side corner right at the coolant hose fitting.
So obviously I'll need a new radiator, but I'm not seeing any sort of leaks or coolant around the cylinder heads. I'm stuck, I don't know if I should have the heads checked too, or just replace the radiator and hope that fixes my temp problem. Any advice would be appreciated.
230 is WAY above where it should be running. Mine runs at about 200, highest 210 EVER. I'd say you need a new radiator, possibly new water pump and thermostat. Does it have the hydraulic cooling fan? It'll have two metal lines running to an assembly behind the fan connected to the power steering pump.
/ 2002 WJ 4.7 H.O. / Flowmaster 50 SUV / Magnaflow Cats / Rocking that 2WD! /
If it didn't have a blown head gasket before, after pegging the temp gage on a 4.7, it probably has one (or two) now. The 4.7 has aluminum heads and a cast iron block. When they get hot, they expand at different rates and the head gaskets are usually the first to go. The 4.7's are VERY sensitive to over heating. Depending on where and how the head gasket blows will dictate issues like coolant/water in the oil or not or gasses in the coolant. Some shops have a gas analyzer (I think that is what they are called) that can test for gasses in the coolant and they sell kits at most parts stores too. 230 degrees is pushing it with this combo, mine stays pretty steady at 210 and I would REALLY worry at 230. You can get away with pegging the gage on the 4.0 but not on the 4.7.
Out of the tailpipe, blue smoke is usually oil burning, black smoke is unburned fuel, and white smoke (steam not smoke) is usually water or coolant. Blue smoke when taking off might point to oil getting past the valve guides.
800 dollars is a smoking deal for any running WJ especially with a 4.7! Does it have four wheel drive?
Fix the radiator and then start looking at the other issues, you'll need to fix the radiator regardless. I would replace the water pump, hoses, thermostat, and flush while you have it that far down. Does it have an electric fan and a clutch fan? If you turn the AC on, the electric SHOULD kick in immediately. If it doesn't, it could be the fan relay. If the clutch fan is 171 thousand miles old, replace it too while it is torn apart. They get weak and cause it to run higher at idle and lower speeds.
If you end up doing head gaskets, there is a lot of labor involved in that. Go ahead and have the heads done (guides, seals, valves/seats cut, surfaced etc.).
Yes its a 4wd, pretty much fully loaded limited. Only thing it doesn't seem to have is a cd player. Everything works on it, I was worried this was going to be more trouble than I was prepared to tackle on my own, and it seems like its going to cost way more to fix than I'm really prepared to spend on it. And take more skill than my driveway mechanic abilities will allow.....
Yes it does have the electric fan as well as the clutch fan. The electric fan does turn on when the ac is running.
The previous owner was only asking for $1000 originally, talked him down to $800. Now if I decide to just turn this thing around and sell it as it sits now needing a radiator, thermostat, and possibly head gaskets, what do you guys think a realistic price would be? Considering that it is a fully loaded 4.7 Limited with working 4WD? Only rust on the vehicle are the rockers on both sides running the length of the doors. I can post some pics tomorrow.
Swap the radiator. The reason it went to 230 was probably because the system was not holding pressure.
Agree that it was not good to run it with the temp needle pegged. Fix it & see what you have. It's all DIY stuff. Fortuately I've never seen a valve seat drop on a 4.7 from 2000 (common issue after an overheat) but losing the head gasket is certainly possible.
oh yeah..forget about not having the CD player. It was crap from the factory and would not be working right by now anyway.
2000 Laredo 4.7L Selec-Trac. 177K miles, Leather, 245 tires, tow package, crappy CD changer, full size spare, roof cross-rails & sunroof. Changes & fixes: Rear Addco sway bar & greasble bushings, upgraded headlights, upgraded tail lights, new hood struts (replaced 2X), new rear hatchglass struts, new radiator (replaced 3X), new oil pressure sending unit (replaced 4X), 2 new speed sensors, 2 new door lock actuators, new ignition key cylinder, chrome front tow hooks, Mobil 1 Synthetic 5/30, Purolator Pure One oil filter, EBC slotted & dimpled rotors, EBC Greenstuff pads, new front shocks (replaced 3X), new rear shocks (replaced 2X), new IRO steering stabilizer, new timing chain cover, new water pump, thermostat, new thermostat housing, new high pressure power steering hose, Michelin-X radials, new sunroof assembly, new single-piece lug nuts, new exhaust manifold studs & gasket on driver's side, new Durango alternator. Jeepforum.com sticker, Visit cobaltboatsforum.com when you can!
Check the trunk and see if you don't have the CD changer in the rear right compartment. But even then, as mentioned by Double E, it was crap.
I had my radiator start to leak right at the upper hose/rad connection (which is made of plastic...) maybe 3 yrs ago. I replaced it before it got a chance to overheat, so I'm not sure what further damage may have resulted from your maxed out ride.