I want to know what is the matter with the mechanics, especially at the dealerships - Chrysler Dodge Jeep to be exact? This scenario is lengthy to say the least! I had the radiator flushed and pressure tested at the local Chrysler dealership who has been servicing my Jeep since my purchase in 2004, last tested and flushed two years ago @ 64,000 miles because I was experiencing pouring coolant into the reservoir every time I turned around. Funny thing was there was no evidence as to where it was going because it didn't show up on the ground. I kept asking, "Where's it going, back into the engine?" Chrysler looked all over under the car and couldn't locate any drips! Funny thing is a few months later when I became extremely aggitated with the local Chrysler mechanic, and the problem worsened and when I took it back to the local Chrysler dealership, they stated nothing was found once again, I took it to a supposedly 5-star Chrysler dealership in another town, and I was informed there was a hole in the radiator. The local Chrysler service manager said, as I thought he would, "You could have gotten a hole just from driving from here to there if a stone popped up." Jeeps have a grille that protects the radiator. I was advised by friends to go to a local mechanic so I had a new aluminum radiator installed (2 yr warranty on parts only). I was still adding coolant and kept complaining to Chrysler and the local mechanic. All of a sudden, all the lights came on the dash, I popped the hood and checked the coolant - it was empty. Checked the radiator after it cooled down and there was no coolant - it was all on the ground. Called the local mechanic who said to take the car to his shop right away. So, a friend filled the radiator and reservoir as full as possible since it came out as fast as put in, so I could quickly drive 5 miles down the road. The plug popped out of this new radiator. And, by the way, the local mechanic swore the radiator was a Chrysler product, yet the Chrysler mechanic couldn't find any emblems that would indicate that fact. The coolant leak continued, now putting coolant in every few days. The local mechanic said it was going to the floorboard under the mat on passenger side because I need a new heater core. Do you see where this is going? After that installation, the coolant still needed to be added every 5-8 days. I was advised that is normal until things get back to normal flow. Now my dash was not reinstalled properly and I have flapper air ducts added to my console in front of the manufacture air ducts that the local mechanic stated was part of my system and it was always there, a busted speaker, a resistor that has since been replaced because I was advised by the local mechanic that is why the A/C and Htr were sporadically operating. Meanwhile the coolant is still being added by me every 5-8 days, and once in a while sooner as soon as all the lights come on and I find the reservoir is empty. The out of town Chrysler mechanic looked at the underneath when I showed them pictures of the puddles in my driveway, and advised me the undercarriage is showing no signs of dripping. The next morning, the drips caused even a larger puddle overnight that I took pictures again. the local Chrysler dealer mechanic installed a new heater hose that was supposedly defective (but I asked for all hoses and belts to be replaced at 100k miles and was told they were all fine and the local mechanic replaced the upper and lower radiator hoses). I still was adding coolant every 10 days or less. Finally, after nearly a year of putting up with the incompetency of the mechanics, I demanded a new radiator from the local mechanic who did not guarantee his labor. Mind you, the dripping was now larger than just puddles in the aluminum tray under the car in my carport. I picked up my car this morning, except it needed jumping because the service rep at the Chrysler dealership advised me the WalMart 1 year old battery with a 3-yr life expectancy (3rd replacement in 5 yrs) is bad. Walmart tested the battery with the hand held tester then took the battery out and retested, and it was fine. So, I replaced the connectors to see if that would make a difference. I drove it home, parked it in my carport, went in the house for a few minutes after turning off the engine, and what did I see after 4 hrs of having my SUV in my possession, but new coolant on the white towel I placed on the carport to catch the residue the local Chrysler mechanic told me I would most likely experience. The radiator removed yesterday was returned to the local mechanic, who turned it into the parts supply house for a replacement. The local mechanic was extremely insulting when I advised him today that I was returning the 2nd radiator for a complete refund because both radiators blew at the seams (the clamps holding the radiator's aluminum wires in tact-1st radiator on the right and the 2nd one on the left). The local Chrysler mechanic pressure tested the last radiator and checked under the carriage and saw no leaks before he released it to me. When he pressure tested it upon my return, we could hear water running and see it squirting all over the top of the radiator. I thought my radiator experience starting more than 2 yrs ago was highly unusual, but what do I know? The local mechanic, at my insistance, called the parts supplier - refund will be delivered in a few days and the radiator will be collected. In the meantime, I sit with no radiator and a dilemma. I saw white drops all over the previous radiator and this last one that was removed today. When inquiring of the local Chrysler mechanic and service rep, when I picked up the last removed radiator to deliver to the local mechanic, I was advised that it was nothing, just splatterings. Chrysler parts dept ordered a new radiator from 1-800-radiator because the price was $200 compared with nearly $400 if I ordered a Chrysler radiator. I paid Chrysler $285 for labor including coolant to install the previous radiator that the local mechanic wanted $300+. The removal was free today, but I paid for a rental car now for 2 days. When Napa quoted me $150 today for their radiator with a lifetime guarantee, I immediately called 1-800-radiator to see how much I would have had to pay, instead of Chrysler, for that radiator. The salesperson knows mechanics and warned me, after I told him briefly my dilemma of installing another radiator, and he advised me about electrolysis and the cost will be on me if that is the culprit for my radiator problems. After researching on the Internet, I am now thinking there is something to that analyzation. I've been complaining about an electrical problem for a very long time - more than 2 yrs., but no one found anything wrong; and as I said, the battery has not lasted its warranty periods, and yesterday the license plate connector was burnt. Supposedly, after uninstalling an after market alarm system the previous owner had installed, it was to prevent any electrical problems from occurring. I replaced the heater core about 6 months ago, which three years ago the local Chrysler dealership replaced as well. Do you see the picture? Who in the hell can I trust with my vehicle if the two dealerships don't know what they are doing when one of them is a 5-star????????????????!!!!!!!!!!!!!!!!!!????????? Any ideas? I even tried to get Chrysler Corp involved. The next thing I knew the Service Manager was replaced with another, but I didn't get anywhere else with them, no recoup. The next thing is BAR and BBB for all four of them including Chrysler Corporate!!!!!!!! And, maybe Fox investigative team would like to hear about this!!!!! What do you think? I had a similar problem with my rear differential, and although I complained to Chrysler Corp because I had just paid for the differential service 6 months prior and they should have seen the metal flakes. Now, I read that the crankcase and metal flakes can have something to do with the electrical system and grounding that can also cause electrolysis in the radiator. WOW!!!!!!

First off, we need to know about what you got. What year is it and what motor and acessories you have? Since it has 200,000 miles on it, for the following discussion, I am assuming it is an older Jeep Cherokee with the 4.0 Liter 6 cylinder engine. This engine has two fans: A small belt driven one and a larger electric fan. You jeep will overheat in hot weather if the fans do no work. In cooler weather, the electric fan hardly ever turns on geting enough cooling from the small belt driven fan. The belt driven fan has a viscous clutch that is temperature controlled. By default, this fan is fully energized at startup nad if its temperature is low, i will begin to disengage with time. After about 5 minutes, it should be at idle condition if cool, that is, the fan will not be at full speed. This fan turns all the time, but when it is not needed, it runs slow. When needed, the fluid clutch comes into play and the fan comes up to speed. It is quite noisy when at speed. If the small fan is working, at startup it should be full on and making fan noise. A few minutes later, it will quiet down if not needed. If the viscous clutch is not working and this fan is not coming on when things get hot, that may part of the problem. It supplies about 30% of air flow capacity to the radiator. The other 2/3 is supplied by the large electric fan. The large electric fan is supposed to turn on when the coolant get hot. Does it turn on? A temperature switch controls this function. I'd have to check my manuals, but this switch may not directly operate the fan; it may signal the engine controller (computer) and the controller operates fan relay. The relay handles the subtantial current draw of this fan. There are 3 items in this chain of control: the temperature sensor/switch, the engine controller, and the relay. The item most likely to fail is the temperature switch, next is the relay, next is a fuse, and then the fan itself. The final failure parts is the engine controller. The big fan is usually off when traveling at highway speeds except if in extreme desert like temperatrues. The big fan comes in to play in stop and go traffic on hot days. A clogged radiator is possible. According to your post, the problem began while traveling at highway speed. Another possibility is a collasping lower radiator hose. The hose is different in construction to the upper hose. The lower hose must contain features to prevent collaspe. Some hoses have a coiled spring wire in the hose while other contain anti-collaspe construction. The thermostat: If the thermostat failed and closed, overheating follows quickly. You said that a new thermostat did not fix the problem. Two possibilites: the new thermostat was installed backwards. A thermostat installed upside down will not open as quickly as it should. The sensing element should face toward the hot side. Consult your manual. If the new thermostat was installed correctly, then look elsewhere (assuming the new thermostat is a good unit). Was it tested in a pan of hot water to see if it works? How do you know that the water level was ok? Looked at the overflow bottle? The radiator can be short of water with a normal fluid level in the overflow bottle. The coolant system is 'closed' in that it is designed not admit air. Again, I make another assumption that you have a proper radiaro cap in place. it has 2 seals in it. The outer seal fits on the top of the fill neck and seals that opening from the atmosphere. The second seal is on the spring loaded pressure valve. This valve limits system pressure. When the set point pressure is exceeded, coolant forces it way past the valve and flows through a hose to the overflow bottle. After the system cools down, a partial vacuum deveops and coolant is drawn from the overflow bottle back into the radiator. If there is an air leak anywhere between the radiator fill neck and the bottle, air is drawn into the system on cooldown instead of fluid. After a few thermal cycles, the engine coolant system is short of fluid. If the fluid level iin hte bottle si not behaving as expected, inspect the path from the bottle to the radiator for leaks. Old oveflow hoses have been known to develop splits on the underside. A water pump is a possibility. it can fail by eroding the impeller until it is a poor pump. I have been drivng a 6 cylinder 4.0 liter jeep engine since 1993 (on my second one) and have not seen an impeller failure. I'd check these items first: 1. Both fans. 2. Radiator cap. 3. Wind blown trash in and across the radiator core. You did remove that piece of cardboard that was put in there for winter driving? If you have an air conditioner, clean its core of trash also. It sits in front of the main radiator and can block part of the air flow. 4. Lower radiator hose. If the temperature gauge shows overheating but everything seems nornal and an external probe measures normal engine temperature, then suspect the temperature sensor for the gage. You could, of course, take it to a shop. Let us know what you find.

Since you damaged you rear quarter panel and a backup lamp, I don't think that your vehicles met square on, but maybe corner to corner. (How else would the quarter panel have been damaged.) The truck may not have been in the view cone of the backup sensor, but should have been visible in a rear view mirror. The Jeep Cherokee has decent ourside rear view mirrors.

The idle speed is controlled by the computer with the idle speed control motor (ISC). Its unlikely the ISC got damaged with the cylinder head being taken off and put back on. There are two likely causes for such a high idle speed, one would be a large vacuum leak, something like the power brake booster hose not being reconnected yet. The other likely cause is either the computer is commanding the high idle speed, or else the computer cannot control the ISC. Inputs like power steering pressure, AC clutch command, and the transmission shift position cause the engine to need to idle faster to prevent stalling. A false input from one of these causes an excessive fast idle problem. The computer looks at inputs such as engine coolant temperature to control fuel delivery and to produce the cold engine idle speed which would be about 3000rpm right when the car is first started, and then it should drop quickly. A break in the wiring between the computer and ISC could be the cause for this problem. The ISC allows air to flow around the throttle plate to control the idle speed. This passage is right at the top of the throttle body, and it should be easy to confirm if the air entering the engine is in fact flowing through the ISC passage. (Loud sucking sound, and idle speed can be affected by restricting the ISC intake port with a finger. Its always possible the ISC has simply failed in the stuck open position, but its not anyone's fault. Cars break whenever they want to.