QuestionMy brother has a 89 laredo limited with 4L engine and he's facing overheating problems to the point that it spits out all the antifreeze from the bottle. This seems to be a common problem in these closed circuit systems. Any hints or recommendations other than converting to an open circuit system?
AnswerPeter,
Actually, the closed system is a fairly dependable system. Normally, any heating problems with this system, can occur in a standard cooling system also. The only problems that I have seen that are directly connected with the closed system, is the reservoir can become brittle and cracked, leaking off pressure and fluid. In this case, you simply replace the plastic reservoir, and it's quite easy to replace.
There are several other problems that can cause over heating. I would start out by flushing out the radiator with a good commercial flush to make sure that all the radiator tubes are clear, and have proper flow. You should check the cap to make sure that it's maintaining the right pressure. Any radiator shop can do this for you. You may need to replace the thermostat, as it may be sticking, or not opening properly. A slipping fan belt can be another problem. A bad fan clutch, or faulty electric fan, are a couple more common problems. Another item that could be bad, is the water pump itself.
Most of these items are fairly inexpensive, and easy to replace yourself. The hardest to replace, and most expensive (other than the radiator), would be the water pump.
Carl
