Reader said:
I just purchased a 2000 XJ with 97,000 miles. I am worried.
1. What are the symptoms of a cracked head?
2. How much does it cost to replace?
3. Is the problem that they started making it out of aluminium and it cracks if overheated?
4. If the head is not cracked yet, what extra maintenance should I have performed to prevent overheating?
5. If it needs to be replaced, is there an aftermarket non-aluminium head or earlier model head that should replace the aluminium head?
1. Biggest clues are loss of coolant, milkshake looking oil, and low low oil pressure. They generally crack in an area that can be seen when the oil cap is taken off and a flashlight is shined down inside...look towards the right if you're checking. However if your coolant level is still good, the oil looks and smells normal, and your pressure is good, you should be fine.
2. Depends on if you go the junkyard route, or buy from a company.
3. I believe it is, but don't quote me on that.
4. I would, as with
any used vehicle, change all fluids. Start with doing a good coolant flush since you're concerned about it overheating. Depending on mileage, it probably wouldn't be a bad idea to put some new hoses on while you're at it, and a thermostat as well. Might as well do a complete full coolant system service, that way it's less for you to worry about. Search around, it's been covered numerous times on here as to where the best places to get the best quality parts at the best prices are (and believe it or not, in some cases, it's actually the
dealership :scared
.
5. Also search around on here. I believe the 0630 heads (the ones that were used from 96(ish) and the heads before that (dont recall the casting number off the top of my head) bolt on with little to no modification.