Hi everyone, My wife has a 2001 Montero Sport LS 4wd and the past 2 weeks a couple things are occurred and now truck is not safe to drive and may think she blew a cylinder.


1st Problem - The truck is not staying in 2wd and keeps dropping into 4wd.


2nd Problem - My wife was driving her truck tonight and all of a sudden one of the wires blew it self out of the block and sounds very bad. I tried replacing the wires and plugs in the thing and it keeps blowing out the first wire going in on the front left side of the block. Could this be a blown cylinder?


Any and all information would be greatly appreciated. I am not sure what to do or where to start. I am mechanically capable of doing most repairs but never have had this type of problem before.


thank you in advance

 

When you say - a wire blown out, do you mean the spark plug wire? Did the spark plug came out with it too? If only a wire get blown out and spark plug is still there, then you may have a loose spark plug and it allows the combustion gas escape and push the wire out. If the spark plug came out too you may again had a loose spark plug or (a worse scenario) a ruined thread in the cylinder head where the spark plug sits. Just thought of another possibility - a cracked spark plug. If a ceramic body is cracked, it may produce the same effect as the first scenario (only wire coming out). In any case, you need to take out the No.1 cylinder spark plug out ASAP and examine it. Check for any cracks in the spark plug body and also check the threads. If you have any aluminum gumming up the threads, than you may have a ruined thread in the head and you'll need to repair it. I know that there are kits for this sort of thing, but i can't point you out to a specific one that will work on your vehicle.
If you are lucky, it will be just a loose or cracked spark plug.
Post back what you find out.

 

Hunter thank you for the information on that. The plug was gone again and when I found it I busted the porcelain on it. Had to put in a new one this morning thankfully the threads were in need of repair didn't take long all done in 20 minutes top. Any ideas on the 4wd situation?

 

Keep in mind, if the spark plug continues to come out you'll need to repair the thread. It is better to do this sooner rather than later - a slightly stripped thread is easier to repair than a complete goner...

As far as 4wd problem. The only possibility that comes to my mind is a vacuum leak or a defective solenoid switch. The 4wd engagement on these vehicles is activated by directing vacuum to the right actuators. Search the forum for "Testing 4WD Solenoid" or "Freewheel Clutch Valve". See what you can dig up on testing yours. You'll need a vacuum gauge to do the test on the vacuum lines. Hopefully this will isolate some issue in the system.