Need Help, Asap

[steven a.]

My 99 explorer, 6cyl, SOHC is dead, It's in the shop. mechanic stated i have one dead cylinder, 3 cylinders misfire caused by a vacuum leak by either a cracked exhaust manifold or cylinder head in which he started to tell me about installing the 00M12 kit. I previously explained to the mech all my recent installations I had done within the last 2 months from new plugs, wires, O2 sensors, IAC, 00M12 kit installed. The mech stated it was a cracked exhaust manifold or cracked head but wasn't sure they would have to start taking it apart to find out the real problemsince they couldn't find the problem in 3 days. It would cost me around $900.00 to fix. How can I accurately tell which of the 2 listed problems is causing the vaccuum leak. I would hate to fix one of the 2 to find out it was the other and start all over again. has anyone done this work before any pointers as I plan to try and fix it with some help. Any help is greatly appreciated.

 

[Rick]

A cracked exhaust manifold won't cause a vaccum leak or a misfire so that's easy enough to discount. I wonder why they would tell you that

I don't know much about the SOHC, but the OHV models were prone to vaccum leaks between the intake manifold and the cylinder heads.

 

[steven a.]

Wish I knew

My guess is that they've been guessing as to what the problem is.