A lot of people seem to report broken exhaust and intake manifold bolts for the 2.5L 4 cyl, how common is this? I have a 1997.
Which bolts are the most prone snapping off and what causes this? Is there a bolt for every manifold hole? Is there a bolt for the last lower hole of the exhaust manifold closes to the firewall or is there a dowel pin in that hole? Is it possible to remove a broken bolt in the last hole if it is a broken bolt and not a dowel pin? Is there enough room to drill out the broken bolt with a right angle drill and stub drills once the intake boot is removed or do you need to remove everything?
How much time is involved in removing everything (intake and exhaust manifolds) so you can replace both intake and exhaust gaskets and drill out broken bolts? I understand drilling and extracting broken bolts can take additional time.
01-16-2010 05:09 AM
My new -to- me 97 4 cylinder with 123,000 miles came with a broken exhaust manifold.Since I was afraid of breaking a stud and heard that broken exhaust manifolds were "common" I bit the big one and had my local Jeep dealer do it.They warrant their work for 12 mo/12,000 miles.They reported 2 broken studs so cost was a shade over $600.I would have been dead if I had tried to deal with that on my own.The dealer said that I was lucky that I was not replacing a 6 cylinder manifold as they are a lot more.I'm not mad at the Jeep due to its age and mileage.I understand that changing it is a drag because you can see that the design has the intake in the way.What were they thinking?
01-16-2010 08:55 AM
Its very common, almost guaranteed. As far as I know, the front-most bolt is the one that breaks most often (I may be wrong). I had a local garage that I trust do the work ( I didn't feel like dicking with it, extracting a broken bolt is enough of a PITA, without worrying about screwing up block threads). They replaced the bolt with a heavier grade unit that should resist the expansion/contraction of the manifold (the common cause of this). The dealer is going to charge more everytime- IMO every gearhead, no matter how mechanically inclined, should have a trusted local garage for the stuff they can't, or just don't feel like doing. Be sure to closely examine the manifold itself for cracks as well.
01-16-2010 09:01 AM
BTW- my guy charged me around $250 to extract/ replace the bolt. Mostly labor involved. But my manifold was okay. No more lawnmower sounds, and shes a happy girl.