We've been working over the '05 Dakota 4.7 bit by bit over the summer as time and weather permits for working on it outside in the open air.
Over the past 2 weeks or so the truck has developed a tick on the drivers side. The tick is present right from startup. It gets louder under acceleration and disappears on deceleration. Strong indicator of an exhaust leak. The tick is right at the front drivers side of the engine somewhere. Awhile ago I fixed a similar tick on the Ram by replacing gaskets and broken exhaust manifold bolts. I suspect that we now have the same issue and the same fix to do on the Dakota. I will not know for sure until next time we get to work on the truck and pull the shields for a looksee.

Couple of questions .... are broken exhaust manifold bolts also common on the 4.7? What about the manifold exhaust flange, is that a problem area? I do have a few bolts leftover from the Ram job. Are the exhaust manifold bolts the same size and length on the 4.7 as the ones on the 5.7 ?

Other fun stuff of note. Last weekend we added some throat space and rumble to the Dakota 4..7. The stock exhaust has two resonators and a main muffler. A resonator behind the cats, then the muffler, then another resonator behind the axle. We took the main muffler out of the middle and replaced it with straight pipe. Left both resonators in place. Has a really nice sound to it now ....... except for that tick which needs to be dealt with.

Thoughts? Comments?

 

I've never heard that manifold bolts or flanges are a problem on the 4.7. Hemi? Yes. Have no idea on the bolt size.

 

Yes there is a design flaw on the exhaust system. Due to the close proximity of the CATs and no flex pipe between the CAT's and the exhaust manifold the bolt closest to the firewall on both sides break off. I went through 2 on each side then up graded to a grade10 bolt. No more broken bolts (knock on wood).for several years now. A lot of stress is placed the back bolts from the weight of the CATs. Easiest way to repair is to take the plastic wheel wells out then reinstall with plastic body rivets. Also use a reverse drill bit, if lucky it will remove the sheared bolt without using an easyout. Have fun.

 

Thanks for the confirmation Bajabob. I've ordered up some Fel-Pro exhaust manifold gaskets and Dorman manifold bolt kit. Hope to tackle it over the next 7 to 10 days. I will let the group know what the outcome is.