Kickinmule Posted March 20, 2015 Posted March 20, 2015 Well now that I have the 88 4.0 MJ on the road with the new cat/muffler, I hear the ticketty tick of an exhaust manifold leak. What should my next move be? Gasket? Or what is the method for finding the leak or crack? If it turns out to be the Mani what is the most opted for manifold or header? And also what all has to come off to replace?
91Pioneer Posted March 20, 2015 Posted March 20, 2015 It's likely either going to be a loose manifold bolt causing the leak, or a crack. Re-torque the bolts and inspect for cracks. Cracks are very common though. What I did for my 88 is found a manifold at the junkyard with no cracks, but long story short I sold the truck before I replaced it. If you want a new part this is a good option http://www.amazon.com/gp/product/B000C123A2/ If you're looking for a manifold, easiest bolt-on replacement is the 87-90 one. The 91+ are different.
Kickinmule Posted March 22, 2015 Author Posted March 22, 2015 Thank you 91. Is a crack going to be quite evident or could I miss it?
91Pioneer Posted March 22, 2015 Posted March 22, 2015 You will likely be able to see it/them. I have one of those snake camera things so it was easy for me to see without taking anything apart ;-)
Kickinmule Posted March 22, 2015 Author Posted March 22, 2015 So I'm off to borrow a python and a gopro camera and some duct tape...
91Pioneer Posted March 22, 2015 Posted March 22, 2015 LOL. At the very least remove the airbox, grab a flashlight and an inspection mirror.
Rockfrog Posted March 22, 2015 Posted March 22, 2015 Use the seafoam or atf trick. A little into a vacuum line will start the smoke, anything not coming out the pipe is coming from somewhere in between manifold and tailpipe, and will be quite evident.
Kickinmule Posted March 23, 2015 Author Posted March 23, 2015 I like it Rockfrog! What would be the best way to do that and at which vacuum line? dribble it in before starting and then reconnect the line? Seriously at a loss as to where and how? Oh and how much?
Rockfrog Posted March 23, 2015 Posted March 23, 2015 I just use a small cup and run a line off a spare nipple ... Dip, bog, dip, bog, dip, bog, smoke, located.
metrictonner Posted March 24, 2015 Posted March 24, 2015 Tickity, tick. Don't forget to check your EGR tube nuts. Those things loosen up over the years at both ends. Only then would I replace the manifold gasket using Permatex spray copper. And while the manifold was hanging I would refinish the EGR tube seats.
Kickinmule Posted March 25, 2015 Author Posted March 25, 2015 Thanks metrictonner, I will be sure to put those ideas to good use!
reubj Posted March 28, 2015 Posted March 28, 2015 If you need to replace the manifold gasket be sure you have a set of swivel sockets (not just a swivel). Ask me how I know ....
Kickinmule Posted March 28, 2015 Author Posted March 28, 2015 Haven't gotten under the hood in a few days, been living, hopefully get to these suggestions soon. Got the Chief in the teepee for now.
1989 Eliminator Posted March 30, 2015 Posted March 30, 2015 I also had a leak and replaced the manifold gasket which was bad. Then about two years later I had another leak and thought it was the gasket again but turned out to be a small crack on the manifold I was unable to see unless I took it off. I then got the manifold welded since it was a small crack. Id also suggest doing the garden hose trick which is just taking a small piece of hose with one end by your ear and moving the other end around different spots by the manifold. Wherever you hear the loudest sound is where your issue is located. The hose is acting as a stethoscope...
Kickinmule Posted March 30, 2015 Author Posted March 30, 2015 I also had a leak and replaced the manifold gasket which was bad. Then about two years later I had another leak and thought it was the gasket again but turned out to be a small crack on the manifold I was unable to see unless I took it off. I then got the manifold welded since it was a small crack. Id also suggest doing the garden hose trick which is just taking a small piece of hose with one end by your ear and moving the other end around different spots by the manifold. Wherever you hear the loudest sound is where your issue is located. The hose is acting as a stethoscope... More great information! Thanks, 1989 Eliminator!
Recommended Posts
Create an account or sign in to comment
You need to be a member in order to leave a comment
Create an account
Sign up for a new account in our community. It's easy!
Register a new accountSign in
Already have an account? Sign in here.
Sign In Now