Jeep Garage  - Jeep Forum

Jeep Garage - Jeep Forum (http://www.jeepgarage.org/forums.php)
-   Engine Performance/Intake/Exhaust (http://www.jeepgarage.org/f196/)
-   -   4.7l Exhaust Manifold bolts (http://www.jeepgarage.org/f196/4-7l-exhaust-manifold-bolts-22138.html)

StephenE 04-22-2011 12:28 AM

4.7l Exhaust Manifold bolts
 
Recently traded my ZJ in for a 2002 WJ. Going from the straight six to the 4.7l was an eye opener. My ZJ had experienced the dreaded CKP sensor failure (randomly stalling).

ZJ:
http://gallery.photo.net/photo/12757732-md.jpg
WJ:
http://gallery.photo.net/photo/12931133-md.jpg

Last Sunday I found out that one of my drivers side exhaust manifold bolts snapped. I picked up a exhaust manifold gasket and set of bolts from the dealer and was disappointed in the bolt quality. I do not think they are even graded bolts (i.e. less than grade 2). After much searching online for alternatives to the factory bolts without any success (still using the factory heat shield). So I decided to make my own brackets that would allow me to use metric grade 10.9 bolts on the exhaust manifold. Has anyone else done this? Have photos they would like to share? I will not get them installed until next week as I am still waiting for a new exhaust manifold to arrive.

Bolts:
http://gallery.photo.net/photo/12997232-md.jpg

Hopefully these will last much longer than the factory bolts.

I will have pictures after they are installed as well.


I also completed the 4 light mod to the rear taillights.

Lights on, no brakes:
http://gallery.photo.net/photo/12997419-md.jpg

Lights on with brakes applied:
http://gallery.photo.net/photo/12997420-md.jpg
-Stephen

2005JGC 04-22-2011 12:46 PM

Re: 4.7l Exhaust Manifold bolts
 
Im interested to he see how these fit in there!

My only concern would be that the shiled would still not fit as that hardware will move it back (or forward, up or down) 10mm or so. Plus I dont like the idea of using phillips screws on exhaust... yes, the screw retainer is thin sheet metal and should break as required if the screw were to strip (after a couple years of moisture and heating).

That said it may function absolutely perfectly, not to mention the downsides I was thinking about shouldnt be an issue as with grade 10 bolts, as the manifold would never need to come off to repair broken fasteners again.

StephenE 04-22-2011 03:28 PM

Re: 4.7l Exhaust Manifold bolts
 
The goal was to replace the bolts, gasket and manifold once. I plan to do the passenger side when it has the same issue. I am mechanically inclined, but will pass on trying to remove the exhaust manifolds (I have a mechanic that will do it).

I am curious if anyone has removed their heat shield, if so are there any negative effects? Would exhaust paint (VHT Flameproof) function similar to the heat shield?

Anyone else out there that has fabricated a replacement to hold the exhaust shield?

StephenE 04-29-2011 01:05 AM

Re: 4.7l Exhaust Manifold bolts
 
Everything seems to fit as I had hoped. Here are some preliminary pictures until I can take some when the weather clears up. There is great comfort knowing that the new exhaust manifold is held on by 8 grade 10.9 metric bolts.
http://gallery.photo.net/photo/13035633-lg.jpg

http://gallery.photo.net/photo/13035634-lg.jpg

It does hold the heat shield a little further away from the manifold and up a little, but after driving for 45 minutes the shield seems to keep the heat in. I will have better pictures posted tomorrow or the next day.

StephenE 04-29-2011 11:47 PM

Re: 4.7l Exhaust Manifold bolts
 
Here is a better picture of the heatshield with brackets. I see that in the future I could make the front bracket about 1/2 the height.
http://gallery.photo.net/photo/13040519-lg.jpg

vicpick58 04-30-2011 04:36 PM

Re: 4.7l Exhaust Manifold bolts
 
Thank you for this post, your write up is very useful information.

StephenE 05-01-2011 12:51 AM

Re: 4.7l Exhaust Manifold bolts
 
Thanks,
Hopefully someone else out there that has had their bolts fail will know that you are not limited to the sub-standard bolts from the dealer ($30 for each manifold). My metric grade 10.9 replacement bolts, washers and supporting hardware for both sides came to $23.

PhattEddie 05-01-2011 01:14 AM

Re: 4.7l Exhaust Manifold bolts
 
Stephen, could you post your info on the 4 light mod

Thanks

StephenE 05-01-2011 01:43 AM

Re: 4.7l Exhaust Manifold bolts
 
I followed the instructions I found here: http://www.jeepgarage.org/f75/how-to-join-the-wj-quad-squad-1079.html
be careful about the hole you drill and the light sockets you use. Not all light sockets are 1 1/4".

vicpick58 05-01-2011 05:15 AM

Re: 4.7l Exhaust Manifold bolts
 
Quote:

Originally Posted by StephenE (Post 406887)
Thanks,
Hopefully someone else out there that has had their bolts fail will know that you are not limited to the sub-standard bolts from the dealer ($30 for each manifold). My metric grade 10.9 replacement bolts, washers and supporting hardware for both sides came to $23.


When mine broke, the Jeep was still covered by extended warranty, so I had the dealer repair it. They replaced the entire manifold. Said it was warped, but I think they just wanted more money out of the warranty company. From what I have read, it is usually the upper rear bolt on the left side that breaks. There must be a lot of stress on that end of the manifold and those poor quality factory bolts can only take so much.

At 183k miles, I am probably about due for one to break again. If (or when) it happens, I definitely will look into doing it your way.

PhattEddie 05-01-2011 08:23 AM

Re: 4.7l Exhaust Manifold bolts
 
Quote:

Originally Posted by StephenE (Post 406912)
I followed the instructions I found here: http://www.jeepgarage.org/showthread.php?t=1079
be careful about the hole you drill and the light sockets you use. Not all light sockets are 1 1/4".

Thank You !

StephenE 05-02-2011 01:37 AM

Re: 4.7l Exhaust Manifold bolts
 
From reading around. The bolts continue to fail. I have another set for the passenger side when it decides to break. I will purchase another exhaust manifold at the same time and be done with it. I think the left rear upper bolt has the most stress as it is on the far side of the y-pipe and the upper bolt seems to be taking the majority of the pull of the exhaust pipe. I am truly amazed that there has not been a recall on these bolts. Some people report having the dealer replace them and then they break 12k miles later.


All times are GMT -5. The time now is 02:06 AM.

Powered by vBulletin® Version 3.8.8 Beta 4
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
Copyright 2012 - JeepGarage.Org
The Jeep Grand Cherokee Owners Community