Hey all,

I've got a '98 Gr. Cherokee that needs a 6-cyl exhaust manifold.  The dealer wanted $900 to fix it; needless to say, I passed.  I can get the non-OEM part for $50.  Since I rate my car skills at "6" (change O2 sensor, brakes, bulbs, electrical, but no engine work), I think I'll have to go to the pros on this.  What is a fair price to get this work done?  Should I trust a "Midas"-type shop to do the work?

Thanks,
BoB

If the bolts/studs don't twist off, then it's a max 2/3 hr job. All bets are off if one of the fasteners goes pop.

Midas replaced a cracked manifold on my wife's 98 Wrangler 4.0 with a barely used unit I supplied for something like $350.  I thought about doing it myself, but there was all sorts of crap in the way and I didn't want to get in over my head.  Only problem is that about a year and a half later and I think the manifold is starting to develop a crack again.  I'll probably just go with headers this time since this seems to be a recurring problem with the factory manifold.

You should be able to do this yourself in an afternoon. LIke previously posted you just unbolt the old one , throw a new gasket on there and bolt up the new one.
Though someone who has done it before could probably knock it out in about 2-3 hours of work at $52 an hour you are looking at around150 dollars to have it installed.
James

Quoted: Midas replaced a cracked manifold on my wife's 98 Wrangler 4.0 with a barely used unit I supplied for something like $350.  I thought about doing it myself, but there was all sorts of crap in the way and I didn't want to get in over my head.  Only problem is that about a year and a half later and I think the manifold is starting to develop a crack again.  I'll probably just go with headers this time since this seems to be a recurring problem with the factory manifold.

Let me guess.......It cracked where it goes 2 into 1 so the pipe can bolt up.

Quoted: Quoted: Midas replaced a cracked manifold on my wife's 98 Wrangler 4.0 with a barely used unit I supplied for something like $350.  I thought about doing it myself, but there was all sorts of crap in the way and I didn't want to get in over my head.  Only problem is that about a year and a half later and I think the manifold is starting to develop a crack again.  I'll probably just go with headers this time since this seems to be a recurring problem with the factory manifold. Let me guess.......It cracked where it goes 2 into 1 so the pipe can bolt up.

You got it - right in the crotch as I like to call it.  I guess the Grand Cherokee has a different layout since you guys are saying it's pretty straitforward and bolts right up.  The Wragler had all sorts of shit in the way.

Quoted: Quoted: Quoted: Midas replaced a cracked manifold on my wife's 98 Wrangler 4.0 with a barely used unit I supplied for something like $350.  I thought about doing it myself, but there was all sorts of crap in the way and I didn't want to get in over my head.  Only problem is that about a year and a half later and I think the manifold is starting to develop a crack again.  I'll probably just go with headers this time since this seems to be a recurring problem with the factory manifold. Let me guess.......It cracked where it goes 2 into 1 so the pipe can bolt up. You got it - right in the crotch as I like to call it.  I guess the Grand Cherokee has a different layout since you guys are saying it's pretty straitforward and bolts right up.  The Wragler had all sorts of shit in the way.

The Wrangler has a lot less room obviously. That is a very common Jeep problem. I switched to a header on my Cherokee and never had anymore problems.

What's a good header and how much do they run?

Thanks for all the info!

Mine cracked too (94 wrangler) but being the lazy guy that I am I just MIG'd it up on the vehicle and keep driving on. Oh, I didn't get it perfect, there are still a few pinholes but I am not that concerned about those.

Quoted: What's a good header and how much do they run? Thanks for all the info!

Banks makes a header. I hear good things. Don't know what it costs.

From what I remember it wasn't cheap. I bought my header used for 100 bucks off of a guy I knew. Price was around 350-400 IIRC for new.

Coupla companies make them for Jeeps, unfortunately it's a lot of "boutique" exhaust companies that are very expensive. Hooker, Hedman, Dynomax etc don't make them as far as I know for newer Jeeps, only the older Jeeps.

The one I had was a Borla if I remember right. Get a couple of 4x4 magazines and should plenty of ads in them. The Jeep 4.0 is a great engine. I found cams, stroker kits, better flowing heads, hotter ignitions. I was really suprised at how much was available.

Quoted: Mine cracked too (94 wrangler) but being the lazy guy that I am I just MIG'd it up on the vehicle and keep driving on. Oh, I didn't get it perfect, there are still a few pinholes but I am not that concerned about those.

Did the same with mine a couple of times. But it kept cracking again and I got tired of pulling the manifold. I always figured it was just too rigid and there was a lot of flex somewhere in the system or a bad weld but it was a huge time frame that they do it. I've yet to hear any Jeep with the 4.0 I-6 that doesn't have the bumblebee crack.

Quoted: From what I remember it wasn't cheap. I bought my header used for 100 bucks off of a guy I knew. Price was around 350-400 IIRC for new. Coupla companies make them for Jeeps, unfortunately it's a lot of "boutique" exhaust companies that are very expensive. Hooker, Hedman, Dynomax etc don't make them as far as I know for newer Jeeps, only the older Jeeps. The one I had was a Borla if I remember right. Get a couple of 4x4 magazines and should plenty of ads in them. The Jeep 4.0 is a great engine. I found cams, stroker kits, better flowing heads, hotter ignitions. I was really suprised at how much was available.

Yep COMMON problem with the 4.0l engine. Mine started to crack @ 40,000 miles. I replaced it with the Borla header. Banks also makes a nice header for the I-6. I did it myself, took about 2hrs or so. Check out www.quadratec.com for prices.

I know a few people who have replaced it with a Borla header and have wound up doing the whole exhaust.  You get somewhat more noise but a noticeable amount more power.  Everyone I know who did this was unhappy about the cost of the Borla (for a while they were the only ones out there) but they were mollified by the added power.

This is one of just a few cases where everyone I know who has done an exhaust replacement feels that it was money well spent, the other two being A2 VWs (20% change in the power, serious mileage increases) and Dodge Cummins trucks with the old 1.5" soda straw exhaust (20% more power with no change in the fuel system).

It sure would be nice to be able to do a small Cummins swap for the older Jeeps.  Cummins makes a lot of small (1.5l to 2.4l, I think) 3 and 4 cylinder engines, some with turbos, and if you could get 120 bph and 260 foot pounds of torque with a Cummins deisel, I think a lot of people would swap out the older 6s.

I have BORLA muffler on my Jeep cherokee 4.0L. Best muffler ive ever had, Ive dealt with flowmaster, thrush and dynomax previously. This has a very nice sound and I noticed some power, not alot, but i added a Jet Chip and K&N filter all at the same time.

Quoted: I have BORLA muffler on my Jeep cherokee 4.0L. Best muffler ive ever had, Ive dealt with flowmaster, thrush and dynomax previously. This has a very nice sound and I noticed some power, not alot, but i added a Jet Chip and K&N filter all at the same time.

The folks I know who did t his replaced everything from the exhaust gasket on back (Borla suggests not using a gasket, or did, but lots of people disagree with that thinking).  If my memory is correct (always a risky assumption), they were supposed to get 40 more horsepower at the rear wheels, but that seems like a lot.  In any event, the only gripe with Borla that I have ever heard was cost.

Sounds like mine is cracked as well ( 98 Wrangler )  been deeling with it for now, but it is getting louder.    I'll be looking into a header as well.

Quoted: Sounds like mine is cracked as well ( 98 Wrangler )  been deeling with it for now, but it is getting louder.    I'll be looking into a header as well.

If it's the classic Jeep crack you can see it. The exhaust steps 3 into 2 into 1. Where it goes 2 into 1 there is a notch or crotch where it goes into the large collector for lack of a better term. That's where they almost always crack. Usually the entire weld between the 2 pipes breaks.

I replaced my 90 XJ manifold with a Borla. $600 I think for parts. Heard Banks is way to go for new models. I also used a name brand metal exhaust gasket, not the one supplied with the header.

It is more of a work job then a thinking job. Hardest part is getting to the lower bolts on the head and removing the power steering pump. The reat is just undoing stuff and putting it back. If you have a manual you should be able to do it. You might have to replace the exhaust pipe if it is in bad shape.

Good time to replace the belt and any bad pullies. Also order new o rings for the injectors. $10 from the dealer. Easy to replace now since you will have them out.

PS. Years ago the Jeep dealer replacement manifold was a Borla.

Guys... a little info.

This is EXTREMELY common on all 4.0 engines.  The stock manifold has a design flaw that has been addressed in new vehicles, and new manifolds.

DO NOT assume buying a header will do anything.  MANY, MANY Borla's have cracked, albeit in different places.  Banks as well.  Their purpose is to boost horsepower, but too often at a loss of low end torque, and it reall requires updating your cat and muffler to realize any benefit.

It is really not hard at all to replace your own.  I did it in about 4 hours, going slow....  I washed my engine the day before, and sprayed the exhaust and manifold bolts with PB blaster for a couple days prior.....  It requires removal of the fuel rail, intake manifold, wiring, and breaking it loose from the exhaust headpipe.  Those are the biggest challenges.

These are stainless, cheap, and have the new design fixes:
www.1aauto.com/1A/ExhaustManifolds/Jeep/GrandCherokee

Do NOT use the gasket that comes with the cheap kit.  Go to your parts store and get a Fel-pro.  Period.

The dealer isn't ripping you off - that is quite simply the real price of hourly shop rate, supplies, and the cost of a Mopar replacement manifold.  Life is expensive.  

You can do it yourself for under $200.  Best you are gonna find someone to do it for is probably $400-$500 out the door.

Here is a good how-to to show what is involved:

www.jeepingsingles.net/tech/manifold.asp

Good luck!  You can find someone to install these cheaper manifolds and save you some coin, if you decide to go that route.  Just make SURE anything you install has the flex pipe improvements or your new one will crack in time.