well my cel light came on and said # 6 cyl misfire detected, so i went out and took a look and noticed pretty much all my boot wires are touching(read that it makes a diff if they are), then also noticed on passenger side rear exhaust manifold bolts are missing both of them, so did i do any damage driving like this,(to valves )not sure how long its been like this , light just came on today and drove a few miles around to grocery store and such, should i just get new bolts and slap them in and call it good, or replace gasket also?(crap i dont know how i didnt notice this earlier , you'd think it be real loud exhaust ticking leak noise)any gasket to recommend i live about 15 min from summit

 

took out number 6 plug looks like it spose to nice tan color, but, the gap was about.046 instead of the stock .040 champion truck plugs gotta get in there and tear that PITA cap out.............. in between beers of course, lol, also look down the throttle body and looks nice and clean down there wich was a suprise

 

What can happen when you've got an exhaust manifold leak is that cold air is able to suck in on the intake stroke and, at the time, the intake valve and the exhaust valve may be open for just a split second which is just long enough to draw cold air up through the exhaust port and into the intake port thus cracking the exhaust valve. When the valve is hot and all of a sudden it gets a blast of cold air, they crack, then you find yourself chasing the misfire around thinking it's the plug wires, cap and rotor etc.

When wiring up Dodge Magnum motors, keep all the wires a min distance of 1.00" away from each other. There's a TSB on that: http://autorepair.about.com/cs/faqs/l/bl654h.htm

That's how you want to wire it up if your running OEM, carbon style ignition wires that are 7MM.

Just get two new bolts and pop them in and tighten it to 20-25 ft lbs. Sometimes, they end up snapping off. If your the original owner of the truck, they may have either been snapped off and are broken in the block or, under vibration, they walked out. Hope it's the latter.

As for the gasket, if it's OEM manifolds that haven't been touched, it would be a good idea to replace those gaskets with new ones for sure - especially if the bolts were missing, the gasket may have partially blown out. You would be better off just removing and replacing the gasket along with using all new fasteners as well.

 

if i hook up a vac gauge will that tell me if i f up the valve? how do you like those pulsestars? *** *** *** me running!!!! i think they are broken off, i loosened the other bolts and tried to put new ones in , no luck, so i used a pry bar a little here and there and tried to put a really skinny screw driver to line up the holes, nothing, maybe i gotta put some hair around it! im thinking there broke off at the head, its dark, im done for the night , look in the morn have to take exhaust all the apart to determine this, not looking good, yeah there stockers and im the second owner at 76,000 miles now has 124,000 on it, im also thinking they might be warped as hell, because we have had -20 below weather here in the last month and about 0 to 4 degrees in the morn, and a couple feet of snow, the back passenger one has gotta be warped as heck right now, crap gotta happen just when i have to smog this bitch before the 20th, IM SEARCHING THE HECK OUT OF THE FORUM RIGHT NOW FOR POINTERS,thanks

 

Oh yeah, that's what I thought- broken fasteners, joy. Yeah, you'll have to drill 'em out unfortunately or, sometimes, (if your lucky), you can simply pry the manifold over them. Then, spray the heck out of them and walk them out with vise grips. The difficult part is if they have fused into the manifold due to rust then, it's more joy! Then, you have to whack the manifold with a soft faced mallet (not too hard though as they will crack) to break them free from the manifold. Then you slide the manifold over the bolts, spray, and work them out.

Now, if that's not an option or, too much work, of, if your manifold is in really bad shape, your best bet is to drill them out with a right angled drill. Oh, by the way (more joy) the fasteners are grade D and, heat treated too! But, look on the brightside, at least their not Grade 8s LOL Sorry, I know it stinks.

I wouldn't worry about them being warped just yet. They may be fine if all it was is just the rear bolt. I know guys who've run them forever with those missing out of the back on Chevy trucks and, they were not warped. Let's hope you just blew the gasket out and that you haven't cracked a valve.

Ok, as for that valve, the way to test for that would be a leakdown test as well as a vac test. Does it make any irregular idling sounds emitting out the tailpipe? Light puff, puff at random or, any slight popping at random?

Run a comp test in the two rear cyls on that side and see what you get for a reading. If she's sitting <100, you've got an issue and, more than not, it's most likely due to a spent valve.

Run a vac test. Let it warm up first before getting a reading. Then, if you note a 2-4 inch drop, you've got a leaking valve. If it's a quick drop followed by a fast recovery, the valve is sticking which, you'll also hear that through the manifold and the pipe if you listen very carefully for it.



Check that out and see what you come up with.

 

hooked up vac gauge, sat solid at 15 or kunt hair below no movement what so ever, no poping sound out the exhaust , idles steady at 600 rpm no fluctuation, ive been looking on here and sounds like its gonna be a fun project, but i did buy grade 8 bolts from the store for my new ones should i forgo putting those in if this happens again, got them from home depot, parts store said it was special order, and take bout a week to get them, summit has a dorman oem manifold for 79.99 i think , would like to do the headers but, dont know yet...also i regapped the plug back to .040 and rerouted the wires correctly , reset the code, drove back to, napa , then home depot, put some berry mans, emission fuel cleaner in it, i think thats what its called, CEL light didnt come back on, got back to the house, and tried to retrieve codes ( if there were any) and it just said "p done" do you know if i will be able to go smog it tomorrow before a CEL light comes back on, or was it not a long enough drive cycle? thanks your pretty helpful to everyone, but gotta make for sure that those bolts are broken off, and you can hear a slight leak when you take off from a stop, almost sounds like a faint lifter tick

 

Regarding that reading of 15 at time of vac test- that's low. It should be 17-22 for a healthy engine. A low, steady reading usually means there's a leak someplace at the intake level or, it's pulling air through the manifold thus the steady, low reading.

They will not SMOG it with the light on. Here's what you do. IF the light goes on, simply pull the negative battery cable. This will clear it out- if it does come on. That should get you through the test as the light usually will not come on unless there's a gross failure.

The PCM allows a number of misfires before setting the CEL. So, the longer you drive it before going in, the greater chance of it hosing up at time of rolling in. And, it's usually when you power down and restart that the lamp comes on after a few minutes. Best thing to do is to pull the negative and let it clear out for ten minutes. Then, start it and drive it over 65 briefly to get a new baseline into the PCM. Don't romp on it as the more you do that, the misfire count will now add up thus tripping a fault. So, don't drive it much before going in. Let it idle and warm up before going in.

Do not use Home Depot fasteners for, I am not certain, but, some of those places were stocking fake Grade 8s. Those are safe to use on non-load, non-critical load applications but, not for a manifold or things pertaining to engine or chassis assemby for risk of the fastener failing.

However, there's nothing wrong with using real Grade 8s. This is why they had to order them, most parts stores don't stock them. You would be best to find them at a industrial supply place that sells machine shop equipment. Grade 8s usually have anti-corrosion properties due to the coating which helps to prevent rusting which, is what you want when your doing mods and you need to pull a header off quickly without fear of a rusted fastener or, later down the road, your pulling off your headers and heads to put on a new block.

Now, the other argument going against using those is that some like the rust. Why? Well, some mechanical engineers like to use non-coated fasteners because the holding power is greater due to rust. The rust improves thread tension and, the force to overcome that tension is greater than a bolt that has been coated and is not rusted in. The problem arises later after the fastener has become so rusted that it's difficult to remove. Then, at time of removal, the heads snap clean off at the radius.

However, while this is absolutely true about rusted fasteners holding better, and, it's been proven, I don't like rusted fasteners period. As long as there's a SS lock-washer under the head, or, you are using the appropriate anti seize medium or thread locker, and as long as they are torqued to spec, they will not walk out. If no lock-washer is used, they will walk out. The guy who put mine on forgot to use lockers. I had leakers on my new headers and, yeah, it contributed to an already weak valve train. I have to replace the heads this week. They were going but, the manifold leak put the final nail in the coffin so-to-speak and killed my No 8 valve. Under vibration and seating of the gasket, all fasteners were finger-loose. This is why I do all of my own work. Since I don't know how to weld, I let them do the entire exhaust system only to find that problem and a cross-threaded O2 sensor that I had to re-tap at the CAT. Couple that with bad welding and not mating the headers to the collector and you've got a leaker. It's time to learn how to weld and get a nice welder. DIY.

I had to pull the fasteners and put lockers on it but, by that time, it was too late. The damage had already been done.

 

yeah i took the rest of the bolts off and pulled the manifold back and the rear bolts are broken in the head, recessed a little in there, **** i dont know what im going to do , i also snapped the middle stud off when i put it back on , had antiseize on all the bolts but one still broke, ***!!!!!!!!!!! not to worried about that one i can pull the manifold over it its sticking out so get a couple nuts in there and back off the second nut, will see if this, works. Im prob better off pulling the head off and doing it right.. ahhhhhhhhh!!!!!!!!!!!!!!!!!!!
oh well what u gonna do.. what are my options, try to fix on the truck, which is gonna be a PITA,? take head off and try to fix,? look for donor head at j/y ? ( will have to resurface at a machine shop plus these heads suck anyways) look into rebuilt heads,for cheap, ?what would you do on limited buget .. not afraid of digging in on this, just cant afford the down time, shop is out of the q's prob want to much. Might as well do the plenum if i take the head off,prevenitive maintence, any thing else?already did whole front of motor with water pump and timing chain.... never taken a head off before but gotta learn sometime

 

Well, since you've possibly got a problem with a valve and perhaps the plenum, I would do it all. But, that's a lot of downtime.

I don't see a need to pull the head off to fix that manifold issue. I think you can get in there by sitting in the bay and / or leaning down and just grunting it out.

Hell, it's just a broken bolt or two. Drill the SOBs right the F-out. You can do it. Just get a top quality left handed drill bit that is smaller than the fastener. The fastener size is 5/16-18 Grade D so, get a nice high speed steel bit that is left handed.

It will be hard, there's no question about that. Whether it's you or the guy at the shop, someone's got to reach around back and drill it out. One thing to do is to remove the manifolds (if possible). That gives you more clearance to gain access at those holes.

You will need to look around for a 90º drill attachment to give you access to those rear holes.

If it were me, I would at least give it one hell of a go to drill those out. I wouldn't think about pulling the heads at all. Later, when you get time and money, that's when you should replace both heads and the intake all in one go along with some nice rockers too. You've already done the timing chain and pump so, that's all done. All you need to do is the top end and that will solve your low vac issue and your valve train issue that's possibly relating to Cyl No 6 misfire due to low compression / possible bad valve.

How's your plugs look- clean and dry or wet and oily?

How about your ignition wires- are they wired like in that link that I posted? If not, please take the time and rewire them to that along with keeping all your boots a min distance of one inch apart along with maintaining two wire spaces away from any other wires - especially Cyl No 4 and 8 and 5 and 7.

Hope that you can get at it, get those bolts out of there, put a new gasket on, put the manifolds back on (check for cracks before placing them on), put new fasteners and lockers, torque from the middle to rears - middle to front to 20 ft /lbs. After driving them for a bit, let them cool down - check torque. Re-torque from the middle to rear - middle to front. Do not exceed OEM torque ratings. Check OEM specs per Haynes manual.

 

sounds good i was doing the math and pulling the head would cost about 200 plus by the time i bought gasket sets, and head bolts, should i get a right angled cordless drill or a right angle air drill? prob electric then i wont have to deal with the hose being in the way...yeah not looking forward to it thats for sure... i appreciate all the input and encouragement...6'1 250lbs hanging in the engine compartment gonna be fun! lol