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VERY SERIOUS exhaust problem HELP!*****UPDATED!!****

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by MudNurI, Aug 18, 2002.

  1. MudNurI

    MudNurI 1/2 ton status

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    As some of you remember, I had a problem a few months back wth my exhaust heating up my back seat floor. Well, I had the passenger side muffler replaced, as that had some very big- "damn I got hot and now I'm 10 different colors" marks.....seemed to work, you could put your feet on the floor and be fine.... well, last night, the truck went on the highway- about 35 miles, and let me tell ya. that damn floor melted my nieces sandle...........

    I have a few could this be the reasons.

    1st, when the guy put on my dual's- he has the pipes going like this.. Start at the front of the truck, and working towards tailpipe-

    Header collector- then the next pipe goes INSIDE the header collector..... the cat goes INSIDE the pipe in front of it, etc... I thought they were suppose to go inside the next one, not outside........ could there be enough "turbulence" in those fittings to make the exhaust this hot?

    It's only the passenger side again, and my new muffler has the SAME nasty heat marks that the old one did...... I can't believe that 2 mufflers were bad right off the bat? Looking at the two cats, the passenger side one is cherried as well, the driver's seems fine. Everything except the 1 muffler I had changed, is the one that was put in 3 years ago....

    The timing is set correctly, so it's not that.... nothing in my exhaust leaks.........

    the worst part is that I have a 3" body lift, and my floor will burn your hand if you put it down after 35 minutes of real driving.....

    I'm just glad I don't have carpet yet... imagine the smell of that backing melting yuck!

    HELP guys, I really don't want to replace my entire exhaust if I don't have to....

    ************************UPDATE**************************************

    Okay pulled the plugs this afternoon, all looks fine... not 1 of them looked like it was hotter, no nasty black crap etc...

    I have no clue which side has an 02 sensor on it......

    I also live in Vermont, land of the free, and nasty emmissions cars, we don't have such a thing....

    I'm going to take it up to the place that just replaced the muffler on the pass side tomorrow if John can go into work late, that way I don't have to take the kids.. it's about 1/2 hour, but it's on a main road, 55mph, heats up quickly.

    The truck is running the same as it always has, it seems to me that it's lost a bit of power lately, but being a 305 it never had it to begin with...... I'm thinking that maybe when the put the pipes in "backwards"....they crushed a baffle in my cat,,,,,,could be causing a lot of backpressure, which is radiating down to the muffler..... the muffler is under warranty still,,,,, so I'm going to have them replace it anyways, since its been pretty damn hot these last few days.

    I'll let you all know tomorrow afternoon if I got to the shop...

    thanks again guys!


    thanks
    Brandy
     
  2. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: VERY SERIOUS exhaust problem HELP!

    If you are running true duals, there shouldn't be enough heat in the exhaust no matter how its run, to burn the floor that far back IMO...thats assuming the converter is basically under the passenger seat or rear floor area. It might get hot, but not melt rubber hot.

    If you have a cylinder dumping raw fuel into that side, it *will* burn in the exhaust, and can make the cat run extremely hot. A plugged converter will glow red and if it were a single exhaust setup, would *noticeably* decrease performance. If you've got a misfire/bad idle, you may try fixing that first.
     
  3. trailblazer87

    trailblazer87 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    Sounds like the passenger side cylinders are running rich. Your cat is heating up from trying to convert all the raw fuel. Remember, the hottest part on any automobile is the catalytic converter. This only applies if you are running true duals, sounds like you are. Is there a heat shield above the catalytic converter? The mufler? If not, then you need one anyway.
     
  4. Blazer79

    Blazer79 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    Blazers came with one heat shield over the cat and another above the muffler.

    Maybe you can install another set over the 2nd cat (if you're running 2) and 2nd muffler?

    I'm running true duals with an exhaust crossover, and didn't need to add shields, but maybe it will help in your case.
     
  5. wrathORC

    wrathORC 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    Pull all your sparkplugs on that side (2-4-6-8) and see if you've got a cylinder misbehaving and trying to set little kids on fire.

    If it's not too much work, you could always swap sides on the converters. It'd tell you if you've got a converter trying to give you afterburners.
     
  6. KRAZIE87K5

    KRAZIE87K5 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    </font><blockquote><font class="small">In reply to:</font><hr />
    see if you've got a cylinder misbehaving and trying to set little kids on fire

    [/ QUOTE ]
    LMAO! Gawd I love this place... people are so damn funny!

    -Dan
     
  7. MudNurI

    MudNurI 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    </font><blockquote><font class="small">In reply to:</font><hr />
    Maybe you can install another set over the 2nd cat (if you're running 2) and 2nd muffler?


    [/ QUOTE ]

    There is ZERO heat shields on this. the entire exhaust is aftermarket. With a 3" body lift, I shouldn't have a hot floor regardless of with or without shields right?

    The cylinder very well could be acting up... its running pretty sh*tty right now......

    It's not the cat that is hot, the cat is under the front seats "feet"..... the mufflers are under the back seats "feet"...The front floor is what you could call luke warm compared to the back floor. The back drivers side floor is hot like a bath, the passenger can fry eggs....I think the driver's is just radiant heat from the other side.....

    I still can't believe with a damn body lift, its still this hot...

    I'll head out now and check the cylinders and let you know what I find.....

    Brandy
     
  8. Skigirl

    Skigirl 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    I'm running true duals, no body lift, no cats, no heat problem at all. Doesn't make sense that it's the exhaust system itself - it really does sound like the hot exhaust area is a symptom, not a cause.
     
  9. Sandman

    Sandman 3/4 ton status Author

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    Re: VERY SERIOUS exhaust problem HELP!

    I had this exact same problem. I melted the bottom of my gym bag. Spacing the mufflers farther back solved my problem. When the previous owners had the duals installed, One muffler went under the cat shield and the other one went on the other side with no shield right next to the transfer case. Now, they are farther back about right where the floor steps up. No more heating problems.
     
  10. dyeager535

    dyeager535 1 ton status Premium Member

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    Re: VERY SERIOUS exhaust problem HELP!

    This is a factory K5 diesel setup http://yeagerd.home.mindspring.com/TablePics/factorydieselexhaust.jpg but I'm running gas.

    The picture obviously isn't totally clear, and you can see that the mufflers are angled, but look at the forward edge of them...even that isn't much below the frame rail, and I have no heat problems whatsoever. No cats, and the factory heat shields are in place, but they aren't anything more than sheet metal standing off of the body a tiny bit.

    Still thinking your problem is elsewhere.
     
  11. bckinblk

    bckinblk 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    What if you used that heat rap stuff thats sold for headers and somehow glue it to the bottom of the floor boards where it is heated the most .And try to use that space age heat defletor pad inside the cab under the carpet..hope this helps good luck...........
     
  12. MudNurI

    MudNurI 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    The problem is that regardless of if I use heat shield. There is NO way that 1 muffler should be 95 different shades of "holy crap I got hot"........

    I know how to "fix" it by adding heat shield, or moving the mufflers etc.... but I don't think the problem is in my exhaust system.....

    Something somehwere else has to be really screwed up...if it was the exhaust you'd think it was the cat's getting hot, since those are the biggest restriction points in an exhaust system.... or my header's would get cherry red.... nada...it's father back in my muffler... but again only 1 side.

    I didn't have time to pull my plugs, but I"m heading out now to do it.....

    Brandy
     
  13. bckinblk

    bckinblk 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    Brandy I remember reading a post a while back that someone here had problems with there manifolds glowing red hot and that it had something to do with the o2 sensor and or pluged up cats .Is the side that is hot the o2 sensor side?? If so maybe it has somthing to do with your problem I bought a new one a while back for $30 maybe try that out to see if it helps .Cause my k-5 was running funny and seemed to run hot before I bought a new sensor and that helped it .Sorry to hear about your nieces little feet getting burnt I am sure that someone here has the explanation as to why your k-5 is heating up like that good luck and let us know how it turns out....
     
  14. mpascino

    mpascino 1/2 ton status

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    Re: VERY SERIOUS exhaust problem HELP!

    okay, well if your truck is running somewhat okay, it shouldn't be dumping that much fuel into the exhaust system. I'm sorry for not remembering, but didn't you say your truck recently went through an emissions test? If so I doubt it's running wrong. I worked in a shop for three years and everytime I have seen this problem it usually had something to do with the Cat. If you find your plugs to be okay, you might want to try removing the Cat.s and replacing them with straight pipe for a couple of days and see if solves your problems. I know it might be a Pain in the A$$.
    Keep us posted and good luck.
    Mike
     

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