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Unread 08-17-2012, 07:26 PM   #1
ejschultz
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Plenum plate replacement

Tomorrow I'm going to be taking on my plenum gasket and plate. I know lots of you 5.2 guys have done this. Looking at the walk through that Hughes supplies, draining the coolant seems odd. Is this necessary to remove the intake?

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Unread 08-17-2012, 07:32 PM   #2
sskilla
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only if you dont like coolant all over your engine from the heater core lines. plus their kit comes with a new bypass hose. i know mine did cause im lookin at it right now lol.
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Unread 08-17-2012, 08:20 PM   #3
JrMechanic
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The coolant needs to be drained below the ports on the heads. Draining the radiator will usually get you there, you shouldn't have to drain the block.
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Unread 08-17-2012, 08:27 PM   #4
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Okay, cool. I'll just do the radiator then. I didn't get the Hughes kit; I'm just using the instructions from it. I actually bought the plate from the guy over on thespeedfreaks.net and ordered gaskets separately. I didn't get the bypass hose or the thermostat. I may pick up a bypass hose if it tends to leak after pulling it off and putting it back on. I'm pretty good with no leaks right now and I don't really want to start.
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Unread 08-17-2012, 08:30 PM   #5
sskilla
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i would. ive had a slow coolant leak from that damn hose since the i did the kegger mod. local parts store didnt have one in their system.
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Unread 08-17-2012, 08:49 PM   #6
JrMechanic
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If you have the opportunity ALWAYS replace that bypass hose.
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Unread 08-17-2012, 08:50 PM   #7
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Quote:
Originally Posted by JrMechanic
If you have the opportunity ALWAYS replace that bypass hose.
What he said and the t-stat too
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Unread 08-17-2012, 09:05 PM   #8
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Well sh*t. Now I feel dumb for not spending money on cheap parts. Looks like I'll be making a trip to Advance or Autozone tomorrow to pick them up. I should have ordered them from Rockauto when I ordered the gaskets.
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Unread 08-29-2012, 09:45 PM   #9
mackcs212
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I am replacing all the gaskets in my engine and when I got to the plenum plate, i became confused. when I took the plate off and looked at the gasket, it looked ok, but i decided to change it anyways but when I went to pull it off, it seems like it is not ment not to come off. I pick at it whith a scribber (dental pick looking tool), but it does not want to come off at all, chips off in small pieces. is this normal? or is it not supposed to come off?
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Unread 08-29-2012, 11:27 PM   #10
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Quote:
Originally Posted by mackcs212 View Post
I am replacing all the gaskets in my engine and when I got to the plenum plate, i became confused. when I took the plate off and looked at the gasket, it looked ok, but i decided to change it anyways but when I went to pull it off, it seems like it is not ment not to come off. I pick at it whith a scribber (dental pick looking tool), but it does not want to come off at all, chips off in small pieces. is this normal? or is it not supposed to come off?
The factory gasket is just a wafer thing pc of metal . Never heard of one bonding to the surface of the intake/plate before , they are usually lubricated

Yes , the gasket should come off . Hope your re-installing a Fel-pro gasket , and , I personally used a anaerobic gasket maker on mine(got mine at the GM dealer) . The factory plate is a little chinsy on it's thickness , this gasket maker remains plyable , and is recomended when using a gasket between two different metals (different expansion rates). In this case , steel and aluminum . Thin even coat is what I did . It's been a while since I did it , but it is still tight and I would do it exactly the same again if using the stock plate .
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Unread 08-30-2012, 01:43 PM   #11
mackcs212
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Quote:
Originally Posted by newfieZJ View Post
The factory gasket is just a wafer thing pc of metal . Never heard of one bonding to the surface of the intake/plate before , they are usually lubricated

Yes , the gasket should come off . Hope your re-installing a Fel-pro gasket , and , I personally used a anaerobic gasket maker on mine(got mine at the GM dealer) . The factory plate is a little chinsy on it's thickness , this gasket maker remains plyable , and is recomended when using a gasket between two different metals (different expansion rates). In this case , steel and aluminum . Thin even coat is what I did . It's been a while since I did it , but it is still tight and I would do it exactly the same again if using the stock plate .

Yeah I am only using Fel Pro for all the gaskets, heard nothing but good about them... i am still trying to chip off the old gasket, it is rock hard and seems like it was bonded in place with an adhesive... wierd
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Unread 08-30-2012, 06:50 PM   #12
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mine was the same, i spent a lot of time with a scraper and a wire wheel on a drill to get it all off.
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Unread 08-30-2012, 08:09 PM   #13
ejschultz
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I had no issue getting mine off. The worst part was torquing the plenum plate for me. 48 in pounds in order, then 84 in pounds in order, and 84 in pounds again. And that wasn't even that hard. I did, however, decide to do my valve cover gaskets at the same time. They were a different story. Well, the driver side was anyway. I scraped off all the green silicone off the top of the head taking extreme care to not get any in the head. Then, I realized I scraped all the rubber off the gasket and wanted to punch myself in the face. To make matters worse, for the life of me, I couldn't figure out why Chrysler used a gasket on the passenger side and silicone on the other. That is why I'm not a mechanic.

All in all though, since I started this thread, I guess I'll comment on how well the 1/4" aluminum plenum plate has worked. My idle has definitely smoothed out. My gas mileage is yet to be determined. I'm assuming I'm going to be getting about the same mileage I was getting before because a week after I did the swap, I installed some new 31s and ditched the factory 28s. We'll see when I go to calculate the next time. I also managed to swap the thermostat and coolant bypass hose while I was in there. It's definitely a great idea to do that since you have to remove the bracket that holds the compressor and alternator on in order to get to them. I figured I really don't want to have to go back in there anytime soon so I'd change them as preventative maintenance. I used Felpro gaskets for all the gaskets. The only thing I didn't like about them is the intake manifold front and rear pieces were cork. I'm hoping they hold up as I've heard bad things about cork gaskets.
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Unread 08-30-2012, 09:44 PM   #14
mackcs212
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Quote:
Originally Posted by sskilla View Post
mine was the same, i spent a lot of time with a scraper and a wire wheel on a drill to get it all off.
I finaly got fed up with trying to scrape it off so i took the torch to it and a scrapper and it came right off, 5 mins max to romove the whole gasket (in charred form)
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Unread 08-30-2012, 10:44 PM   #15
sskilla
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yeah those cork gaskets are sketchy for me too. i think they did it because of the shape of the area its supposed to seat in? i think a healthy smearing of well placed RTV is called for to keep it from leaking.
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It's got guts. Jeep guts. Jeep, the toughest four letter word on wheels. F@#% Yeah.

R.I.P. 2000 TJ
R.I.P. '95 YJ

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