metrictonner Posted March 24, 2015 Share Posted March 24, 2015 Actually they are\were mylar gaskets, that's right: thin little clear plastic thingies, in those FLAME ARRESTORS. They are designed to dissappear if you ever had a severe flame induced backfire and their absence lets your AMC mechanic diagnose your problem better. They are part of the valve cover package...no separate part number. You want new gaskets? You buy the whole valve cover...somewhere. But since there are no more new valve covers or AMC mechanics anything that will make the arrestor covers tight in their mountings will do. Link to comment Share on other sites More sharing options...
Rockfrog Posted March 24, 2015 Share Posted March 24, 2015 Never had an issue deleting the gaskets, always tightened up fine. The aluminum VC above has no gaskets, pulled them when I cleaned and modified it. Ran it without issue for a year before swapping my '00 XJ VC onto it. My '00 XJ has a 93 VC without them as well. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 24, 2015 Share Posted March 24, 2015 It's so simple. And there's good reason to get the harness WITH rear grommet at Napa or another parts store. Come all together. And, you get the updated grommet with the hose and the updated orifice in it. It was changed from the earlier models to further reduce the chance of oil being sucked into the engine. The tube from the rear of the valve cover to the intake manifold is part number BK 715-1365 or Dorman 46005 and comes with the valve cover grommet. The vacuum harness that attaches to the front of the valve cover and includes the grommet/fitting, and is called the front harness, is Napa part number BK 715-1367 or is a Dorman 46003. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 24, 2015 Share Posted March 24, 2015 The 97 and up has much larger CCV tubing than the early HOs and Renix systems. I swapped everything out with the 97 stuff on my pre-stroker engine and it cured the blow-by I had completely because it breathes better. Would be great for the Renix cover if possible. Would think you would have to change the valve cover though.... How-to HERE Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 24, 2015 Share Posted March 24, 2015 Actually they are\were mylar gaskets, that's right: thin little clear plastic thingies, in those FLAME ARRESTORS. They are designed to dissappear if you ever had a severe flame induced backfire and their absence lets your AMC mechanic diagnose your problem better. They are part of the valve cover package...no separate part number. You want new gaskets? You buy the whole valve cover...somewhere. But since there are no more new valve covers or AMC mechanics anything that will make the arrestor covers tight in their mountings will do. Good info. Link to comment Share on other sites More sharing options...
schardein Posted March 25, 2015 Share Posted March 25, 2015 Interesting thread... I have three 1991 4.0 motors (1991 XJ, 1991 MJ, 1991 XJ motor in a CJ7). All of them have aftermarket exhaust header, 1999+ intake manifold and p/s pump & bracket, matching belt (95"), 1997+ steel valve cover with blue gaskets. Every piece used from the junkyard, to include the valve cover gaskets, with no leaks. I had an 89 XJ Wagoneer back in the day, and replacing the full vacuum harness (both pieces) was some of the best money I spent on that Jeep. And I'm pretty sure you don't need those gaskets. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 25, 2015 Share Posted March 25, 2015 Interesting thread... I have three 1991 4.0 motors (1991 XJ, 1991 MJ, 1991 XJ motor in a CJ7). All of them have aftermarket exhaust header, 1999+ intake manifold and p/s pump & bracket, matching belt (95"), 1997+ steel valve cover with blue gaskets. Every piece used from the junkyard, to include the valve cover gaskets, with no leaks. I had an 89 XJ Wagoneer back in the day, and replacing the full vacuum harness (both pieces) was some of the best money I spent on that Jeep. And I'm pretty sure you don't need those gaskets. I'm positive you don't need those gaskets. My Tip 25 came from JeepTech when I was Service Manager at a Jeep dealership. That Tip never came out as a TSB and I was fortunate to get it, along with many others, and document them for use today. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 25, 2015 Share Posted March 25, 2015 I'm positive you don't need those gaskets. My Tip 25 came from JeepTech when I was Service Manager at a Jeep dealership. That Tip never came out as a TSB and I was fortunate to get it, along with many others, and document them for use today. Losing the gaskets is one thing I can understand since they were just Mylar film, not a good gasket material at all. Mylar phased out cellophane in many applications that required a stronger more resistant material, especially in aircraft. But hacking off 1/2" or so off the baffle towers is something I'd never do w/o proof that it actually was beneficial. But that's just me. Link to comment Share on other sites More sharing options...
schardein Posted March 25, 2015 Share Posted March 25, 2015 Interesting thread... I have three 1991 4.0 motors (1991 XJ, 1991 MJ, 1991 XJ motor in a CJ7). All of them have aftermarket exhaust header, 1999+ intake manifold and p/s pump & bracket, matching belt (95"), 1997+ steel valve cover with blue gaskets. Every piece used from the junkyard, to include the valve cover gaskets, with no leaks. I had an 89 XJ Wagoneer back in the day, and replacing the full vacuum harness (both pieces) was some of the best money I spent on that Jeep. And I'm pretty sure you don't need those gaskets. I'm positive you don't need those gaskets. My Tip 25 came from JeepTech when I was Service Manager at a Jeep dealership. That Tip never came out as a TSB and I was fortunate to get it, along with many others, and document them for use today. My lame attempt at sarcasm. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 25, 2015 Share Posted March 25, 2015 I'm positive you don't need those gaskets. My Tip 25 came from JeepTech when I was Service Manager at a Jeep dealership. That Tip never came out as a TSB and I was fortunate to get it, along with many others, and document them for use today. Losing the gaskets is one thing I can understand since they were just Mylar film, not a good gasket material at all. Mylar phased out cellophane in many applications that required a stronger more resistant material, especially in aircraft. But hacking off 1/2" or so off the baffle towers is something I'd never do w/o proof that it actually was beneficial. But that's just me. Worked great back then and works great now. I can attest to it. Others who have done the mod can also. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 25, 2015 Share Posted March 25, 2015 Let's hear from the others then. No documentation from JeepTech? Link to comment Share on other sites More sharing options...
cruiser54 Posted March 25, 2015 Share Posted March 25, 2015 Absolutely not. This is one of those deals where they provided me with info to fix vehicles and it never came out as a TSB. Many of my Tips are from just such situations. They were field engineers. They found fixes and went to those up above and had them make production changes and the like. I have no idea what criteria they used to determine if the fix warranted a TSB or not. I was just happy to have the fixes and as a result we were the first Chrysler Five star dealer in the state of Arizona. It's only the right thing to do now by sharing. Don, I will email you a photo of "the book". It's a spiral bound notebook of all the Tips we got from JeepTech during the day. I still have it. Link to comment Share on other sites More sharing options...
HOrnbrod Posted March 25, 2015 Share Posted March 25, 2015 Got it. That's very cool. I can relate; I was a field guy for many years in DoD and had to make the comms work in conditions never imagined by the equipment design engineers who never left their desks for real world testing and were bound by theory, marketing, compromises, and "best case" model results. Sent a lot of stuff back that looks similar to like your spiral bound notebook. :yes: Good stuff. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 25, 2015 Share Posted March 25, 2015 Someday, I'll share a neat story of how we worked with them. A dying issue that was caused by RF interference to the ECU from a bad spark plug/wire. We had 28 hours in the "out of warranty" 87 or 88 XJ, doing things like wrapping the ECU in aluminum foil and the like. Keep good plugs and wires in those 87 and 88s boys!!! Link to comment Share on other sites More sharing options...
shelbyluvv Posted March 25, 2015 Share Posted March 25, 2015 I had the same issue with RFI from bad leads. The car was an 87 Shelby Charger and would run great on hot, dry days. If it got cooler and the humidity got above 70% it would run like total crap. It took me months to figure that out. I tried to keep my date coded wires for originality but ended up going with Magnacore 10MM to cure a couple different ignition related issues after I went to 18 psi of boost. It's amazing what weird problems you can encounter with a computer controlled engine! Link to comment Share on other sites More sharing options...
drase Posted March 27, 2015 Author Share Posted March 27, 2015 For Renix .. As for rubber/steel Valve cover retainer grommets, they are only used on the steel valve cover used from 97 to 06 on the 4.0l Steel 97-06 Aluminum (this one is 87-90, 91-95 mounts the same but uses 1/4 turn CCV grommets with a flat round rubber gasket) And the rubber/steel VC retainer grommets go on the 15 bolts that screw the VC to the engine block? Link to comment Share on other sites More sharing options...
Rockfrog Posted March 27, 2015 Share Posted March 27, 2015 ONLY for the 97-06 valve covers ... The earlier ones DO NOT use them. Link to comment Share on other sites More sharing options...
cruiser54 Posted March 27, 2015 Share Posted March 27, 2015 ONLY for the 97-06 valve covers ... The earlier ones DO NOT use them. Correct. Link to comment Share on other sites More sharing options...
Rockfrog Posted March 27, 2015 Share Posted March 27, 2015 Not that that hasn't been mentioned before ... Multiple times Link to comment Share on other sites More sharing options...
cruiser54 Posted March 28, 2015 Share Posted March 28, 2015 Not that that hasn't been mentioned before ... Multiple times Okay. Now that we have covered this ad nauseum, let's recap. There are no gaskets available from the factory for the triangular flutes to the valve cover. There is no need for sealer on them either. This would be an excellent opportunity to address a known problem by performing my Tip 25 on those flutes. As for the rearmost grommet on the valve cover, purchase a Dorman 46005 or Napa BK 715-1365. As for the front grommet on the valve cover, purchase Dorman 46003 or Napa 715-1367. Reinstall the valve cover using a Felpro gasket VS 50522T which does not include or have the need for fricking grommets and spacers!!!!!!!!! My spoon feeding is done here. Mods, please close this thread!! Link to comment Share on other sites More sharing options...
Rockfrog Posted March 28, 2015 Share Posted March 28, 2015 Wait, so which gasket do I need for the .... Link to comment Share on other sites More sharing options...
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