|
I'm trying to think of a test you can do that doesn't carry a risk of doing damage, or the risk of screwing something up while you try and figure this out. You could change your oil, look for shiny stuff, maybe even cut the filter open, and if it comes out nice and clean, which I think it will, then just change that side's header gasket. If the oil comes out with a bunch of shiny stuff in it, then there's a problem that will require professional assistance.%/
|
I think I would run the car with one spark plug wire on the right side disconnected at a time. If it is an exhaust leak the sound should dissipate when the affected cylinder is not firing. Spun rod bearings usually make more noise when RPMs are decreasing.
|
Quote:
|
Yea, I saw this video. It will show which cylinder is making noise, whether it's a bad lifter or a leaking header gasket I suppose.
https://youtu.be/Pu2RHsIGBXU And next, I guess I'll change the oil and cut open my filter. Couldn't hurt aside from wasting fresh oil. lol I got time. I'm still on lockdown! lol |
Sure sounds like an exhaust leak to me...
Haven't seen any talk about the header to side-pipe flanges? Before i went to one use stover nuts, those things used to loosen and FALL OUT...
Not sure which car this is, FF have four holding them together, SPF have eight... Tried there? |
Well, it's cylinder #6. See video. Noise totally goes away when that plug wire is removed.
https://youtu.be/w8tL6kpdXwQ So that means it's either a bad lifter or the exhaust leak is isolated to that cylinder? Does this test, and the fact that the noise goes away as RPM increases, tell me that it's not the rod bearings? |
Are you sure plug #6 is tight (fully torqued)?
|
2 Attachment(s)
Darn it! Where was that suggestion an hour ago before I pulled the header gasket! As soon as I read that I remembered that #6's cylinder's threads didn't feel good when I removed the plugs when I bought the car! Sure enough, it wasn't fully seated now. I pulled the plug and I guess I'll chase the threads now because look at the plug!
On another note, I did have a slight header gasket leak but on #5! Anyone know what brand gasket this is? I may get the same one. |
Well that's a whole lot better than a spun bearing. I can see an "HTX" on the gasket so I'm going to guess it's an Edelbrock EnCore HTX-900. Try a thread repair on the head, replace the plug, and you should be all set.
|
New plug is installed after chasing the threads. 👍🏻
My paperwork for the heads says to use Fel-pro 1415. That's clearly not this gasket as it's metal filled. I'd prefer to use this one or one that holds up without using copper permatex, just to make the next repair easier. I'll try and match it, maybe call the prior owner. But yes, MUCH better than a spun bearing! And it gave me something to do today. Lol |
Oh, and THANKS everyone for the suggestions and for playing Name That Tick!
|
Quote:
|
That was a great mechanical story with a happy ending. When I was in college
a friend had an MGA with a tick that we couldn't find. One day driving along and BANG! A loose spark plug had finally unscrewed itself completely and fired out of the block with enough force to dent the hood...from the inside! |
Great story, diagnosis, and thanks for following through with confirmation on the solution! So many times we hear "it's broken" but never get to hear about what fixed it!!!
|
Quote:
Quote:
Well, I knew I was going to have to chase that spark plug hole in #6 next time I changed plugs, so at least that's fixed. And now I'll have a new header gasket to boot. Anyone else wanna help ID that gasket? I can't find a matching Edelbrock. Like I said, the paperwork calls for Fel-Pro 1415, which is Edelbrock Exhaust Gaskets 7227, but that's clearly not what I removed. |
Hey, I'm thinking this is my current gasket. Would you agree? I do have BBK headers, so this would make sense.
https://www.bbkperformance.com/exhau...-1-5-8-in.html My local speed shop's web site lists it as being made from HTX-9000 https://www.skspeed.com/bbk-performa...er-gasket-set/ (Pic of my old gasket is above.) |
Header gasket installed. Check.
HELL RIDE, I mean, test drive. Annoyed the neighbors. Check. Let it cool down, retorqued header bolts then installed lock washers. Check. Report back to Club Cobra. Check. The engine sounds much better, better than before. I guess that exhaust leak was more prevalent than I realized. Next up... windshield, tires, new mufflers, maybe new seats with head restraints. But those are all on different threads. |
One thing ive learned...
Quote:
...its almost ALWAYS an exhaust leak. Also a tip, het some marker paint and put a dab on yor exaust fasteners, you can 1. See if they are there, and 2. See if theyve turnrd...my biggest fight has always been the header to side pipe flanges. |
I have lock washers on, so that's good. The noise was the spark plug, but there was a small exhaust header gasket leak that compounded things. But I'll be checking those header bolts regularly just to be sure, plus recheck those flange bolts.
|
Adam,
Experience(!) has shown header bolts to be problematic - as in: they vibrate loose and back off, even falling out on occasion. Similarly, lockwashers can be hit and miss. Sometimes they too fall out. I ended up putting these on more than 30K miles ago - no regrets, no loosening: https://www.jegs.com/p/Stage-8/Stage...49275/10002/-1 I had to modify a few of them to clear the header primary tubes by grinding a relief in them. Otherwise not too hard to install. Hope this helps, Tom |
| All times are GMT -7. The time now is 05:15 AM. |
Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2026, Jelsoft Enterprises Ltd.
Search Engine Friendly URLs by vBSEO 3.6.0
The representations expressed are the representations and opinions of the clubcobra.com forum members and do not necessarily reflect the opinions and viewpoints of the site owners, moderators, Shelby American, any other replica manufacturer, Ford Motor Company. This website has been planned and developed by clubcobra.com and its forum members and should not be construed as being endorsed by Ford Motor Company, or Shelby American or any other manufacturer unless expressly noted by that entity. "Cobra" and the Cobra logo are registered trademarks for Ford Motor Co., Inc. clubcobra.com forum members agree not to post any copyrighted material unless the copyrighted material is owned by you. Although we do not and cannot review the messages posted and are not responsible for the content of any of these messages, we reserve the right to delete any message for any reason whatsoever. You remain solely responsible for the content of your messages, and you agree to indemnify and hold us harmless with respect to any claim based upon transmission of your message(s). Thank you for visiting clubcobra.com. For full policy documentation refer to the following link: