Exhaust Doughnuts

[Creedmoor]

I'm hearing a fairly loud ticking coming from the left side exhaust system. Sounds like only one cylinder making noise. My little 260 has dual exhaust and the left side manifold to pipe connection is suspect. i took a quick pic of the junction and it doesn't look quite right. Is it normal for it get drawn together unevenly like this? Would it screw up the doughnut that I presume is between the two? I'm wondering if it isn't the manifold to head gasket since the noise is clearly one cylinder. What do you all think?

[cyclone460]

I'm not sure if its normal to have a uneven doughnut but, I've seen it quite often and with no leaks. I agree with you on the exaust manifold to head gasket. If I remember correctly, while the engine is running, using a pair of spark plug boot pliers , pull one plug wire at a time and re connect till you find the one that stops ticking . Overall, I'm sure it's the exaust manifold to head gasket.

[poboyjo65]

I have a mechanic's stethoscope & have used a stick/broom handle, but for me the best thing to track down a noise is a section of garden hose used like a stethoscope. it only gets loud when the noise is right in front of the end of the hose. & if you bump a moving pulley or something, it is rubber & wont deafen you or shock you if you find a bad plug wire like the stethoscope will.
as long as the donut is tight & not leaking,it shouldn't burn out.

[Comechero65]

It's not uncommon for the pipes to be a little out of square to each other but that is what the donut is for to compensate for misalignment and make a good seal. Hopefully the donut is the fiber type not the cast iron version which may not seal as well. Those donuts do go bad but replacements are available. Mustang and falcon venders as well as most good n=muffler shops have them.
Ron

[Creedmoor]

Cyclone,
I'm leaning towards replacing the exhaust manifold gasket (driver's side). It looks pretty tight in there. How difficult an undertaking is this usually?
Thanks in advance for any insight.

[popscomet]

JUST pay attenttion,don't twist a bolt into,if the gasket isn't leaking,I'd leave it alone ,but if leaking ,then you gotta fix it! just be careful and use some spray on rust inhiberter,most times the head of bolt will be rusted to the manifold,so be careful pop

[Creedmoor]

Pop,
It IS leaking. I re-torqued all 8 bolts to spec. It improved a little bit but not enough. The manifold must come off. Is there really enough room in there to do it? Man, I thought it was cramped down there on the cuda!

[popscomet]

Pop,
It IS leaking. I re-torqued all 8 bolts to spec. It improved a little bit but not enough. The manifold must come off. Is there really enough room in there to do it? Man, I thought it was cramped down there on the cuda!

SURE there is E'nuff room..!! this ain;t no MOPAR,,,the design is way better then any MOPAR ever thought about being !!!!this is a FORD product,and it don;t get no better ....and if you;ve already re-torqed the bolts,they ain't stuck or rusted so it's a cake walk,leave the 2 end bolts screwed in the head by a couple of threads,take all center bolts out,slip new gasket in and let hang on end bolts and re-in stall center bolts and tighten even and all is good......AS FOR ME...I always wire brush each bolt and apply anti-siez on the threads before re-applying,and on the bolt shoulder,that way if it ever has to be done again ,those bolts are a cake walk to mess with...pop

[cyclone460]

Cyclone,
I'm leaning towards replacing the exhaust manifold gasket (driver's side). It looks pretty tight in there. How difficult an undertaking is this usually?
Thanks in advance for any insight.

So sorry about the slow reply. I'm thinking that you have a single exaust system. The picture you show of the exaust doughnut shows me the 2 nuts can be sprayed with a penatrant like PB Blaster and loosened without too much problems.Spray the exaust manifold bolts also. Remove the spark plugs. Remove the exaust manifold bolts. The gasket material may be stuck to the head and manifold when you remove the manifold. Because Murpheys law follows me around 24/7 I stuff small pieces of damp rags into the exaust ports and spark plug holes to keep pieces of that material from entering the cylinder or entering the exaust port and getting caught between an open exaust valve and seat. Remove all gasket material from both surfaces. Cover carburator unless you have the air cleaner on, and lightly blow with compressed air to remove material from the area. Remove all damp rags from ports and plug holes and notice how much crap on the rags that could have entered the engine. Install new gasket and install manifold to correct torque specs. I think it's 28 ft. lbs but not sure look it up.. You may be able to reuse the doughnut and return the new one. Any questions just ask away! I hope this helps.