Ok, I have done searches and none of the threads on ticking make sense for my situation.
Background on my CTD. 98.5, 24v, 5spd, 150k miles. Runs great. Banks Stinger kit installed 1 week ago, 150 miles on it.

Then;
I installed a BD exhaust brake on Friday. After I installed and adjusted the brake I took it out for a test run. Ran a few low speed tests (25mph) everything fine. I get out on a back road and get up to 50-55 mph, activate the brake, was fine for about 10 seconds then the motor starts ticking. EGT was at 600 - 700, oil pressure at 65 psi (stock guage), water temp at 180 (stock guage). I was only 1 mile from home so I baby it back. Pulled valve cover, everything looks good, turn motor over by hand and check freeplay, all look OK. I start thinking must have spun a bearing. Getting late so I go in and have a Margerita thinking I just toasted my motor.
Flash foward to this morning, I go out and recheck the valves, engine now cool, all are still in spec. Check oil for obvious metal particles, I had just changed it last week when doing the Banks kit, along with the fuel filter.
Oil looks good no metal to the naked eye. So I start it up, noise is gone let it warm up and noise comes back. I try tracing it with a stethascope, cannot find where it is coming from. I go for a little drive and find it is louder under deceleration, when accelerating it is there, and while at constant speed it gets much quieter. There is also no noticable performance difference from before.

Now for the million dollar question what the bleep is going on!!!

Thanks for reading my novel, any suggestions are greatly appreciated.

Krmn59

 

okay, just a dumb guess, but exhaust brake is not on, correct?

 

Blown exhaust manifold gasket.

 

That's a description of an exhaust leak if I ever heard one... common on modded gassers - known as header ticks. New/better manifold gasket is your best bet; increased back pressure from the exhaust brake should've caused it.

 

OK did some more testing out. Checked the blown gasket, do not see any blow by around ex manifold. took truck for 10 mile test run, goes almost completly away when under boost. Quieter but there at steady throttle, much louder when coasting, goes completely away when I kick in the ex brake??? Sounds maybe might be a ex leak but cannot find any other signs.

Thanks for all the reply's
Krmn59

 

I concur that it is an exhaust leak. Look at it this way; the problem started shortly after you did the last job on the motor. So logically where would you start to look for the problem? If the BD is installed and opperating correctly, then look of things that the BD can cause. The most obvious is a blown exhaust manifold gasket. This blown gasket may not be obvious as it is probably a very small leak. Murphy's law says that the leak will be in the hardest place to reach or see on the manifold. Suggest you bite the bullet, buy a new gasket and install it, irregardless if you can't see or feel any obvious leaks. While you have the manifold off, check it carefully for cracks and warped flanges.
I will suggest something that may be debatable. Whenever I install an exhaust manifold gasket, particularly on an older engine, I always place a light coat of grease on both faying surfaces. Why? Because these surfaces may not be totally smooth and the grease will allow the gasket to "flow" minutely and better to take the shape of each surface and hence provide a better seal. Yes, it will smoke and stink for a couple of miles, but that soon goes away. Note: I said a LIGHT coat of grease, not lathered on.

 

Also, the graphite gaskets seal better than the steel ones, and doubling gaskets oftentimes seals problematic mating surfaces without resurfacing.
Some aftermarket exhaust gaskets are made extra thick for extra crush sealing, and high-temp gasket sealant will also help... anti-seize compound for stainless steel welding comes to mind.

 

OK, After trying to pinpoint noise for past 2 days, the noise is almost gone. When it first happened on Friday I thought I had either dropped a valve or spun a bearing, was very noisy. Last night trying to find exhaust leak it barely made any noise. This morning I took it for a 100 mile trip, I have to listen real hard to hear it over the normal engine noises.

So this week I will get new exhaust gaskets and see if that completely cures the problem.

Thanks again for everyones help.

Krmn59

 

Before you replace the exhaust gasket(s), try increasing the volume on the radio until the problem corrects itself...

 

sounds like it could be an injector knock???

 

Did you check for exhaust leak at the shaft that actuates the exhaust brake butterfly valve?
Since it is not a mechanical noise you would not pick it up with a stethoscope.
Pull the diaphragm off the stethoscope and search with the end of the tube.

 

Thats about right,I don't know why nobody seems to want to understand that its most likely a cheap and easy fix (Exaust man gasket) that would be a good place to start,before tearing the truck apart.

 

check the downpipe, it may be a little loose. Mine did the same thing and it was the downpipe