[tracer]

Originally Posted by pdm

Has anyone thats worked on the noise problem actually heard it first hand?

I took one mechanic for a ride but it was bobtail truck only. The noise was there but light and the mechanic confirmed he was able to hear it... But he said, "A lot of guys with CAT engines come to us to complain about this and we're telling them it's normal." He practically laughed at me. I did top set anyway just to be sure it's not the valves but it didn't help. I'm not a mechanic but I'm the guy who gets to drive this "normal" truck 10 hours a day and I'm positive the engine shouldn't make this clanking/tapping noise. Drove a FTL Columbia and Volvo before for 2 years. This si my first CAT (since April 2007).

Sorry Tracer been busy What I am talking about in finding were the leak is by feeling the exhaust manifold is simple were the exhaust manifold bolts to the block right there. Right there by the block and exhaust Manifolds Kitty CATS are known to leak especially the ACERTS from talking to a head mechanic buddy of mine that is at a test fleet for them they avarage 3 a week that leak out of a fleet of 200. Normally the one that leaks is behind the turbos and is hard to find and that is why a POOR mechanic is apt to say this is NORMAL for a Cat. Another way he says to find it is take a CO meter and use that there will be CO gas in the area of the leak. Cat is working on a fix for this right now he says that might involve spring loaded bolts he says they are testing that right now and he says it is working for them.

[tracer]

Originally Posted by ironeagle2006

What I am talking about in finding were the leak is by feeling the exhaust manifold is simple were the exhaust manifold bolts to the block right there. Right there by the block and exhaust Manifolds Kitty CATS are known to leak especially the ACERTS

Aha, so I was doing the right thing this morning. I figured that's what you meant so I started the truck and poked around the manifold when it was still cold. The problem is I couldn't determine which connector was colder. The one behind the turbo seemed a bit out of synch with the others but then the next minute they all felt the same ...

Originally Posted by ironeagle2006

Normally the one that leaks is behind the turbos and is hard to find and that is why a POOR mechanic is apt to say this is NORMAL for a Cat. Another way he says to find it is take a CO meter and use that there will be CO gas in the area of the leak.

Great tip, thanks. I'll try to find a CO meter. That way I'll know for sure which one leaks. Where do they sell these? In a car parts store?

Right there IS YOUR leak Reacer the manifold should get warm at the same rate since all the gasses are the same temp coming out anyone that is not either has a miss or is leaking. Reason the Mechanics are missing it is they are NOT TAUGHT the basics anymore in the so called tech schools anymore. So called Mechanics around here if the problem can not find it are lost I have a friend with a 78 Thunderbird they have NO CLUE how to work on it at all since there is not one computer on the thing.

[tracer]

Originally Posted by ironeagle2006

Reason the Mechanics are missing it is they are NOT TAUGHT the basics anymore in the so called tech schools.

It seems they only teach them how to REPLACE parts as a whole. Wipers don't work properly? "You need a new windshield wiper motor!" The cab heater has problems? "You need the new A/C-heater module."

So True they are not thought DIAGNOSTICS anymore the computer is always right and they forget the basics. I can diagnois most things faster than most mechanics. 90% of the time with newer cars when the Check Engine light is on guess what the issue is a loose gas cap. Yet without a computer these nw Machanics aka Part cahngers can not tell you. Sorry I was trained the old school way and do not need computers to tell me wwhat is wrong called check the basics got fuel Yes got Compression OK check Timing thats off there is the issue check for a sheared cam timing gear. These new guys would be lost. Overheating first check for LEAKS then look for blockages then look for flow. The forget the mechanical crap is the SAME and has been for OVER ONE HUNDRED FREAKING YEARS.

The only things that has changed is a computer now runs the fuel mangement system not you directly.

[pdm]

I had a thought on your noise if its an exhaust leak....on the car side they use a smoke machine to find leaks in the evaporative emissions systems on cars & also for vacuum leaks. I'm wondering why it couldn't be used on something like this, it would feed smoke into your exhaust system through the pyrometer connection & if there is a leak the smoke would show up.

As far as new wiper motors, heater controls etc? Try buying any sevice parts from the parts dept...............good luck!! & most of these parts are assembled in such a way the're damaged opening them up.......much like computer printers etc.

[tracer]

Originally Posted by pdm

I had a thought on your noise if its an exhaust leak....on the car side they use a smoke machine to find leaks in the evaporative emissions systems on cars & also for vacuum leaks.

I'm not sure how I'd go about putting smoke in the cylinder. I prefer the tip about using a CO meter. Just checked online - these babies cost 200 bucks - but with a meter it's pretty much a bull's eye...

[Kranky]

If you've got a leak at one of the exhaust manifold gaskets that's bad enough to cause a ticking or popping noise, you'll also have black soot stains around it.

[tracer]

I used the yellow paint from a can CAT gave me last time for free, and sprayed the exhaust manifold in the spots where it's bolted to the cylinder block. The engine was cold... I gave the paint half an hour to get dry and started driving. THE TICKING NOISE DISAPPEARED! I didn't paint the gasket area on the cylinder block - only the areas around bolts on the manifold so that's where the leak is. It must be a pretty small hole as regular paint was able to stop it...

I'm still not sure which part/connector on the manifold is the culprit but the leak is basically confirmed

As I was driving enjoying the quiet operation of my Cat, it occurred to me that the noise should reappear when the paint is melted or heated. It's regular paint - so it cannot withstand 5,000 degrees of the exhaust gases. My guess was correct - in about 55 miles, after roughly an hour of pleasant quiet driving, the noise reappeared. Well, at least now I know what I have to fix.