99 Ram 2500 V10 with a tick tick tick noise.

99 Ram 2500 with 153,000 and a V10 that all of a sudden starting a tick tick tick noise while running/idling. The noise came on instantly. I immediately did a compression test. High number was 160. Low number was 135. I saw a youtube video that someone had the same ticking noise as my truck engine. He removed the valve cover and a rocker arm bolt had sheared off causing the tick noise.

My question is: Without removing the valve covers to look for broken/loose rocker arm bolts, would the compression test readings tell me what I need to know.
Meaning: wouldn't I get a real low reading if the intake valve can't open and no air is able to enter the cylinder on the piston's downward stroke?

This isn't answering your question but the first thing I do when I hear a "tick" is to get out the stethoscope. You can isolate the area where the "tick" is coming from.

It could be an exhaust leak.

One of those video boroscopes with a camera head less than 9 mm in diameter might be able to get in and let you see the valve train. The USB borescopes that attach to cell phones or tablets are very reasonably priced now.

My 2004 Dodge Ram 1500 has had a ticking noise since it was new. The only time I really hear it is when I pull into the drive thru window at the bank. When I'm inside that drive thru tunnel I can hear a tick tick tick. No idea what it is, been that way for 15 years without fixing itself or getting worse.

I tried to use the stethoscope before I posted to pinpoint the noise but it didn't help me. The best I can pinpoint, it sounds like its coming from drivers side. When the noise first started, I was driving it...............and I felt a power loss...............like the loss of a cylinder. I checked all plug wires. They are all snug. Also, I made sure each cylinder was getting fire......and they are.

Possible crack in the exhaust manifold Or warped on the face of the manifold

160 to 135 is too much of a difference between cylinders if you ask me. Yes the compression will be lower if the intake valve can't open at all, might be higher if the exhaust can't open but even if they partially open then compression will be affected. I think you need to pull the rocker covers.

Mine had a similar issue and with a dead miss.

Pulled valve covers and found broken bolt in the rocker arm stand

The same exact thing happened to mine with 48K miles on it.

Pull a valve cover & take a look.

OK. Here's an update. I just removed the valve cover from driver's side. The valve train looks good. No sheared off bolts. Everything is snug. No loose parts. No broken valve springs. But here is what really concerned me. I noticed small traces of anti freeze pooling in the head. What does that mean?

That means really bad things.

Most likely culprit is a crack in a cylinder head.That's the only way i can think of coolant getting under the valve cover other than being blown in through the breather. That, in itself, would also be a very bad thing.

I was afraid when I saw the anti freeze under the valve cover that the motor was toast. I just stopped working on it and figured its time to hunt another v10.

First thing I would do is crack the drain plug in the oil pan and see how much green comes out first. Then I'd pressure test the cooling system before I went into panic mode.

Kevin

This ^

Update: I did a coolant pressure test on the dodge V10. I pumped it up to 15-16 lbs. After about two hours, it had only dropped to 14 lbs. Looking down into the radiator, the coolant looks oily but draining the oil from the crankcase, I didn't notice oil and anti-freeze mixed together. Any thoughts?