Norm13
Junior Member
As a professional mechanic for over 35 years, I feel that the Hemi tick usually develops from poor/ worn out/ cheap and/or poorly filtered oil. Changing oil based solely on mileage is a very bad idea. Use hours and operating conditions instead. Short trips, cold temperatures, idling time, all are hard on oil.
I refuse to use Wix/Napa filters. When the fleet I work for had them on contract we kept having a problem with the screen in our oil drain plugging up. It was plugging from fibers from the filters! Switched to Baldwin and the problem went away, still using the same oil. Nuff said..
I have never seen a cam or lifter go bad in any older Hemi. The oldest I have seen was in a 2011 3/4 ton that didn't have MDS. It had 117,000 miles with a few oil change intervals over 15000 miles and lots of idling time. I couldn't put a finger on what the first failed part was, but my best guess is some kind of catastrophic failure of the lifter like the roller bearings in the lifter roller coming apart or seizing or disintegrating. The whole inside of the motor was sparkly from the metal in the oil. I put in a new cam, lifters, and timing set, changed oil 4 times in 500 miles, and it was just fine, ran another 50,000 miles, and then we sold it, still sounded normal, didn't use oil.
I personally have a 2005 Hemi in a 3/4 ton pickup with only 130,000 miles, and a 2007 Jeep Grand Cherokee with 178,000 miles. The Jeep will sound fine when started, let it idle for about 10 minutes, and it will start to have a tick. Bring the RPMs up to around 1500 for a few seconds and let it return to idle and the tick is gone for about 20 seconds then gradually comes back. When warmed up it's completely quiet. The pickup sounds like a diesel when it's cold. I mean, lots of rattling, not just 1 or 2 ticks, but the literal continuous rattle sound like a diesel. No exhaust leaks. When it warms up it almost completely goes away. Has been like that since I bought it, about 45,000 miles or so, hasn't changed. putting in a 0w-20 or 0-30 oil makes it QUIETER. I'm assuming that the pistons aren't getting enough oil with the heavier oils. Wanna make it really loud? put in 10w-40.. Havoline PRO DS 5w-20 makes it quieter than any other 5w-20 oil, don't know why. The pickup motor has over 8000 hours on it {seriously}, it was owned by an electrical contractor originally so lots of idling time. Am I worried about either one? Nope. From what I've seen, it just is a design that likes to make noise. The ones I've seen come apart don't generally have any abnormal sounds to them until just before they let go..
Also, a lot of them develop exhaust leaks that can sound kinda similar to the Hemi tick and go away when it warms up a little. Look for broken exhaust manifold bolts, the right rear one breaks a LOT. When the motor is cold, stick your finger between the manifold and heat shield and see if you can pull it away from the manifold. If you can, the bolt is broken. I have seen some break on the left manifold, but not common.
Excessive idling might be a contributing factor in some cases of cam problems but I can't prove it. Production tolerance stackup can also be. I have also heard of some of the cams being soft but I haven't seen anything that suggests that to me personally. I believe in some cases it's an oiling problem but only in some engines where the production tolerance stackup goes in the wrong direction, if you know what I mean.. There are NO 2 motors that are exactly the same. I don't think any exist that match the design blueprints exactly either. Change oil regularly using quality products and drive it! Don't overthink it!
I refuse to use Wix/Napa filters. When the fleet I work for had them on contract we kept having a problem with the screen in our oil drain plugging up. It was plugging from fibers from the filters! Switched to Baldwin and the problem went away, still using the same oil. Nuff said..
I have never seen a cam or lifter go bad in any older Hemi. The oldest I have seen was in a 2011 3/4 ton that didn't have MDS. It had 117,000 miles with a few oil change intervals over 15000 miles and lots of idling time. I couldn't put a finger on what the first failed part was, but my best guess is some kind of catastrophic failure of the lifter like the roller bearings in the lifter roller coming apart or seizing or disintegrating. The whole inside of the motor was sparkly from the metal in the oil. I put in a new cam, lifters, and timing set, changed oil 4 times in 500 miles, and it was just fine, ran another 50,000 miles, and then we sold it, still sounded normal, didn't use oil.
I personally have a 2005 Hemi in a 3/4 ton pickup with only 130,000 miles, and a 2007 Jeep Grand Cherokee with 178,000 miles. The Jeep will sound fine when started, let it idle for about 10 minutes, and it will start to have a tick. Bring the RPMs up to around 1500 for a few seconds and let it return to idle and the tick is gone for about 20 seconds then gradually comes back. When warmed up it's completely quiet. The pickup sounds like a diesel when it's cold. I mean, lots of rattling, not just 1 or 2 ticks, but the literal continuous rattle sound like a diesel. No exhaust leaks. When it warms up it almost completely goes away. Has been like that since I bought it, about 45,000 miles or so, hasn't changed. putting in a 0w-20 or 0-30 oil makes it QUIETER. I'm assuming that the pistons aren't getting enough oil with the heavier oils. Wanna make it really loud? put in 10w-40.. Havoline PRO DS 5w-20 makes it quieter than any other 5w-20 oil, don't know why. The pickup motor has over 8000 hours on it {seriously}, it was owned by an electrical contractor originally so lots of idling time. Am I worried about either one? Nope. From what I've seen, it just is a design that likes to make noise. The ones I've seen come apart don't generally have any abnormal sounds to them until just before they let go..
Also, a lot of them develop exhaust leaks that can sound kinda similar to the Hemi tick and go away when it warms up a little. Look for broken exhaust manifold bolts, the right rear one breaks a LOT. When the motor is cold, stick your finger between the manifold and heat shield and see if you can pull it away from the manifold. If you can, the bolt is broken. I have seen some break on the left manifold, but not common.
Excessive idling might be a contributing factor in some cases of cam problems but I can't prove it. Production tolerance stackup can also be. I have also heard of some of the cams being soft but I haven't seen anything that suggests that to me personally. I believe in some cases it's an oiling problem but only in some engines where the production tolerance stackup goes in the wrong direction, if you know what I mean.. There are NO 2 motors that are exactly the same. I don't think any exist that match the design blueprints exactly either. Change oil regularly using quality products and drive it! Don't overthink it!
