I have a 99 ram v8 magnum 5.2. I just bought it, with 130,000 on it. I'm a Ford guy and don't know much about dodges. I do hear a vacuum leak of some sort no biggy. I'll find that. My concern is the loud rattle on heavy acceleration. It's not burning oil at all. It did go through about 1/2 a gal of coolant in about 2 weeks but it doesn't smoke at all except obviously when first started. I put 93 octane in it to see if rattle went away. No help. Don't think it's the plenum, checked in throttle body very very little oil. All I could think is I have a bad lifter. Anyone have a clue cuz I'm at my wits end.

 

Coolant loss = head gasket issue or a leak.

Is it running hot or blowing coolant out of the overflow?

 

I filled up the overflow to the full line about 2 weeks ago. It's empty now but doesnt run hot at all. Another thing I noticed is when I put my heat on the a/c clutch is engaging. I assume if it's the head gasket I'd get at least a little smoke. I'm not getting any. I have to check the thermostat. Someone told me it could leak from there and dry on the block so it looks like it's not leaking.

 

There are a few places it could be leaking from that are difficult to detect. It's happened to people here and they've posted pics. My own truck had head gasket issues where it was leaking, but rather than sucking in coolant and pushing it out of the exhaust (aka white smoke), mine was pushing exhaust gasses into the cooling port and pressurizing the cooling system, causing coolant to spew out of the overflow.

 

See my truck the coolant is disappearing from the overflow and I don't understand how. The tube to the radiator is like 2in it doesn't even go down in the overflow. How is it emptying

 

Your overflow bottle could be cracked, hence the leakage.

 

I had a similar issue with coolant disappearing from the radiator and the overflow tank. I also had a consistent leak onto the passenger floorboard.

So I got super lazy and got a bottle of Bar's Liquid Copper radiator stop leak and I **** you not the radiator stays full and the overflow stays full.

Now, I know sooner or later the "fix-it in a bottle" will fail and it will start leaking again, but I've bought a little bit of time.

 

Sounds like pinging to me. Did you remove the TB to look for oil in the intake, or just look down the butterflies? (fail). As far as the coolant loss goes, that could be many things. Heater core, by pass hose, timing chain cover leak, thermostat housing, head gasket, water pump, just to name a few. The coolant can burn off before you see a leak. You might want to rent a coolant pressure tester or have a shop perform the test for you.

 

I've got to fix the plenum on my truck and at times the valve's will rattle like crazy, and it has NO power when they rattle. You could take off your valve cover's and took a look around, see if anything is loose or broke.

But in my experience I'd say it's a plenum related issue, at least the valve rattle upon heavy acceleration.

 

For the rattle on heavy acceleration, I would check or go ahead and replace the plugs, plug wires, and distributor cap before I did the plenum. I like to try the cheap and easy first. Kinda like you do with the ladies before you get married, ya know? On the coolant loss, could be the reservoir is cracked like VW said, or could be any number of other things, as Zman stated. The coolant loss may or may not be related to the rattling. I had a radiator that would leak on the passenger side where the plastic ends join the alum radiator, took me a bit to find it. Had to wait until it leaked bad enough to drip instead of just evaporate. I smelled antifreeze for probably 2 months but never saw any under the truck until the leak got worse.