3.8 rattle sound January 31, 2009, 05:09:40 PM tried to make a vid to sample the noise, but it's all noisy :)i thought my smog pump was making noise, so i took off the belt and ran it without one..... i noticed a rattling(?) noise on the way back to idle when i slapped the accelerator and sometimes when i held it at about 1500rpm.... it sounds like it's coming from the front near the distributor base...... i'm guessing this has a timing chain and i'd hate for it to be worn (car has true 85,000 miles)... could it be something in the distributor? Quote Selected
3.8 rattle sound Reply #2 – January 31, 2009, 06:11:33 PM What's your oil pressure? You might want to get a stethoscope and see if you can isolate the noise. Quote Selected
3.8 rattle sound Reply #3 – January 31, 2009, 09:10:24 PM it doesn't sound like rocker arms or valves (unless it's from the front cylinders, it does sound like the timing chain, but i'm hoping not.... i do need to stethascope it to pinpoint better, but i could swear it's around the distributor.... here's a video with the sound... you may not be able to hear it clearly due to the other noises and poor quality, but listen to the rattling when the rpm dropshttp://vids.myspace.com/index.cfm?fuseaction=vids.individual&videoid=51494238you can hear it really well 2 or 3 times, and it sounds a lot more high pitched in the recording Quote Selected
3.8 rattle sound Reply #4 – January 31, 2009, 09:54:39 PM Is it possible ,it could be the alternator? Quote Selected
3.8 rattle sound Reply #5 – January 31, 2009, 10:21:10 PM step by step to check timing chain slack in my diy...........rotate crank in its normal running rotation and stop when the pointer is on zero deg per the harmonic lined up with the pointer.remove dizzy capbarely rotate crank the opposite direction while watching rotor button.just at the moment you see the rotor move, stopjot down the degrees you see on the flywheel.your done. Quote Selected
3.8 rattle sound Reply #6 – January 31, 2009, 10:23:48 PM A wooden dowel up to your ear on one end and the other touching various spots on the engine work as a stethiscope. You dont need to buy anything.A long screwdriver / pry bar or the like also works well to pinpoint noise. best advice ive seen so far here is to check your oil pres manually. Get the guage kit real cheap at your local parts place and install it up in where your oil sending unit resides now. You really dont need to buy the oil pres tester when the aftermarket guage kit becomes a tool anyway for super cheap. 85k doesnt discount bearings. if you have let the oil go too long or the rings let the gas get into the oil, it thins out the oil. Quote Selected
3.8 rattle sound Reply #7 – February 01, 2009, 01:28:27 AM Quote from: Chooglin;254707Is it possible ,it could be the alternator?the serp belt was off so only the crank pulley was turningi just got the car so there is no telling what oil changes were done, and i'll check the timing like you said in the morning..... that seems easy enough :) Quote Selected
3.8 rattle sound Reply #8 – February 01, 2009, 01:36:14 AM worse case, just make sure to run thicker oil if presure is low. That will buy tons of time as long as you dont hot dog it. If it is the oil presure, the name of the game is to keep the slop shimmed up with oil as long as possible. Quote Selected
3.8 rattle sound Reply #9 – February 01, 2009, 05:00:34 AM Well, my 3.8l motor decided to eat a lifter, but it sounded like a low end knock at times and a "tick tick tick" at others, and that sounds like a very odd rattle. I also know that the exhaust manifold heat shield on mine rattled, but that doesn't quite sound like it. And you said the Serpentine belt was off, so it isn't the water pump. Quote Selected
3.8 rattle sound Reply #10 – February 05, 2009, 09:26:33 PM sorry it took so long to check..... i'm sure it's my timing chain, it has 12-14 degrees before the distributor turns... that's bad, right :)also i noticed a coolant leak..... i attached a pic because it looks like it's coming from the part that jets out with the water pump where it meets the block.... the head area is dirty, but didn't feel "wet"... is there a specific place these head gaskets go bad, or is the leak i'm seeing from the water pump extension thingy (is there coolant in that big hump?) Quote Selected
3.8 rattle sound Reply #11 – February 05, 2009, 09:32:45 PM Timing cover leak. Wooo!Both of my 3.8s leak oil/coolant from them. Quote Selected
3.8 rattle sound Reply #12 – February 05, 2009, 09:33:48 PM is that what that is..... i'm only leaking oil from the front crank seal :) Quote Selected
Topic: 3.8 rattle sound (Read 1978 times)
previous topic - next topic
