New noise in engine, 3.8L
 

I am looking for advice from anyone who might have heard what I'm going to attempt to describe below. I had a post all typed up that was longer, but my wifi router crapped out! Bear with me as I try to relate what I hear to the written word...

Recap: I bought a 2008 Jeep Wrangler with the 3.8 last week. It has just over 35,000 on the odometer. When I bought it, all was good. No weird noises or any other indicators something might be wrong. My wife drove the Jeep for a couple of days, and in preparation for a road trip to TN she is taking, I decided to change the oil. I don't know what the engine had in it, so I decided to use 5W-30 full synthetic and a Wix filter. I checked everything after the change and it seemed fine.

My wife drove the Jeep the next day and put maybe 50 miles on the new oil change. That night, after driving it home, she tells me the engine is making a strange noise. I check it out, and sure enough, there is what I can only describe as a chugging sound. It seemed as though it might be coming from the front of the engine. Since the only thing I did was change the oil, I figured maybe somehow the 5W-30 synthetic wasn't agreeing with the engine, so I did another oil change. This time I used 5W-20 dino oil and a Mopar filter. I did not hear the noise at first, so I thought I found the cause. But, today, after driving it for a while, the noise is back.

I investigated the sound more closely. I discovered in addition to the chugging sound, there is also what sounds to me like drumming on the oil pan. If I apply light pressure to all the four sides of the pan, I am able to make the sound stop when I touch the driver's side of the oil pan. I cannot tell if the chugging sound in the front stops because I'm laying underneath the Jeep. But, the drumming sound most definitely silences when touching the left (drivers side) of the pan. What is weird is that I don't "feel" anything rapping on the side of the oil pan. The sound just stops when I apply a light touch to it.

Both of these sounds cause me some concern. I don't know if they are related, or if they are serious. I am planning to take the Jeep to the dealer to see if I can get a better diagnosis, but I wanted some input from the forum first. Can anyone provide some help to me? I apologize for lack of better descriptive words! I can try to clear it up in the remarks if possible.

One more thing... the drumming from the pan is only heard when I lay under the Jeep. It isn't heard when standing next to the Jeep.


The chugging sound heard from the front seems to be coming from the passengers side. I can't quite locate the sound. Seems loudest near the air intake tube area. This sound/noise may be unrelated?

Thanks for any help y'all might provide.

I checked out your intro thread.. and I like your attitude..

The last time I've heard of any sort of noise coming from the oil pan area.. what the oil sending unit was damaged while driving 1999 Jeep wrangler through ice and snow. As for the other noise.. It's said that the jeep has a knocking sound at first start up during cold weather.. and I agree.. cause this has happened to us as well. As for the changing of your own oil.. it is a personal preference.

However, If you want to keep the lifetime powertrain warranty up.. I would follow the recommended settings or if a real issue occurs.. Jeep/dealership may void the warranty. This includes but is not limited to lifted jeeps or "other" alterations. Granted the Magnuson-Moss Warranty Act does have a bit of good info about these types of addons.

Hang the forum.. and you're going to get a variety of answers based on personal preferences as well as recommended improvements. I attempted to make several improvements based on comments made here and at other forums relating to the type of oil, the frequency of the oil change and the type of oil filter. It took a couple of good wake up calls that helped me realize, not everyone has great advices..In this instance.. We are running Castrol 5W20 with the Bosch ultra/extended life filter..

Lifetime warranty nonexistant on that Jeep.

Correct, I did not buy it new.

You're going to get random noises because the motor is an old school design. The mechanics are just noisey. But don't let those noises fool you. Those motors can last 100's iod thousands of miles.

Use 10-30 or heavier oil, maintain the engine and you'll be fine. There are tons of old dodges on the road with these motors that won't quit.

I sure hope so! I changed over to Castrol GTX 10w-30 yesterday, we'll see what affect that has on some of the engine noise. However my knock is something else. It started after I bought it. I changed out the water pump but that wasn't it.

While doing that job, I noticed the pulley on the power steering pump has some slop in it. It will move back and forth with some pressure and makes a distinct knock with each push and pull. It has to be what I'm hearing.

I'm gonna put a new pump on this week and see if that eliminates the noise. If not, I will learn to live with it.

It wasn't the power steering pump either. Changing to the 10W-30 made no difference, so I will learn to ignore it. I'm thinking it might be the exhaust manifold on the passenger side.

Are there any catastrophic results associated with a cracked manifold? It seems this might be a common problem. According to forums at least!

I don't know but sounds like after 3 oil/filter changes, a water pump, a power steering pump...might be just as well off waiting for something to break and fix it if there is even a problem at all:thinking:
Might be chasing a tail that will always be behind you.

An exhaust manifold leak can cause burned exhaust valves, improper fuel trim as the leak introduces extra oxygen that is picked up by the oxygen sensor, and slow warm-up time which also causes high fuel consumption, which will also cause your catalytic converter to fail prematurely, and the exhaust fumes can easily enter the vehicle cabin through the heating system and cause the passengers to get carbon monoxide poisoning, etc,etc. With that said I have had horrible luck with replacing exhaust manifolds. I would recommend a good quality header. I'm on my 3rd exhaust manifold due to the driver side cracking.