So my engine makes ticking noises but im not sure its normal for the 3.8, its a constant ticking not sporadic. Secondly, under load an going uphill i hear a rattle from the engine from 2k-3k rpms. I checked heatshields etc and dealer told me some BS that the rattle was normal. I use 87octane and have 19k miles. Are thes noises normal?

 

I had this. I had some dirty spark plugs with gap way out of spec. Installed new plugs with proper gap and 5-30 oil and my jeep purred

 

Do you think my spark plugs could be bad at 19k and ive never touched them? Im going to request 5-30 oil next oil change

 

I will bet that it is your heat shields on the exhaust right by the cross member. I used the metal zip ties but you can also use a hose clamp. Easy fix and cheap.

http://i180.photobucket.com/albums/x.../Photo0104.jpg

If you have a lift, bigger tires with numerically lower gears - it could also be your engine lugging because you are not at the right RPM range.

 

It wasnt so much that they looked burnt, rather the gap tolerances were way out to lunch. .50 is stock. Mine were anywhere from .57 to .68

That was my problem. Changed the plugs and it went away. They say you should do your plugs at around 100k or something. I call BS. I was at 55000km and they were shot! Our 3.8 are under geared and underpowered so they run hot, thus i believe causing my plugs to expand.

 

I ran mine 93K miles. Changed only because I was installing dual-battery tray, so it was convenient. No difference in vehicle performance/MPG before and after.

Plug gap is a starting place for optimal performance. Plugs are fine as gap widens. They are designed that way. Are you sure 50 thousandths gap is correct? Would double-check that.

 

The rattle sounds like its coming from the engine though, i looked at the heatsheilds and they werent loose. Would they still make that noise if they were secure?

 

Any other suggestions??

 

noises can be hard to trace but if its constant and well synchronized it's more than likely engine related. Get yourself a mechanics stethoscopic and listen around, it should be easy to trace. Also, the heat shield as mentioned above would (or atleast in my case) tick and rattle on acceleration and at the rare occasion while idling, it was a tack weld that cracked

 

@jksfu Can you define the tick any better? Have you ever heard lifter ticks? Sometimes the oil is cold or the clearances in an older jeep engine become worn and don't lubricate properly. Not sure if your engine has that problem but in my older inline motors, I run a heavier oil in the summer and a slighlty lighter oil in the winter to combate the noise. I would hate to think your newer engine has lubrication problems.