I have a 98 with the 4.0 with 215k miles, a couple months ago I heard a ticking sound coming from the back of the motor you could hear on top of the valve cover at cold start. It didn't get louder or speed up when I revved the engine. Once my jeep warmed up and I drove it home, I checked under the hood again an the sound was completely gone. Last night I replaced my valve cover gasket and changed my oil and the sound came back after I started the jeep. Hadn't had this problem since the first time I just described. I let it warm up and drove it home and once I got home the sound was completely gone. Just started my jeep this morning to go to class and there's nothing, sounds fine. Any ideas as to what this could be? Both times this occurred it was 35 degrees out, almost freezing. I'm not too stressed about it since the sound is gone again but I'd like to know what it is or if I have some problems coming up down the road. Thanks guys.

 

What weight and brand of oil are you using? What filter?

 

sounds like a lifter leaked down and running pumps it back up.

 

just throwing this out there but it could be something as simple as the gas you bought, my 88 MJ used to be very temperamental and would do this same thing if the gas was week, I'd have to run 89 octane or higher for the ticking to stop.. if I bought gas from the same station, however I stopped using there gas and it was a none issue..

I had the injectors cleaned with the drip at a shop and it cured it..

if its at the front maybe the water pump..

filter and weight is another contributor...

 

For cold weather ops you may want to consider using 5W-30 oil. With 215K miles, I recommend Valvoline Max Life 5W-30. Also, add 12 ounces of Marvel Mystery Oil to your crank case; it may help to loosen up sticky tappets.

Also, select, and use, a quality oil filter. I recommend a WIX, part number 51515, for your application. The 51515 is a large capcity oil filter - a tad more filtration area than the standard filter recommended for your 4.0.

 

wow didnt realize it could be so many issues. i run the Rotella 5w-30 for winter and i use the Mopar filter MO-090, the Jeep had a low fuel light on last night and i didnt get gas till the morning. I usually buy gas at Wawa because its cheapest and i run 87. how bad is it to replace lifters? might have to try a WIX filter next time around as well.

 

I drove my Jeep around all day today and the ticking hasnt reoccured the oil change really quieted up my motor in general though. at idle it sounds a lot healthier than it did with the previous oil i used.

 

Okay in my book. But MMO does assist in freeing up sticky tappets.

Replacing lifters requires head removal, which I don't think you want to do right now.

 

The "drip" doesnt clean your injectors, it cleans carbon deposits in the intake manifold. Usually its a 3 step method, 1. Vaccuum line additive (drip), 2. oil additive, 3.fuel additive. But either way... It helped!

 

i will have to try using some. and no i have no desire to take the head off lol. i want to run this motor as long as possible while i piece together and build a 4.6 then ultimately do the swap.

thanks for all the input guys

 

It was about 13 yrs ago and that's the only time I've had it done, I'm almost positive they 'sold' me on it as an injector cleaner but I could be wrong as it was so long ago, but yes it did help I could even run the 87 with questionable gas without the ticking..

cost about $40 to have done and there was smoke everywhere pouring out, needless to say the outcome was impressive..

 

Yep. The smoke is the carbon and cleaner burning up. Thats how you know its working. Its just like using seafoam. At my shop the service goes for $64.99 todays rates. I actually do this to every vehicle I buy. Every time with OBVIOUS improvements. A lot of the people that work the counter at these oil change places get a fuel system cleaning service confused with an injector cleaning service when explaining it. Thus passing the confusion on to the customer. When in reality, if they would have told you that it was a FULL fuel system cleaning, you may have been MORE inclined to purchase the service... haha