jimd4x4

I do not own a Jeep yet. I am looking to purchase one for my son. I have been looking at different posts to learn. I have found a 2001 Grand Cherokee Laredo 4.7 engine 96000 miles. This engine has a ticking noise. I am unable to tell if it is from the bottom or top. I have not used my stethascope on it. I have only test drove once. So my questions are. Are there a lot of issues with these engines? What kind of mileage is typical? The dealer has been driving it. And stated that it will come and go. Whatever that means. Any advice or suggestions you may have will be appreciated.

RRAM

well I only have 50k miles on my gc. I had a durango with 250,000 km on it and it ran as good as the it was new. It is still driving around town. Now I have not heard any ticking from any of the 4.7s i have had. Tickin to me first off sounds like a lifter, or it could be injector tickin. Not fun to purchase something that sounds broke before you get it. Although what price you pick it up for may dictate how worried you are about a repair. Its possible that previous owners didn't change oil as often as one would like and the lifter got gummed up. A couple of quick oil changes with good oil may clean it up. Even a good highway drive may help.

As far as know issues, I don't know of any, and do not know of anyone who has had trouble with the engine it self.

jimd4x4

I do not think it is fuel injector. It is way more solid than that. It is hard to hear moving. But at stand still it is real prominate. Is the 4.7 a roller rocker engine or a hydraulic lifter engine?

9XJSPORT7

Sounds more like lifters, buddy of mine has a ram with 200,000 on his 4.7 but has had all the lifters replaced on it. I have herd that was a common problem on the 4.7 but not sure the truth to that.

jimd4x4

Buddy of mine that helped build the Cruiser. Mentioned an exhaust leak. Any issues with exhaust on the 4.7.

seed

there is also a jeep TSB that notes one cause of an engine tick to be the duty cycle purge solenoid,check that too

jimd4x4

OK I will bite! What is a duty cycle purge solenoid. I intend to bring it to my garage and scope it out. Any pics of what it looks like. Is this a recall by Chrysler?

seed

technical service bulletin,doesn't cause any damage if it's ticking..it's part of the EVAP system and should be bolted to the DS inner fender behind the air box

jimd4x4

I will check it out. Any other advice would be appreciated.

tsconver

By the way, the 4.7 is an overhead camengine and does not have lifters. Is has hydraulic lash adjuster or followers that keep the rocker tight to the valve but they are not between the cam and teh rocker like in a pushrod engine. The cam lobe acts directly on the rocker which acts directly on the valve stem, the lash adjuster in on the other sid of the rocker and keeps it all tight and noise free.

There have been a few reports of the rockers becoming out of place and ticking or the follwer failing and causing a tick. But the biggest noise maker seems to be the purge valve, it is a little selenoid onthe drivers fender with vacuum hoses and electrical connects, one of the hoses has a screw off test point that should have a green cap on it.

jimd4x4

So I have not made it back to the Grand Cherokee. Everybody seems to be pointing in the same direction. What is the fix to the duty cycle purge solenoid? I believe that there is a schrader valve under the cap. With a label if IRCC says 1psi. Does the evap system build pressure and that causes the ticking? Also thanks for all the help.

tsconver

If it is the purge solenoid ticking then no there is no fix it is normal, some are just louder than others.

seed

the only "fix" jeep had was a rubber isolator and bracket to stop the tick from being magnified through the body

jimd4x4

Gentlemen THANKS!! for the responses and feedback. I belong to a Landcruiser forum and you guys are as fanatical as them. I have been spending a lot of time on this forum learning. I have owned 4WD's for 20 years and never owned a Jeep. Have had my 74 FJ40 for 10 years.
So like the Jeep goon's I am used to beating my head on the wall. Way different technology though.
Maybe my son will have a Jeep in the stable soon.

Thanks Again
Jim

gumbi47

I have a 2001 Grand Cherokee and found the ticking problem. Mine spun a rod bearing and it is the one farthest from the oil pump go figure. Every engine that I have been able to find in the salvage yards have the same noise. I think that Jeep doesn't want to admit there was a problem with that year model. My Jeep has only 130,000 miles and the Jeeps that I found had around the same.