starkizer Posted April 27, 2017 Share Posted April 27, 2017 So I'm not doing anything at the moment but I am planning on removing the valve cover on my 4.0 and pushing down on the rockers to see if I might have a shot lifter. I have the tick sound that plagues our Comanches. Pretty much all the time. Sounds like a diesel engine. You know the drill. So I figured I'd start there. I have read pretty much everywhere online and even in my Haynes manual that it's important to put push rods and rocker arms back in the same spot they came from. I'm the kind of guy that likes to replace everything while I'm in there so I don't have to go back in there. I found a set of push rods and lifters for like $65.00 on eBay. I've never done this, and am wondering if it's important to put the rods back in the same spot, then can I put in new ones? I have read also that I do not have to replace the cam if replacing the lifter, but I would have to replace lifters if replacing cam. I don't want to mess with the cam. Sorry for such a long post. 1989 Pioneer, 4.0L, 4x4, Long bed. Link to comment Share on other sites More sharing options...
sinkrun Posted April 27, 2017 Share Posted April 27, 2017 You are going to have to pull the head to get the lifters out on a 4.0. I would do the cam and lifters both. Check the rods for ware and to see if there bent look on youtube for some good videos. Link to comment Share on other sites More sharing options...
big66440 Posted April 27, 2017 Share Posted April 27, 2017 ^^^ X2, kind of a pain in the @$$ to have to pull the head for lifters but there's no other way. Link to comment Share on other sites More sharing options...
starkizer Posted April 27, 2017 Author Share Posted April 27, 2017 Would it be beneficial to replace the pushrods and rockers while I have it all apart or just replace the lifters. I really don't want to replace the camshaft. Link to comment Share on other sites More sharing options...
Eagle Posted April 27, 2017 Share Posted April 27, 2017 How many miles on the engine? What oil do you run and what's your oil pressure at idle and at 60 MPH? Link to comment Share on other sites More sharing options...
starkizer Posted April 27, 2017 Author Share Posted April 27, 2017 158k approximately. Previous owner broke the speedometer cable so not sure exactly how many miles, but I fixed it and that's what it says now.... I had the internal engine professionally cleaned with run rite about 5 years ago. Have always used full synthetic Valvoline with Max Life. 5qts plus a bottle of Lucas oil stabilizer. 10W30 usually. Not sure if the oil pressure gauge has ever worked. It's usually around 20? At idle. About 40 on the highway. That's always concerned me but others have said that's normal for us. Link to comment Share on other sites More sharing options...
FrankTheDog Posted April 28, 2017 Share Posted April 28, 2017 My old 1998 4.0 says 30 or so at Idle and 60 at speed. It has 448k on it and the internals have never been touched. Ymmv Link to comment Share on other sites More sharing options...
Minuit Posted April 28, 2017 Share Posted April 28, 2017 That's a little low. My '91's original engine is in good shape and makes 60 psi cold idle, 40 psi warm idle, and 60 psi on the highway. Readings were verified by a mechanical gauge and the truck has Mopar senders. The oil pressure jumps immediately from 40 to about 55 psi taking off from a stop once warm. The factory says 13psi at hot idle is the minimum allowable level, and that it should be between 37 and 75 psi above 1600 rpm. Link to comment Share on other sites More sharing options...
Jtrux Posted April 28, 2017 Share Posted April 28, 2017 10psi per thousand RPM is considered good by most. My '06 LJ has the tick from time to time. Certain oils made it worse, some better. I've had the best results with Castrol synthetic 10W30. As far as keeping rockers and push rods in the same place, it is truly not necessary, but if you happen to have a spare roll of masking tape handy, get after it. Personally, I never do, and I've had no issues. As far as lifters go, the only time I really mess with keeping track of them is if the cam has a profile with different exhaust and intake lifts. If they are the same, I would argue that it truly doesn't matter. The lifter is not fixed in the bore, and therefore, the relationship between the cam lobe and lifter surface changes constantly. I know most will make it a point to put them back in the same spot, but if they get out of order, no need to sweat it. Sent from my LGLS992 using Tapatalk Link to comment Share on other sites More sharing options...
Eagle Posted April 28, 2017 Share Posted April 28, 2017 158k approximately. Previous owner broke the speedometer cable so not sure exactly how many miles, but I fixed it and that's what it says now.... I had the internal engine professionally cleaned with run rite about 5 years ago. Have always used full synthetic Valvoline with Max Life. 5qts plus a bottle of Lucas oil stabilizer. 10W30 usually. Not sure if the oil pressure gauge has ever worked. It's usually around 20? At idle. About 40 on the highway. That's always concerned me but others have said that's normal for us. Those pressures are within spec. The spec is 13 psi minimum at warm idle, and 37 to 75 above 1600 RPM. Newer 4.0L engines typically run 55 to 60 psi at highway speed, but as bearings wear you lose some. 40 psi isn't bad. My point in asking those questions was that pulling the head to replace the lifters is a lot of work, and on a higher mileage engine that may need a rebuild soon(-ish) it probably doesn't make sense. For a Jeep 4.0L 158,000 isn't high -- except that yours isn't 158,000, it's that plus however many miles the previous owner piled on when the odometer conveniently wasn't working. Figure 175,000 to 200,000. At that point, some lifter noise is normal and to be expected. I haven't heard your engine, so I don't know how loud it really is compared to other Jeep engines of similar age and miles. If it were mine, I think rather than doing any mechanical changes I would just switch to 10W40 or 5W50 (or 15W50 if you can't find 5W50) synthetic oil and keep driving. Link to comment Share on other sites More sharing options...
mjeff87 Posted April 30, 2017 Share Posted April 30, 2017 The 4.0 I put in my old MJ (got it second hand in several pieces, lol) had about 2 psi at hot idle with 10/30, and on a good day had 25-30 under throttle. I ran 20/50 with a bottle of "restore" which got me about 15@idle and 45-50 driving. As far as I know it's still bombing around.... Link to comment Share on other sites More sharing options...
Minuit Posted April 30, 2017 Share Posted April 30, 2017 My 89's engine has probably been making single digit warm idle pressure for 10 years, and it's somehow still kicking. These are durable engines, don't sweat it :thumbsup: Of course, verify the oil pressure with a mechanical gauge. You may be pleasantly surprised. If the pressures are really that low, I might not pull the head to replace lifters if I was in your position. The readings are in spec, but they are barely within spec. Link to comment Share on other sites More sharing options...
starkizer Posted May 1, 2017 Author Share Posted May 1, 2017 Thank you everyone. Eagle, I'll get a video of my engine running for a sound comparison. Hopefully it won't be to bad. I'll post it as soon as possible. Link to comment Share on other sites More sharing options...
starkizer Posted May 2, 2017 Author Share Posted May 2, 2017 https://youtu.be/iISYM6Tx2Gs Tell me what you think, please. I also have bad exhaust leaks, but I'm sure it's more than that. Link to comment Share on other sites More sharing options...
Eagle Posted May 2, 2017 Share Posted May 2, 2017 Sounds normal to me. Certainly not bad enough to be tearing the engine down. Link to comment Share on other sites More sharing options...
Minuit Posted May 2, 2017 Share Posted May 2, 2017 That sounds like they all do. You've got nothing to worry about. Link to comment Share on other sites More sharing options...
starkizer Posted May 2, 2017 Author Share Posted May 2, 2017 Awesome. I'm planning on replacing the entire exhaust system because it's full of holes, I'm sure it won't sure it, but it'll sound better I'm sure. Thanks all. Link to comment Share on other sites More sharing options...
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