4.0l Ohv complete rebuild, still makes same knocking noise

[gaz]

@Nick Ranger - Private Eye ,
Hello,
LIFTER PRELOAD:
Engines that use hydraulic lifters use a "lifter preload" adjustment to keep the valve train working at optimum.

It is not accomplished the same way as the valve lash adjustment, as with solid lifter (which produces a gap); it is an amount of adjustment PAST the push rod contact with the rocker, which forces the push rod into the lifter a specific amount (range, usually somewhere between 0.020" to 0.080", depending on the engine) of the lifter's plunger travel.

Great to hear that you did a good job cleaning up those rocker arms . It may be worth the small amount of time/effort/expense that it takes to determine what actual length of push rods your specific 4.0l now requires.

 

[4.0blue98]

I found a TSB 13270 (NHTSA#6090699) and there were others for different years. Think they were all for the 4.0ohv. Just describe a noise but no solution. Found a few threads where people speculate but don't see a solution. Short piston skirts, wrist pins, push rod and rocker wear, and lifters are all mentioned like some here have mentioned too. Couldn't find the cylinder geometry one I mentioned but probably related to the short skirts. Usually short skirts are a good thing...

 

[Nick Ranger - Private Eye]

That does sound like valve train noise to me. Possible that one of the rockers is worn just a bit where the shaft slides through it?

I had a Malibu that would make piston slap noises, the 3.1s were pretty well known for that and it sounds nothing like your noise, much more low pitched and it went away as the engine warmed up. The V10 in my F250 does it too. It's a dull thud noise.

All the rockers are new and had good fitment on the rocker shaft when installed. When I removed the rocker arm shaft to inspect the pushrods, the rocker arms still all had good fitment then too. No measurements were taken but my feelers didn’t notice anything. Everything was installed with assembly lube as well.

 

[Nick Ranger - Private Eye]

@Nick Ranger - Private Eye ,
Hello,
LIFTER PRELOAD:
Engines that use hydraulic lifters use a "lifter preload" adjustment to keep the valve train working at optimum.

It is not accomplished the same way as the valve lash adjustment, as with solid lifter (which produces a gap); it is an amount of adjustment PAST the push rod contact with the rocker, which forces the push rod into the lifter a specific amount (range, usually somewhere between 0.020" to 0.080", depending on the engine) of the lifter's plunger travel.

Great to hear that you did a good job cleaning up those rocker arms . It may be worth the small amount of time/effort/expense that it takes to determine what actual length of push rods your specific 4.0l now requires.

Thanks I’ll take a look into that. I will likely have to take the heads back off and remove the lifters, measure each lifters plunger travel, and see about possibly leakdown testing them as well. Maybe someone has a video about these procedures on YouTube. They just don’t make these parts like they used to.

 

[Nick Ranger - Private Eye]

I found a TSB 13270 (NHTSA#6090699) and there were others for different years. Think they were all for the 4.0ohv. Just describe a noise but no solution. Found a few threads where people speculate but don't see a solution. Short piston skirts, wrist pins, push rod and rocker wear, and lifters are all mentioned like some here have mentioned too. Couldn't find the cylinder geometry one I mentioned but probably related to the short skirts. Usually short skirts are a good thing...

It’s crazy that the noise only shows up after 340k, I’ve never experienced any other noise from the 180k miles I put on it except for the occasional cold start lifter clatter, which I always remedied with some rislone engine oil treatment. When I got the pistons with the connecting rods back from the machinist, who did not disassemble them but said they all had no wrist pin play, I also put them each in a vise and felt for play and couldn’t feel any. Not sure how long a wrist pin can go with excessive play but seems like it would hammer down an aluminum alloy piston pretty fast, and it hasn’t gotten much worse in the few thousand miles since it started. Shoulda done the 5.0swap like I wanted….

 

[Shran]

4.0's are a weird beast. I put one in an '89 Ranger, engine had something like 230k on it but it ran good. Sold it to my buddy and he decided that it needed to be freshened up so he spent almost $4000 having it bored, cleaned up, new heads, pistons, new cam, the works. Right away it had a lifter tick and a stumble right off idle that was eventually attributed to some tuning thing... but it never went away and just was never perfect. Work was done by a reputable friend of his that had done a bunch of other engines for him. I said, you should have just left it alone!

 

[Nick Ranger - Private Eye]

Did you inspect and reuse the cam? I didn't see you say it was new.

Did the block get tanked... new casting plugs and a good clean up on the oil galleys?

Still running the break in oil?

I inspected the cam and so did the machine shop and they said reuse it. The block was hot tanked, new freeze plugs all around, everything was spotless, I blew out all oil passages with air before I reassembled. I changed the break in oil at 500 miles, now running 5w30.

 

[pjtoledo]

I've used 15-40 oil in a couple of hi mileage engines to quiet them down.
it's a diesel oil but some brands are spark rated, check the label.
might be a cheap fix if it doesn't get too cold.

what is the oil pressure at hot idle?

 

[franklin2]

It’s crazy that the noise only shows up after 340k, I’ve never experienced any other noise from the 180k miles I put on it except for the occasional cold start lifter clatter, which I always remedied with some rislone engine oil treatment. When I got the pistons with the connecting rods back from the machinist, who did not disassemble them but said they all had no wrist pin play, I also put them each in a vise and felt for play and couldn’t feel any. Not sure how long a wrist pin can go with excessive play but seems like it would hammer down an aluminum alloy piston pretty fast, and it hasn’t gotten much worse in the few thousand miles since it started. Shoulda done the 5.0swap like I wanted….

I wonder if he mic'ed the pistons at the skirt and the cylinder bores? Probably not since that takes time. Might be a little bit excessive clearance causing the piston to bang around a little bit. I have a hunch this engine would run a long time with this noise.

 

[4.0blue98]

Mine doesn't seem as bad as it was at one time. Maybe I'm getting used to it. I run conventional 10w30 in the winter and 10w40 in the summer for the past 10 years or so. Last change I put in 4 quarts of 15w40 diesel oil and 1 quart of Marvel's. I do that about once a year. BTW I tried some full synthetic 5w30 many years ago and it was pretty loud for the first 1000 miles. Mine also tends to leak from various places with full synthetics. This is my daily driver at about 200-300 miles a week.

 

[alwaysFlOoReD]

Mine doesn't seem as bad as it was at one time. Maybe I'm getting used to it. I run conventional 10w30 in the winter and 10w40 in the summer for the past 10 years or so. Last change I put in 4 quarts of 15w40 diesel oil and 1 quart of Marvel's. I do that about once a year. BTW I tried some full synthetic 5w30 many years ago and it was pretty loud for the first 1000 miles. Mine also tends to leak from various places with full synthetics. This is my daily driver at about 200-300 miles a week.

My understanding of winter use its the first number that matters, especially when first starting the engine. So the 10 is what's important. I tend to use 5w or 0w for the winter months if I use 10w for the rest of the year.

 

[4.0blue98]

My understanding of winter use its the first number that matters, especially when first starting the engine. So the 10 is what's important. I tend to use 5w or 0w for the winter months if I use 10w for the rest of the year.

Yeah the first number is cold relevant but I'm in north central Maryland. Never gets very cold. We may get some single digits briefly. I followed the recommended 5W30 for the first decade I had my Ranger. We had some teens recently and it spun easily and fired right up with the slightly diluted 15w40. I am planning on installing a mechanical oil pressure gage soon.

 

[gaz]

@Nick Ranger - Private Eye

You do not remove the heads to measure the push rods length; the required length can not be measured with the head off.

The measurement is taken with a device called a push rods measuring tool. It will measure the distance between the lifter and the rocker, when the OHV 4.0l rocker arm studs are properly torqued (since it is non adjustable in it's stock state). I would add 0.025"-0.030" to the measurement and compare it to your push rods. If your pushrods are shorter then you may be onto something ..)

You do not need to measure the plunger travel, it is 0.100". As suggested, this non adjustable valve train presents undesirable negative performance issues, this in my opinion is the ugliest...new rebuild, the stock push rods are likely not to produce proper preload unless it has been determined what size push rods are required.

Call the Smith Brothers, I am not an authority on the issue, they unquestionably are. They sell the measuring tool and make custom adjustable and non-adjustable push rods sets for a reasonable price.

 

[Nick Ranger - Private Eye]

sounds like valvetrain noise.
pull the oil fill cap and listen.
is "chassis ear" a hose or a metal probe?

Chassis ear is a very handy little box with 6 microphones on long leads you can clip on to different places on the vehicle, then switch between them while listening through headphones.

 

[pjtoledo]

Chassis ear is a very handy little box with 6 microphones on long leads you can clip on to different places on the vehicle, then switch between them while listening through headphones.

can it cancel out wifes & mother in laws?