Just started rebuilt 4.0 - Rod knock?

[Pollarican]

Hey guys,

Pretty much ****ting my pants right now - Just started the rebuilt 4.0 and it has a loud knock that seems like its coming from the bottom end - sounds to me like a single rod not like the whole motor is knocking back and forth. Engine Idles smooth as butter, well for having a 410 cam. No dummy oil light telling me I have no oil/ no oil pressure. Idles perfect except for this noise. Does it really take that long to build solid oil pressure? Is it possible there is a lifter not pumped up that's making this noise? I swear I can hear it from the back end of the motor laying below the oil pan.

-410 Cam
-Smithbros pushrods
-Rebuilt stock Lifters by professional rebuilder
- Plastigauged all bottom end bearings, all direct middle of spec they belong in, and installed sealed power bearings.
- New Sealed Power Chromoly rings
- Si Valves
- New recast heads

 

[Pollarican]

It does sound a lot like this:

http://www.ratwell.com/technical/HydraulicLifters.html

Maybe slightly more pronounced but like that noise - sounds like a lifter wont pump up - its ran for about 5 minutes at this point - just trying to be very cautious as I have a lot of time and money into this!

Is it harmful to let the engine idle/ have the revvs steady at around 1500 rpm for a few minutes to see if the lifter pumps up?

EDIT: Just watched a lot of rod knock/ spun bearing videos which lead me to believe this is a lifter problem. The noise I have seems to happen 1/2 as frequent as a rod knock noise - putting up a flag that it is valvetrain related and either intake/ exhaust. Lifters were perfect when I pulled them, and had them rebuilt by Mizpah Precision Manufacturing, a company that specializes in lifter rebuilding.

 

[j8346]

its a lifter,, did you presoak them? before install???

may clear up after setting for a few min,, with engine off..

 

[Pollarican]

I didn't soak them too long before installing, and I didn't prime them while submerged in oil - I figured the engine running would pump them up fairly easily. The engine has been sitting for several months since I reinstalled the lifters, and was apart for a total of roughly 9 months. Before that the car was ran for maybe 10 minutes after sitting in a insurance claims yard for 6 months.

After work, I'm gonna double check the oil levels/ that the filter has a good amount of oil in it and fire her up. Then follow the proper cam break in procedure, which I believe is like 1500 rpm for 15-20 minutes then turn the engine off. Crossing my fingers it will pump up during that time.

Any other advice would be greatly appreciated!

-Jeff

 

[rookieshooter]

I know nothing of that particular engine. But is it possible to pull valve cover and check out the valve train action? I know on my pushrod V8 that it would be easy to tell by watching the rockers and pushrods. If you don't want to run it, just turn engine by crank bolt if possible. You can even feel each rocker also and just tell by the feel when at TDC. But seems to me this noise would come from higher up on engine then the rods.
Plus I always submerge lifter and push on the plunger while submerged, you'll even see bubbles coming out. Then add some moly to bottom of lifter.

 

[Pollarican]

Went ahead and started it after work and held it at 2k rpms for 15-20 minutes to break the cam in. Had to stop the engine a few times because of the cooling system burping all over the garage- I thought I had a combustion leak it was so much air coming out. Threw a rad cap on, and it was popping with steam - filled it back up thinking maybe too low - then I saw my upper rad hose was collapsed and my lower felt like it had no warm coolant in it - put a new radiator cap on and boom fixed that problem.

The lifter quieted down a good bit - you can head it upon startup but when it runs for a minute or two its just the typical explorer ticking. Now I have some little high pitched squeak type noise when you give it some rpms - I'm leaning towards a pulley - listened with the mechanics stethoscope to each area of both valve covers - all sounds pretty uniform.

Will update again in a few - gotta go clean up the coolant mess lol

 

[Dono]

Sounds like your going to be ok. If you have to, you can pull a valve cover and rockers. Then look for a collapsed lifter (I sure hope not).
The squealing is from the coolant burping everywhere. Hope you don't have to replace your belt because of it.

 

[Pollarican]

After listening a bit more it seems like it might be rocker arm contact that is making the light squealing noise - it sure does seem like it's coming from the rear area of the passenger valve cover. I'll have to give it a listen tomorrow, or more importantly, after I put muffler on (I'm currently running cats with a 2 foot long pipe behind them).

Have to bleed the brakes, and set a rough alignment, then I can take her down the backroads for a test drive.

This is a full rebuild of this Explorer - I had no motor, trans, transfercase, axles, or suspension in at one point. It's nice to actually hear it run and be able to move it in and out of the garage under its own power. I will admit I'm kinda bummed about this residual lifter noise - Might even be louder than before I ripped the motor apart.

Cam sounds great though with just a dump pipe. Sounded even better before I filled/ bled the power steering pump - gotta love Ford's whiny POS pump!

 

[QueenCitySleeper]

Don't exactly need to "break in" the cam. The first startup should be long enough to get the engine to operating temperature then shut it down. From there you wait until motor is cooled down. After that you can drive it easy for a couple weeks running up and down the rpm range. listen to valve chatter and checking the oil filter for metallic flakes are important. No need for 2krpm break in cycle. Not necessary with most hydraulic lifter/cam applications. It can actually be detrimental to the wear in process. Congrats on the recent engine build!!

 

[Pollarican]

Got some more time in the garage today after work.

Pulled the serp belt to see if this would remove the high pitch intermittent squeal I was getting from the engine bay. Dono hit it on the money, the sound was no longer present sans accessory drive. Lifters are still damn loud but it was cold today and I didn't even run the motor up to operating temp. They did get a bit quieter as it warmed up.

Knew I had a leak coming out of the oil level sensor - found out that it was barely finger tight and took care of that one.

Added some coolant to it to get it to the right level, and finished buttoning up hose clamps/ odds and ends in the engine bay. Filled the front diff which I hadn't done since I reinstalled the whole suspension.

Still have to bleed the brakes, and get my camber roughly correct - give her a once over then it's test drive time!

 

[jd4242]

What size pushrods did you use? Also did you replace your rockers?

 

[Pollarican]

Rockers are Saeled Power Replacements.

Pushrods are Smithbros 5.550 IIRC.

Cam is a Comp Cams 410.

Oil pump is a Melling High Volume.

Lifters are factory lifters that were pretty quiet before I tore the motor down - had about 135k on them and had them rebuilt.

 

[jd4242]

Rockers are Saeled Power Replacements.

Pushrods are Smithbros 5.550 IIRC.

Cam is a Comp Cams 410.

Oil pump is a Melling High Volume.

Quality partsthe ohv is just a noisy motor and a cam will make it a little louder also.hopefully it will get better

 

[Derek Greenwood]

Valve guides too tall?

No it should not be that noisy. I just finished building my 4.0 last Saturday and it is no longer noisy. I put mine together with a cam and it was very noisy. It turns out it had a collapsed lifter but that was not all. The valve guides were too tall in the aftermarket heads and so the valve retainers were hitting the valve seals. This will of course beat up the valve seals and could cause a lot more damage. I had to pull heads off again and have a machine shop cut down the valve guides. Now it runs nice and quite. If anyone is putting on aftermarket heads make sure the cam lift won't cause the seals to be hit. Also, this is not just a problem with performance cams. After examination I found they would hit with the stock cam which is why my seals were slightly beat up before I did the rebuild.

 

[jd4242]

No it should not be that noisy. I just finished building my 4.0 last Saturday and it is no longer noisy. I put mine together with a cam and it was very noisy. It turns out it had a collapsed lifter but that was not all. The valve guides were too tall in the aftermarket heads and so the valve retainers were hitting the valve seals. This will of course beat up the valve seals and could cause a lot more damage. I had to pull heads off again and have a machine shop cut down the valve guides. Now it runs nice and quite. If anyone is putting on aftermarket heads make sure the cam lift won't cause the seals to be hit. Also, this is not just a problem with performance cams. After examination I found they would hit with the stock cam which is why my seals were slightly beat up before I did the rebuild.

How do you even know how noisy it is? What aftermarket heads do you have? The guides must have been sticking up A LOT.what size pushrods did you run? How much preload do you have? What cam are you running? You should have atleast .510" clearance from top of the guide seal to the retainer.most heads have that.if you run the 422 cam you have to machine the spring seats and trim the guides and seals to run dual springs.there is no way a stock cam will hit unless the guides are installed wrong or they are the wrong guides, just not enough lift.with any aftermarket cam that produces .500" of lift or more it should be checked but any good machine shop will check that.if his noise is coming from hitting the seals you will know in no time because it will start burning oil BAD and start smoking BAD.

And yes the ohv or any cammed pushrod motor is going to have some noise, especially one with poor oil design

 

[Derek Greenwood]

Sure its going to have some noise, all motors have some noise and pushrod motors can have more noise then OHC motors but I can tell you that my motor except for the accessories and a little bit of fuel injector noice is quite quiet. The guides were cast into the head in the aftermarket heads but I am saying that they were machined too tall from the manufacture. And yes there were hitting with the stock cam. Just barely hitting but they were in fact, measured at the machine shop, hitting with stock lift. With the high lift cam and of course the correct length smithbros pushrods they were destroying the valve seals and making noise. Not as much as the stuck lifter but there was still a lot of valve train noise. After they were cut down with enough clearance the valve train is amazingly quiet. I replaced the ebay crap lifters with mizpah rebuild lifters and they pumped up in 2 seconds and there is no clicking lifter noise.

The point of my original post is to make sure and have the clearance checked with aftermarket heads. Especially if you are using an hi po cam.

 

[jd4242]

Sure its going to have some noise, all motors have some noise and pushrod motors can have more noise then OHC motors but I can tell you that my motor except for the accessories and a little bit of fuel injector noice is quite quiet. The guides were cast into the head in the aftermarket heads but I am saying that they were machined too tall from the manufacture. And yes there were hitting with the stock cam. Just barely hitting but they were in fact, measured at the machine shop, hitting with stock lift. With the high lift cam and of course the correct length smithbros pushrods they were destroying the valve seals and making noise. Not as much as the stuck lifter but there was still a lot of valve train noise. After they were cut down with enough clearance the valve train is amazingly quiet. I replaced the ebay crap lifters with mizpah rebuild lifters and they pumped up in 2 seconds and there is no clicking lifter noise.

The point of my original post is to make sure and have the clearance checked with aftermarket heads. Especially if you are using an hi po cam.

What heads are you using??

 

[Derek Greenwood]

Unfortunatly I don't know. I bought them from a nationwide rebuilder that happens to be in the Largo Florida area. They said that nearly all factory 4.0 heads are cracked so they just get aftermarket heads.

 

[Dono]

Good thing the machine shop caught it.
It just seems that its worth having any head (new or old) checked by a machine shop you trust before installing them.

I'm about 4300 miles on my motor now, and so far so good. Machining did cost me a boat load of cash, but my motor is working. Worth it? Id say so.

 

[Pollarican]

I've fired it up a few more times and let it run for some time - I still have an incessant buzzing coming from the valvetrain - almost as if there is just enough gap between the rocker arms and pushrods that its making that noise. Guess I'll have to pull a valve cover and take a look a the next few days. The buzzing is loud enough I can hear it 20 feet away - its no longer a knock type of noise like a dead lifter.