1996 4.0 ohv rebuilt engine clatter from top end only warmed up

[ZAP.143]

Hello everyone I have a 1996 explorer which I just installed a rebuilt engine that a friend built in the college we both went to together about 10 years ago. Engine sat 10 years fresh rebuild never ran. Brand new heads rockers push rods lifters. Probably forgetting a bunch of stuff. I’ve been a mechanic for awhile just throwing that out there. I’ve changed the oil and filter already to make sure it wasn’t stuff in the engine that got in the oil. So far I’ve only ran it a few times haven’t driven it. Starts up sounds perfect after a few mins the top end starts clattering pretty good. Seems strange that it would be quiet at first? Does that whenever it’s cold started sounds perfect. Give it a few minutes tap tap tap tap tap seems loudest rear of passenger valve cover. But I’m not sure. Just wanted some suggestions before I start taking this thing back apart after finally getting the engine in. Thanks!

 

[EB4X]

Just spitballing, long shot etc... wondering if something fell / got into oil pan (rag whatever) when putting engine back together and is now getting sucked up to the pump screen ( I know, very unlikely)... when you drained oil did it rush out as normal...continously? .... What is the oil pressure gauge showing when it's running?
Another off the wall thing to throw out here, I put a new head on a Jeep and didn't fully tighten down one of the plugs (don't ask why) ...when started up sounded great and then a minute later (heat etc) compression/ exhaust strokes were leaking in harmony past edge of plug....tap tap tap tap....sounded just like valve chatter....and the sound emanated in a way it wasn't cut and dry it was coming from plug...wasn't causing a miss either. It did this every time....started up quiet and purring....then minute later.... tapping away.
Probably neither one of these but just sharing.....

 

[ZAP.143]

Just spitballing, long shot etc... wondering if something fell / got into oil pan (rag whatever) when putting engine back together and is now getting sucked up to the pump screen ( I know, very unlikely)... when you drained oil did it rush out as normal...continously? .... What is the oil pressure gauge showing when it's running?
Another off the wall thing to throw out here, I put a new head on a Jeep and didn't fully tighten down one of the plugs (don't ask why) ...when started up sounded great and then a minute later (heat etc) compression/ exhaust strokes were leaking in harmony past edge of plug....tap tap tap tap....sounded just like valve chatter....and the sound emanated in a way it wasn't cut and dry it was coming from plug...wasn't causing a miss either. It did this every time....started up quiet and purring....then minute later.... tapping away.
Probably neither one of these but just sharing.....

I appreciate the response. I never pulled the pan but the oil did come out quickly. I actually put 3 qts of oil and 2 qts of kerosene in the motor while it was still out and primed the oil system to try and flush everything. Dropped the engine in and drained that out then filled with 5w-30. Cranked it with no fuel or spark for while, then started it. Great oil pressure on gauge I should probably get a manual gauge to check. Then I let it sit a few days and drained that oil and replaced with 4qts oil 1 qt marvel mystery oil and new filter. Also I torqued the plugs to spec while the engine was still out of the vehicle. Thanks for the ideas! I’ll try to post a video I took of it running last night on YouTube with a link here. It’s like 10 mins long but can hear how quiet it starts out compared to the noise at the end with a few revs to hear the pitch and pattern of the noise.

 

[Gary Crist]

I think you have it right with the real oil pressure gauge. Your
real oil pressure might scare you too when engine is at operating temp.

 

[fast_dave]

@ZAP.143

First, try a little heavier oil = 10w-30

5w-30 was spec'd for CAFE fleet fuel standards...

Also, there is a certain amount of L/R adjustment built within the rocker rail - and it isn't mentioned in any rebuild articles I've read.
I only found this out hands on - read on...

OK - so you can loosen the (3) hold down bolts and adjust the (3) "hold down pads" L/R to ensure that the rocker faces are hitting the valve stem tips dead on.

There is enough adjustment available that if the rocker arm rail is installed without any concern to this adjustment, the face of the rocker can be as much off as to cover only half of the valve stem tip. I saw something close to this on my engine - direct from the factory.

Centering up the rocker face/valve stem tip should help lower the valve train noise as well as the wear on the face of the rocker arm.

Regardless, the OHV/Rail design (based on the 1960's FE engine) on this engine is noisy straight from the factory, and
even after a complete rebuild that included new pushrods and rocker arms.

It's a truck engine...

Hope that helps -

 

[ZAP.143]

Just spitballing, long shot etc... wondering if something fell / got into oil pan (rag whatever) when putting engine back together and is now getting sucked up to the pump screen ( I know, very unlikely)... when you drained oil did it rush out as normal...continously? .... What is the oil pressure gauge showing when it's running?
Another off the wall thing to throw out here, I put a new head on a Jeep and didn't fully tighten down one of the plugs (don't ask why) ...when started up sounded great and then a minute later (heat etc) compression/ exhaust strokes were leaking in harmony past edge of plug....tap tap tap tap....sounded just like valve chatter....and the sound emanated in a way it wasn't cut and dry it was coming from plug...wasn't causing a miss either. It did this every time....started up quiet and purring....then minute later.... tapping away.
Probably neither one of these but just sharing.....

 

[ZAP.143]

heres a link to a video of it running cold and at the end the clatter becomes more apparent. I will probably pull at least the passenger valve cover to check things out. If I find anything I’ll have to pull off the intake plenum again to take off the other side. Thanks for the replies!

 

[fast_dave]

Curious - What year 4.0 OHV engine was the rebuilt engine that was installed in your '96 Explorer?

 

[ZAP.143]

Curious - What year 4.0 OHV engine was the rebuilt engine that was installed in your '96 Explorer?

The following is all the info I received from the guy I bought it from

“The engine itself is out of a 98 Explorer, the fuel system is set up for a 2000 Ranger (which is returnless) so you would have to swap your fuel rail over.”

“.030 over pistons, SOHC Pan/Main Bolt Conversion, brand new Alabama Cylinder Head brand heads, new OEM Rockers/Shafts/Rocker Bolts, OEM Main Bolts, like new Accesory Brackets, Headman Headers, Brand new Water Pump, thermostat housing, etc.”

“Stock cam in it. I replaced the Pushrods and the Rockers in it when I rebuilt it. The Heads were completely new builds as well. The only things I reused were the cam, the connecting rods, the crank and the Block. Other than those everything is all new.”

“Yes, lifers were new as well.”

 

[fast_dave]

@ZAP.143

Thanks - that covers it - here's my guess & summation, based on a YouTube video (with a lot of fan nose)

OK - If your block is out of a '98, you have a roller camshaft engine - which is good.

What I think I'm hearing in the video is an out-of-specification roller lifter "make itself known" when the rpm's drop from the initial cold start (high rpm) and as the oil warms up, and the oil pressure lowers in concert with the lowering of the rpm's.

Background history to pull it all together.

When these engines were starting to be REBUILT en masse the first go-round between 2005 - 2011, the original GERMAN roller lifters were priced as high as $70 each and a little hard to source. FORD Stealership had them (at a HIGH price) and Ebay had them occasionally BUT they were swooped up as fast as they were advertised.

Although you mentioned OEM parts for some of the replacement parts, that's NOT mentioned with regards to the roller lifters.

When rebuilding, many guys balked at paying $50 - $70 each X (12) for the Genuine German OEM Roller Lifters, and went the Chinese Aftermarket route at about $16 - $20 each X (12).

Now that you know that, take into account the following; The history of these engines, from the factory, is that they were very tolerance sensitive with regards to the GERMAN factory lifters - and those were manufactured to a very high standard...

Despite the German's attempt at tight quality control, there were LOTS of noisy 4.0 OHV's right from the factory with one or more German lifters ticking. The subject was quite popular on this forum back in the day when I joined - 2005. Overall, the consensus was "just drive it" - it's a truck engine.

But still - many guys gave it a shot and performed a lifter replacement, only to have the noise pop up in another cylinder either immediately or a little time later...

With Chi-Com aftermarket lifters, well, consider how tough it was for the Germans to manufacture them, and then imagine your typical Chi-Com in charge of manufacturing AND quality control of a high precision roller lifter - and you get a clearer picture

That's what I'm guessing is more than likely your problem - a bad lifter - but your mileage can vary.

Perhaps another video with the serpentine belt disconnected is in order (that way you won't get the fan noise).

Personally, as long as it passes SMOG, I would FIRST give it a shot with some thicker oil (10w30) and see if that helps.

If it does, I'd drive it 'till it drops VERSES tearing it down for one or two lifters.

You could be entering Pandora's Box territory opening up the engine - I've read it here too many times...

HTH -

PS - Your post - #9 - seems to be cut & paste from an e-mail inquiry to the guy that built the engine.

With that said, If you do have a chance to ask about the lifters (again), I wouldn't put words in anybody's mouth - I'd simply ask "where did you source the lifters - they're tough to find"

An answer of anything other than FORD will more than likely be chi-com.

BUT - as I wrote, even the Germans made quite a few bad ones despite their precision machinery AND high level of Quality Control

 

[ZAP.143]

I appreciate your input very much. With the research I did over that past week or so since the first start I was leaning towards lifters. It was just strange to me that it seemed so quite when cold because normally if I hear a lifter having an issue it’s first start ticking and then quiets down. But then I read stories on this forum about people buying lifters and having issues with tolerances and whatnot and I feared that may be my issue. I also had planned to tear down my gm 5.3 in my Silverado which has a lifter that I believe has a flat spot that catches when it’s nice and hot out at idle it will start tapping real bad. Gotta pull the heads to do that one too yay! Sorry for the fan noise I made that video to show my boss and didn’t plan to post online. Last time I started it up the never used water pump that was on the engine started puking out the weep hole. So I ordered another pump so when I have it apart for that I’ll try to video without the fan or just take the belt off. I have the original engine for my explorer still here 112k miles spun a rod bearing and the rod came out the side of the pan/block.. piston still in the cyl! Would run on 5cyls very interesting.. would it make sense to try to swap the lifters from that? That thing never made a peep that’s why I found this new engine seemed loud. My grandparents bought my explorer new in 96 and gave it to me in 06 for my 16th birthday so I’ve spent a lot of time listening to my ohv purr before it decided to go kaboom. Sorry for dragging on... I don’t pretend to be an expert especially not in engine rebuilds or internals. But I’m pretty finicky when it comes to noises lol.

 

[fast_dave]

@ZAP.143

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