Brand new engine has tick at idle

[NPGuy]

Greetings,
I was on this forum under a different screen name a few years ago but could not reset my password.
Now to the problem description.
I have a 1991 Ford Explorer Eddie Bauer edition with a 4.0 liter and a A4LD.
I have just completed a complete engine rebuild and everything was new with the exception of the block and rods and a few external parts. New Pistons, crank, cam shaft, lifters, basically everything, heads have all new valves and springs also.
So I was careful and measured all the clearances and super clean building the engine. Everything was coated in assembly lube as it went together. Followed the book to a T thinking I would have a engine that would run like new. Fast forward to now. Got the engine in and everything all put back together, primed the engine and fired it up and it started right up and seemed to run ok. Figured after all the new engine paint burned off and things seated it would run nice and smooth. I followed the engine break in procedure in the service manual for seating the rings.

Now to the problem
After about 100 miles now I still have a tick at idle. It sounds to me like a lifter tick from somewhere around cylinder two or three. I can't hear it above idle and it is only after it warms up good and warm. Quiet at idle while engine is cold.
I did find a TSB for something like this for a different ford engine that effected 1991 engines.
It made reference to a bad or out of spec cam shaft thrust bearing. That is one of the only internal parts that was not changed due to not being able to find a source of that part.
Now for more of the story
The engine had a tick at idle prior to tearing it down, it did sound like it was coming from the other side of the engine though and a few mechanic friends and myself figured it was a rod bearing with 175,000 it seemed plausible.
So who here can help me solve this issue before I have to pull the engine again. I need the engine to be reliable so I will do whatever I have to.
Thanks in advance for your help.

 

[malohnes]

What about pushrods and valve gear, what did you do there? You said basically new everything but omitted these in your description.

I'm inclined to not worry about it much. Since you're still in the breaking period I'd keep tabs on it and when you feel comfortable to give it some go-go, see if it does it under hard acceleration and hill climbing. Lifter ticking isn't going to be easy to cure without taking apart the top end again just to pull the suspect part and investigate.

 

[natenkiki2004]

Usually lifter tick doesn't get worse as the engine warms up. What weight oil are you using? Can you get a video of the ticking?

 

[Number4]

I'm with [MENTION=117556]malohnes[/MENTION], did you replace the rockers? Pushrods?

 

[FR-425]

Maybe the engine is so quiet now he can hear the injectors? and one particularly loud injector..

 

[NPGuy]

Feedback

So I did forget to comment on the rocker shafts and pushrods, pushrods were all measured and rolled on the table and all looked good, no bent ones or anything all the same length. The rockers and shafts are also reused but looked good. I guess it is possible something is up with one of those. So prior to pulling it apart there was a tick at idle from what sounded like cylinder number four. So if I swapped the rocker shafts that would make the trouble back to three where I am currently hearing it.
So I am using 10-w30 standard oil right now.
Injectors were all cleaned and run on the bench with a little test box I bought that pulses them. They all flowed good and were quiet.

So what would/could be wrong with a rocker/shaft assembly that could cause noise after the engine warms? Possibly excess clearance between the shaft and rocker?
What I might do is swap the shaft assemblies and see if the noise follows?!
Thanks for the feedback
Joe

 

[NPGuy]

Posting a video

Not finding how to post a video right off, any help?

 

[malohnes]

OK, reused valve gear means you might be suffering from worn pushrods and/or the rocker. from the worn pushrod. This is an issue due to the OHV design of poor oiling to the valvetrain.

FR425's comment on injector is another good point too...and worthy of inspection My gut tells me the problems still worn rocker and pushrod pair.

 

[natenkiki2004]

OK, reused valve gear means you might be suffering from worn pushrods and/or the rocker. from the worn pushrod. This is an issue due to the OHV design of poor oiling to the valvetrain.

FR425's comment on injector is another good point too...and worthy of inspection My gut tells me the problems still worn rocker and pushrod pair.

x2 on this. Gotta be one of the two.

Quick & dirty, you could try unplugging the injectors one by one and seeing if the tick goes away. If it does then I'd get a new set just for peace of mind. If not then it's gotta be internal and likely something in the valvetrain.

Just to throw this out there... I performed a hail mary valvetrain tune-up which consisted of new pushrods & rocker arms as well as turning the shafts 180 degrees. This didn't fix my ticking so it has to be lifters but I used Sealed Power brand parts. The pushrods were nice but the rocker arms, I had to return 2 of them. The castings and machining absolutely sucks. I'd almost buy these parts locally so you can inspect them before taking them home. Federal Mogul ain't what it used to be. I see why people recommend buying these parts from Ford if you can find them.

 

[NPGuy]

I am thinking I am going to swap the rocker arm assemblies on the heads to see if the noise follows before I get new parts. I guess it could be a clearence issue of a rocker arm on the shaft. As the oil warms and thins it opens up Clearence? Everything felt tight on the shaft and pushrods. I pulled it apart when it was hot to see if I could see anything loose.
It makes sense to me that it could be a rocker arm issue now since like I said earlier there was a noise around cylinder four prior to tear down and now it is around cylinder three. This makes sense if rocker arms were swapped, four would be in threes place

 

[NPGuy]

Injector noise?

Had a guy come by tonight with another buddy that worked ford ford as a mechanic. His opinion was that what I am hearing is the injectors. The reason I can't or don't hear them on the other side is because the upper intake manifold is blocking the drivers side injectors. It seems to idle nice and smooth and has no other problems. Going to put a few hundred miles on it tomorrow and see how it does.
Guessing the reason I can't hear it until it warms up is the elevated idle while cold.
Will report back tomorrow

 

[natenkiki2004]

Here's something free, quick and easy that will confirm your suspicions; stethoscope. You can use a screwdriver in a pinch but stethoscopes are cheap and when you hear the tick, put them on and start probing the injectors and see if it sounds the same and has the same frequency.

 

[NPGuy]

I will do that! I probed with a long screw driver a bit but I believe I have a stethoscope somewhere and see what I can hear. I am going to test drive it this morning about 300 miles on a short trip to see how it does.

 

[malohnes]

I am thinking I am going to swap the rocker arm assemblies on the heads to see if the noise follows before I get new parts. I guess it could be a clearence issue of a rocker arm on the shaft. As the oil warms and thins it opens up Clearence? Everything felt tight on the shaft and pushrods. I pulled it apart when it was hot to see if I could see anything loose.
It makes sense to me that it could be a rocker arm issue now since like I said earlier there was a noise around cylinder four prior to tear down and now it is around cylinder three. This makes sense if rocker arms were swapped, four would be in threes place

Pay attention to the wear under the rocker, where the pushrod mates to it and to the tip of the corresponding pushrod. This is a very common problem.

 

[2000StreetRod]

changed oil filter?

Engine pre-lube will collect in the oil filter. If there is enough it will clog the filter and the filter bypass will open. After a rebuild start up I let the engine idle and check for leaks until normal operating temperature is reached. Then I shut the engine off and replace the oil filter.

 

[NPGuy]

I am planning on changing the oil soon. I put about 300 miles on it today and averaged 16 mpg. I was getting a check engine code of bad oxygen sensor so I picked one of those up on the way home and am planning on changing that prior to testing it again. I am hoping that the mileage goes up a bit. I was hoping thinking maybe 20mpg, opinions on if this is good bad? I will have to check gearing but it is a 4.0 liter with an A4LD running in four wheel drive highway combination hills and flat in -10 weather today.
Thanks for the feedback.
The manual said to run 500 miles on the first oil change for break in oil.

 

[natenkiki2004]

Usually oxygen sensor codes mean there is a rich or lean condition. They don't usually mean that the sensor died. Unless you have an oscilloscope, it's hard to tell what is going on exactly since we can't see live data.

So... don't be surprised if the new O2 sensor gives you the same check engine light.

 

[malohnes]

I am planning on changing the oil soon. I put about 300 miles on it today and averaged 16 mpg. I was getting a check engine code of bad oxygen sensor so I picked one of those up on the way home and am planning on changing that prior to testing it again. I am hoping that the mileage goes up a bit. I was hoping thinking maybe 20mpg, opinions on if this is good bad? I will have to check gearing but it is a 4.0 liter with an A4LD running in four wheel drive highway combination hills and flat in -10 weather today.
Thanks for the feedback.
The manual said to run 500 miles on the first oil change for break in oil.

Thats good mileage for cold weather 4wd use! Don't expect 20mpg in that kind of weather with 4wd. I get 22-24 in the summer with highway driving in 2wd only. It tops out a 21 in the winter if the road is clear of snow and grooved ice and not too cold out.

I second the comment about your o2 sensor.

 

[NPGuy]

So I was getting a lean code on and off so I went ahead and changed out the oxygen sensor as it was the original 1991 model anyhow and guessing it had exceeded its service life by a few weeks?
Cleared up that problem, no more check engine light now anyhow.
As for the ticking noise, added some marvel mystery oil at the last fill up and noise is now gone! So does that mean the injectors are wearing or was the tick just from me cleaning them with a good carb cleaner stripping all the junk out of them? I have a plug tool that pulses them and I hooked a hose up to air at 40 pounds and sprayed carb cleaner into the hose first. Then applied air pressure and pulsed them on, did this a few times until they sprayed a clean pattern. Then changed all the hard wear on them.
So the thing seems to idle nice and smooth now and is really quiet. Was wondering what it should idle at, I know it is set but I can't seem to find where it is suppose to idle at. Once it is warmed up it looks like it idles at approx 1,000 rpms at least according to the tach on the dash.

 

[malohnes]

Well, Im happy to hear the noise is gone!

If all you did was add MMO to the oil for the sound to clear up, then it shouldn't have anything to do with your injectors. Now, Im unclear when you cleansed the injectors in relation to the addition of MMO, but if you cleaned the injectors and added MMO at the same time, then its hard to say which affected things. Personally, I still think its valve train related...

Without rereading the thread to find out what tranny you have, your idle should be closer to 650rpms, at least on a manual tranny equipped Explorer. Mine will idle at 1000 briefly at initial startup and stay there for a bit, but will drop down as it warms up, weather and seasonal conditions dependent. There is a procedure for resetting the idle, but it really is more about calibrating the TPS, IAC and TB so the computer does its job correctly. Messing with the TB set screw is not the way to handle the issue and I urge you to not use it until the other items have been attended to.

I believe there is a link to it not he main Modified page. Look for Wood1 sticky link to useful threads. Lots and lots of info in there. Also visit therangerstation site. Their Tech pages are great.