• Welcome Visitor! Please take a few seconds and Register for our forum. Even if you don't want to post, you can still 'Like' and react to posts.

Concerning engine noise and oil pressure fluctuation


cstarbard

Member
Joined
Aug 10, 2017
Messages
225
Reaction score
4
Points
18
Age
30
Location
Oakham, MA
Vehicle Year
1996
Make / Model
Ford
Engine Size
2.3
Transmission
Manual
My credo
It do like it be
Hey guys,

This one has me confused. I have a 1996 2.3 truck (manual trans) and the engine which by all measures seems very healthy, makes an awful knocky sound that can be heard at idle (realistically I'm sure it makes it at all RPMs I just can't hear it above fan noise etc past idle). Sounds like rod knock, but I really hope not/don't think it is. I just filled up with 93 octane to make sure what I'm hearing isn't some sort of weird spark knock, and with a full tank of premium it still makes this noise, so I'm guessing it isn't spark knock... truck doesn't even really spark knock anymore anyway even on regular... I have been under the truck and can not find anything external vibrating that might cause that noise, I have a brand new PS pump that is super quiet, water pump is not damaged, so I don't really think an accessory is making the weird sound. When you listen all around the truck it seems like the sound comes from near the bottom of the engine.

Truck has 150k miles, does not burn or lose a drop of oil, runs pretty good. Oil never has shavings or other foreign stuff in it (last oil change I inspected the used oil in direct sunlight on white paper towels, could not find anything metallic or otherwise in it at all)

The next thing that is odd is that sometimes my oil pressure gauge will freak out a little bit. Sometimes it falls quite low on the gauge, and then bounces between low and midway. This just started happening and does not happen often, and when it does nothing changes in how the truck is running, so I *hope* that's an issue with a sensor or the gauge, but I wondered if it might be related. I heard this is a dummy gauge setup, is that true?

I've heard some year 2.3 trucks have an oil pan gasket that breaks down over time and starts clogging up the oil pump screen. With a 96 could I have this issue? Could it be related to the strange sound? Should I be worried about clogging my oil pump and or could this be contributing to the knock sound and oil pressure fluctuation? What do you all make of such a rod-knock like sound in a truck that does not burn oil or have shavings etc in the oil? I'm obviously no expert but I would think that if something was rod-knocking, it would show some other signs of being quite unhappy

The sound has always been there, but has gotten much more pronounced over time. I haven't modified the engine in any way, all I have done so far is regular tune up stuff and switched to synthetic (same weight that manual recommends changed on same interval as manual suggests)

Thanks in advance to any info on any of the above issues and how I might be able to diagnose better. I will record a video of the noise ASAP.

Chris

EDIT: I'm not sure if this is the case or not, but it seems like all of this only started after I did a timing belt. I did turn the oil pump sprocket and cam sprocket by hand to get it re timed right, which caused some strange top end like sound after the initial startup, but which quickly went away... not sure if any of that could be related but thought I ought to mention
 
Last edited:


RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,292
Reaction score
8,296
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Rod knock noise is cause by a gap that forms in the connecting rod bearing.
As the piston in that cylinder passes TDC the connecting rod is pulling it down so any gap would be at the top of that bearing.
When the cylinder fires, After TDC, that gap is closed very quickly making the "knock" noise.

So to see if you do have a rod knock you can disable each cylinder, one at a time, to see if knock lessens or goes away.

On the 2.3l with dual spark plugs you should unplug the 3 wire connector on the intake side coil pack, turning it off.
Start the engine, just using the exhaust side spark plugs
Then using INSULATED pliers, unplug 1 spark plug wire at a time from the exhaust side coil pack
Yes the engine will miss, lol, but if the noise drops off then that cylinder has the problem

Warmed up engine is probably better, less likely to stall when 1 cylinder is turned off

An exhaust leak "can" sound like a rod knock, and will also go away when that cylinder is off, so just a heads up.
 

tomw

Well-Known Member
U.S. Military - Veteran
Joined
Aug 15, 2007
Messages
1,613
Reaction score
46
Points
48
Location
toenails of foothills NW of Atlanta
Vehicle Year
1985
Make / Model
ford
Engine Type
2.3 (4 Cylinder)
Engine Size
lima bean
Transmission
Manual
2WD / 4WD
2WD
My credo
vertical and above ground
Ron, wouldn't the paired spark plug also quit firing when you pull the plug wire? 1&4, 2&3 are paired, so they fire using the same spark voltage. If you pull one plug wire, either a positive flow or a negative flow of electricity through both plugs will be interrupted as one or the other has lost ground or volts, and the second plug is looking for the 'flow' of juice to continue.
I haven't noodled it through, but for sure one plug wire could be touched to ground, and that would disable that plug, and allow spark for the other plug. Which plug? Dunno. Maybe grounding the plug wires that are disconnected would allow the transformer to work, but holding the plug wire 'out in the air' would seem to make it impossible for the electricity to conduct. I think.
The upper rod bearing insert is being compressed during the compression stroke, and also on the firing stroke and the exhaust stroke. It only would be 'pulled down' or unloaded on the intake stroke, I think.
Moving the aux shaft should not have any effect. Depending on model year, it may run the distributor, the oil pump, both, or the oil pump on the shaft itself(I think).

If you removed the crankshaft pulley or damper, if it was re-installed and not torqued tightly enough, it could be moving around on the crankshaft. The crankshaft actually speeds up and slows down as the cylinders fire, not noticeable to people, but enough to make the damper 'clank' under some conditions, I think. Was it torqued to spec on re-assembly?
tom
 

cstarbard

Member
Joined
Aug 10, 2017
Messages
225
Reaction score
4
Points
18
Age
30
Location
Oakham, MA
Vehicle Year
1996
Make / Model
Ford
Engine Size
2.3
Transmission
Manual
My credo
It do like it be
Hey guys,

Thanks so much for the helpful replies.

Thanks for a thorough explanation on what rod knock is. I guess I'm confused as to how it would develop other than abuse/neglect. And I am definitely very nice to this truck on maintenance and don't work it hard. Is it possible a bearing cap could loosen up on its own?

Interesting tests, they make sense.

Tom, in my case the AUX shaft runs just the oil pump as far as I know- a dual plug 2.3 with coil packs is distributorless, correct? And there is no camshaft synchronizer like the 3.0 has?

I did not remove the camshaft sprocket from the camshaft when I did the timing belt. Are they prone to loosening up though?

Also, this is a bit of a tangent, but can anyone explain why I got such loud top end noise while doing the timing belt? On the first startup after the new belt the top end was ticking like mad. It went away, but I don't understand how turning over the camshaft sprocket by hand while lining timing marks up caused that noise. A few people in other threads said their 2.3 did the same thing on first startup after timing belt. Does the procedure somehow cause oil to leave the hydraulic lifters..? This part is just for my own understanding in general
 

RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,292
Reaction score
8,296
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
tomw, yes, spark plugs are in series, and unplugging one spark plug wire can disable 2 cylinders, but the point of the test is to determine if "noise" is rod knock, so if noise goes away then probably a failing connecting rod bearing, which would require more investigation that would involve more than working on just one(or two) cylinders.

cstarbard, oil can drain out of the main oil passages when an engine sits, most oil filters have a flap/valve the prevents this, oil can flow out to engine but can't flow back.
And then there are the main and connecting rod bearings, oil higher in the engine can drain down and out thru these depending on positions when engine is shut off.
Or what you remove or turn when working on an engine, oil is held in higher passages by lack of air flow, i.e. holding fluid in a straw by putting your finger on one end, release your finger and fluid drains out.
If you turn the cam shaft manually it opens passages letting air in, so testing time mark alignment lets oil flow out of the top of engine

So what you end up with are oil passages without oil in them.

On startup it will take a few moments to refill the passages, called a "dry start" and not great for the engine parts that need oil.
If oil pump has lost its Prime, oil has drained out of pump back into pan, it can take 20-30seconds or more to get oil and oil pressure to the top of engine.


All fuel injection computers have a "Clear Flooded Engine" routine, this disables fuel injection while cranking engine over
I use it every morning on my high mile 4.0l
Turn key on
Press gas pedal down to the floor and HOLD IT DOWN all the way
Crank engine

Engine should NOT start, just crank, injectors are off, spark is still on

After cranking a few seconds, pumping up oil into engine, release gas pedal and engine will start
This is a simple way to prevent "dry starts" after engine sits or has been worked on

It also has other "test" uses, i.e. leaking injectors

Clear flooded engine uses TPS(throttle position sensor)
If your engine starts with gas pedal to the floor then your throttle cable has stretched and you no longer have Full Throttle
Google: Ranger throttle cable mod
Very simple fix
 
Last edited:

cstarbard

Member
Joined
Aug 10, 2017
Messages
225
Reaction score
4
Points
18
Age
30
Location
Oakham, MA
Vehicle Year
1996
Make / Model
Ford
Engine Size
2.3
Transmission
Manual
My credo
It do like it be
Ron I really owe you.

That is a ton of great information. Totally makes sense. I wish I had known all that before doing the timing belt.

I'll do your test for rod knock when I can and update this thread. Hopefully nothing has been badly damaged. These are things I would never have considered which is why guys like you are the best for helping us learn.

Chris
 

cstarbard

Member
Joined
Aug 10, 2017
Messages
225
Reaction score
4
Points
18
Age
30
Location
Oakham, MA
Vehicle Year
1996
Make / Model
Ford
Engine Size
2.3
Transmission
Manual
My credo
It do like it be
It took me forever to take a video of the engine noise I have but I finally did so here's a link. Anyone's thoughts on issue/cause would be greatly appreciated. I know it's hard to hear, sorry I couldnt film it any better. You can hear it loudest when I move the phone towards the exhaust side. I really can't figure out where it sounds like its coming from but it does sound louder towards the exhaust side.

https://www.youtube.com/watch?v=zXNGAbP--8k&feature=youtu.be

video may still be processing but should work shortly
 
Joined
Nov 1, 2017
Messages
226
Reaction score
9
Points
18
Age
28
Location
St Petersburg, FL
Vehicle Year
1991
Make / Model
Ford
Engine Type
2.3 (4 Cylinder)
Engine Size
2.3
Transmission
Automatic
2WD / 4WD
2WD
Tire Size
215/75/14
I'm having same issues I've already replaced oil pump and still have nasty noises sounds like metal to metal contact somewhere, here video.

https://youtu.be/eL3pORW5Xhc
 

cstarbard

Member
Joined
Aug 10, 2017
Messages
225
Reaction score
4
Points
18
Age
30
Location
Oakham, MA
Vehicle Year
1996
Make / Model
Ford
Engine Size
2.3
Transmission
Manual
My credo
It do like it be
Oh jeez! Sorry to hear. Hopefully someone can help us out.

What is very weird is that mine is now intermittent- some days it's kind of loud, somedays no weird noise at all, sometimes its there but quiet
 
Joined
Nov 1, 2017
Messages
226
Reaction score
9
Points
18
Age
28
Location
St Petersburg, FL
Vehicle Year
1991
Make / Model
Ford
Engine Type
2.3 (4 Cylinder)
Engine Size
2.3
Transmission
Automatic
2WD / 4WD
2WD
Tire Size
215/75/14
Oh jeez! Sorry to hear. Hopefully someone can help us out.

What is very weird is that mine is now intermittent- some days it's kind of loud, somedays no weird noise at all, sometimes its there but quiet


same here it goes quiet after, Luckily its a project truck and it not my daily driver worst come to worst i just rebuild block its not that hard.
 

cstarbard

Member
Joined
Aug 10, 2017
Messages
225
Reaction score
4
Points
18
Age
30
Location
Oakham, MA
Vehicle Year
1996
Make / Model
Ford
Engine Size
2.3
Transmission
Manual
My credo
It do like it be
For what its worth, I put two bottles of sea foam into my gas tank yesterday right before filling up at the pump, and I then drove home and did two runs of the sea foam through the intake-

since then, none of that weird intermittent knocky noise.

Should I chock this up to a top end issue? Or carbon buildup causing a light spark knock? I'm guessing rod knock is not likely since that should really not be intermittent, or solved by seafoam :icon_rofl:

When I did the timing belt I really fought the cam to keep it lined up while putting new belt on, and I know turning it independent of oil (which I did several times) would have caused a not so great dry start after new belt was installed, since I didn't realize this would be an issue and therefore did not crank engine over prior to starting to restore oil supply to top end.

Any thoughts appreciated. Thanks.
 

RonD

Official TRS AI
TRS Technical Advisor
Joined
Jun 2, 2012
Messages
25,292
Reaction score
8,296
Points
113
Location
canada
Vehicle Year
1994
Make / Model
Ford
Transmission
Manual
Oil in the engine is used to COOL the bearings and lube the other parts, not a big deal to turn over the engine quite a few times, in either direction, when working on it.
If won't be a dry start, oil coating will still be there.

After an engine rebuild, oil passages are usually drained, thats when you want to crank it over a few times before starting.
 

cstarbard

Member
Joined
Aug 10, 2017
Messages
225
Reaction score
4
Points
18
Age
30
Location
Oakham, MA
Vehicle Year
1996
Make / Model
Ford
Engine Size
2.3
Transmission
Manual
My credo
It do like it be
Thanks as always Ron!

Any one have and idea what the intermittent knocky noise is that seoaming my truck seems to quiet for a while? It's virtually gone every time I seafoam it, and will be there regardless of running regular or premium.
 

Sponsored Ad


Sponsored Ad

Staff online

Today's birthdays

Member & Vendor Upgrades

For a small yearly donation, you can support this forum and receive a 'Supporting Member' banner, or become a 'Supporting Vendor' and promote your products here. Click the banner to find out how.

Latest posts

Truck of The Month


Kirby N.
March Truck of The Month

Recently Featured

Want to see your truck here? Share your photos and details in the forum.

Follow TRS On Instagram

TRS Events

25th Anniversary Sponsors

Check Out The TRS Store


Sponsored Ad


Sponsored Ad

Sponsored Ad


Amazon Deals

Top