I'm a new member with an '03 FX4 4x4 4.0l SOHC.

When I start it cold, I think I'm hearing rods knocking. It sounds like 6-8 knocks, then it goes quiet. A friend of mine thinks its the rod bearings.

I want to remove the oil pan and measure the crank and bearings and need to know if the oil pan will come off with the motor in the truck.

Are there any tricks to make this easier? Do these motors have a problem with rod bearings?

I've seen a lot of Youtube videos about timing chain problems with these trucks. My truck has 126,000 miles on it, how hard is it to change the tensioners? Any tricks or pitfalls involved?

Does anyone have any other advice about the knocking noise on cold start?

Thanks in advance
-James

are you sure it isnt the timing chain tensioners? that happens on the 4.0 OHC on cold starts

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2021 F150 5.0 Screw

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It is probably the timing chain tensioners. My wife had a 99 Explorer Sport that had 225K on a 4.0SOHC & it did it on cold starts, once it warmed up it went away

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2000 Ranger Extd Cab XLT, 4X4 Off Road, 4.0L, Auto, 8.8 - 4.10's, 01 grille & lights swap.
69 Mustang, modified 5.0, & 5spd.(project)
99 Explorer Sport, 4.0 SOHC, Auto, 8.8 - 4.10's, PW, PL, PM, Cruise, Tilt. (Wife's DD)
05 F-150 2WD Regular Cab. ( My DD)

Thanks for the replies.

No, I'm not sure.

It only rattles for 1-2 seconds, and only on a cold start after it sits for a couple of days.

I'll start it and let it run for a few seconds, turn it off, and it wont rattle if I start it again.

The Youtube videos I've seen on timing chains don't sound like my engine on cold start.

I've considered the chains as a possible problem, and that's why I'm asking about changing the tensioners, as well as the rod bearings.

How easy is it to get to the rod bearings?

Thanks
-James

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-2003 Ford Ranger 4.0l SOHC

That sounds exactly like the tensioners. Replace them. Easy to do

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2021 F150 5.0 Screw

Past:18 F150 2.7, 16 F150 5.0, 14 F150 5.0, 07 F150 5.4, 03 Ranger 4.0

Master Certified Ford Parts / Warranty Admin

As far as I can tell, I would have to remove the intake manifold to get the front tensioner, is that correct?

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-2003 Ford Ranger 4.0l SOHC

Thanks for this reply

This answer "sounds' like your motor was continuously making noise until it was warm.

My motor makes noise for 1-2 seconds and clacks like a diesel for about 6 clacks.

I know in the long run the chains are suspect, but I just don't think they are my problem right now.

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-2003 Ford Ranger 4.0l SOHC

Thats definitely your tensioners. the rear is a breeze to change but the front is more involved.
Make sure you get the metal gasket off the old tensioners or you will have a leak...i didn't see the gasket when I did my rear tensioner and it started pouring oil on my exhaust.

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1998 Jeep Wrangler TJ 4.0 5spd - Sold
2001 Mustang Bullitt - Sold
2005 Level II - Sold
2001 Integra GSR - Sold
1999 XLT - May 2013 TOTM - Totaled

To answer this question I've heard guys say to put the motor at TDC to get a little more clearance.

I would take their advice on the tensioners as well.

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97 ORIGINAL
4.0 XLT Reg Cab Manual on Manual Transfer
Best truck I've ever owned.

Thank you all for the attention you are giving us and out tensioners.

We are researching tensioners in our local JY's, as well as this site. These are our current results....
^^^NOT THE NOISE^^^
^^^NOT THE NOISE^^^
^^^NOT THE NOISE^^^
^^^NOT THE NOISE^^^
^^^NOT THE NOISE^^^
^^^NOT THE NOISE^^^
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Similar to 33-36 second mark on this video, only 6-8 clacks cold starting and not ever afterwards, not while revving or anything else...only the first daily cold start
Only listen to the 33-36 second section, none of his revving is the same, only 33-36 seconds....
Our sound is a little heavier clunkier sounding also.
Can we get a little advice on question #5 below??
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JY Learning
.We pulled 11 tensioners from 5 different motors (6 fronts & 5 rears) and found they all feel almost the same for spring tension.

..We found 3 of the 5 rears had thick copper washers (0.060") and 2 had no washers, with none leaking oil until they were removed. It kind of says maybe 2 were replaced at one point in time, (or were 3 replaced). All 5 of the rear tensioners were clean looking-not having any coking accumulation, (but they gushed lots of oil when they were removed, maybe they were submerged all the time?).

...We found 4 of the 6 front tensioners were heavily coked and 2 were almost new/clean, and none had a thick copper washer, but some had a very thin shim type of washer, (maybe 0.005" thick).

....Also we noticed some tensioners (maybe 4) only compressed about 3/8" and became firm, (maybe they were pumped up with oil?), and the rest compressed all the way until they were flat with the main body, and all were very close in compression force, After playing with the 4 that would not compress initially they became compressible as well.

.....We also compared a new parts store tensioner to the removed used ones and it felt to be of similar strength/resistance to being squeezed into its main housing. (we know you do not recommend chineese parts store parts, but this was only a spring compression feel test).

So now for the questions---
1. Out of the 11 samples above, could they ALL be faulty? Even the cleaner-newer looking ones?--All were Factory Ford Parts with Ford part numbers.

2. How soft do they get before they are considered faulty?

3. Does anyone have a spring force-weight-pound rating on the spring? (If you were to compress a tensioner pointed down, on a bathroom scale, what would the scale read just before the main body contacted the scale?) Does anyone have a new Ford unit to compare the bathroom scale readings to? How about a bad tensioner reading??

4. 3 of the 5 rear units had thick copper rings, and none of the fronts had copper rings, should we install a left-over thick copper ring on the front unit? Is the thick copper ring correct for the front? For the rear? Is the thin shim ring correct? Are they the same front & back or different from each other?
Thin Washer 0.005" thick?

---We will probably remove & inspect the current tensioners in the truck this weekend & we just want to have an idea of what a good one looks & feels like vs a bad one. We will then have 13 to compare to each other.

5. Can the complete oil pan assembly come off of the motor while the motor is still in the truck?-No one has commented on this question. Please? Tips?? Tricks??? General Knowledge????

Thanks again for all of the advice,
James

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-2003 Ford Ranger 4.0l SOHC

The link you posted to my video was an exhaust leak at the intake manifold.

What you have is the timing chain tensioners. Even if it isn't you still should replace them because it'll save the engine in the long run. The diesel clack noise is the loose chain slapping around

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At this moment we still do not KNOW what the noise problem is, but we do know the engine bearings are in excellent condition. We pulled the oil pan & cradle off and there was barely a scuff mark on the bearings, so as most of you have said, -->CHAIN TENSIONERS<-- are next. Also there were no plastic pieces in the pan either.

***No one has offered answered my question about testing the cam chain tensioner springs on a bathroom scale to see what a good spring strength is and what a weak spring may show as.***

I am hard headed, especially when the evidence does not match the circumstances as shown by the video/audio links we have provided above.

We have a new problem--before the tensioner evaluation...

In dropping the oil pan & cradle we had to lower the front differential/axle assy(4x4). Now we can not seem to see how to reconnect the drivers side of the front axle tube to the frame. There just seems to be no reasonable access to the front nut, . . . unless, . . . can we remove the drivers front tire to get access to the front of the axle tube mount area.

It is cold & wet & dark, and we just did not get the wheel off tonight.
Is this a practical way to access the front nut on the drivers side axle tube mounting bolt?

Thanks for your advice
James

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-2003 Ford Ranger 4.0l SOHC

Are you referring to the nut that holds the CV axle to the hub? If so then all you have to do is pop the hubcap off the wheel and it's right there. Torque to 186 FT/Lbs

And there isn't really a scale you can measure the tensioners "pressure" at. But if you look at some videos on YouTube, tired tensioners often are relatively easy to push in, and new ones require a lot more force.

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Once you get your truck back together, you will most likely find that you still have the engine noise you have been talking about. Start basic, change the oil and make sure you use a motorcraft brand filter. some of the cheaper aftermarket filters will allow some of the oil from the filter area to drain back into the oil pan and give you the same type of noise you hear after an oil change. Also, Ford requires 5/30 oil. The 4.0 SOHC requires it. The timing chain tensioners that everyone has told you about is a common problem with the 4.0 and I believe Ford even had a TSB about engine noise and replacing the tensioners first. I know that some of Fords tensioners are oil pressure operated, so they can bleed off when they begin to fail and allow excess play in the timing chain. Once you start the engine, they fill back up with oil and maintain tension until the next time the engine sits for a prolong period of time.

Start simple, cheap and basic, then move up to labor intensive options, like pulling oil pans.

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2007 RANGER FX4 LEVEL II 4.0 AUTO

Thanks for your answers 02RangerFX4, but...

No it is not related to the CV Axle nut. It is the axle tube mount on the drivers side, between the starter and the body, near the heat shield for the brake lines. The bolt points forward and has a tabbed nut on the front of the frame, which we can not reach well enough to hold the nut in position while the bolt is being tightened.

We have not seen any videos demonstrating the weak tensioner vs fresh tensioner, do you have a link??

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-2003 Ford Ranger 4.0l SOHC