[Medic213]

Hey, guys!

2003 Exploder 4.0L 4WD (I'm assuming it's a balance shaft motor), 182k. Engine is making noise. Sounds like the dreaded timing chain rattle. Since the timing chain tensioners are spring loaded hydraulic pistons I'm thinking of running a thicker viscosity oil and/or adding Lucas to see if the boost in pressure from the thicker oil will help. Just wondering if anyone has run a thicker viscosity oil in their 4.0L. If so, what was it and how did it go? I'm thinking Mobil 1 15w50.

Thanks!

 

[DILLARD000]

...2003 Exploder 4.0L 4WD...balance shaft...182k
...timing chain rattle...tensioners are spring loaded hydraulic pistons
...thinking of running...thicker viscosity oil...15w50

Wow! I would definitely NOT run 15w50 in a V6~4.0L~SOHC.
Unless driving Sahara desert 130f conditions, 15w50 is much too thick compared to stock 5w30; suspect 15w50 would clog those Tensioners PDQ.
Is chain rattle just during very cold starts; does it continue with engine warmed up?
Your profile is sparse on vehicle specs & climate\driving conditions.
I drive HighAltitude cooler conditions, 0w20~FullSyn Winter, 0w30~FullSyn Summer, good results. 0w prefix means oil is same thickness cold or hot, so OilPressurized TimingTensioners get oil quicker at ColdStart. In a more typical climate I'd use 0w30~FullSyn year round; in a hotter climate 0w40~FullSyn year round. Those TimingTensioners+Guides need a good Supply\Flow of Oil; thicker Oil may increase Pressure but not Flow. Whatever oil weight you choose, most critical is that you change the Oil+Filter often.

Sounds like you should
~ drop OilPan
~ check for broken TimingGuide pieces
~ clean OilPump screen
~ confirm presence of BalanceShaft, seen up thru engine girdle, mounted in front of OilPump
If you don't find broken pieces in OilPan, you may be lucky & not have broken guides yet
~ replace LeftFront+RightRear OilPressurized TimingTensioner with new FordOE only
~ dont use cheap Chinese Tensioners, they fail often+early
If you find broken pieces in OilPan, you need to
~ open left+right ValveCovers
~ inspect LeftFront+RightRear TimingChainGuides\Cassettes
If LeftFront Guide\Cassette is broken, it can be replaced without pulling engine.
If RightRear Guide\Cassette is broken, replacement requires pulling engine.

Hope this helps.
Detailed info on replacing OilPressurized TimingTensioners in a V6~4.0L~SOHC at

Engine Oil Pressurized TimingTensioners

As of this 2020 writing, I am just dumb lucky, not having had any TimingChain component failure with this 20Year old V6-4.0L~SOHC engine; the only item noticed is momentary rattling with very cold morning starts. The recent removal of the lower oil pan & pumps screen was clean without any...

2001fordexplorersporttrac.fandom.com

Engine Oil Pan+Screen

16mm+13mm+10mm+5/16"HexHead Wrenches+Sockets+Driver+SwivelExtension+Ratchet Clean PuttyKnife: ThinBlade Oil Filter OffOnlyWrench For TightSpace: GearWrench Or ModifiedWrench CatchPan, ReCycleContainer, AbsorbantLitter, ShopRags, WheelChocks, Jack, JackStands Carb+Throttle SprayCleaner: CRC \...

2001fordexplorersporttrac.fandom.com

Engine Oil Change+Filter

Oil+Filter changes are an often neglected, greasy, lowly task, however they do preserve & extend a vehicles life. For vehicles or engines under warranty, best to Use+Document OEM spec Fluids+Filters+ServiceIntervals, so to not void that consumer protection. For a new vehicle\engine, changing all...

2001fordexplorersporttrac.fandom.com

 

[Medic213]

Wow. Excellent information! All I was able to obtain thus far was that you have to replace both timing chains and all associated parts and since Ford planned on the timing chains not being serviceable you have to pull the engine.

Considering that, if I'm pulling the engine out I'm putting in a new one. Not replacing timing chain and associated parts and putting it back in, and that's not gonna happen on this Explorer. Unfortunately the guy I bought it from drove it around up north and didn't take proper care of it. It actually looks okay from the outside except for a small rust spot on the passenger side rear quarter panel above the wheel well, but open the doors and it's rusted clean through in most places.

I know the text book answers as to what oil to run, but imo the push to 5w30 and 5w20 was fully related to squeezing as much gas mileage out of vehicles as possible and the changes made to clearances were more about preventing oil burn and blow by than it really prevents you from using a thicker oil. I know plenty of other newer engines spec'd for thinner oil where people have been running thicker oils long term with no issues, so I was hoping to find someone that has done this on a 4.0L. There's actually a guy on another Explorer page that answered that he's been running Rotella 15w40 for 5 years on his 4.0L with no issue.

Mobil 1 15w50 and Lucas went in a few days ago. The timing chain noise was bad and now it's barely audible. I think the tech who did the oil change was even more surprised than I was. Only time will tell now, but I suspect the timing chain issues will take out the motor long before the valves or anything else, and call me crazy, but I think the motor itself actually sounds better now.

A 5w or 10w oil would be better for cold start, but 15w oils are recommended for use at temperatures as low as -4°F. For NC, where I am, that's fine. I think the SAE 50 should be just fine. SAE 30 kinematic viscosity range at 100°C is 9.3 to 12.5cst. Mobil 1 15w50 kinematic viscosity at 100°C is 18. Regular Mobil 5w30 has a kinematic vicsosity of 63.2 at 40°F. While we all know that it's not good to run your engine at that temperature for a prolonged period of time, engines run at and below that temperature at start up all the time without blowing lifters, bearings, etc. I feel pretty comfortable with the operating temperature kinematic viscosity of 18.

I know everyone will still be skeptical, so figured I'd be the guinea pig, but this new found information has me reconsidering if I should try to address the actual timing chain issue itself. Thank you!

 

[DILLARD000]

@Medic213
Do update this thread in a few weeks\months, as to how 15w50 works for you.
If you don't know if\when the two Left+Right OilPressurized TimingTensioners were replaced new,
that should be done, about every 75k~100kMiles. Parts cost $100~$150 for both.
RightRear is easy to change; LeftFront is a bit more difficult depending on IntakeManifold version.
Again most important thing is that you become OCD about changing the Oil+Filter.

 

[4.3Lxj]

I can agree with the OP on running thicker oil on high milage engines. Yes the move to oil with less viscosity was an effort to get some fraction of milage for the CAFE standards. As an engine wears, it requires an oil with more viscosity to take up the slack in the engine bearings. That thin as water oil being recommended now does not do that. Many engines from the various companies start failing prematurely as the bearings wear and suddenly develop engine knock. A classic example of this is the Jeep 4.0L that went from a 300K+ engine to a 150K engine with the change to the thinner oil. One thing I think would be good for the 4.0L, and will be going in our new acquition with the first oil change, is a product called Power Punch. It is old school stuff, predating other products like Lucas oil additive. But according to their engineers it does not affect engine oil viscosity. It is an extreme pressure additive. I have used the gear oil additive for years with great success in various vehicles. I can imagine it would probably extend the life of those timing chain tensioners too.

 

[grumpenstein]

Hey, guys!

2003 Exploder 4.0L 4WD (I'm assuming it's a balance shaft motor), 182k. Engine is making noise. Sounds like the dreaded timing chain rattle. Since the timing chain tensioners are spring loaded hydraulic pistons I'm thinking of running a thicker viscosity oil and/or adding Lucas to see if the boost in pressure from the thicker oil will help. Just wondering if anyone has run a thicker viscosity oil in their 4.0L. If so, what was it and how did it go? I'm thinking Mobil 1 15w50.

Thanks!

I tried just that in a 2004 with same engine and same issue. the heaver oil took over half the rattle out at cold start but went back to the same rattle within a minute or so. I don't think there is a quick fix at all, sorry.