1991 Ford Explorer 4.0 OHV Cologne: Oil Recommend?

[natenkiki2004]

I tried doing a search on here and didn't see much in the way of discussion for these 4.0L engines. I just got myself a used 1991 Explorer that has done a bit of sitting around for the last 2 years. Assuming the previous owner was doing 3,000 OCI (he has the next change due in 2,873.2 miles) it has been driven 126.8 miles in the last 20 months. The previous owner was very good at maintenance and proper care but he didn't have much use for this vehicle and was looking to move on (it's got problems due to age but not enough to scrap the car).

When I got it home, I put 12oz of MMO in the oil (due to a valvetrain tick when cold) and 12oz in the half-full tank. I plan to drive it a bit more to let the MMO do it's thing but I'm wondering what oil you guys would recommend. I'm not too concerned on price as this won't be a daily driver and will likely only have 1 oil change a year. It's hard to tell but I think the engine has 224,526 miles on it but as far as I can tell doesn't burn or heavily leak oil. I've pulled a couple spark plugs and they are old enough to be rusting and have some electrode wear but otherwise look good in terms of fouling.

I'm leary of synthetic in an older engine but I've done 2 changes with Valvoline MaxLife High Mileage which is labeled as a blend in a 92 Suburban without complaint.

Shoot me some suggestions, I'm open to anything! Thanks.

 

[daves87rs]

I'd throw o\in the cheapest oil (house brand somewhere) dino, drive it for a few thousand miles, keeping an eye on the oil. Hopefully at that point you will see where you are at.

Thinking any high milage oil after that would be a good start....

 

[Thax]

I would use Pennzoil High Mileage 5w-30 or QS Defy and throw in some Motorcraft plugs. A bottle of Redline Si-1 or Gumout all in one might be a good idea as well.

 

[natenkiki2004]

I'm going to get some Motorcraft copper plugs tomorrow along with a NAPA gold air filter and oil filter. When installing the plugs, I'll check the wires with a multimeter.

As for the oil, it's going to be a bit hard for me to put a couple thousand miles on it. I got this car to basically learn how to work on cars. There's a typical trans issue with it and lower ball joints and u joints need replacing. Until those get done, I don't feel good with packing too many miles on. With that said, it does drive as-is and I do want to run it, if nothing else just to see what else needs doing on it. If the MMO doesn't seem to help in the next 100 miles or so (I know it was a low dose and low amount of miles) then I might drain and fill with cheap dino and stronger dose of MMO or something else depending upon recommendations.

 

[901Memphis]

Maxlife syn blend or Pennzoil HM.

 

[toneydoc]

Thax gave you good advice

 

[exranger06]

Those old 4.0s are known to tick as they get high mileage on them. The rockers and push rod tips don't get enough oil and get worn, which causes the tick. No oil nor MMO will fix that. The tick is pretty harmless and the engine will run a very long time despite the tick.
Changing spark plugs isn't too bad. The one on the passenger side closest to the radiator is the hardest one to change. You need to remove the plastic inner fender liner to get to it.

I have a 1st generation Explorer too and I've put a lot of work into it. I know a lot about these trucks. Let me know if you have any more questions.

 

[Bandito440]

Start with Maxlife 5w-30. You can jump to the 10w-40 if you find it using a lot of oil. I wouldn't worry about the MMO. That's just going to dilute and thin out the high mileage oil.

A bottle of Techron or the Red Line fuel treatment in the first couple of tanks will help too.

 

[SwampSurvivor]

If the trans is having a problem, it would need a rebuild ...

I recall a lot of noisy 4.0 OHV engines. And I have seen a few of them in parking lots with broken lower ball joints.

 

[4D-56]

Sounds like a good Kreen candidate. Use it in the oil and the fuel, as per directions, dont get scared to put in the oil and leave it for a full 3K OCI, its crazy good stuff.

Having used both Kreen and MMO in my old '89 300K Astro, there was NO comparison between the results.

 

[95busa]

Motorcraft filter for the win

 

[05LGTLtd]

12oz of MMO in half a tank is quite a dose. Personally I'd top that tank off with some fresh quality gas to full. Unless you have a 30 gal tank, you will still be over the recommended dose.

Any HM 5w30 as has been suggested. Motorcraft filter and plugs. Check the age dating sticker on the battery with winter coming on and clean up your terminals and grounds. No need for the MMO in oil, of you want to run it, just add to oil the last 200-300 miles before next oci. I like MMO, but as others have stated its not a cure all.

Two door of four? Pics?

 

[natenkiki2004]

Originally Posted By: 05LGTLtd
12oz of MMO in half a tank is quite a dose. Personally I'd top that tank off with some fresh quality gas to full. Unless you have a 30 gal tank, you will still be over the recommended dose.

Two door of four? Pics?

I got some more gas in it today, 3/4 tank now. It shouldn't hurt much having a higher dosage. Seafoam says more won't hurt I think. They're all pretty much the same. Solvent and thin lubricant I believe. Here's the only picture I have right now:
https://dl.dropboxusercontent.com/u/4643...5_131224867.jpg


Originally Posted By: exranger06
Those old 4.0s are known to tick as they get high mileage on them. The rockers and push rod tips don't get enough oil and get worn, which causes the tick. No oil nor MMO will fix that. The tick is pretty harmless and the engine will run a very long time despite the tick.
Changing spark plugs isn't too bad. The one on the passenger side closest to the radiator is the hardest one to change. You need to remove the plastic inner fender liner to get to it.

I have a 1st generation Explorer too and I've put a lot of work into it. I know a lot about these trucks. Let me know if you have any more questions.

I have read on the tick and that it could be wear related or possibly not enough oil due to gunk buildup. In case it's the latter, I put $4 down on a bottle of MMO. If it does nothing for the tick, I might try a stronger dose and if that doesn't do anything, I'll give up and focus on other issues. I know the previous owner went through the whole valvetrain and I believe replaced a fair bit of parts but it still ticked after that.

I did the spark plugs today, the one closest to the firewall on the passenger side made me utter a few choice words, especially when my socket decided to leap from my hands and wedge it's way into a nook that I only found 40 minutes later. I was finally able to get at it and torque the new one in properly. Can't say it changed much as far as cold startups but at least it's done and I'm becoming more comfortable with the vehicle.


Originally Posted By: Miller88
If the trans is having a problem, it would need a rebuild ...

I recall a lot of noisy 4.0 OHV engines. And I have seen a few of them in parking lots with broken lower ball joints.

It's been rebuilt, twice

I believe the major issues were worked out in it. The cold shifting issue it has is likely the governor on the output shaft. Lucky for me, all these common issues are well-documented and there's a few tutorials on how to fix them

Anyway, looks like Valvoline MaxLife High Mileage or Pennzoil High Mileage. I'll see what the prices are at Walmart. I might try Redline or Kreen after this session of MMO runs it's course. If I do put something else in the oil, I'll just get cheap dino and do a quick OCI. I picked up a NAPA Gold filter today (air and oil). I'm seriously thinking of getting one of those cone air filter kits just to do away with all the plastic and extra space the stock airbox takes up.

Thanks for the input guys. Any other thoughts/ideas are welcome.

 

[901Memphis]

I have another suggestion which was already mentioned once...MOTORCRAFT FILTER! You simply can't beat them at walmart for less than $4.

 

[natenkiki2004]

Originally Posted By: 901Memphis
I have another suggestion which was already mentioned once...MOTORCRAFT FILTER! You simply can't beat them at walmart for less than $4.


I'm assuming oil filter? I thought it was just recommended due to it being "OEM", not because it performed extraordinarily well. NAPA is significantly closer than Walmart (20+ miles each way to Walmart, probably 1 mile total for NAPA). I'll do some research on here and if they're worth it, I'll pick up a spare Motorcraft.

In all reality, being that this vehicle won't be a daily driver, it'll be lucky to have 1500 miles on an oil change in a year. While I do want to buy quality products, surely NAPA gold is better than 70% of the [censored] on the market?

 

[901Memphis]

If NAPA is closer i would go with the Napa Gold, but i prefer the Motorcraft filters. The Motorcrafts come with silicone ADBVs in some of them and the correct thread end by pass valve for cheap.

 

[natenkiki2004]

Well I gotta go to Walmart to get some high mileage oil so I'll check the filters too. I looked on the website and it showed 3 Motorcraft filters. Is that all there is? Do you or anyone else happen to know the model I would need?

 

[901Memphis]

The correct filter for your engine is the FL1A, which is one that Walmart will has, since its so popular with most ford motors. Also the FL400S will fit but is smaller in size, it has a silicone antidrainback valve, but either will work.

If your engine has the oil filter mount with the opening of the filter at the top an completely vertical like i think it is, then you would probably want the FL1A, since its got a higher capacity and since its at the perfect angle you won't need the silicone valve.

If you want another high quality filter check out the Fram Tough Guard TG8A they sell that there too.

 

[natenkiki2004]

Cool, I have made a note of it

Thanks for the help and info.

 

[Lyman]

Im running the Pennzoil HM in my 4.0. I normally use the Motorcraft filter but Walmart was out of stock last time. I grabbed a Purolator Classic. I run 5k OCIs with mine but it has a lot less miles then yours.