I'm in the process of buying my dad's 98 Ranger XLT 4.0. The truck has around 180,000 (highway) miles, very well maintained, near perfect shape. Only problem is he's used Penzoil 10W-30 for every oil change. I'm not a big fan of Penzoil, and would like to run Valvoline like I do in my other vehicles. Does anyone see a problem with switching oils after 180,000 miles of uing Penzoil? Just don't really want to cause any problems by doing the change.

Thanks!

I don't see a problem switching oils. you might what to take the oil pan off and clean it first. Penzoil has a reputaion for sludge buildup in the oil pan.
pat

You should be just fine with the switch.And ya check for sludge.

My 2.9 has had Pennzoil 10w-40 in it since it was new; after 213,000 miles I have never had a problem with it, and my block is as clean as can be no sludge ever. I know what you mean, the reputation of Pennzoil turns a lot of people away but I perfer it over many other oils...

Note: It was the old formula many years back which commonly sludged up...

As long as it's a dino to dino switch, there should be no problems.

Also, while I don't know how or why the old school rumor of Pennzoil causing sludge got started, nothing out of that company in at least the past 10 years would cause sludge over any other motor oil. Pennzoil dino is one of the finest dino oils on the shelf today.

If anything, Valvoline dino has a not great rep as an oil that shows marginal VOA results and average to above average UOA results.

If you are concerned about sludge, run the over 100,000 mile Auto-RX program on it with quality filters (Motorcraft, Wix/NAPA Gold, etc., no Fram) and cheap major parts store oil (such as Advance Auto brand, AutoZone brand, etc)...then after that switch to a dino of your choice and call it a day.

Chevron Supreme/Havoline in the jugs at Walmart is probably the best price/performance you'll find anywhere...

Chuck

If the oil was changed regularly, there shouldn't be any sludge build up. If the engine has 180,000 miles of trouble free driving, why switch?

Penzoil and Quaker State use parafinic crude oil, which contains parafin wax. At least they used to, now the CLAIM they dont. Sure it lubricates better, but causes mad buildup everywhere else. So use your own judgement when using these oils.

Joe,

I don't believe that to be the case anymore, or even if it is, I doubt it matters.

Here's just one of many links over on BITOG that discusses it:

Noob Question About Penzoil (http://theoildrop.server101.com/forums/showflat.php?Cat=0&Board=UBB1&Number=198953)

In short, Pennzoil will not cause wax or sludge buildup any faster than the other quality dino's (Mobil, Chevron/Havoline, Castrol, Valvoline, etc)....

Chuck

Penzoil does STILL cause sludge. My truck had MASSIVE slug build up from using pensoil.

However its an easy fix,just run ATF fluid in it for 500 miles,watch that oil pressure RISE!

Muffinmann- If you had massive sludge, then it was from something other than the Pennzoil...coolant ingestion maybe...

...running modern Pennzoil in a healthy engine is not going to produce sludge....if it did, it'd be getting slammed over at BITOG left and right, and the opposite is true.

Also, the reason some see a pressure rise when dumping ATF into the crankcase is that ATF is a light 20W, so it gets in where the thicker (even if what's being used is a 5W-30) regular oil can go.

ATF does not have the amount of detergents in it that regular motor oil has...maybe 50 years ago that was true, but it is not for modern lubes...

Chuck

Penzoil and Quaker State use parafinic crude oil, which contains parafin wax. At least they used to, now the CLAIM they dont. Sure it lubricates better, but causes mad buildup everywhere else. So use your own judgement when using these oils.
Most all motor oils are from parafinic crudes. This is the base. And although it is a waxy substance, it IS NOT like candle wax, and will not cause sludge. Years ago, all the oils would develope sludge if the oil was not changed regularly. But the sludge was mostly caused by contaminants getting into the oil, not the oil itself. The carburetor was the biggest contaminator of all. joe b

Got to love oil threads.....
Like someone else said, if it's been doing fine with all these miles why change? Why don't you like Pennzoil? Did someone tell you something about it without hard facts?
Most oils today are detegent oils so they are self cleaning. Changing your filter cleans the crap out. Have you ever seen change you oil in xxx miles but change filter in 1/2xxx miles?
Most old oils were nondetergent. A big problem back then was when some kid would buy grandpa's car that ran perfectly fine and the kid puts detergent oil in. Now all that sludge breaks loose and causes all sorts of problems.
That crap about using synthetic oil in an older engine is crap too. My old S-10 used to get the Amsoil oil I drained out of my motorcycles after it had 100,000 miles on her. Then in the winter when I didn't feel like climbing under her she would get dino oil at Expresslube. She has +170,000 miles on her and just the other day the old guy that bought her from me was telling me how much pep she had passing another truck.
Of course nowadays thanks to some dumbass judge's ruling there are only 3 companies that are truly full synthetic and Amsoil is one of them. He decided that synthetic oils made from dino oil base (saves big bucks for the oil companies) can be called synthetic.
Most oils are good today the important thing is for the owner to make sure the oil and filters are changed. Yes, you don't have to change every 3,000 miles anymore. That was back in the day when oil was sold in open glass containers with metal spouts and the gaskets and seals were real crap in the motor. Yes, I remember those containers out in front of my uncle's garage.
If you doubt this in any way, just take oil samples and have them tested (NAPA is one place that does testing). I know a motorcycle rider that has over 500,000 lifetime miles just on motorcyles and has done it for years. The proof is in the analysis not what someone tells you or what your "gut" tells you.

I was never a Pennzoil lover either, but I've got an old motorhome that has kind of made me change my mind.

It's a 1978 model with a Dodge 360 engine in it. One of the exhaust manifolds cracked and I broke every stud and bolt off trying to get the manifold off. Ended up having to pull the intake and head to replace the broken studs/bolts.

Inside the valve covers looked brand new, shiny and just an oil film, no buildup at all. And the lifter valley was the same way, where you usually get sludge buildup in the low areas it had absolutely none. I imagine it had regular changes and it's only got 65,000 miles on it, but it is 28 years old and never had anything on the engine removed before. And every oil change sticker on it had 10w-30 Pennzoil on it. Plus the engine is quieter than the one in my Ranger.

I'd say if it still runs good and has no noises, leave well enough alone.

I'd stick with what got it to 180,000 miles!

Years ago the carb was the major cause of oil dilution. Gas
would get washed down the cylinder walls and get in the oil .
Maybe some that change their own oil will remember how runny the oil was when it was drained. That was part gas, mostly oil.
The newer vehicles with fuel injection ( everything working properly ) are much harder to flood and hence, much less prone
to oil dilution. I've babied some vehicles with nothing but the best and others got the Walmart special oil. Except for starting
in the winter, I didnt notice a difference. The only constant was regular oil changes and oil filters.

NGZ