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Pennzoil and Sludge!

38K views 63 replies 43 participants last post by  weirdbeard 
#1 ·
Pennzoil and Sludge!

Now I'm trying to find out as much as I can about this old time reputation that Pennzoil was renown for Slugging engines.

I want to collect info from both sides of the fence, the technical info to back up that they don't / or do sludge, and real life experiences from engines builders and the general public.

Of cause, if your one of these people that only change your oil once a year then I would expect it to have a sludge problem over time, but I would like to hear as much as I can from the people that do regular changes and there comments and experiences.

I know there are many people that say, this is imposable with the current standards that oil has to pass and so on, but I'm trying to find out where this myth started form, and if anyone has any first hand experiences, past or present.

So I would be so appreciative of any info at all I can get.

Just out of interest, the first comment I have received:

(I recently spoke with one very well know retired engine builder in the states that is apparently well known among Hot Roders, who told me , that over the years of rebuilding engines, he noticed a common sludge issue with customers that were using Pennzoil oils)
 
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#2 ·
The worst sludged engine I ever tore down was using Pennzoil.
But that was in the 70s

Troy

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#3 ·
Well this isn't very technical but my mom also has an 85 Caprice, hers has 170,000 miles, the last 140,000 she put on it are Pennzoil miles and there is no sludge build up, and that motor runs great, but to be fair the oil gets changed every 3,000-3,200 miles.

I wouldn't be surprised if Pennzoil was more likely to cause sludge build up when driven past normal change intervals, it appears to have more impurities in it than most oils.


Check this forum out, they are dedicated to motor oil.
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#6 ·
from what i know, which is alot more than 36willys on this subject, :pimp: that reputation came about back when penzoil came from pennsylvania, which it no longer does, because there isnt any oil there anymore.
 
#8 ·
On the Pennzoil issue. Yrs ago around 72,I got started working on fuel cars.Everyone used Pennzoil,and I noticed that when the oil came out of the engine,it looked like baby you know what when it came out in the drain pan.Also the #3 and #4 Main had to be changed every pass. Now this was when we still had iron blocks with forged cranks,but I noticed that another racer used Valvoline and never had the pan off.the oil looked like oil coming out. I queried him and he said didnt have any probs with mains,unless he got his tune off of course.Now the weights were 60 pennzoil,70 Valvoline.I got 12 qts and put em in and the mains looked gd the next pass.this was with the old pennsylvania based crude.Convinced me!
 
#9 ·
Bull is partially right. It used to be that if you used PennZoil you needed to stick with Pennzoil, Quaker State, and a couple of other brands that came from that area. The same went with the oils from the Texas / West Coast area. If you stayed with those brands and changed oil on a regular basis you would not have sludge. The biggest factor was changing oil on a regular basis though. The majority of owners would put on twice or more miles than the recommended oil change. Then it was alway said that the Texas based oils were a petroleum base oil and the Pennsylvania oils were a parrafin based oil. The combining of these two oils was not completely compatable and would produce a thicker sludge like base. That combined with past due oil changes only added to the factor. PennZoil got a bad rap around here because it was so popular. People started sswitching to Texas based oils but would throw in some Penn because it was more convenient and on the shelf so when things happened..... But cars have changed drastically, the refinement of oils have changed drastically, and there are very few refineries although there are still a multitude of brands of oil. The largest factor is change oil every three thousand, change the filter at the same time, and your cars engine will last. For just a few bucks every three months you can't ask for better protection.
 
#10 ·
Pennzoil

I have been a Honda Tech for about 10 years.You can always tell when the people have been useing Pennzoil.After taking the valve cover off to adjust the valves.The rocker arms will have a redish color to it.I have seen engines sludged,but as already stated it is always from lack of maintance.
 
#16 ·
Pennzoils old time formulation had a high level of parrafins which would congeal after high mileage on engine surfaces, this is from the turn of the century when designing oils for lubrication was hardly a science. I doubt a rated oil will cause you any problems if changed regularly, not quite a wives tale but in this day and age it is approaching that level along with the battery on concrete BS.:rolleyes:
 
#19 ·
I'd like to add to S10Blazer's post.

If you go to synthetic, does it hurt if you go back to non-synthetic?

My cousin was told by a lube shop that if you go to synthetic, you have to stay with it, else it will harm the engine.

Another thing, do heavier weights (ie 20-50) make an engine last longer that lighter weights (10-30 or 5-30).

Personally, I use Mobile One synthetic in my Bird and 4Runner and Castrol GTX (10-30) in my Blazer.
 
#20 ·
oils

A little unrelated but possiblty a tip off - I do know that if you swith either way - standard vs synthetic- in BRAKE FLUID - you better clean it out very very well. I don't know if that is because of fluid pressures being affected by the opposite material but it makes me wonder about engine oil changes.
 
#21 ·
sludging Pennzoil

I'm not an expert, but during my years of operating a Texacp gas station (remember them?) I tore apart a number of engines and each time I would ask the customer which oil they used, how frequent the oil changes and the type of driving. And here's some of the info I found:

It appears that both Pennzoil and Quakerstate had the higher level of sludge build up on vehicles which drove short distances or a lot of stop and go. However, on engines which performed many highway runs, the engines were cleaner but did have a fair amount of tarnish buildup.
And engines which used Valvoline, Castrol, or Kendall appeared cleaner, and interestingly, had more miles.
Now, an old timer once told me that the reason for this was because Pennzoil and Quakerstate come from the same region and both have a higher level of sulfur content. Is this true? Sounds good.

I hope this helps, somewhat.
 
#22 ·
Years ago when I took organic chemistry, we learned there was a definite advantage to using the Pennsylvania oils because they had a higher resistance to breakdown under heat. With the advantages of modern additives, this may no longer be the case.

Pennsylvania still has plenty of oil,it's just not as cheap to produce it.

I like Pennzoil. 15 years ago, when I bought my wife a Subaru wagon, the dealer recommended Pennzoil. I change my oil every 3-3500 miles and so far have 217,000 miles on this engine which still runs great.

I think the answer to the discussion here is MAINTENANCE.
 
#23 ·
Most synthetic oils have a high detergent content and switching to synthetics on older high mileage engines may create leaks. Sometimes sludge is the only thing keeping the oil from seeping past deteriorated seals.

Synthetics should be good at preventing or even removing sludge buildup.
 
#24 ·
For new engines, I typically use Valvoline 10-40 through the break-in period, then switch over to a Valvoline synthetic. On older engines I use dino oil and don't waste the money on syns.
It's true, though, that sometimes the sludge is the only thing holding things together. I've seen this occur more than once - better leave well enough alone.
 
#25 ·
Sludge

Back years ago, early and mid-sixties we were always told Quaker State caused sludge. Ran nothing else in my 54 Ford. No problems as long as that was all you ran. They said it was because it was parrifin based. Don't know but that's the rumor. I always swore by QS cause that what the engine used since new.
 
#26 ·
My father and grandfather both swore by Pennzoil and Quakerstate. In fact, my grandfathers 1960 Starliner had over 200K on it. And, they both said once you start one brand of oil stick with it.
Now years later here's my take on oil:
Use a name brand (they all pretty good these days)
Change it frequently - even be anal about it
Always, always change the filter (use the best filter, too)
And drive, drive, drive!
The more the engine spins at higher (typically above idle) RPM, the higher the temperature thus the lower moisture accumulation in the engine and other volatile buildup.
 
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