: Royal Purple in 1980 coupe deville?



durrk
01-16-06, 02:49 AM
hello... Im new to this forum and have a question,

I recently bought a 1980 Cadillac Coupe Deville, and its in excellent condition... It has a little over 87,000 original miles on it, runs very, very nice. The owner had classic plates on it and told me he never drove it in winter so to take care of it.

Many people have told me it is very rare to find a 1980 coupe deville in this condition and I'd like to give it the best treatment.... I have to give it a tune-up and get a few electrical problems solved but thats besides the point.

Id like to start giving my car Royal Purple starting the next oil change because I have heard too many good things about it. but one friend told me not to use synthetic oils in older cars because it could leak through engine seals... But royal purple isnt an ordinary synthetic oil.

I emailed royal purple about that, this is what they said...
"Using higher performance oils such as RP will not cause seals to leak but it will expose damaged or marginal seals. If your engine is tight and does not have external oil leaks or consume more than a quart of oil in 1500 miles of driving, you should not have any oil related problems. Your friend is not wrong but he also is not right. Conventional oil can also cause leaks as it leaves abrasive deposits, etc which damage seals and causes oil leaks as well."

Id really like to start using royal purple because Ive seen what it has done for some cars and Id like to start giving my car the treatment it deserves. Its been sitting in a garage most of its life.
Is it cool to start using RP, how can I check if my car has marginal or damaged seals? Im almost sure it doesnt because of the cars condition, but how can I check?

Id appreciate any advice or feedback, thanks...

durrk
01-16-06, 01:10 PM
Anyone?:crying2:

Mr_Bam
01-16-06, 02:24 PM
I've heard good things about Amsoil and Royal Purple, however cannot offer any first-hand experience... I just picked up a 79 CDV with 81,xxx and she got the same oil as all my others (well, one car does get tri-synthetic, haha)

cadillacdeville
01-16-06, 06:02 PM
My brother used it in his 79 lincoln it had a small oil leak before he used it and it didn't seem to get any worse.

ReagansRollsRoyce
01-16-06, 06:13 PM
I've never used Royal Purple but I have gotten synthetic since July '04 when I bought my Brougham. There has been no leakage thus far.

Destroyer
01-17-06, 01:41 AM
I use Mobil 1 in my 91 FWB. Its got a 5.7 out of an '87 Iroc in it. I have noticed no leakage but then again this motor was rebuilt less than 8k miles ago. You will be taking a chance. If the folks at Royal purple say your friend may be right, its not a good sign. Its a low compression emissions motor, so I'd play it safe and just put regular oil in it.

N0DIH
01-17-06, 02:21 PM
Honestly as Destroyer said. The Ester/Diester base stocks of the synthetics have high detergent properties and clean the dirt/sludge out of seals and gaskets and often start new leaks that would not have ordinarily shown up.

With modern oils, there is really very little reason to use synthetics over petroleum oils. With an older car, 15W40 is a good choice. The high TBN (total base number) of the semi oils allow it to neutralize the acids for a long time, and the 15W40 (Semi oils like Rotella T, Delo 400 and Delvac) have a high amount of antiwear additives which is helpful for any car with a cam driven dristributor gear like the LT1 (yes, it still has it to run the oil pump), 307, 350's, 305's, etc. Engines without a cam retaining plate should be closely monitored for camshaft wear and timing chain wear as it will easily wipe the cam distributor gear when the cam isn't being pressed into the back of the block. Roller cam cars do not have this issue. I don't know the BB Cad's enough to know if they have this gear or not. All 1985-up Olds 307's are safe from this. 84 and older (any) gas V8's are not safe and need to be carefully monitored for cam wear.

Nutshell, run a good quality dino oil. I run 15W40 and in SE WI winters so far, I have had zero issues with -5F to -10F cold start and still getting near instant oil pressure.

durrk
01-17-06, 05:40 PM
really, ok thanks for the replies fellas...

Being a noob at cars I can honestly tell you I dont know what your talking about with the restricter plate etc. So is there something I should be worried about?

How can I find this out?

durrk
01-17-06, 06:39 PM
Oh yeah, what do you mean by not safe?

So your saying my coupe deville's not safe? Can anyone else confirm this?
Or explain to me in noob terms? Id appreciate it.

N0DIH
01-17-06, 07:03 PM
It is the cam holddown plate under the timing chain. Check out this picture here: http://sporttruck.com/howto/p9195_image_large.jpg that is plate being tightened down. I don't think too many engines have the problem, I learned of mine the hard way. It was a 77 Olds 350 with stock cam that was worn down and the cam starting walking back and forth till it wiped the distributor gear.

No, don't lose sleep over it. It is not that common to fail except on high mileage engines or ones that had the cam broken in w/o cam install lube. And AFAIK Olds it the problem child of it. And only with engines w/o the cam retention plate.


really, ok thanks for the replies fellas...

Being a noob at cars I can honestly tell you I dont know what your talking about with the restricter plate etc. So is there something I should be worried about?

How can I find this out?

durrk
01-18-06, 02:00 AM
Well, Im not sure what I should do...

I still would like to use royal purple, but dont have enough info yet. By looking at their site and hearing what its done for some people is what made me want to try it. Id really like to free up some power and let my engine run smoother, I just dont know how....

My car only has a little over 87,000 miles on it, so I dont think oil leaking would be an issue, but Im not really sure... How can I get my engine seals checked or see if they are damaged or marginal?

BluEyes
01-19-06, 08:56 AM
An '80 CDV should have a 368ci motor (or 425? not sure). I don't believe there is a cam retainer on those engines, the taper on the cam lobes provides a rearward foprce on the cam to retain it in the block.
I'd go for synthetic. Maybe not RP, Mobil 1 is great and more available + less expensive.
Don't like that 15W40 for winter running. Despite what the pressure gauge says (and many engines have the pressure sender in the wrong place), you're not going to convince me that is good cold flow with that thick of an oil in cold weather. A 5W40 will give much better oil flow on a cold start with the same hot-running viscosity as 15W40, so the same resistance to wear. I'm pretty sure the Rotella & etc brand 5W40's have the same additives as the same brand 15W40.

N0DIH
01-19-06, 10:21 AM
Motor oil isn't going to give you enough power that you can really feel it or call it a "mod", the gains are subjective at best. The risk of synthetic causing leaks is very high in older engines that used gaskets instead of seals like many of hte new engines. My LT1 was a pretty tight engine till I ran Rotella T 5W40 synthetic. It now leaks a little on the rear seal that wasn't there before with 15W40. I am sorta committed now, but if I thought the seals (neoprene rubber) were better than they are, likely would not have run it.

As for running smoother, compare it to FRESH oil first. Most everyone's claims are comparing old worn out stuff against new high tech and make claims that it makes a huge difference. Like Splitfire plugs vs old 50K mile AC Delco's. Sure it ran better... So old oil and new synthetic, yes it will run smoother.

Low miles have little to do with leaks, likely will cause more because it sits more. Every car that I have see or worked on that is low miles has ben more of a headache for almost everything than a high mileage car that was well take care of. Case in point, my 96 Suburban has 225K miles. Leaks nothing, idles nearly as good as my LT1 Cad (which is smoother than any N* I have seen, as well as any MBEnz, Lexus, and the like, glass at idle in gear). My friend has a 72K mile 96 Suburban and we have replaced the water pump already and other minor things that a low mileage vehichle shouldn't need replacing. And it doesn't even idle as good as my high mileage truck (note mine is a K1500 350, his is a K2500 454). But low mileage.

Is mine gonna last longer, not likely, the oil pressure is only 45 at cruise, his is 60-65. Mine is likely worn on the inside more. But I won't let synthetic in it due to the mileage at all.

Look closely at the raer main, that is one that often gets cleaned out. And the front seal. Then the valve cover and oil pan gaskets. My 250K mile Aerostar was solid as a rock for oil leaks till I put in 5W40 Rotella T, and the front cover started leaking. Those 4.0L's run forever if taken care of. The body fell apart @ 280K and the engine still didn't burn a drop of oil...


Well, Im not sure what I should do...

I still would like to use royal purple, but dont have enough info yet. By looking at their site and hearing what its done for some people is what made me want to try it. Id really like to free up some power and let my engine run smoother, I just dont know how....

My car only has a little over 87,000 miles on it, so I dont think oil leaking would be an issue, but Im not really sure... How can I get my engine seals checked or see if they are damaged or marginal?

N0DIH
01-19-06, 10:34 AM
Which is a good reason to run 15W40 Diesel oils. Save that cam.

As for wrong or right place on sender, until the oil galleries back up, line pressure will not read pressure till it is backed up and pressurized. Closer to the pump might actually take longer to read than being at the end of the gallery.

Contrary to popular (thanks to Slick 50's massive brainwashing campaign as well as the oil change industry pushing 3000 mile oil changes....) belief, the oil does not drain out of the engine, nor does it dry start when you crank it. If you have ever rebuilt an engine, it takes forever to clear those oil galleries. Overnight won't do it.

With my 94 LT1 w/176K miles and 5W40 Rotella T and my 1996 Subruban w/Vortec 350 and 15W40 Delvac, I can see no issues with rod knock or cold start issues in -10F weather here in Wisconsin. IT cranks right up, oil pressure is instantaneous (the <4 psi low pressure light never stays on), and Burb has instant 60 psi cold oil pressure with no issues.

But, that is just me.... If I haven't wiped the engine yet, I dont' think I am going to.


An '80 CDV should have a 368ci motor (or 425? not sure). I don't believe there is a cam retainer on those engines, the taper on the cam lobes provides a rearward foprce on the cam to retain it in the block.
I'd go for synthetic. Maybe not RP, Mobil 1 is great and more available + less expensive.
Don't like that 15W40 for winter running. Despite what the pressure gauge says (and many engines have the pressure sender in the wrong place), you're not going to convince me that is good cold flow with that thick of an oil in cold weather. A 5W40 will give much better oil flow on a cold start with the same hot-running viscosity as 15W40, so the same resistance to wear. I'm pretty sure the Rotella & etc brand 5W40's have the same additives as the same brand 15W40.

durrk
01-19-06, 04:35 PM
well, Im not looking to modify my car, I just want it to run a little smoother...

I wanted to use RP 10w40 for a number of reasons... if not synthetic, which is the best kind of conventional oil?


Here, please check out this link, this is why I wanted to use RP....
Look where it says it micro poilishes surface irregularities.


http://www.royalpurple.com/techi/whyrpi.html

N0DIH
01-19-06, 05:19 PM
10W40 voids the warranty on most any car since around 1982, maybe even sooner. I don't know why it is on the market, but I would avoid. There is supposedly too many additives in it and cause ring sticking issues. ALL car manufactures will void you for using it.

The last time I checked, you had to use abrasive material to polish something. Can't say if they are substantiating that claim I would ever use them.

If you reduce friction, you reduce wear, polishing is accomplished through wear.

durrk
01-19-06, 08:00 PM
well,10w40, thats what it tells me to use in the manual....
What should I use? opinions are appreciated....

have you read the rest of the stuff in that link?
What do you think about them?