Switching to High Mileage Oil made a huge difference..

[Eldorado2k]

I’ve been using conventional Pennzoil 5w30 in my 02’ Cadillac Deville since I bought it last October, and like most Caddys it’s leaked oil at a somewhat moderate rate... I usually top it off with .5 quart every 3 weeks or so.

Here’s a picture of how much oil it typically leaked once parked after a normal drive.

Oil leak adds up over time... It’s a good thing I’m not OCD when it comes to the driveway.

I dunno, I’ve driven Cadillacs my whole life and to me oil leaks are like low MPG’s... It’s the only life I’ve known so it’s never been something that bothered me. I simply fill the tank and top off my oil more often than others. Lol.

But 3 months ago I decided to switch to Pennzoil High Mileage for my topping off. At 1st I thought I was crazy but I immediately noticed a dramatic decrease in the oil my car was leaking.

I finally decided to check how much, if any oil my car currently leaks after going for a drive this morning and leaving it parked for 3hrs. This is what it looks like. I think the difference is pretty remarkable compared to before.

Some people had advised me to switch to synthetic oil instead of the high mileage... After doing my own research, I’m glad I went with the High Mileage Oil.

Not shilling, just keeping it real. This stuff really made a difference.

Thanks for reading.

 

[Desertnate]

If you have a leak, it is best NOT to switch to a synthetic from what I understand. While the viscosities are the same, for some reason a synthetic oil tends to leak more.

My wife had an old Jeep Cherokee when we first married. I switched it up from conventional to synthetic and it started to leak all over the place. I then switched back to a conventional high mileage oil and the leaks stopped. From then on, I'd only make the switch to synthetic early in the vehicle's life before the age-induced mystery leaks set in.

 

[Rsurfer]

I don't get it..topping off (1 qt or less)with Pennzoil High Mileage decreased the leaking significantly?

 

[Eldorado2k]

I don't get it..topping off (1 qt or less)with Pennzoil High Mileage decreased the leaking significantly?

Yes.

 

[Bill D]

Maybe I ought to try this on my Cadillac too but I have a brand new,never used jug of Castrol GTX sitting in my garage. I guess I will keep this in mind for another time.

 

[IH8SPM]

I don't get it..topping off (1 qt or less)with Pennzoil High Mileage decreased the leaking significantly?

High mileage oil is designed to bridge the gap per say. It provides viscosity and additives that are known to rejuvenate worn and dry seals as well as minor scoring on engine parts. Consider it a good polish and sealant for our engines.

Sent from my SM-N960U using Tapatalk

 

[Eldorado2k]

Wierd thing is the car still goes through the same amount of oil... The correct amount to fill a 4.6 Northstar is 7.5 quarts which measures at exactly halfways on the hashmarks on the dipstick... But no matter how hard I try to keep it there it always seems to burn/drink/or otherwise dispose of that .5 quart in a short amount of time and then keep itself near the bottom of the hashmarks aka the line where it says to add a quart [you’re not really supposed to add a full quart, only .5]

My 97’ used to be the same way...

I take it out on the open road and do a good WOT run every so often as recommended to clear the carbon buildup from the top of the pistons/oil rings in hopes of decreasing my oil consumption... There’s been times where I’ve seen nice black clouds of smoke coming out the exhaust when doing that, but it still consumes oil.

I did 4 consecutive WOT runs late last nite. Pedal to the metal till it hits redline in 2nd gear.

 

[Eldorado2k]

My 97’ used to be the same way...

Correction: On my 97’ I used to try my best to keep it filled to the top of the hashmarks on the dipstick [that’s before I found out the correct level is halfways on the hashmarks] but it would still somehow drink/burn/dispose of .5 qrt. very quickly and settle down for its gradual consumption after that... These cars can be really quirky sometimes.

Funny thing is even though it leaks, I’ve never ran into a situation where 1 of my Cadillacs leaked for so long that it was at a dangerously low level of oil. They’re never thirsty for more than 1 quart at the most. Lol.

 

[IH8SPM]

Switch over to high mileage and retest. Keep in mind if your seeing puffs of smoke you'll damage your Catalytic Converter and O2 sensors. In any case enjoy the ride

Sent from my SM-N960U using Tapatalk

 

[Eldorado2k]

Switch over to high mileage and retest. Keep in mind if your seeing puffs of smoke you'll damage your Catalytic Converter and O2 sensors. In any case enjoy the ride

Sent from my SM-N960U using Tapatalk

I consider the engine already on high mileage oil...

As far as the clouds of black smoke, I only saw what resulted in a shocking moment the 1st time I did it in this car... Ever since then I haven’t seen anywhere near that visible cloud as there was the 1st time.

I don’t think the catalytic converter is in danger of being harmed because any bits of carbon should hopefully make its way through its vent holes. At least I hope that’s the case. Lol.

I ruined the catalytic converter in my 97’ due to waiting too long to fix the check engine light aka O2 Sensor... On this car I fixed a check engine light/O2 Sensor the day after I got the check engine light. Believe me I don’t want to ruin my cat.lol.

 

[PaulMys]

Wierd thing is the car still goes through the same amount of oil... The correct amount to fill a 4.6 Northstar is 7.5 quarts which measures at exactly halfways on the hashmarks on the dipstick... But no matter how hard I try to keep it there it always seems to burn/drink/or otherwise dispose of that .5 quart in a short amount of time..........

Yeah, there is the leaking (which actually looks worse than it is on concrete) and then there is the oil that slips past the rings and makes it into the combustion chamber and gets burned.

Most people think of this as "A Lot" of oil which would cause smoke at the tailpipe, but most times this isn't the case.

It is just enough (combined with your leaks) to use just the amount you describe, Ric.

 

[Klasse Act]

If you have a leak, it is best NOT to switch to a synthetic from what I understand. While the viscosities are the same, for some reason a synthetic oil tends to leak more.

My wife had an old Jeep Cherokee when we first married. I switched it up from conventional to synthetic and it started to leak all over the place. I then switched back to a conventional high mileage oil and the leaks stopped. From then on, I'd only make the switch to synthetic early in the vehicle's life before the age-induced mystery leaks set in.

Its due to the level of refinement of the synthetic oil. In the mid 90's I had an 87' GN and the rear main seals on those engine were known to leak, mine did and the engine called for 10w30 oil, I switched to 15w50 Mobil 1 and the leak went away and never came back. The thing is this, with a thicker viscosity its just that, THICKER and thus wouldn't escape through older, worn seals. I also was running about 22 psi of boost, along with supporting mods, so the heavier oil made more sense too.

Hope this helps you next time around.

 

[TTQ B4U]

Some people had advised me to switch to synthetic oil instead of the high mileage... After doing my own research, I’m glad I went with the High Mileage Oil.

Synthetic advice on an old beast that's likely never been on synthetic is the opposite of what you would want to do. You my friend did well and I'm glad it's working out. Our old Jeep had a super small drip from the rear of the valve cover gasket when I picked it up but being we have a new pristine concrete drive, it was one of the first projects I tackled to keep the concrete clean. Even still, nothing but conventional oil for her and oil changes every 3k on the old girl.

 

[Eldorado2k]

High mileage oil is designed to bridge the gap per say. It provides viscosity and additives that are known to rejuvenate worn and dry seals as well as minor scoring on engine parts. Consider it a good polish and sealant for our engines.

Sent from my SM-N960U using Tapatalk

Part of the reason I’m so surprised at the difference it made is because of my past experience using Prestone Power Steering Fluid with Stop Leak and seeing how it always made absolutely no difference when it came to stopping or even slowing down a power steering fluid leak...

I don’t even know why they bother claiming it can help stop the leak. The stuff is garbage in that regard.

 

[SWETM]

Did you do a completly oil change or just started to top it up?

If you topped it or not. I would do a completly oil change with switching the oil filter. If your new oil cleaning up if it was a mess in the oil channels. The oil filter can be accumulate a lot of this old burned oil and residue. So for the safety of the engine it's a good practice to do an oil change with the change of the oil filter. Soon after going up to a higher quality oil.

The 5w-30 is the viscosity and basicly in what environment the oil holds a good viscosity. 5w is the winter value and the 30 is the summer value.
Then you have which size and or which the effect is in the engine. I think that you would have an API value of the oil and also a recommendation in the handbook of the car which API you should have. For an example a very little and weak engine is a SA in the API value and a stronger high volume engine around SF. It's ranges from SA-SN the API. And use what's recommended. As with a higher API value than what's recommended to use the engine can loosing it's ability to move it around cause of the weaker oil pump. I think you have API American Petroleum Institute is the shortage. Otherwise you have the ACEA value on the oils. If ACEA value it's C1-C4 with the kind of engine you have.

The later years car manufactures has created their own classifications of motor oil. A way to use only 1 brand from them. But useally it can be translated to the API value or ACEA value.

 

[Eldorado2k]

Did you do a completly oil change or just started to top it up?

If you topped it or not. I would do a completly oil change with switching the oil filter. If your new oil cleaning up if it was a mess in the oil channels. The oil filter can be accumulate a lot of this old burned oil and residue. So for the safety of the engine it's a good practice to do an oil change with the change of the oil filter. Soon after going up to a higher quality oil.

The 5w-30 is the viscosity and basicly in what environment the oil holds a good viscosity. 5w is the winter value and the 30 is the summer value.

I’ve just been topping it off... I know it sounds crazy but I’ve only driven the car a little over 2,000 miles since October, so while I have thought about changing the oil, it still hasn’t reached the usual time.

But I agree with what you’re saying.. The oil cap says 5w30 but the owners manual states that 5w30 is ideal and recommended for winter and 10w30 can be used in the summertime/hotter climates. I’ve been debating whether or not to switch to 10w30 right about now but most likely I will be changing the oil soon and going with 10w30.

 

[Black Bowtie]

I’ve just been topping it off... I know it sounds crazy but I’ve only driven the car a little over 2,000 miles since October, so while I have thought about changing the oil, it still hasn’t reached the usual time.

But I agree with what you’re saying.. The oil cap says 5w30 but the owners manual states that 5w30 is ideal and recommended for winter and 10w30 can be used in the summertime/hotter climates. I’ve been debating whether or not to switch to 10w30 right about now but most likely I will be changing the oil soon and going with 10w30.

Just go ahead and stay with the 5w30 will be fine. Never change over to a straight synthetic on an older engine that has always used dino oil. it will free up old deposits in the engine and you will have all kinds off leaks. if you want to learn more about lubricants, check this site out. it can make your head spin.
A Review of Mineral and Synthetic Base Oils - Bob is the Oil Guy

 

[Eldorado2k]

Just go ahead and stay with the 5w30 will be fine. Never change over to a straight synthetic on an older engine that has always used dino oil. it will free up old deposits in the engine and you will have all kinds off leaks. if you want to learn more about lubricants, check this site out. it can make your head spin.
A Review of Mineral and Synthetic Base Oils - Bob is the Oil Guy

I skimmed through that page real quik... Yea that could definitely make my head spin if I were to patiently read the entire thing. Lol.

Other than the 5w30 being fine for my car during summer, in your opinion is there any negatives in switching to 10w30 now? BTW this is the 1st time I’ve ever ran 5w30 in any of my Cadillacs and the only reason I did was because this is the 1st time it said so on the oil cap. Otherwise I’ve always used 10w30.

 

[tomsteve]

switching to a 10w 30 might even do more. 5w is pretty thin and for colder climates. switching from 5w to 10w stopped a lifter tick in my 08 grand prix.

 

[Eldorado2k]

switching to a 10w 30 might even do more. 5w is pretty thin and for colder climates. switching from 5w to 10w stopped a lifter tick in my 08 grand prix.

Hmm... I’ve got a slight lifter tick going on too. Enough for a couple of people to have mentioned it, but when I asked the dealer to have a listen he said it sounded completely normL.
Thanks for the info.