Best oil for '99 Chevrolet Lumina with the 3100?

[ShaunB]

Greetings all,

I have, as my subject says, a 1999 Lumina with the 3.1L GM V6. It has about 140k on the motor, but it's the second motor in the car. I picked up the car about a year ago with a bum cylinder, consuming incredible amounts of oil. Turns out the previous "mechanic" to do an intake manifold gasket on there put the pushrods in upside down...

As well, the oil was not changed regularly, based on the black sooty mess that was in there. I think these combination of problems led to the dead cylinder (20 psi compression).

Long story short, I obtained a motor with about 1000 more miles than the motor I took out of the car, from my mother who had a Lumina as well and got a new car.

Since I've gotten this car back on the road, I've done about 4-5 oil changes at 4k intervals using full synthetic NAPA 10w30 (I work for NAPA, it's Valvoline Synpower, or at least stupidly close), and trying to reverse some of the abuse of it's previous owner. My mother only drove 10-20 mile stints, if even that on most of it's travels, and tended to forget to tell me when the oil was due for changing.

The synthetic is treating it well, with the oil still a deep amber at 4000 miles, but I think I want to move up to something heavier, possibly in the M1 grouping of oils. I do a lot of sustained high speed driving, and like to do some more, "spirited" jaunts. I drive about 4k a month, so I'm doing oil changes once a month. The motor runs fairly quiet, but as we all know, the 3.1Ls love piston slap, and are fairly noisy on start up.

I was thinking either a M1 0w40 (though from what I've read on here it's quite close to the 5w30 that the car recommends), or a 15w50, which is a little heavier at temperature but still has a good flow point for some of the cold NY mornings.

Any recommendations would be appreciated and heeded!

-ShaunBone
(I'm a trombone player, nothing dirty here 'cept my oil haha)

 

[tig1]

Since you drive a lot try M1 5-30EP for 10-15,000 mile OCIs. Also it will serve you well in the winter months in NY.

 

[benjamming]

What gasket design is in this "new" motor? Did you replace it yet? I would do a UOA before doing anything more than 5k miles, even highway. They leak coolant like crazy until it is properly fixed by Fel-Pro metal/rubber gaskets. Even then they can still leak if not done properly.

Off topic but what makes you think that the previous failure was caused by pushrods upside down? How does that work out?

edit: oh and

 

[jstutz]

First, i am one of those guys that still kinda lean toward slightly higher oil viscosities. I Personally feel that 15w40 is unnecessarily heavy for that car. I have used HDEO in many older chevy 350 or 4.3 engines and have had good long term sucess. There have also been others, including myself that have used 5w30 in the same engines with well over 200k miles on them. If you are not burning oil, i would stick with something around the weight you are using. If you want a little heavier oil, use a high mileage oil. You will usually get an oil that is on the heavy side of the w30 scale. Many report great results with valvoline maxlife oils and they are pretty heavy for a 30w. Living in NY personally i would probably use a 5w30 year round with maybe a 10w30 in the summer. I see this is your first post and dont know what you know so i will list a couple mistakes that some make.

Assume that 10w30 is heavier than 5w30 at operating temp. This is not true in all cases. Classic case is M1 5w30 vs 10w30.

Assume that heavy oil is better. Choosing an oil is based on tradeoffs. In many cases incresed flow is better than higher viscosity. Most will agree that the majority of wear comes from startup. Oil is very heavy at cool temps, Yes 100F is cool for an engine.

Assume oil is still in good shape becuae it is not black. Many people judge oil based on its appearance. Many oils have a lot of life in them well after they are very dark. Others will be completely depleated and still look okay. dont judge a book by its cover in this case.

These are just a few things you will see all over this site. If yo are wondering about cold weather flow, throw a bottle of 15w50 and 5w30 in the freezer and visually look at the viscosities.

Another point to add is there is a guy on here named Frankn4 or something like that, that used i believe 15w40M1 in just about everything and has had great luck with it. I think he may actually live in a cooler state, not sure.

Summary, if i were you being winter is comming, stick to a xw30, no need for xw40 or 50. if oil consumption is not an issue

good luck

 

[Drew99GT]

Any oil recommendation is a moot point unless the gaskets are good to go in this new motor. If it has the originals, or some of the early replacements, they'll fail. It's been proven here time and time again.

Is the coolent level staying consistent, or is it dropping?

I'd do a UOA to see if there's coolant in the oil before doing anything.

IMO, this is the last vehicle you'd want to spend a lot of money on oil for! No offense - I have a beater car as well. I'd simply use something like Napa 5w-30 for the winter since you can probably get it cheap. Or maybe a high mileage oil.

 

[il_signore97]

Hey ShaunB,

My mother's 2002 Venture has a very similar motor (3.4L 3400 V6). These motors are very easy on oil, and simply do not require a thicker oil, although they have no issues running a thicker oil if you choose to do so.

In my experience with these (I've had 3 vehicles with 3100/3400 engines so far), the thinnest oil possible on startup will reduce the time that the pistons slap for (and will also reduce hydraulic lifter noise on start-up). I've had great luck with 0W20, 0W30, and 0W40 in this engine. Any other grade makes the piston slap / HLA noise last longer from the point the engine is started.

But as Drew said, they are not hard on oil, and really do not need a synthetic. But if you are going to put one in, I'd get a 0W-xx oil for good flow at startup to quiet down the slap.

 

[Kruse]

Originally Posted By: Drew99GT
Any oil recommendation is a moot point unless the gaskets are good to go in this new motor. If it has the originals, or some of the early replacements, they'll fail. It's been proven here time and time again.



I agree here. I was given a '97 Monte Carlo because the owner got tired of the IM replacement costs. He had his replaced at he dealer and it was doing it again. My vote is to get the intake manifold gaskets replaced with some FelPro gaskets and refill it with GO-5.
As for oil, any SM rated oil fill be fine. They are normally good engines after the IM replacement.

 

[addyguy]

I'd just stick with the NAPA syn 10W-30 if it's working well.

You have easy access to it, get a discount(?) on it, and it's a good oil.

 

[ShaunB]

Alright, a little bit of back information.

I picked up the car for $500 back with a skip in the motor that was in it. The oil was pretty nasty in it, but the all the other parts to the car were in good shape. It was burning a bit of oil and kept plugging the EGR port. Upon further inspection, it was found that Cylinder 2 has next to no compression in it. With the condition of the oil, it was obvious that the oil changes were not that regular. Also, when the valve cover was pulled off, there was some sludge and upon inspecting the valve springs and such, it was found the pushrods were all upside down or vice versa. The intake manifold has been done and it looks like there was a [censored] poor job putting it back together. In any case, the motor was junked.

My mother had gotten a new car, and had a similar vintage Lumina that she donated to me for the motor. This engine has had the intake taken care of with good Fel-Pro gaskets, and I do not lose any coolant. Also, I do not consume any oil, though I have a seeping seal, but a slow seep, and only lose about 1/4 quart in 4000 miles, if that.

I do know that the oil changes originally on this motor were not as regular as they should have been, going 5-6k between oil changes and A LOT of short trips. Since I've had it's been 4k like clockwork.

jstutz - I don't assume anything. I've been doing my research on here. I realize that two 10w30 oils can have much different viscosities from one another at 0 degrees and at 300 degrees, even though they are both the same "grade."

Drew - :-O This is not my beater! I love my Lumina, and it's got to last me for a while. This is the second one I've had, and probably the 7th in my extended family. My sister's has 225k on it and still going, and that poor thing is ABUSED...

il_signore97 - So if I wanted something a little thicker for when it's at operating temperature, 0w40 isn't a bad oil to give a try? And while the motor itself may not be hard on oil, I'm hard on the motor, so I want something that will give a little bit better cushion to the internals at temperature and speed.

 

[il_signore97]

Shaun,

I do agree with the others regarding the intake manifold gasket issue. I've used the Fel-Pro's and still have no issue. Since you've done the same, I wouldn't worry about it. I'd probably remove the dexcool though and go with some standard coolant that's good at inhibiting corrosion in iron blocks. I've got the Amsoil propelene glycol in my mom's Venture right now - it's working great.

As for the oil, you can absolutely use a 0W40 with no issues whatsoever. It will work well in the winter and summer, if you choose to go with that grade. It will provide you with more protection than you will care to receive

My mother's Venture is kind of like a workhorse for all of us! She doesn't use it much in the summer, so I typically use it for towing my trailer all summer long. I use the 0W40 in it for those months and it works very well. It's been several years now.

During the winter, my mother uses it for her daily commute, which is a whopping 1.5 miles long! The van gets at least 4 cold starts a day, and sometimes down to -40F weather! I've been using the 0W20 for the past couple of years for this purpose, since the oil never warms up at all. It sounds great, even on those super cold mornings.

So all in all, it's a good engine, and very tolerant to different oil viscosities. It just seems to work well with whatever you put in there! Like I said, just try to keep it as thin as possible at startup (i.e. 0W-xx) to reduce the time it takes for the slapping / HLA noise to stop. This is my experience with these engines.

 

[ShaunB]

Alright, one more question. On a good synthetic oil change, knowing that I drive at the least 40 miles round trip to work every day, and other than that it's all 55-80 MPH on the highway for the majority of travel, with a few... More spirited miles thrown in lol... How long should I go between changes? I've always been the 3k stickler, but after reading some of the testimonials on here, I think I can change it a little less frequently, I just would like some advice on the matter.

 

[ThirdeYe]

My mom has a 3100 in her Malibu and I've used Castrol GTX 5W-30 with excellent results. I used Havoline Synthetic for a few oil changes but the Castrol GTX UOA came back flawless. The Havoline Synthetic wasn't bad, but the GTX was better at least in terms of the UOA. Regarding the OCI length, I change it between 4,000-5,000 miles.

 

[jstutz]

Yes, you could easily use the 0w40 in that car. M1 0w40 is a lighter 40 weight and tends to sheer to a heavy 30 weight over a "couple of K miles". Agian you could look at max life becuase it is on the higher end of w30. If you must go with a 40 weight, then probably M1 0w40 would be the one. I have heard people say that M1 0w40 is the best 30 weight out there. Whatever best means..... It does carry some great ratings so i would not be nervous about using it.

 

[il_signore97]

Originally Posted By: ShaunB
Alright, one more question. On a good synthetic oil change, knowing that I drive at the least 40 miles round trip to work every day, and other than that it's all 55-80 MPH on the highway for the majority of travel, with a few... More spirited miles thrown in lol... How long should I go between changes? I've always been the 3k stickler, but after reading some of the testimonials on here, I think I can change it a little less frequently, I just would like some advice on the matter.



My mother's Venture on ALL very short trips can easily go 7k miles with whatever grade of Amsoil I put in there (probably farther, but at 7k miles, its less than 2 changes a year). So with mostly highway cruising and decently long trips, I'm sure you'd be able to push right past 10-12k, especially in the summer. This motor is easy on oil. Just keep it full - they don't usually burn any, but check often anyway!

So pick whatever OCI you're comfortable with, and go for it. Use a UOA to validate your decision and make sure the oil is holding up over the OCI that you've picked. A UOA is also good to check for coolant - because if those manifold gaskets ever go on you again, you'll be out of an engine if you don't find and fix them soon after...