97 GMC Suburban 454 Oil recommendations...

[KiNETiCA]

Hi! I'm new here, (been browsing this forum for a while actually, now registered)
I've got myself a new to me 97 Suburban with 454 motor in it, about 350k km on odo, the vehice was used for towing a travel trailer on holidays by previous owner. He used coventional 5w30 of various brands in it. Oil pressure looks ok, ~40psi cruising ~18 off idle hot, but when hot I can hear a faint knock, also sometimes on warm restart, oil gauge sits at zero for a moment and then picks up (does not make any weird noises though)
Anyway I was thinking about using either Castrol GTX 10W30 or Shell Rotella 15W40 HDMO in it.
I'm planning on using this vehicle daily for my towing/hauling needs both in the city stop'n'go traffic and on a highway year round (in the winter it gets super cold in Calgary) I also plan on keeping this for a while, so would like to minimize wear on the motor, what are your thoughts?

 

[xshoex]

rotella 5w40, pricey,

 

[Nick1994]

I would not be using a 10w30 or 15w40 in a Canadian winter.

At the very least a 5w40 or a 0w40.

 

[c502cid]

5w-40 year round

 

[MinamiKotaro]

6 quarts of Lucas. Get one of those cleanable mesh filters but leave out the mesh so that you have nothing to restrict flow.

 

[NH73]

Stick with 5w30 if you want to stay with a conventional. 10w30 will work for the warmer months. I wouldn't use what you are thinking for a Canadian winter. Otherwise, if you like to switch to synthetic which would be good for wear and the Canadian winter. If you get below -20 F, then GM recommend to use a 5w30 synthetic or 0w30. So a 5w30 or 0w30 synthetic oil would a good all around oil for you.

 

[KiNETiCA]

Originally Posted By: MinamiKotaro
6 quarts of Lucas. Get one of those cleanable mesh filters but leave out the mesh so that you have nothing to restrict flow.

And what good that's going to do?

 

[KiNETiCA]

Originally Posted By: c502cid
5w-40 year round

I thought about 5W40 too, Is Castrol any good? Or Pennzoil?
Is that what you're running in your 454?

 

[KiNETiCA]

Originally Posted By: NH73
Stick with 5w30 if you want to stay with a conventional. 10w30 will work for the warmer months. I wouldn't use what you are thinking for a Canadian winter. Otherwise, if you like to switch to synthetic which would be good for wear and the Canadian winter. If you get below -20 F, then GM recommend to use a 5w30 synthetic or 0w30. So a 5w30 or 0w30 synthetic oil would a good all around oil for you.

I've read that those motors like thicker oil, I'm planning on doing a lot of heavy towing, would 5w30 shearing to 20wt be an issue?

 

[NH73]

Originally Posted By: KiNETiCA
And what good that's going to do?


It will hold up to your cold winters and toeing. Otherwise, I don't know why GM says not to use other vicosities.

Originally Posted By: KiNETiCA
I thought about 5W40 too, Is Castrol any good? Or Pennzoil?
Both of them are good oil. 5w40 are usually for european cars and pricier. But its your vehicle and you do what you want to do.

 

[NH73]

Originally Posted By: KiNETiCA
Originally Posted By: NH73
Stick with 5w30 if you want to stay with a conventional. 10w30 will work for the warmer months. I wouldn't use what you are thinking for a Canadian winter. Otherwise, if you like to switch to synthetic which would be good for wear and the Canadian winter. If you get below -20 F, then GM recommend to use a 5w30 synthetic or 0w30. So a 5w30 or 0w30 synthetic oil would a good all around oil for you.

I've read that those motors like thicker oil, I'm planning on doing a lot of heavy towing, would 5w30 shearing to 20wt be an issue?


That is more of an issue with conventional 5w30. If they like thicker oil, why does GM recommend 5w30?

 

[Ramblejam]

"As thin as possible, as thick as necessary..."

Oil Pressure (Minimum):
6 psig @ 1000 RPM
18 psig @ 2000 RPM
24 psig @ 4000 RPM

You're well above those GM figures. Unless you can articulate reasoning for going to a thicker viscosity (other than "I've read"), I see no reason to deviate from the GM recommended product (synthetic 5w-30 for their 454HO crate engines).

As for the faint knock when hot, hit the easy button first -- try Chevron Techron Concentrate and midgrade fuel.

 

[KiNETiCA]

Originally Posted By: NH73
Originally Posted By: KiNETiCA
Originally Posted By: NH73
Stick with 5w30 if you want to stay with a conventional. 10w30 will work for the warmer months. I wouldn't use what you are thinking for a Canadian winter. Otherwise, if you like to switch to synthetic which would be good for wear and the Canadian winter. If you get below -20 F, then GM recommend to use a 5w30 synthetic or 0w30. So a 5w30 or 0w30 synthetic oil would a good all around oil for you.

I've read that those motors like thicker oil, I'm planning on doing a lot of heavy towing, would 5w30 shearing to 20wt be an issue?


That is more of an issue with conventional 5w30. If they like thicker oil, why does GM recommend 5w30?


Toyota recommended 5W30 for 1MZFE motors, then updated the rating to 5W20, many 99 and older motors started ticking after 5W20 was put in by dealers (yes I know, some people stick with the dealer for maintenance)
I told my friend to ditch the dealer and use 5W30 synthetic and the noise stopped, so I'm puzzled about manufacturers ratings... Don't know what 454 was originally rated for thought.
My 99 Astro runs Rotella 15W40 year round without issues, hence my idea of using same oil...
Still I'm happy to see your opinions and want to hear more

 

[donnyj08]

Originally Posted By: MinamiKotaro
6 quarts of Lucas. Get one of those cleanable mesh filters but leave out the mesh so that you have nothing to restrict flow.


OP don't put anything Lucas in your vehicles please. Run a good 5w40 or 10w40 and see if that will increase your oil pressure.

Stay far away from any thick oil additives, especially Lucas.

 

[KiNETiCA]

Originally Posted By: donnyj08
Originally Posted By: MinamiKotaro
6 quarts of Lucas. Get one of those cleanable mesh filters but leave out the mesh so that you have nothing to restrict flow.


OP don't put anything Lucas in your vehicles please. Run a good 5w40 or 10w40 and see if that will increase your oil pressure.

Stay far away from any thick oil additives, especially Lucas.


That's what I thought, Lucas oil probably would freeze solid here !

 

[KiNETiCA]

Originally Posted By: Ramblejam
"As thin as possible, as thick as necessary..."

Oil Pressure (Minimum):
6 psig @ 1000 RPM
18 psig @ 2000 RPM
24 psig @ 4000 RPM

You're well above those GM figures. Unless you can articulate reasoning for going to a thicker viscosity (other than "I've read"), I see no reason to deviate from the GM recommended product (synthetic 5w-30 for their 454HO crate engines).

As for the faint knock when hot, hit the easy button first -- try Chevron Techron Concentrate and midgrade fuel.



Yeah, I've been running nothing but regular gas in it so far, will try better gas and see if there's an improvement.
My reasoning for thicker oil would be Toyota 1MZFE's ticking on 5W20 that I've seen all around, and my own E150 van with Ford 4.6 2valve that died at 27k kms running 5W20 - dealer said insufficient lubrication, good I had a service plan with them and kept maintenance records, on the other hand I could've gotten a lemon...

 

[Ramblejam]

https://en.wikipedia.org/wiki/Texas_sharpshooter_fallacy

 

[KiNETiCA]

Originally Posted By: Ramblejam
https://en.wikipedia.org/wiki/Texas_sharpshooter_fallacy



Castrol GTX 5W30 just went in, I don't hear anything strange, so far so good...
If I'll notice anything suspicious after running loaded all day I guess I'm going to go with 5W40 for next OCI

Thank you all for your opinions!

 

[Torrid]

30wt will be just fine. I ran 15w50 and 0w40 in my LS1. I went through the German Castrol 0w30 phase too and the only thing I noticed was a bit of lifter tap with more standard 5w30. Before running the other grades I used Mobil 1 5w30 and ZDDP additive. The sound difference was more than I thought it would be. I think the extra ZDDP in the race oils and Euro formulas was the real difference.

 

[Garak]

Originally Posted By: KiNETiCA
Castrol GTX 5W30 just went in, I don't hear anything strange, so far so good...

The GTX 5w-30 will serve you just fine. If you insist on a synthetic HDEO, be aware that there also are 0w-30 and 5w-30 HDEO options with more than sufficient HTHS for your application, and significantly thicker than GTX 5w-30. And, they are available at a better price than anything you'll find at Walmart Canada or Canadian Tire.

For example, if cold cranking is your biggest concern, get some Mobil Delvac Elite 222 0w-30 from Imperial Oil. It'll have better cold cranking performance than most other products out there, plus you will have a difficult time beating the price.