Northstar V8 Oil stories..

[porkfarm]

Just wanted to tell a story about my 05 Caddy STS with the Northstar V8 and look for comments.

Since I got it a few years back with 12K on it, It has had noise issues from the motor. I tried just about everything to get it quiet and this what I have done.

AutoRX normal run
AutoRX double dose run.
AutoRX maint.
All the good gas treatments ( yes BITOG favs. )
GM 3 part fuel treatment.
MMO flush before fill.
Maxlife Syn 5w-30
SLOB here and there.
PP 5w-30
M1 5W-30
M1 0W-30
ST 5W-20
ST 10W-40 / 5W-20 mix.
M1 0w40 3qts 5qpts 0w30

Here is what I have found. The ticking, tapping, clacking on a very warmed up motor, was only quiet on a dino 10w40 5qts 5w20 2 qts and MMO, but it used a qt.

When it is quiet, the mileage is down 2MPG, and the exhaust is quiet also. With 0W30 - 0W40 mix (current) the mileage is back up, but the exhaust and engine are much louder.

Best I have ever done on my OLM is 46%, I just keep searching for a quiet combo, but now do I just turn up the stereo or take a hit on MPGs ?

I try to keep the ring pack clean with WOT's and MMO and that sure is fun, but maybe the Northstar has loud injectors and a valvetrain that just is louder than my other cars I have or had.

the car now has 55K I love it when I catch it in a good mood and it is quiet, smooth and coasting great.. Shut it off and start it back up.. It's like it's evil sister took it's place. ( ok maybe the diet coke of evil, it's not that bad.. )

Anybody else have a situation like this ?

 

[rclint]

I suggest ignoring the sound. Engines make so many noises, and even what people will define as a smooth running engine in fact is pretty clanky in the morning of course, however if you were to walk around the engine bay area, of even listen carefully while in the cab you can still hear noises. Your caddy may have been designed to be really quiet thus any noise may be magnified ? If there is no metal debris in the oil, and if this is common to this engine with documented reports of the sound be it internet forums, or from the manufacture itself would also put a mind at ease. Use the oil you think is best, and of course first, and foremost what the manufacture calls for.

 

[chad8]

My parents 06 sts is very quiet all the time. You have a mechanical problem. probably valves. Luckily , theirs had a 100000 bumper to bumper 7 year warranty because they bought it with 5000 miles from a caddy dealership and was certified.My dad is 78 and loves to take the car in for a hobby. [censored] seats was the best one and they did have a tsb on that one. Check your warranty information. It may have transferred.

 

[chad8]

I can't even say far#ing! what the hec#

 

[lipadj46]

And now you will get a warning email from the owner for circumventing the censor

 

[porkfarm]

seeing as it only is ticking at idle, I am thinking about just living with it. Over 18mpg city means that the motor is efficient with the thicker 30Weight. ( not many get that with the tall gears ) Maybe the valves are opening more with that weight and make a bit more noise under throttle.

I have 40K more under my warranty, so if it gets worse, I will beg and plead with Caddy service to believe me that I have an issue, but I bet that falls on deaf ears.

 

[ZGRider]

Originally Posted By: porkfarm
Just wanted to tell a story about my 05 Caddy STS with the Northstar V8 and look for comments.

Since I got it a few years back with 12K on it, It has had noise issues from the motor. I tried just about everything to get it quiet and this what I have done.

AutoRX normal run
AutoRX double dose run.
AutoRX maint.
All the good gas treatments ( yes BITOG favs. )
GM 3 part fuel treatment.
MMO flush before fill.
Maxlife Syn 5w-30
SLOB here and there.
PP 5w-30
M1 5W-30
M1 0W-30
ST 5W-20
ST 10W-40 / 5W-20 mix.
M1 0w40 3qts 5qpts 0w30

Here is what I have found. The ticking, tapping, clacking on a very warmed up motor, was only quiet on a dino 10w40 5qts 5w20 2 qts and MMO, but it used a qt.

When it is quiet, the mileage is down 2MPG, and the exhaust is quiet also. With 0W30 - 0W40 mix (current) the mileage is back up, but the exhaust and engine are much louder.

Best I have ever done on my OLM is 46%, I just keep searching for a quiet combo, but now do I just turn up the stereo or take a hit on MPGs ?

I try to keep the ring pack clean with WOT's and MMO and that sure is fun, but maybe the Northstar has loud injectors and a valvetrain that just is louder than my other cars I have or had.

the car now has 55K I love it when I catch it in a good mood and it is quiet, smooth and coasting great.. Shut it off and start it back up.. It's like it's evil sister took it's place. ( ok maybe the diet coke of evil, it's not that bad.. )

Anybody else have a situation like this ?


Do you have a life away from that car? Try just driving it and quit trying to remanufacture the engine with liquids. It obviously has some mechanical components that make the noise and need to be remedied.

 

[bigbird_1]

Friend's 2004 SRX with Northstar V8 and only 85000 km is very quiet. She only uses the recommended oil from the dealer, Mobil 1 5W-30.

 

[bobfather99]

Tried Rotella syn 5w40???

 

[Durango]

porkfarm,

Recently I changed my factory fill oil out to Mobil 1 synthetic and was very happy until one morning I warmed up my engine and had a fairly loud tick/engine clatter that lasted for a bout a 60 minutes and eventually went away. I considered it a fluke as during it 6K miles it made no noise what so ever. Even still keep and eye on it.

So far I've always been very happy with M1 as well as some others I've tried in the past. M1 is my standard that I use in my truck and car.

Durango

 

[Ben99GT]

Try Redline, RL 5W-30 masked/eliminated a lot of the noises in my 4V that I thought were always going to be there, as aluminum block multivalve engines can tend to be "clattery", especially at idle.

 

[ZGRider]

Yeah, the "brand" of oil you use is going to make the engine overcome any mechanical problems it may currently have.

My MB 190e has worn cam chain adjusters, I bet if I run AutoRX, the noise will go away magically. Or maybe if I use Mobil 1? I wonder what oil would make it so I don't have to adjust the valve clearance and make that noise go away too?

No oil is going to fix engine mechanical issues. Most engine noises have their origin in some defective or deficient component. You can't fix mechanical problems by changing oil brands or running a "cleaner" thru your engine.

Find out what is causing the noise and correct the problem (if there is one) and then choose oil to prevent future issues.

 

[bigbird_1]

Originally Posted By: ZGRider

No oil is going to fix engine mechanical issues. Most engine noises have their origin in some defective or deficient component. You can't fix mechanical problems by changing oil brands or running a "cleaner" thru your engine.


How true.

 

[porkfarm]

Originally Posted By: bobfather99
Tried Rotella syn 5w40???


I am thinking that might be my summer change.

 

[porkfarm]

Originally Posted By: Ben99GT
Try Redline, RL 5W-30 masked/eliminated a lot of the noises in my 4V that I thought were always going to be there, as aluminum block multivalve engines can tend to be "clattery", especially at idle.


Now this is what I am thinking Ben ! normal sound for a car that runs super fuel all the time.. Others that say my dads's or my friends Northstar is quiet, do not drive it every day and might not be as tuned in as I tend to be. I do not.. DO NOT think it is a mechanical issue, and even if it is, Good luck getting GM service to do anything about it.

It really is just a clattery idle. Just a tick more throttle and the world is good. Other than that, it's a beast. Volant CAI and Borla cat back.. It's a sweat sound. MPG's still doing well today.. 18.7 city.

Done with adds for now. Next will be MMO 1K before the dump. Hope to get to 10% on the OLM.
Then maybe a oil sample will be sent off to see how it looks.

( I know what your thinking.. but it made the sound at idle before any of the mods. )

 

[porkfarm]

Originally Posted By: bigbird_1
Originally Posted By: ZGRider

No oil is going to fix engine mechanical issues. Most engine noises have their origin in some defective or deficient component. You can't fix mechanical problems by changing oil brands or running a "cleaner" thru your engine.


How true.


What ? If I paint my house, the plumbing might work better... Off to the depot..

 

[GMBoy]

The Northstar engine had issues with Carbon buildup. Carbon will make your engine noisy. I would do a good intake cleaning with GM Top Engine Cleaner or Seafoam. Or you could do the water methoed, it works well too. Another option is fuel injector cleaning at the fuel rail since that cleaner is very concentrated and includes a top end cleaner for getting at the carbon on the valves. I personally do it myself, but you may not have that equipment so go somewhere and get a good cleaning. It's a good start and really wouldn't hurt anything since it's probably never been done and fuel cleaners in the tank won't be strong enough to tackle tough carbon.

 

[porkfarm]

Originally Posted By: GMBoy
The Northstar engine had issues with Carbon buildup. Carbon will make your engine noisy. I would do a good intake cleaning with GM Top Engine Cleaner or Seafoam. Or you could do the water methoed, it works well too. Another option is fuel injector cleaning at the fuel rail since that cleaner is very concentrated and includes a top end cleaner for getting at the carbon on the valves. I personally do it myself, but you may not have that equipment so go somewhere and get a good cleaning. It's a good start and really wouldn't hurt anything since it's probably never been done and fuel cleaners in the tank won't be strong enough to tackle tough carbon.


All, have already been done. I know very well about the carbon issue and I make sure that I don't get any build up.. No change with any of the adds. Yeah, I am also on caddy forums.

 

[ZGRider]

Originally Posted By: porkfarm
Originally Posted By: Ben99GT
Try Redline, RL 5W-30 masked/eliminated a lot of the noises in my 4V that I thought were always going to be there, as aluminum block multivalve engines can tend to be "clattery", especially at idle.


Now this is what I am thinking Ben ! normal sound for a car that runs super fuel all the time.. Others that say my dads's or my friends Northstar is quiet, do not drive it every day and might not be as tuned in as I tend to be. I do not.. DO NOT think it is a mechanical issue, and even if it is, Good luck getting GM service to do anything about it.

It really is just a clattery idle. Just a tick more throttle and the world is good. Other than that, it's a beast. Volant CAI and Borla cat back.. It's a sweat sound. MPG's still doing well today.. 18.7 city.

Done with adds for now. Next will be MMO 1K before the dump. Hope to get to 10% on the OLM.
Then maybe a oil sample will be sent off to see how it looks.

( I know what your thinking.. but it made the sound at idle before any of the mods. )


Keep running that garbage MMO in that engine and you won't have to worry about the current noises, 'cause you'll have many new and louder noises. That engine is designed for high-quality, clean, fresh oil, not some "gimmick," snake-oil from the Ford Model-T days. Top-end cleaner? Right....

 

[Vizzy]

Quote:

Keep running that garbage MMO in that engine and you won't have to worry about the current noises, 'cause you'll have many new and louder noises. That engine is designed for high-quality, clean, fresh oil, not some "gimmick," snake-oil from the Ford Model-T days. Top-end cleaner? Right....


Agreed !

I don't know WHY folks keep INSISTING on using OLD snake oil technology in their modern engines with tight tolerances...GM and others specifically recommend AGAINST such oil additives for most late models they make.

MMO is a joke..yet thousands of suckers keep right on buying...I almost get the feeling that MMO is a PAYING ad sponser on the forums here....