just got one yesterday, an '04 with 80,000 miles. has the Northstar engine, what oil do you think would be best? I'd like to have something to go about 7,500-9,000 mile OCI. probably put on close to 1,500 miles per month, maybe 50/50 on hwy/city driving.
Cadillac DeVille
- Thread starter Treb
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10w30 dino
anything sm rated Dont even think of using synthetic dino will be fine syn will leak on most northstars.
There is nothing like a Cadillac in my book i always liked them there are some of those northstars that have head bolt issues.
anything sm rated Dont even think of using synthetic dino will be fine syn will leak on most northstars.
There is nothing like a Cadillac in my book i always liked them there are some of those northstars that have head bolt issues.
if it makes it to 90k without the headbolts pulling out of The block it may be ok.
I'm running synpower in an 06 DTS with no problems whatsoever. 10w30.. Only put around 3k a year on it and change once a year.
By 2004 many of the issues that plagued older N* engines had been either greatly reduced or eliminated.
The engine in your car uses the newer high pressure casting block to improve strength and reduce porosity, head bolts with different and longer threads and improved rear main seal as well as a host of other minor improvements.
That what they fixed now for the stuff they didn't.
Although compression was reduced in 2000 slightly carbon knock continued to be an issue as did piston ring deposits contributing to oil burning. The bores on these engines are claimed to have an honing pattern that also contributes to oil consumption.
Neither issue usually requires a tear down but they need to be addressed nevertheless if things are going to be kept under control.
Carbon knock can be easily identified by a light knocking noise at idle when the engine is cold and disappears once its up to operating temperature.
Higher than normal oil consumption is a sure sign of piston ring deposits on these engines. Some oil usage is normal on these engines IMO a qt every 1000 miles is getting high.
A piston soak with GM top engine cleaner should take care of these issues.
Don't bother with Seafoam down a vacuum line it will not take care of these issues on this engine.
Running Redline SI-1 @ 1oz/gallon and a full bottle every 3K has shown good results in keeping the top ends clean long term.
I find its only a minor inconvenience to keep them clean than it is to go through the top engine cleaning fiasco.
Keeping the rings clean is easy, just do 5-6K OCI with a high quality synthetic, i would definitely go with 5w30.
PU claims to keep pistons cleaner than others but any brand should perform well for 5-6K.
The engine in your car uses the newer high pressure casting block to improve strength and reduce porosity, head bolts with different and longer threads and improved rear main seal as well as a host of other minor improvements.
That what they fixed now for the stuff they didn't.
Although compression was reduced in 2000 slightly carbon knock continued to be an issue as did piston ring deposits contributing to oil burning. The bores on these engines are claimed to have an honing pattern that also contributes to oil consumption.
Neither issue usually requires a tear down but they need to be addressed nevertheless if things are going to be kept under control.
Carbon knock can be easily identified by a light knocking noise at idle when the engine is cold and disappears once its up to operating temperature.
Higher than normal oil consumption is a sure sign of piston ring deposits on these engines. Some oil usage is normal on these engines IMO a qt every 1000 miles is getting high.
A piston soak with GM top engine cleaner should take care of these issues.
Don't bother with Seafoam down a vacuum line it will not take care of these issues on this engine.
Running Redline SI-1 @ 1oz/gallon and a full bottle every 3K has shown good results in keeping the top ends clean long term.
I find its only a minor inconvenience to keep them clean than it is to go through the top engine cleaning fiasco.
Keeping the rings clean is easy, just do 5-6K OCI with a high quality synthetic, i would definitely go with 5w30.
PU claims to keep pistons cleaner than others but any brand should perform well for 5-6K.
thanks for all the advice. i was leaning with 10w30 but wasn't sure if a synthetic would be best or a dino good enough. i'd rather go with the synthetic if it's better, even if it does cost a little more. i was leaning with either PP or QSUD.
mods, not sure how i got this in the sponsor section, but have been the fat fingers with my cell phone when i started the thread. move it if needed.
mods, not sure how i got this in the sponsor section, but have been the fat fingers with my cell phone when i started the thread. move it if needed.
as someone who has had over 200 northstars over the years in my shop for rebuilds i would still stay away from synthetic..
Some of those engines had head bolt problems but many more had leaks.
They are not bad engines just misunderstood Cadillac used those engines in almost everything for a lot of years and millions are still around..Carbon formation in the early ones were a problem techron was recommended by engine people in the know. If you have a starter problem the top of the engine has to come apart. If you have a head gasket problem the engine should be removed
Some of those engines had head bolt problems but many more had leaks.
They are not bad engines just misunderstood Cadillac used those engines in almost everything for a lot of years and millions are still around..Carbon formation in the early ones were a problem techron was recommended by engine people in the know. If you have a starter problem the top of the engine has to come apart. If you have a head gasket problem the engine should be removed
I do not think you will get a lot of benefit in using synthetic for this engine. I believe 7K OCI on a high quality conventional is easily due-able with your driving habits. If you prefer to use a HM oil with extra additives and seal "conditioners" may provide a extra benefits but just keep it topped off with oil and you will be fine.
sounds like PYB might be my best choice. that and a P1 filter, and i'll see how that goes. car is in great shape, got it for $6k. engine was rebuilt so i hope i don't have any head gasket problems. i heard that common in 04 and earlier engines. i wanna try to avoid a HM oil if i can.
it should take 7.5 qts, any harm in putting in 8qts since they do seem to consume oil?
it should take 7.5 qts, any harm in putting in 8qts since they do seem to consume oil?
No harm done, even if your engine does not consume oil.
Personally I was shocked to learn the Northstar was used in various GM production cars until 2011!
A forged steel crank added in 2003, and continuously variable valve timing VVT was a very high tech feature.
If you are determined to go with a conventional why not give a 10w30 HDEO a try for your 7,500 OCI? Extra cleaning and extra protection can't hurt...
Cheers!
p.s. My brother still has my Mom's last car: a 1982 Coupe deVille with the HT4100 aluminum V8 and it is still running strong on just about any 10w30 you choose to use. Of course since it is domiciled in Florida it doesn't have any real hills to deal with anymore.
A forged steel crank added in 2003, and continuously variable valve timing VVT was a very high tech feature.
If you are determined to go with a conventional why not give a 10w30 HDEO a try for your 7,500 OCI? Extra cleaning and extra protection can't hurt...
Cheers!
p.s. My brother still has my Mom's last car: a 1982 Coupe deVille with the HT4100 aluminum V8 and it is still running strong on just about any 10w30 you choose to use. Of course since it is domiciled in Florida it doesn't have any real hills to deal with anymore.
Originally Posted By: Treb
i'm not determined to use a conventional, just wans't sure if a synthetic was best to use or not.
There is no best when comparing motor oils. But use the one you want to use the most.
i'm not determined to use a conventional, just wans't sure if a synthetic was best to use or not.
There is no best when comparing motor oils. But use the one you want to use the most.
The point is, in the end, all Caddys Leak oil
Originally Posted By: GumbyJarvis
The point is, in the end, all Caddys Leak oil
At one point in time this kind of statement was historically true for all Harley Davidsons...
That was then: this is now.
IMHO all Caddys don't leak oil, now, either...
Cheers!
The point is, in the end, all Caddys Leak oil
At one point in time this kind of statement was historically true for all Harley Davidsons...
That was then: this is now.
IMHO all Caddys don't leak oil, now, either...
Cheers!
For what it's worth, the Northstar called for 5w30 after 1999. Prior to 1999, they used 10w30.
Yes. I bought a late 99 in 05 that already had the 5w30 cap on it.
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