Northstar Oil Consumption

[JIMDTS]

I'm using 1 qt. of oil every 625 mi. The car has always had Valvoline 10w40 in it. I'm thinking of switching to another oil Any recommendations as to any oil that might get better oil consumption. More miles per qt.. Also I notice black shoot inside the tail pipes I wipe it out and it's back in a short time. I imagine it's from oil blow by but I don't get any smoke.

Any ideas, the dealers fix is new rings and pistons due to the oil consumption and cold knock on start up but I'm not sure I want to go that route. The car has 42k on the clock.. and is a 01 dts deville..The car runs great other than using oil I'm happy with the car.

Thanks

Jim

[Vince P]

Jim,

My recommendation is to use the recommended oil.

That oil is 10W-30 that meets the GF-3 or GF-4 spec

Note that very few, if any, 10W-40 oils can meet the GF-3 spec.

Vince P

[JIMDTS]

Hi Vince

I really don't know what oil is in the car other than on the oil change bill from the dealer it mentions 10w40 I see valvoline signs around the dealer i guess I'll change the oil myself this time

Thanks

Jim

[JasonA]

I really don't know what oil is in the car other than on the oil change bill from the dealer it mentions 10w40 I see valvoline signs around the dealer i guess I'll change the oil myself this time

Jim, see the rod-through-the-block thread. I'd try Pennzoil High Mileage. I've been real happy with it in all of my cars. I wonder why your dealer was putting in 10W-40 oil?

[JIMDTS]

Hi jadcock

I'm not sure it's actually 10w40 some bills say 10w30 some 10w40 maybe it's just a clerical error by the billing dept. I would assume the use 10w30 but some of the bills say 10w40 Go figure So I'll pick up a case of 10w30 later today & Delco filter and give it a shot Not sure what I will use but I see a ad for Havoline for 15 bucks and some change on sale thats tempting I never used Havoline but I'm sure it's ok..The best luck I have had with oil is Quaker state which I used due to you can buy it anywhere and usually on sale..I don't like to swith brands every oil change like some of my friends do I find one and stick with it..I'm at less then 20% left on the oil change indicator so it's getting time to do it but the oil is refreshed with 2qt's evey 1000mi for the past 6000miles..so it's probably still good I hate to change the oil myself it's easy to do but you have to dump the old oil that's the pain in the a--..I'll check out the Penzoil

Thanks

Jim

[Brad]

Jim,

I have been down this bumpy road before with my '99 Concours. Mine was using a quart every 500 miles or so for a long time. I tried everything that has been recommended on this board, filling oil up the "add" mark on the dipstick, switching oil brands, tons of WOT's, 2nd gear WOT's, etc...etc....

Nothing worked. After a while I began getting awful discharges from the exhaust from engine blow-by. Due to the extreme low mileage on my car and the warranty, I chose to go the dealer route with logging the oil consumption, then two doses of the decarbonization process, and finally it came to the piston ring replacement.

The dealer had the car for about 7 days. They disconnected everything and pulled the guts out, replaced the rings, slapped it all back together and returned it. I have to say, the dealer service I received was excellent and thus far, I am not using any oil and have had no discharges from the exhaust.

I know the procedure is very risky because of all the things that can go wrong, but in my extreme case it was the only thing that worked. In my case, using oil was one thing, but I hade huge blue/black clouds shooting out of my tailpipes everytime I used hard acceleration.

One piece of advise though, as has been mentioned before on this topic, if you choose to have the piston rings replaced, make sure the heads are timeserted. Since I had the rings replaced, I have put about 10K miles on the car. Really seemed to cure my problem. Having the warranty was the key factor for me though. No way, did I want to pay for something like this.

Hope this helps a little and that you get your consumption under control.

[seventimescadi]

use 10-30 and drive the car don't baby it, wot as much as possible, the northstar needs to be driven hard

[JIMDTS]

Hi Brad

Thanks for the reply. I hear you I'm in the same boat that you were in. Just finished the oil consumption program burning 2 qts every 1000mi. and mine shows soot in the tail pipes so it's getting some blow by I'm sure .I also have the cold knock and the car sounds like a diesel when you first strat it up from a cold start.I have about 18 months left on the warrany so I'm good from that standpoint The fix they want to do is new pistons and rings along with timeserting the head bolts but I pay for the timesrting and it's a nominal fee as far as I'm concerned.I imagine changing the oil isn't going to do any good after the oil consumption program verified that I'm using about the same as you did. The tech at the dealer is good but people make mistakes so you never know esp. when these problems crop up 20 or 30k later I planned on keeping this car for my wife which I'm using her car(98 deville) to keep the milage down on the 01dts. Mine has now 42k on the clock I did the same thing plenty of WOT's running it low on the add mark no luck.. I can live with it as is but it would be great to at least get the car to 1000mi per qt. I'm sure GM knows there is a problem on some cars otherwise the would not have developed the rings and piston deal and esp fix it under warranty.They should have just bit the bullet on these cars and give you a new engine Shoot 500 mi a qt isn't good in anyones book esp. not mine.. I imagine I'll go for the overhaul in the end but I'm sketical at best about that.

Thanks Jim

[JIMDTS]

seventimescadi

that does not always work I have driven this car hard plenty with many many wot's On some of the northstars this just does not work. Trust me I have one..

Jim

[Scotty]

Jim this thread began 4/21/2004 it was titled Piston Ring Replacement, Oil Consumption, pay attention to posts by Shiden_Kai, I believe you have seen these posts but Ian always had good field information IMHO....

Here is one of his posts from 4/21/2004:

I've done a few of the re-ring jobs and so far they seem to have worked out well. The updated ring design should do a better job of controlling any oil consumption. For whatever reason, the amount of carbon buildup is very high on these engines. I just finished installing a set of updated pistons in a 2003 engine with 30k kilometers on it. The complaint was cold start piston knock and we tried the obligatory decarb treatments, but this engine was noisier then most. Anyway, once it was apart, it was amazing how much carbon was on the top of the pistons, and a few of the rings were stiff in their ring grooves.

We have another 2003 engine that will be getting the updated pistons. I hope it's not a sign of things to come, as I'm not real interested in doing this job very often. By the way, you may have a hard time convincing the dealership to "timesert" the engine as they are repairing it under warranty. Lately, we haven't been able to just "timesert" across the board with low mileage warranty engines. If we happen to run into a problem, "then" GM lets us do the timesert procedure. So far, the low mileage engines on warranty haven't really been a problem.

Hopefully, your problem will be cured.

Ian

Here are his posts from 6/7/2004, Piston Ring Replacement Continued, Just dropped the Caddy off....

1) Well, you actually did a pretty good job of describing what the job entails. But, I can go into a little bit more detail. I drop the engine/transmission/subframe out of the car. From there, I get all the wiring harnesses out of the way and positioned back by the transmission end. Then, remove enough stuff to get the engine disconnected from the transmission. This usually involves the front mount, a/c compressor, alternator, ps pump...etc. Engine get put on an engine stand. Water crossover and water pump and the flexplate are removed before the engine goes on the stand. Then it's a simple matter of removing the front cover, valve covers, timing chains, cylinder heads, oil pan, and lower case half. Remove pistons, install new rings and connecting rod bearings, and slide her all back together. It's really like a big jigsaw puzzle with some technical knowledge thrown in along the way.

Ian

2) I would agree with Jason, if you want time serts done, you need to sit down with the service department before hand and simply say, "I want them done, I'll pay the extra cost for them that GM will not cover". It's as simple as that. We always give the customer the option when the mileage is higher and we are repairing the motor under some sort of extended warranty (they definitely will not pay for the timeserts) and they always go for the added cost. On a straight "customer pay" job, I simply do not give the customer any choice. The engine gets timeserted as a matter of course, and it's built right into the estimate. The additional cost is about 5 hrs of labour, and the price of 20 timeserts.

Ian

[JIMDTS]

Hi Scotty I have seen those post before but thanks for the refresher course on them.

I have seen the rings and pistons first hand, the newer rings & pistons that I have seen for the 01's have teflon on the sides of the pistons I imagine it's just to mask the cold knocking.. Also I have seen the running changes to the pistons I know on the newer ones they went to a bigger wrist pin etc I don't recall what the break points are as far as the year these changes took place.It was explained to me but I don't recall all the info..interesting to say the least. From what I understand this high consumption and knock goes up to the early 03 models and maybe beyond..I have seen the engines torn down for this job at the dealer they always have one in a bay doing one.They have a back log on them with a long waiting list to get an appointmant to do the job.I,m not sure if it's the same piston in 01 as the 03 maybe the 03 has the bigger wrist pins. I probably will go for the rebuild and keep my fingers crossed that the mechanic installs everything properly..However people make mistakes which can come back to haunt you many miles down the road..I already worked out the timeserting of the head bolts but after seeing dtsdrivers job it sure makes you think..of all the little things that can go wrong and wind up worse than before..Hey the guy could torque everything install all the clips properly and just install a bad piston or ring due to a manuf. defect or someone could have dropped it and put cracks in it before installation etc.I have seen stuff like that before

Jim

[navion]

JIMDTS,

Hopefully you will not have a problem with you engine following the ring & piston replacement. If your shop is reputable, they will not try to weasle out of a mistake, if they do make one.

In DTS driver's situation, he will need all the help that he can get. I is apparent that a problem was induced at the time his engine was worked on. If the shop dosen't step up and admit responsibility, I hope that DTSdriver posts the name here so that the shop can be avoided by Caddyinfo's readers.

As far as not doing the repair, I advise to go ahead with it. As you say, the shop is always working on this same problem. So the tech should know all the pitfalls for this paticular job. I would just be sure that they assigned a tech that has done this work several times. Stay away from a "newby" .

Good Luck,

Britt

[Brad]

Yep, it is 6 of one and half a dozen of the other. All comes down to what you want to get out of the car. If you plan on keeping the car, the tear down may be your only option.

I definitely know where you are coming from. Since I am on this boat and my warranty is up next month, I have been on the lookout for another Caddy. It isn't that I don't want/like my Concours, I am just skeptical about what may occur down the line. It's all one big crapshoot. It could run forever, or die tomorrow. Who knows.

It ends up being what you are comfortable with and the probability of what may happen, good or bad.

[Scotty]

Hi Scotty I have seen those post before but thanks for the refresher course on them.

I have seen the rings and pistons first hand, the newer rings & pistons that I have seen for the 01's have teflon on the sides of the pistons I imagine it's just to mask the cold knocking.. Also I have seen the running changes to the pistons I know on the newer ones they went to a bigger wrist pin etc I don't recall what the break points are as far as the year these changes took place.It was explained to me but I don't recall all the info..interesting to say the least. From what I understand this high consumption and knock goes up to the early 03 models and maybe beyond..I have seen the engines torn down for this job at the dealer they always have one in a bay doing one.They have a back log on them with a long waiting list to get an appointmant to do the job.I,m not sure if it's the same piston in 01 as the 03 maybe the 03 has the bigger wrist pins. I probably will go for the rebuild and keep my fingers crossed that the mechanic installs everything properly..However people make mistakes which can come back to haunt you many miles down the road..I already worked out the timeserting of the head bolts but after seeing dtsdrivers job it sure makes you think..of all the little things that can go wrong and wind up worse than before..Hey the guy could torque everything install all the clips properly and just install a bad piston or ring due to a manuf. defect or someone could have dropped it and put cracks in it before installation etc.I have seen stuff like that before

Jim

I hear you! Seeing this thread its a scary proposition! Imagine doing it yourself? Even Ian said, "It's really like a big jigsaw puzzle with some technical knowledge thrown in along the way". It's that "technical knowledge" that scares me!

[JIMDTS]

I hear ya Scotty

These are cars. I worked my whole career with aircraft started as a mechanic then became a factory representative (tech rep)..With aircraft tools like torque wrenches have to be calibrated and a regular basis say every 14 to 30 days which really don't mean it's good someone could have dropped it threw it out of cal. etc

Which I'm sure a most auto shops do not have calibrated wrenches.. I have seen things cracked bolts, frames metal structure that you could never see cracks with your eyes it goes out the be x rayed comes back bad with cars they don't do all the inspections that you do on aircraft stuff. With aircraft if you were the mechanic and had to torque something that was critical you would have a QA inspector standing over your shoulder witnessing that you did it according to spec..then you and them sign off on it same thing installing a critical component it's always verified by an inspector and QA.. Just a whole bunch of things can go wrong. You have to apply Murphey's Law to most of this stuff..

Makes you think I have seen a whole bunch of stuff go wrong and just pencil whipped that is was done correctly..

Jim

[Scotty]

Very Interesting... Cracks, I can't remember the last time I heard parts being magnafluxed, in the old manuals, you would see reference to it all the time. When I rebuilt my 66 Caddy 429 in 1974, the heads, pistons and rods were magnafluxed (supposedly, I paid extra). If I were having the pistons replaced I would insist that the parts were magnafluxed (maybe the pistons are made of a material that can't be magnafluxed?).. Don't let your aircraft experience influence your decision to get your engine back to proper performance. When I did my search for Ian this morning, I noticed that you have been struggling with this problem for quite some time! I have not seen Ian for a long time, he had some very helpful insights into these engines.. Good Luck with this, Mike

[JIMDTS]

Hi Scotty

In Aircraft it's all NDI non destructive inspection mostly x ray but the magnafluxed stuff does not work as good heck a scratch can show up as a crack with the magnaflux stuff. It was ok in it's day.Old school now.

It has been a long time I have been using the 01dts as a second car trying to keep the milage low until the problem is resolved.Every 100mi. back to the dealer well that's a done deal with that BS I figure they keep jerking you around and mybe you get tired of comming back or total the car or sell the car and they are off the hook.Some bean counter probably cooked this stuff up.. Hopefully this will be over shortly Well in the next couple months anyway..

Jim