98 Park Avenue with mild oil consumption

[rclint]

History is my Mothers 98 Park Avenue all decked out every electronic device, gauge etc, and the outstanding 3800 engine with the uhgg intake manifold gasket... It has had the engine replaced due to the gasket going bad, it was cheaper to replace the engine than tear it down replace the damaged internal parts... the engine runs strong, and I'm sure set up for several years it was a documented low mileage engine (~40,000 miles) it does consume oil about 1 to 2 quarts during an oil change which she goes by the OLM which goes off at a set 3000 miles.. I'm going to try to get her in a new maintenance schedule as she drives this car easy, and 90% highway 10% city nice long trips to work around 35 miles each way.

I have some good oil in my stash I'm going to see if I can help find an oil that will reduce oil consumption... mind you the consumption is no problem but Mama don't want to fool with this, and worries all the time about it,, she takes very good care of the car while reading how women don't know, or don't care if every woman was like my Mama you would never have to worry about purchasing a used car about how the oil has been changed !!

The manual states it has a short trip, and long trip indicator light, I'm going to keep up on mileage this time, the short trip is what she has been using, I'm not sure how to change it over to long trip which is 7500 miles. I'm going to run a synthetic oil for testing I hope to reduce consumption by choosing a 40 weight if need be, however I have some Castrol 0w-30 ( Germa Castrol) I'm going to try first, and then move up to either Maxlife 10w-30 or Mobil 1 0-40 ... I also have been thinking about running Rotella 10w-30 in this engine as I have had outstanding success using this oil.. I wonder if the rings have "stuck" or have become coked/dried out deposits from sitting for long period of time in the junk yard ? If so is there anyway to combat this problem other than piston soaks with seafoam etc ? I don't think ARX will be a solution for this engine.

If the synthetics do not work I will just drop back to using a 10w-30 conventional, however I'm really hoping the Mobil 1 0w-40 will work out as I have read so many good things about this oil... and Mama would click her heals 3 times if I can reduce or eliminate the need to add engine oil between changes.. I also know there is no mechanic in a bottle as well, but maybe there is some reduction in a bottle ? Any opinions, solutions, recommendations will be appreciated as my Mama is pretty much disabled having had several back surgeries, and very independent as well... a fine woman, and the best Mama that ever was..

 

[The_Eric]

First try replacing the PVC valve, spring and o-ring. Whoever put the new engine in may not have changed it, or worse - they may not have used the spring and o ring... I've seen it before.

 

[Geo_Prizm]

I am sorry to hear about that.But a documented-low-mileage engine burning oil?Either the engine is not low mileage, or if it is, it is not a good engine.

 

[lucerne06]

what engine did you replace it with and what year is the engine?

 

[sciphi]

Check for oil pan gasket leaks, or valve cover gasket leaks. Those are two known leak areas on the 3800.

 

[mechanicx]

I agree with the other suggestions, and to use a 10W30 HM or a stout 10W30 synthetic for cleaning. Have you tired giving it an italian tuneup to reseat the rings? Take it on the highway in 3rd, WOT to about 70mph then coast down closed throttle to about 50 mph. Repeat that several times.

 

[Gene K]

Shell Rotella T 10W30 completely eliminated the oil use between changes in our 3800. It worked pretty well changing annually at 9,000 or so miles of mostly short city trips. The conventional is hard to find now but Shell Rotella T5 Synthetic Blend 10W30 seems to be available at most WalMarts.

 

[rclint]

This was a documented low mileage engine, and I agree I have seen this family of engines with almost 400k on them with around 1 quart use between oil changes.. I can't remember the year the engine is or any of that, I may be able to find out.. however the yard we got the engine from is very trustworthy, that's why I was thinking of the rings... as we have purchased several engines from them in the past every one being as represented.. they have a warehouse with the engines, the engines are tagged with mileage, year, car etc etc..

The engine does have a very minor leak, however a few drips that will not make a quarter size puddle over a weeks time... so I was looking elsewhere for the usage. The car is driven almost daily on the interstate so it gets an I-talion tune-up regularly LOL.

I have not checked the PVC valve yet, I will do so being the engine sat, and changed I agree that was something I overlooked, and in this case very well could be I hope so.

 

[sciphi]

Could be the PCV valve. When you do that, check the old valve for any remaining O-rings. There will be an O-ring on the PCV valve, and another larger one on the top piece that may have fallen off. If you don't put both of them back on, you'll get a whistle when the engine's on.

Still check the gaskets mentioned above. Those can leak lots of oil without making much of a mess.

 

[Benzadmiral]

My '03 PA with 76K miles is having similar issues. Posters here suggested the same things they've thrown out to you. I've replaced the PCV valve myself, once when I bought the car in '07 (at 44K) and again last summer; I used the part from the Buick dealer and have had no whistles. The oil consumption didn't ramp up until a little while after I changed to Castrol Edge 5W-30 in April.

My plan now is to go with Mobil Clean 5000 10W-30 for the winter change, and if nothing improves, maybe I'll try the Rotella T5.

I'll be very interested in how it works out. Let us know what happens.

 

[rclint]

I have run several oils in this car 10w-30 or mama has, conventional bulk oils, Mobil 1 EP, Castrol, PYB etc etc.. I'm also interested in anything you find Benzadmiral. I will be taking a look over the car this week, i will check the above items, and I'm also going to do an oil change while I'm at it so I may not pinpoint it to an exact component I will be doing more of a blitz attack then start trouble shooting after that.

 

[lucerne06]

I own a 06 lucerne with only 21,000 miles. I just had an authorized buick repair shop near me, get the ok to do some warranty work on the car, which the reason is due to oil usage. it started using a qt every 1200-1500 miles, and I found out about a silent recall for lack of a better word. bulletin 05060135A. The tech bulletin is to replace the VALVE STEM SEALS on the exhaust valves, which is supposed to take care of the oil burning/ussage condition.

We shall see, i was told that they have done two of these repairs on two different 3.8l engines that had the problem and that the oil burning condition was solved.

 

[lucerne06]

bulletin on this for oil consumpution.#2034062 Some customers may comment of excessive oil consumption on the 3800 Series III engines. An engine that has excessive oil consumption uses 0.9L (1 qt) of oil or more within 3,200 km (2,000 mi).
This condition may be caused by the retaining ring on the exhaust valve stem seal not securely holding the seal on the cylinder head guide boss. If this occurs, the exhaust valve stem seal(s) may move off the cylinder head guide boss and no longer provide a sealing function between the exhaust valve stem and the valve guide.this bulletin covers 06-08 lucerne with 3.8 vin code 2 and 4.

 

[lucerne06]

Oh I also forgot to tell , that the dealer said to use 10w-30 instead of 5w-30, and they put in wolfs head 10w-30, I posted a UOA of it, during that time the car used about 12oz between oil changes, over the winter mainly short trip city driving, since then I switched to 10w-30 QS full Syn, and have been doing mainly highway miles, it so far has used about 8oz in 800 miles.

So either high speed highway miles in the mountains of PA, or full Synthetic oil or a combo of both is not a good match for this engine...just my observations. I think I will end up going back to a thicker dino oil from now on. I also just think that the car just might be a bit too heavy for this engine, and even though it will probaly run for 200,000 care free miles(knock on wood)they are just going to use oil no matter what and you need to monitor it.

I posted these to benzadmiral a few days ago, not sure if he saw them, also it may apply to you rclint..good luck

 

[sciphi]

I suspect the full syn oil is doing some cleaning on a gently-driven motor that's being used more. High-speed hill-climbing is helping the process along very nicely. So you are burning more oil.

Give the full syn oil a second chance. I bet your consumption on syn oil goes down.

FWIW, my 1999 LeSabre with 84k miles has used syn oils for most of the 50k I've had it. It's not burning it. But the pan gasket has a small leak.

 

[mrsilv04]

Definitely use a 10w-30.

Try something like a Valvoline High Mileage 10w-30, which is a synthetic blend. It is a very robust oil, and I've had good luck with it in other vehicles.

My folks have a '99 Park Avenue with the same engine. Theirs has 85,000 miles on it, and they are the second owners, bought at 44,000 miles in 2006. It only goes through a quart in 5000 miles.