Northstar oil consumption

[sallen1]

Any of you Cadillac dealers experiencing customer complaints on excessive oil consumption? This mostly is on 95 - 98 models, the 99's don't seem to have the problem. Here's what to expect.

Oil consumption of more that a quart per 1000 miles or so is (and should be) excessive.

Here is what GM will tell you to do. First, do an oil consumption and dye test (for leaks). The customer will come back with low oil, no leaks and concerned that you are stalling. Then, you will want to fix the lifter guides if they are 'loose', usually new cylinder heads accomplish this but you can get a local machine shop to do the job much cheaper and you may do rings, etc. Once again, the customer will return a little agitated this time. You will now want to replace the engine, and your rep will not, so WATCH OUT. You've already spent a couple thousand buck screwing around and this is the third time back for the same problem.

What should you do? Here's my suggestion. On the first visit, do the dye test and consumption survey and DOCUMENT. Obviously, a 1qt. leak will be obvious (on the driveway) but do the test and consumption survey FIRST. If the problem is real, the second step may be to replace the engine. Why? The cylinders may be out of round, and if they are, there's nothing you can do except a replacement. Pull the heads and have each cylinder measured and DOCUMENT, pictures are a good idea too. There are specific tollerances in the service book (don't know them off hand) and if any cylinder is out of tollerance, the replacement will fix the problem. lIke I said, not every car has the problem as do the new assemblies.

Let me know what you find out.

scott

[This message has been edited by sallen1 (edited 06-16-99).]

[Michael White]

We had 1Devilles in our rental fleet and literally everyone of them was using oil in the 1300 to 1600 mile range. There is a new bulletin that says under normal driving. 2000 per quart is the magic number. Now the Northster has particular concerns: valves and valve guides, as well as out o of round cylinder walls. Occasionally you will find rings not seating. It is a major problem with Cadillac, and if it was not nor the dealer and the industry promoting early oil changes, there would be a major problem. Cadilla, no GM, must realize if a engine is using 1 qurat in 3K miles, customers do not accept this. They may not force the issue, but they sure will consicer buying another Cadillac. Judging by the radical drop in sales in the S.F. Bay area, customers are definetly going to Mercedes, volvos, Lexus and BMW. Cadillac is in deep do-do here. I hope they can fix it.
Mike

[D.L. BAGWELL]

I know several years ago we had a problem with rings not seating in on v-8 pontiac engine's, we had a way of seating in the ring's, maybe a little unorthadoxed and maybe not even recommended by G.M. but it works (remove belt or disconnect coolant fans to get engine hotter than usual and sprinkle bon-ami in intake area not too much small amount forces rings to get seated. You could also just get engine warming than usual with out the bon-ami. I maybe that they just haven't seated in yet

[MARY SHERICK]

WE HAVE HAD SEVERAL,AND AFTER THE OIL CONSUMPTION TEST, WE DID THE HEAD R AND R AND MEASURED CYLINDER WALLS, WE HAVE HAD TWO ENGINES THAT WERE OUT OF ROUND. WE DID NOT HAVE THE REP PROBLEM WITH THE ENGINE REPAIR VS. REPLACE ISSUE, BUT BOY WILL IT KILL YOUR COST PER VEHICLE. WE STAGGERED THE PAY DATES INTENTIONALLY TO COMPENSATE. THIS WILL CONTINUE TO BE AN ISSUE, BUT THE REPAIR IS NECESSARY, AND AS LONG AS YOU CAN JUSTIFY IT, TELL AN ARGUING REP THAT YOU DID NOT BUILD IT, YOU ARE JUST FIXING IT.

[sallen1]

Here's an update on an old topic.

We showed our rep how one engine had many cylinder walls that were out-of-spec. Guess what? We made a new engine! That's correct, we send the block out for boring and rebuilt the engine with oversized pistons and rings. It's now 4.8L and runs great. Will it fix the oil problem? Who knows. When I get all the bills together, I'll post the results!

I suspect that the engine replacement was the better repair, but the rep. and regional warranty person said to make the fix. It took about a month to get it done (the first one is always a problem). I hope GM doesn't choke on the rental bill...

We're looking for a shop that will perform the full lower end re-man. While we could do most of the work, we still need machining. We're in the Los Angeles area, please let me know if anybody knows a good shop. Were planning to perform about 100 of these repairs.

Thanx

scott

[This message has been edited by sallen1 (edited 08-03-99).]

[Michael White]

Scott, having the customer in a rental for 30 days makes the overall cost fairly close doesn't it? What pistons did you use and did you do the assembly and the machine shop just do the machining?
Cadillac has known for a long time about this concern.I do not know what the long term affects will be. However, I would be concerned about recommending a high miles 4.6L to a good friend with so many valve problems,head bolt problems, and cylinder wall concerns. The 4.6L is a drop in the bucket in comparison to BMW engine concerns.
I hope Cadillac can fix the concerns.
Mike White

[sallen1]

I'm not sure what the ptnos. for the pistons, et. al. are, but I'll find out.

As far as reliability is concerned:

1) We have sold thousands of 4.6L powered vehicles starting with the Allante in '93.

2) So far, we've only had about 100 complaints of excessive oil consumption. Not many when you compare the total in the field. And if you compare 3rd party testimonial, JD Power ranks Cadillac with high reliability. We only see the problems at the shop, most customers are not concerned.

3) According to GM via a service bulletin, 1qt per thousand miles is 'acceptable'. Check with your rep. on Chevy, Buick, etc. and see what they recommend. Apparently, the Lexus 32-valve engine burns alot too. They recommend a 3000 mile interval for oil change.

4) Some customers tend to neglect regular maintenance and with the popularity of 'self-serv' (read: no service) gas stations, no one really checks their oil anymore. I'm only 36yrs and I remember going to the gas station with my dad and having oil added to the car with a fill-up. Those motors were oil burners too.

I believe Cadillac has fixed the problem on this generation of motor. The replacement engines (which are re-mans, by the way) are tighter, have less vibration and so far (one has 25,000 miles) do not burn as much oil.

For the 2000 Deville, Cadillac has updated the 4.6L motor: different intake, valves, pistons, etc. I think they got the message.

scott

[Michael White]

Scott, there is a updated bulletin that came out for all GM vehicles except Saturn(which has a consumption problem) which states under normal driving, 1 qt in 2000 miles is normal. It goes through inspection procedures, etc. At one time we had 15 96 Devilles for our rental fleet. All used quart between 1300 and 1700 miles since new with no changes. After selling them only 2 customers complained. Both got new engines for cylinder problems. See your service manager for the bulletin. We have 3 Lexus stores in our group. I have talked with 2 of the service managers. They said they have never seen a consumption problem in the last 4-5 years.
Mike White