11th Oct 2015, 22:08

Where is the major oil leaking? Is it coming from the crank shaft seal on the left side?

1st Oct 2016, 23:33

I own an 04 Seville since it was new.

253000 miles and I have bought the parts myself when possible and had them installed. All oil leaks have been fixed over the last few years and the maintenance has been thorough and quite involved. The hardest things were the motor mounts, which involved replacing the front and rear several times until I finally got the OE front directly from GM. The aftermarket front mounts are not made the same and are not strong enough.

The other recurring problem baffled everyone and had to do with tire balance, which is so typical in the 55-70 mph range and can drive people crazy with unnecessary repairs. I could help a lot of people with this problem. There is a yellow or red dot on some tires that must be lined up with the valve stem for proper balance. Nobody seemed to know this and I had experts balance my tires five times, and the tires appeared to be balanced, but were not.

Now, they are and the car has had complete suspension replacement three times from so many miles and every bushing and mount gone over meticulously. It rides and handles like new. But it was a long process to get it all in proper order each time with so many unnecessary alignments and mounts etc.

The list of parts that have been replaced over the years is too extensive to list here.

But keep in mind there is a reason why they can fly airplanes for fifty years. It is only because of maintenance, and that maintenance is much, much less than buying a new one. The advanced technology may be a reason to buy a new car, but the Northstar was and is the best of the best in cost effective, advanced automobile production. Fuel consumption is included in that statement. Gasoline consumption is only one part of the overall picture. For the highway traveler it don't mean much at all when a Northstar cruises with authority and gets 27 MPG. OK I can get a hard ride with more fatigue in a BMW and accelerate faster and get 35 MPG. It sure doesn't feel as stable and smooth as a Northstar V8.

Stick your yuppie Beemer. I chose the more advanced and beautiful Cadillac Seville for $20,000 less which has far superior leather seating and gorgeous Zebrano wood interior trim. A BMW feels like a cold machine shop inside when you compare the two.

My Seville has 253000 miles and uses about a quart of oil every 1000 miles because it is supposed to use it like that.

It is designed to use oil like that and it may be why I can run it hard regularly and it has lasted this long. Be grateful your Northstar uses oil. No engine design was more advanced than the Northstar and they use oil by design.

The engine has gradually gotten louder over the years and has some ticking sounds, but the power is not noticeably different from new.

These are exceptional cars and just need good old fashioned maintenance, which requires a commitment in order to enjoy such a fine ride. I do not believe that Mercedes or BMW ever made a better ride or design than the late model Northstars (2000-2004).

PS. The heads have never been off my Seville.

The head bolt problem must have been solved on the later model Northstars. The rear main seal never leaked either on this work of art. It took 14 years of a separate Northstar engineering staff to fine tune it all and they did a fabulous job right down to the advanced higher density pressure cast aluminum used to make the block.

Aluminum block, pistons, heads, even the power steering pump is aluminum. This car was the most advanced of its time and still is up there with the best.

The average new car cost three times what you pay to keep a Northstar running tip top and riding smooth.

GM still sells brand new Northstar engines for replacement and I would not hesitate to get one installed when needed.

That could be a while from the way it looks.

Jerry