Drew99 I think what they were trying to tell you is that out of all the engines GM makes the 3.8 has the best track record. It tends to be about as problem free as you are going to get from GM.
THis engine does not have knock issues and does not show high wear numbers. If maintained it tends to last a long time. The upper intake problems have just bacome a recent thing with the advent of Dupont 66 intake manifold. My 97 Buick has this design and I am not to pleased with it. You can see that at some point before I bought this car oil was seeping past the upper intake manifold seal.
In all fairness to GM any time you have a V configuration and have angled mating surface leaks are going to be expected reguardless of manufacture. THe key is that they have consistently had magnified problems with both upper and lower gasket sealing issues in recent years. I think that the smart thing would be to use neoprene gaskets and maybe cut flat o-ring design in the future to prevent this.
If you look at imports with V8 of recent design they try to make the mateing /sealing surface with as flat as possable to seal and cut o-ring in alot cases. The use of neoprene, silocone and nitrile is abundant. You do not see alot of cheapp compressed fiber gaskets or paper gaskets on them at all these days.
The issue of leaks is such a major concern that when DC designed it's new 5.7 Hemi it was just as concerned with elimanateing leak paths as it was with low cost design. DC was very proud of it's design from a seal integraty stand point! They went on record on more then one occasion touting this as a major advancement for them.
You have to remember that the engines in mass production for most Domestic brands are either designs from the 1940's-1960's with small updates here and there. Paper, leather, natural fibers and natural rubber was about all you had to seal an engine. Manpower was abuntant, peoples incomes were growing and the buying power of the dollar was great! When a car cost $1500-$3000 dollars new who cared if the intake manifold leaked at 60,000 miles?
Now 30-60 years later a cheap car can cost anywere from $9000-$17,000 dollars and a really nice car or truck will run you $25,000-$80,000 dollars. Labor is $70-$100 dollars an hour and nothing is easy to get to on the newer cars due to packageing and full deliver systems.
Most domestic car companys are just now reliaseing that they have some serious quality and durability issues. They have been in denial for about 30 years as to the extent of their short comeings! They can not afford to develop and release alot of new power trains all at once if they want to keep share holders happy. To make matters even worse some of the recent power train releses are what they should have been building 10 years ago so they are still not truely competitive.
The engine from most domestic brands have the following problems. Dirty emission control systems, lack of rotateing assembly ballance, gasket integerty problems, and narrow power bands. They also tend to lack refinment interms of NVH. The sad thing is that the designs are usualy pretty good. You can clearly see that it was a cost issue that stoped a design from being what it could have been. A key example is the new generation of V8's from GM. They have the potential to be a world class engine!! It would not take much to make them a world class engine!!
I am going to give away my ideas about this engine. They need to give it better thrust control, ballance the rotateing assemble better, move the top ring down a bit, increase the skirt area about 15%, aim the injectors betters and reduce the power output to clean up the EGR system a bit. If they made the power band flatter with the use of varible valve timeing they would not need to dump so much fuel into the engine. GM is dumping to much gas into the cylinders to get power output up and this causes carbon issues and fuel dilution issues.
[ August 16, 2003, 12:37 PM: Message edited by: JohnBrowning ]
I have one question for you 3.8L experts. The service writer indicated that the leak was at the upper intake gasket, mainly as a result of the warped plenum. I thought the gasket leaks were at the lower intake gasket. It's my understanding that there are no coolent passages through the upper intake plenum. I know for a fact that on 3.1L and 3.4L motors, that is the case and it is the "lower" gasket that fails. Anyone want to clarify for me just for my own sanity? At any rate, I caught it in time. He said that it was about to "blow" and just fill the crankcase with coolent; exactly what happened to my brother's 96 Jimmy.
