: Odd Tune Up Question



Yaemish
07-14-04, 03:47 PM
My friend has asked me about tuning up his car. Now he doesn't drive a northstar but he was unable to find a place on the net that can help. He has a GM 3800 from 1995 and needs a little walk through on what kind of plugs he should get and what he has to do. He will greatly appreciate any help.

eldorado1
07-14-04, 04:37 PM
I'll make the assumption it's DIS. :rolleyes: I'd change the fuel filter, spark plugs, air filter, PCV (filter if any), spark plug wires (if they're getting old). You'd be in about $70 if you did all that. Spark plugs, get the cheap AC delco/whatever came stock ones. Don't get any of the latest marketing hype like +4s or whatever they are :helpless: Also, changing the fuel filter may best be left up to the pros. Figure maybe $30 labor.

Oh, if you need a walk through on any of those, just buy a cheap chiltons/haynes. If you still need more help after that, its probably best to take it to a pro.

Ranger
07-14-04, 08:56 PM
AC Delco 41-606 are the plugs spec'ed for my wifes '96 Bonneville, VIN-K, L36 engine (probably the same). Be advised that those 3800's are notorious for having the upper intake plenums go bad. The symptom is a slow loss of coolant. The cure is replace the upper intake plenum, not just the gasket (won't help). If he has not had the problem yet, he will. I am going to replace my wifes tomorrow.

Roswell256
07-16-04, 10:49 AM
Keep us informed on how the replacement of the upper intake plenums goes. I'm curious to know whats all involved. or PM me with the details.

My parents have a 3.8 V6 in an 88 Cutlass Cierra w/ 297k on it. (I know what your thinking "they didn't make those until 89!!" they did made a few in 88 and we have one:bouncy: :coolgleam )

It was retired this last year do to the fact the car is falling apart around the engine. We now have a 95 LeSabre w/ a 3800. The mechanic that we take all of our vehicles swears by them. He feels they are some of the best engines ever made.



Thanks
-Roswell-

Yaemish
07-16-04, 02:03 PM
When I finished high school my dad gave me his 88 Park Ave. At the time it had 200k on and he figured it would last me a few semesters being that it had the original engine and transmission. I drove that car to 250k with no problems with any powertrain components. While the car looked like it just came off the lot, there was so much rust on the chasis that the mounts for various items began breaking. Having had such great luck with it, he purchased an 87 Park Ave Type for my sister with only 70k on it. Surprisingly enough my old Buick had just as much power and smoothness as hers as well as my Uncle's 98 Park Ave.

Ranger
07-16-04, 04:16 PM
Keep us informed on how the replacement of the upper intake plenums goes. I'm curious to know whats all involved. or PM me with the details.

My parents have a 3.8 V6 in an 88 Cutlass Cierra w/ 297k on it. (I know what your thinking "they didn't make those until 89!!" they did made a few in 88 and we have one:bouncy: :coolgleam )

It was retired this last year do to the fact the car is falling apart around the engine. We now have a 95 LeSabre w/ a 3800. The mechanic that we take all of our vehicles swears by them. He feels they are some of the best engines ever made.


Thanks
-Roswell- Overall I would not argue with your mechanic. The 3800's are very good engines. The one design flaw is the upper intake. There is much information on the Bonneville forum. The problem is, there is a "stove pipe" that comes up from the lower intake thru the upper, right behind the throttle body. That pipe delivers EGR gasses to the intake. The pipe is a light press fit in the upper so it makes contact with the upper and apparently gets hot enough to deteriorate the plastic in that area, warping the throttle body mounting surface (causing a leak) and worse, burning through into the water jacket. When that happens, coolant will leak into the intake and then it is only a matter of time before you suck in a slug and hydrolock the engine. Mine (107K) was using coolant at a very slow rate. I figured, "an ounce of prevention......". When I got it disassembled I did not find much deterioration in the area of the EGR delivery tube but I am sure it was getting brittle and was only a matter of time. I must admit it was in better shape than I expected but if you are over 100K keep a close watch on your coolant level. If you are over 200K you are overdue.
I hate to admit that it took me much longer than it should have. In my defense, I stopped to have something to eat, wasted time trying to get the last of three bolts off the throttle body. It was on very tight and I rounded a socket and the nut so I had to resort to a hacksaw which entailed another interuption for a trip to the dealer for a replacement which led me to find out they have a replacement type so I got all three. Then came another delay in which I machined a sleeve to fit in the upper intake EGR passage and a new stove pipe with a .050 clearance so as not to have any contact and eleviate GM's shitty design. The result is somewhat like a double walled chimney pipe. The adapter I made can be found at http://www.ken-co.com/manifold/default.htm for $80. Yeah, a bit steep for such a simple thing (that's why I machined my own to a perfect fit). However they don't sell to the public so if you want one you'll need to find someone who sell them of can order for you.
As far as what was involved, I guess the basics. drain coolant, depressurize the fuel rail, remove everything in the way or attatched to the intake ie: vaccuum hoses, electrical connections, fuel rail and injectors. In my case ('96 Bonneville) I had to swing the alternator out of the way to lift the manifold. The one tip I can give you is do not bother trying to seperate the throttle body from the intake til the upper intake is free from the lower. The exhaust crossover is in the way of the two lower mounting studs. I must admit after cleaning the mating surfaces and sucking the pooled oil out of the lower intake, it went together much quicker than it came apart (doesn't it always).
After pressure washing the engine this morning I started it and took it for a shaked down cruise and all is well (no leaks). Now all I have to do is heal all the cuts, scapes, bruises and burns. By the time that happens, I should be able to straighten my back up again. If I can be of any further assitance email me at grandolfo@yahoo.com