2003 Buick 3800 II & 4t65e odds n/ends maintenance

Status
Not open for further replies.
Joined
Aug 17, 2016
Messages
1,498
Location
Alberta
Just thought I'd share my recent maintenance experiences (car has 158k miles now)...
Thermostat change 3 months (4700 miles ago) - The old one was running low at 180 deg.(for the last year or so), new one runs at 195 deg. Oil consumption seems to have reduced from 1 litre (quart) in 3500 miles to now 1 in 4300(ish) miles. My theory is that the old thermostat was causing some fuel contamination of the oil??? Of course, may be too early to tell for certain yet.

Trans pan drop and filter this weekend, took 7 litres (7.4 quarts to refill). Decided instead of flush to just drop the pan again in a year or so. This was messy enough without doing the full flush. I did a little research here and on the web, saw lots of good reviews for Valvoline Max Life high mileage Dex(6)/Merc, so went with that. The pan was actually pretty clean, just a little stuff on the magnet (did a full flush, pan drop and filter at 85000 miles, used Dex 3 at that time). Anyway, I like the Valvoline, shifts are definitely smoother now.

Changed my first set of front struts this weekend. I used Monroe quick struts, they come with fully assembled with new springs and top mounts, making them pretty easy to install. Or they were easy to install once I figured out I had to jack up the entire front end (two jacks), so that the sway bar doesn't keep the suspension somewhat compressed on the side your working on. Thought why in the #@&%^ is this strut too long?, until I had the sway bar thing figured out.
 
It got tweaked... had to hit one of the bottom bolts pretty good to get it out. Have an align scheduled for tomorrow.
 
I have the same trans in the Malibu, every 5k when i change the oil&filter,i remove the torque converter plug and it drains about 2.5 qt. of atf. Over the last 6 changes i have drained and refilled over 15 qts. I find this much easier than dropping the tranny pan. I use Valvoline Dexron-V1 full synthetic atf which is officially licensed & GM approved.
 
I've had good experiences with the Maxlife Dex/Merc. The 3800 and 4T65 are stout units - I maintain three with 181K, 215K, and 268K miles, and all run very well. Mid 90's-mid 2000's Buicks are durable, comfortable cars that aren't real bad to work on.
 
Originally Posted By: Alex_V
I've had good experiences with the Maxlife Dex/Merc. The 3800 and 4T65 are stout units - I maintain three with 181K, 215K, and 268K miles, and all run very well. Mid 90's-mid 2000's Buicks are durable, comfortable cars that aren't real bad to work on.


+1 I had a 2000 Lumina with a 3.1 which is similar. Loved working on that generation of vehicles. Super comfortable and generally easy to work on. Maxlife is a great fluid for that. I would stick with a good conventional oil. Shell, Pennzoil and enjoy many miles. How about the headgasket and LIM? Were those replaced with the upgraded gaskets?
 
If your car has plastic coolant elbows, you may want to change those out before they fail on you. My wife's old Pontiac broke one of the elbows at 160K miles when she was on an extremely narrow highway with no shoulders. I was out of town so she had it brought to our local mechanic and he put in the aluminum type of elbows (total cost was $275). Unfortunately, the mechanic forgot to put in the cooling system sealant tablets and the elbows started weeping within a year. I ended up replacing the elbows again myself (https://www.amazon.com/Genuine-3634621-Cooling-System-Tablet/dp/B000QIH3C4)
 
Originally Posted By: Merkava_4
Non adjustable camber. Shouldn't need alignment as long as nothing was tweaked.


Camber certainly is adjustable on that setup. Those holes have enough slop to get a few degrees in either direction.
 
Originally Posted By: IveBeenRued
If your car has plastic coolant elbows, you may want to change those out before they fail on you. My wife's old Pontiac broke one of the elbows at 160K miles when she was on an extremely narrow highway with no shoulders. I was out of town so she had it brought to our local mechanic and he put in the aluminum type of elbows (total cost was $275). Unfortunately, the mechanic forgot to put in the cooling system sealant tablets and the elbows started weeping within a year. I ended up replacing the elbows again myself (https://www.amazon.com/Genuine-3634621-Cooling-System-Tablet/dp/B000QIH3C4)


I mentioned the elbows earlier. The permanent fix is not the coolant tabs but Permatex black. The metal elbows are not expensive and a bead of Permatex after cleaning the surfaces is a permanent repair.
 
Originally Posted By: IveBeenRued
If your car has plastic coolant elbows, you may want to change those out before they fail on you. My wife's old Pontiac broke one of the elbows at 160K miles when she was on an extremely narrow highway with no shoulders. I was out of town so she had it brought to our local mechanic and he put in the aluminum type of elbows (total cost was $275). Unfortunately, the mechanic forgot to put in the cooling system sealant tablets and the elbows started weeping within a year. I ended up replacing the elbows again myself (div>


Sounds like you had some bad luck.... I have owned and worked on several of similar cars with the series 2 3800. In my experience don't mess with the plastic elbow between the lower intake manifold and belt tensioner assembly unless you have to, like for instance when you're replacing the upper intake plenum and lower Intake manifold gaskets. They shouldn't break unless they have been previously messed with or when you try to remove it after 15+ years.

One risk of trying to replace that elbow is you will need to unbolt the belt tensioner assembly and I have seen on several occasions the coolant nipple on the tensioner assembly where it seals to the water pump housing, break off, in which case you will be replacing the belt tensioner assembly ($70.00+ the last i bought one)

I would assume by 158,000 the upper and lower intake issues have been dealt with? If not, does it have disappearing coolant?
 
No, amazingly enough still the original gaskets. I check the coolant level frequently, and it isn't dropping. I should do them sometime soon though, they're a known problem on these engines.
 
Originally Posted By: IveBeenRued
If your car has plastic coolant elbows, you may want to change those out before they fail on you. My wife's old Pontiac broke one of the elbows at 160K miles when she was on an extremely narrow highway with no shoulders. I was out of town so she had it brought to our local mechanic and he put in the aluminum type of elbows (total cost was $275). Unfortunately, the mechanic forgot to put in the cooling system sealant tablets and the elbows started weeping within a year. I ended up replacing the elbows again myself (https://www.amazon.com/Genuine-3634621-Cooling-System-Tablet/dp/B000QIH3C4)


Thanks for the link on the tablets, I think I'll order some, would be good to have on hand.
 
I just did the upper plenum and lower intake gaskets on a series 2 this past weekend. The car is a 98 Olds Intrigue, 147,000 miles, still rocking dexcool. see if you can spot the problem (this was the front bank gasket which was the better of the two
wink.gif
)


 
Last edited:
Originally Posted By: rshaw125

I mentioned the elbows earlier. The permanent fix is not the coolant tabs but Permatex black. The metal elbows are not expensive and a bead of Permatex after cleaning the surfaces is a permanent repair.

I should have mentioned that I used the tablets and I used Permatx Form-A-Gasket No. 2 sealant. After three years, no leaks were detectable even with the UV dye and light when I inspected it prior to sale.
 
Originally Posted By: Tman220
I just did the upper plenum and lower intake gaskets on a series 2 this past weekend. The car is a 98 Olds Intrigue, 147,000 miles, still rocking dexcool. see if you can spot the problem (this was the front bank gasket which was the better of the two
wink.gif
)





Looks like there are holes in the gasket material. Was it losing coolant, or any other signs of trouble?
 
Originally Posted By: carviewsonic


Looks like there are holes in the gasket material. Was it losing coolant, or any other signs of trouble?


Yes there are many holes in the gasket material, in case you are not super familiar with these engine or gaskets, the smaller rectangular hole roughly in the center of the photo is for coolant and the tall narrow rectangular passages for the intake tract. The white around all the ports is what does the actual sealing and there is basically a structure around the white sealing ring to support it. The support it has towards the actually ports is broken and failing and you can see how they got pushed into the ports. You can see the path of flow from the coolant passage to a slight cavity in the gasket and over to the intake ports. These passages should all be uniform rectangular shapes, so you can see how much distortion there is especially in the coolant path.

This engine was losing coolant, but not as much as you would think, I would guess maybe about 4-8 ounces a week. I could tell by the oil fill and cap the issue was coolant related. sure you will always have some moisture in the cap and neck on a series 2 in the winter and eventually you know what is normal and what's not, but you shouldn't have globs of yellow snot.
 
Status
Not open for further replies.
Back
Top