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

[Lubener]

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)


You don't need the tablets. The o rings that come with those Dorman elbows are junk, peel them off and put the AC/Delco o rings on those aluminum elbows, lube the o rings with silicon grease and you will never have a problem.

 

[carviewsonic]

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.

Interesting, and informative. My Buicks aren't losing coolant now, so I need some nudging to do the gasket replacement. Doesn't look too tricky, but it would take me probably a full day (at least) to do the job for the first time. It's a good thing I don't make my living fixing cars, I'm careful and can get it done, but I'm slow as molasses at these repairs.

 

[Nick1994]

Originally Posted By: Merkava_4
Non adjustable camber. Shouldn't need alignment as long as nothing was tweaked.
Changing struts and springs changes the ride height, which changes the toe.

I put in new Monroe Quick Struts in my grandmother's 2002 Chevy Trailblazer and it started wearing the outer edges of the tires before I took it in for an alignment.

 

[Alex_V]

Originally Posted By: carviewsonic
Those are some high mileage units, have you had to do the intake gaskets on any of them?


No, but only on the one with 181K would I venture to say they haven't already been done as the others have only been coming to my shop for about 18 months. However, if it's not losing a substantial amount of coolant or showing up in the oil I don't investigate further, but I may take a little less lenient troubleshooter's eye on that after reading this thread. Yeek!

 

[John_Conrad]

sometimes you won't get much evidence of the coolant in the oil, but the problem will show up as sucking air and engine refusing to idle, ie start and die.

and on edit, these engines are solid.

 

[Tman220]

Originally Posted By: John_Conrad
sometimes you won't get much evidence of the coolant in the oil, but the problem will show up as sucking air and engine refusing to idle, ie start and die.

and on edit, these engines are solid.


This reminded me of something. Part of the sucking air issue is probably from the upper(plastic)plenum. In my case there wasn't any sign of coolant intrusion from one of the typical areas which is from the coolant passages for the throttle body to the EGR stand pipe to the plenum due to heat from the EGR pipe compromising the gaskets in this area.

For the people that haven't had to do this yet, and are trying to hold off as long as possible start by checking the torque on the 10 bolts holding the upper plenum down. Most of mine were barely more than hand tight because of the compaction of the gasket over the years, the final torque is only 89 inch pounds (~7.5 ft lbs) which is hardly anything but tons more than hand tight. Maybe checking the torque on this are would decrease the size of the leak which quickly fills the lower plenum with coolant, then you cylinder, thus hydrolock. This is what happens in the event of a catastrophic upper intake plenum gasket failure by the EGR stand pipe.

 

[carviewsonic]

Originally Posted By: Tman220
Originally Posted By: John_Conrad
sometimes you won't get much evidence of the coolant in the oil, but the problem will show up as sucking air and engine refusing to idle, ie start and die.

and on edit, these engines are solid.


This reminded me of something. Part of the sucking air issue is probably from the upper(plastic)plenum. In my case there wasn't any sign of coolant intrusion from one of the typical areas which is from the coolant passages for the throttle body to the EGR stand pipe to the plenum due to heat from the EGR pipe compromising the gaskets in this area.

For the people that haven't had to do this yet, and are trying to hold off as long as possible start by checking the torque on the 10 bolts holding the upper plenum down. Most of mine were barely more than hand tight because of the compaction of the gasket over the years, the final torque is only 89 inch pounds (~7.5 ft lbs) which is hardly anything but tons morend tig than haht. Maybe checking the torque on this are would decrease the size of the leak which quickly fills the lower plenum with coolant, then you cylinder, thus hydrolock. This is what happens in the event of a catastrophic upper intake plenum gasket failure by the EGR stand pipe.


Excellent suggestion! I'll look up the torque sequence on-line, and check all three of my old Buicks.
An easy yet potentially grief preventing project, for next weekend.

 

[Merkava_4]

Originally Posted By: Tman220
Camber certainly is adjustable on that setup. Those holes have enough slop to get a few degrees in either direction.


No slop at all on my Buick. The holes in the spindle are splined to a real precise fit. I can replace the struts and the alignment won't change.

 

[Tman220]

Originally Posted By: Merkava_4
Originally Posted By: Tman220
Camber certainly is adjustable on that setup. Those holes have enough slop to get a few degrees in either direction.


No slop at all on my Buick. The holes in the spindle are splined to a real precise fit. I can replace the struts and the alignment won't change.



Are we talking about the same thing? on a lot of macpherson strut setups the two mounting holes shown attach to the steering knuckle. The slight amount of slop created between these holes is how you control camber on these things.

 

[Merkava_4]

Originally Posted By: Tman220
Are we talking about the same thing?


I think so yes because all the OP's Buicks will have the same setup as my 2000 LeSabre. The bolt holes in the lower strut mount that correspond to the bolt holes in the spindle are just barely big enough for the two lower mount bolts to go through. If you want to adjust the camber, then you got to enlarge one of the holes in the strut and install an adjustable camber bolt kit. I believe there's a line on the strut that tells you how far to enlarge the hole. I can't remember whether it's the upper hole or the lower hole though.

 

[The_Eric]

Originally Posted By: Lubener
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)


You don't need the tablets. The o rings that come with those Dorman elbows are junk, peel them off and put the AC/Delco o rings on those aluminum elbows, lube the o rings with silicon grease and you will never have a problem.


I agree completely.

 

[R18Civic]

All 3800s have plastic elbows. My 09 series III has them and they suck. Ended up having to replace my lim gaskets because a piece of the elbow fell into the coolant passage when I removed it.

 

[mk378]

A few days ago, my friend's 2006 Buick with a 3800 series III developed an elbow leak. I just put in the Dorman elbows as they were. We'll see how well they last.

My understanding is that upper or lower manifold gasket leaks not very common on a series III. Is that true?

 

[R18Civic]

Originally Posted By: mk378
A few days ago, my friend's 2006 Buick with a 3800 series III developed an elbow leak. I just put in the Dorman elbows as they were. We'll see how well they last.

My understanding is that upper or lower manifold gasket leaks not very common on a series III. Is that true?


That's true. The upper intake is made of Aluminum now instead of plastic so the EGR Stovepipe doesn't warp/melt the throttle body coolant passages like the Series II did. GM also upgraded from plastic to metal crush gaskets on the lower intake so they don't fail anymore.

 

[neo3]

With the elbows it's essential to get them from the dealer, the cheapo parts store ones will start leaking within a year due to bad o-rings (the actual plastic elbow isn't the problem).

Also, the Dorman replacement upper plastic manifold corrects the problem that caused melting around the EGR pipe, since they have a space around the pipe (the stock ones had the pipe touching the plastic, not a brilliant design).

- 2001 Pontiac GP 3.8

 

[R18Civic]

Originally Posted By: neo3
With the elbows it's essential to get them from the dealer, the cheapo parts store ones will start leaking within a year due to bad o-rings (the actual plastic elbow isn't the problem).

Also, the Dorman replacement upper plastic manifold corrects the problem that caused melting around the EGR pipe, since they have a space around the pipe (the stock ones had the pipe touching the plastic, not a brilliant design).

- 2001 Pontiac GP 3.8




The ones that failed on me were OEM from the factory. From what I can figure the groove that the o-ring sits in is the weakest link, they tend to crack from the inside through that groove. The o-rings are not reusable, the heat from the coolant melts them slightly which creates a better seal.