2001 Buick LeSabre - 50k miles... Stay with the Dexcool?

The Dexcool is fine if you don't want to flush it. I flushed mine and used the Walmart all makes all models stuff. No issues in 70k, but I also did the intake gaskets when I got it and they were just about to fall apart so I am glad I did. Metal elbows are the way to do it for sure, mine are starting to leak now after 70k but they are the dorman ones with the o rings that they came with. Might have to pull them out and switch to delco o rings. Great car, just keep up with any issues. I was able to fix my transmission with a shift kit and 70k later it is still good after barely being drivable when I got it.
 
Good points, thank you! Yes, all original. As a poster said above... G-05 is not supposed to have the plastic eating 2-EHA. (I've used G-05 in my Miata for years BTW...)
Assuming the intake gasket is still intact, the question now is.... Do I switch or is the DexCool a gamble?? Yes, it's been in there for 19 years... but??? If the compostion is chewing away at the gaskets...?? Am I buying time or just delaying the inevitable?

I don't see these much anymore but when I was doing quite a few of them I would do the LIM gaskets and replace the upper plenum with the ATP unit as a preventive measure. Failure is inevitable but when is anyone's guess.
Loss of the 4th gear input shaft is very common as well as other issues with the transmission.

Use dex for now and plan on doing the LIM gaskets. When you do the gaskets you can remove the thermostat and lower radiator hose first and really flush it out as well as the heater core so there is little chance of cross contamination with the dex. I use JD Coolguard II in these engines, after 6 years it still tested good with the JD test strips.

The reason for replacing the upper plenum is the original egr chimney burned through, the ATP unit uses a metal sleeve and a reduced diameter chimney which cures this issue permanently. The quality and fit is very good, this is a very easy weekend diy job, use GM OE gaskets only.

 
I don't see these much anymore but when I was doing quite a few of them I would do the LIM gaskets and replace the upper plenum with the ATP unit as a preventive measure. Failure is inevitable but when is anyone's guess.
Loss of the 4th gear input shaft is very common as well as other issues with the transmission.

Use dex for now and plan on doing the LIM gaskets. When you do the gaskets you can remove the thermostat and lower radiator hose first and really flush it out as well as the heater core so there is little chance of cross contamination with the dex. I use JD Coolguard II in these engines, after 6 years it still tested good with the JD test strips.

The reason for replacing the upper plenum is the original egr chimney burned through, the ATP unit uses a metal sleeve and a reduced diameter chimney which cures this issue permanently. The quality and fit is very good, this is a very easy weekend diy job, use GM OE gaskets only.

Agree, the ATP is the one to use and solves the burn through issue for good.. Just another bad idea on a good engine GM had running a coolant passage right next to the normally hot EGR passage in that plastic plenum. All that just to keep the throttle body from icing. I have to add that Fel Pro is a good alternative to the GM gasket as it is metal backed also.
 
Personally I’d just use the Dexcool, but if you’re that worried about it, I guess just throw whatever universal coolant you want into it (assuming you do a full flush). Either way you’re not going to have issue because of the coolant, if you do have some it’ll be because it’s a 19 year old car (and a very reliable 19 year old car, that’s probably the best drive train GM has built).

The car has been in my family since new and rarely driven by an elderly person. The car did have a transmission issue when it was approximately one-year old, but was still under warranty, and the dealer replaced the part and flushed the transmission. Other than that.... it's been an awesome vehicle! I know it's almost 20 yrs old, but it's so nice and rides quietly... Plus... 27-30mpg on the highway? Yeah, GM really killed this car and probably because it was "too good" if that makes sense.
 
I don't see these much anymore but when I was doing quite a few of them I would do the LIM gaskets and replace the upper plenum with the ATP unit as a preventive measure. Failure is inevitable but when is anyone's guess.
Loss of the 4th gear input shaft is very common as well as other issues with the transmission.

Use dex for now and plan on doing the LIM gaskets. When you do the gaskets you can remove the thermostat and lower radiator hose first and really flush it out as well as the heater core so there is little chance of cross contamination with the dex. I use JD Coolguard II in these engines, after 6 years it still tested good with the JD test strips.

The reason for replacing the upper plenum is the original egr chimney burned through, the ATP unit uses a metal sleeve and a reduced diameter chimney which cures this issue permanently. The quality and fit is very good, this is a very easy weekend diy job, use GM OE gaskets only.


Thank you for the tips! I suppose as long as I'm doing the elbows.... What's the worst case scenario if the gaskets go? Will I get notice or just see steam coming from the engine bay? Do you also have a link for the upper plenum? Thanks... I appreciate the knowledge everyone has shared!
 
Thank you for the tips! I suppose as long as I'm doing the elbows.... What's the worst case scenario if the gaskets go? Will I get notice or just see steam coming from the engine bay? Do you also have a link for the upper plenum? Thanks... I appreciate the knowledge everyone has shared!

Thank you for the tips! I suppose as long as I'm doing the elbows.... What's the worst case scenario if the gaskets go? Will I get notice or just see steam coming from the engine bay? Do you also have a link for the upper plenum? Thanks... I appreciate the knowledge everyone has shared!
Just watch your coolant level. You do not want to ignore the issue.Worse case, when the leak get too bad, the cylinder(s) will fill with coolant and hydrolock the engine. The result, bent connecting rods and a worthless engine. I have had to replace the lower aluminum manifold too because the gasket sealing surfaces got so badly pitted, it was doubtful the gasket would have sealed properly. Here's the link for the upper manifold. Rock Auto is a good source. It is not a very difficult job, just time consuming. You will need a torque wrench as you do not want to overtorque the bolts for the plastic upper manifold.

 
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Just watch your coolant level. You do not want to ignore the issue.Worse case, when the leak get too bad, the cylinder(s) will fill with coolant and hydrolock the engine. The result, bent connecting rods and a worthless engine. I have had to replace the lower aluminum manifold too because the gasket sealing surfaces got so badly pitted, it was doubtful the gasket would have sealed properly. Here's the link for the upper manifold. Rock Auto is a good source. It is not a very difficult job, just time consuming. You will need a torque wrench as you do not want to overtorque the bolts for the plastic upper manifold.


Thank you very much for this! I do have a torgue wrench and have done a lot of work on cars. (Changed the timing belt and water pump on my Miata 3-times etc.) Yes, don't want it hydro-locked! Well... We both know GM had to put something in there just so we could call it a GM car...;) Otherwise...

I think as long as I am doing the elbows, I may as well tackle this manifold also. I appreciate the link to the Intake! It appears to be a well-engineered kit. Would you use their gasket or go with another brand? (Previous posts mention this.) I hate to be anal here... but??? I will replace the metal elbow gaskets with new ones. I've see a YouTube (Car Wizard) actually recommends using "AC" O-rings. (The Green ones) Apparently these are made of a much better material and resist chemicals. heat etc. Any thoughts?

Thank you again!
 
Thank you very much for this! I do have a torgue wrench and have done a lot of work on cars. (Changed the timing belt and water pump on my Miata 3-times etc.) Yes, don't want it hydro-locked! Well... We both know GM had to put something in there just so we could call it a GM car...;) Otherwise...

I think as long as I am doing the elbows, I may as well tackle this manifold also. I appreciate the link to the Intake! It appears to be a well-engineered kit. Would you use their gasket or go with another brand? (Previous posts mention this.) I hate to be anal here... but??? I will replace the metal elbow gaskets with new ones. I've see a YouTube (Car Wizard) actually recommends using "AC" O-rings. (The Green ones) Apparently these are made of a much better material and resist chemicals. heat etc. Any thoughts?

Thank you again!
As long as you use the metal backed LIM gasket set from GM or Felpro you will be fine and likely won't have to deal with it again. I would put a new OEM thermostat in too since you will have the manifold off. I would get the OEM o-rings intended for the application from the dealer not a/c o rings. Atleast if you go OEM, you know you are getting the precise sized ID and OD and are designed to handle the heat which the a/c o rings do not encounter and who knows if they can handle the heat. Just put a dab of silicone grease on the o rings prior to inserting the elbows and make sure the hole which they insert into is clean, smooth and free of roughness..
 
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All very good points, thank you! And good point about silicone grease on the O-rings. I've done this before and makes a huge difference in application.
 
I’m still running dexcool in my 98 S-10. I had the manifold gasket replaced long ago. No issues or concerns.
id keep Dex in there.
 
Thank you very much for this! I do have a torgue wrench and have done a lot of work on cars. (Changed the timing belt and water pump on my Miata 3-times etc.) Yes, don't want it hydro-locked! Well... We both know GM had to put something in there just so we could call it a GM car...;) Otherwise...

I think as long as I am doing the elbows, I may as well tackle this manifold also. I appreciate the link to the Intake! It appears to be a well-engineered kit. Would you use their gasket or go with another brand? (Previous posts mention this.) I hate to be anal here... but??? I will replace the metal elbow gaskets with new ones. I've see a YouTube (Car Wizard) actually recommends using "AC" O-rings. (The Green ones) Apparently these are made of a much better material and resist chemicals. heat etc. Any thoughts?

Thank you again!

You need an INCH POUND torque wrench. The UIM bolts tighten to 89 inch lbs in 3 steps; working from the center out just like head bolts, tighten to 22 then 44 then 89 inch pounds. Here are the instructions that come from ZZPerformance:
 

Attachments

  • GM 3.8 Series II Upper Intake Torque Sequence.pdf
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You need an INCH POUND torque wrench. The UIM bolts tighten to 89 inch lbs in 3 steps; working from the center out just like head bolts, tighten to 22 then 44 then 89 inch pounds. Here are the instructions that come from ZZPerformance:

Thank you for this and the attachment!
 
I’m still running dexcool in my 98 S-10. I had the manifold gasket replaced long ago. No issues or concerns.
id keep Dex in there.
I've read so many different opinions on this... Some say it was just the "Gasket design" sucked, and some relate it to the coolant composition... Maybe its both?!
 
As long as you use the metal backed LIM gasket set from GM or Felpro you will be fine and likely won't have to deal with it again. I would put a new OEM thermostat in too since you will have the manifold off. I would get the OEM o-rings intended for the application from the dealer not a/c o rings. Atleast if you go OEM, you know you are getting the precise sized ID and OD and are designed to handle the heat which the a/c o rings do not encounter and who knows if they can handle the heat. Just put a dab of silicone grease on the o rings prior to inserting the elbows and make sure the hole which they insert into is clean, smooth and free of roughness..
When I installed the metal elbows , I just used Dexcool to lube the o-rings .
 
I've read so many different opinions on this... Some say it was just the "Gasket design" sucked, and some relate it to the coolant composition... Maybe its both?!

It's the Gaskets. I've replaced many on my own cars, family and neighbors. No more problems after installing GM 89017825 Gaskets and the metal elbows. GM still uses Dexcool. https://www.valvoline.com/our-products/antifreeze-products/antifreeze-education/engine-coolant
And these 3800 engines are so reliable & bulletproof in the bottom end, they are/were raced in their own class. ZZPerformance makes lots of aftermarket parts for them and sells bolt on turbochargers for them. https://zzperformance.com/collections/3800 Browse awhile on their website; you can find lots of goodies for your Buick! I am a Lesabre Lover and have owned several, currently have 3 with combined mileage over 450K. Once you get the intake gasket issues and coolant elbows taken care of they'll run until you're tired of driving them! Feel free to PM me if you want to discuss anything about them...
 
It's the Gaskets. I've replaced many on my own cars, family and neighbors. No more problems after installing GM 89017825 Gaskets and the metal elbows. GM still uses Dexcool. https://www.valvoline.com/our-products/antifreeze-products/antifreeze-education/engine-coolant
And these 3800 engines are so reliable & bulletproof in the bottom end, they are/were raced in their own class. ZZPerformance makes lots of aftermarket parts for them and sells bolt on turbochargers for them. https://zzperformance.com/collections/3800 Browse awhile on their website; you can find lots of goodies for your Buick! I am a Lesabre Lover and have owned several, currently have 3 with combined mileage over 450K. Once you get the intake gasket issues and coolant elbows taken care of they'll run until you're tired of driving them! Feel free to PM me if you want to discuss anything about them...
Thanks very much for your input and links, websites etc! How awesome! With only 50K miles on my LeSabre, my dilemma is this - DO I just change-out the broken elbows and flush the coolant, or.... Do I also open-up the manifold and lower intake and add that to the list. I am pretty sure it's just the elbows at this point. Perhaps the other parts are still holding out. I hate to repair something that isn't broken...
 
I've read so many different opinions on this... Some say it was just the "Gasket design" sucked, and some relate it to the coolant composition... Maybe its both?!

The gasket design was a big part of it. There were apparently incompatible materials, that in the infancy of employing this stuff, they didnt realize yet.

Some vehicles had a radiator neck and cap that wasnt great for using Dexcool. It would allow some sort of seepage and/or air entry, which was not good for the coolant. My truck has this 45 degree radiator fill, but Ive not had issues. The recommendation early on was to use a metal Stant cap instead of the plastic GM one. Youll note that newer engine and coolant system designs often have a pressurized overflow bottle, which avoids these issues altogether.

The other major issue was when silicated antifreeze was added as a "top up". These are incompatible, and tend to cause the silicates to drop out and create a gel that is a pain to remove and clean. This was a concern especially early on, when shops that provided free top ups with service would pour whatever they had in there, sometimes mixing chemistries.

Overall, especially at this point, there are billions of miles of experience with dex, and lots of high mileage examples of vehicles that lived their whole life with Dex. These legacy engines were problemmatic because of both design, materials, and user error at a time when the situation was changing. That's long past.

If your dex looks good, if the radiator looks clean, and you dont have any evidence of leaks into the engine/oil, Id keep running Dex. Its a pain to change over chemistries, and takes a lot of flushing and coolant wasted. If you suspect an issue, do it as a best practice. Otherwise, keep with Dex. Its cheap and ubiquitous.
 
Thanks very much for your input and links, websites etc! How awesome! With only 50K miles on my LeSabre, my dilemma is this - DO I just change-out the broken elbows and flush the coolant, or.... Do I also open-up the manifold and lower intake and add that to the list. I am pretty sure it's just the elbows at this point. Perhaps the other parts are still holding out. I hate to repair something that isn't broken...

(Years ago), there were so many people having problems with the LOWER intake gaskets that GM did a factory recall. At that time, I owned an Impala with a 3400 (different intake configuration) and my Indy mechanic told me it WASN'T on the recall list. My advice to you (which you are free to disregard as being worth what you've paid for it) is that you're not fixing what isn't broken. You're avoiding a distinct possibility of hydrolock and wasting an engine over a KNOWN defect in manufacturing. Perhaps ask yourself "Why did GM revise the lower intake gaskets?" If you start rereading your own thread, how many users have steered you to GM 89017825 to use for new gaskets? Why would we all try to steer you wrong and yet in the exact same wrong direction? The answer sir is that several very knowledgeable and capable (NOT ME) users are very much attempting to HELP you. Trav, doublebase, and Lubener are assets on this board.
If you're under the hood, look at the engine on the driver's side, just above and to the left of where the coolant temp sensor is...the lower intake gasket is visible right here at the corner (about a half inch to the left and below the thermostat housing). Clean the gasket here with some carburetor cleaner. If the cleaned gasket is black, it's OEM and failure waiting to happen. If it's grey, it's aluminum and has already been replaced with GM 89017825.
Watch this guy do it from beginning to end in just over 20 minutes:
Then you can search for the operation on Youtube and there are myriad videos, this is a known common problem: https://www.youtube.com/results?search_query=replace+gm+3800+lower+intake+manifold+gasket
 
(Years ago), there were so many people having problems with the LOWER intake gaskets that GM did a factory recall. At that time, I owned an Impala with a 3400 (different intake configuration) and my Indy mechanic told me it WASN'T on the recall list. My advice to you (which you are free to disregard as being worth what you've paid for it) is that you're not fixing what isn't broken. You're avoiding a distinct possibility of hydrolock and wasting an engine over a KNOWN defect in manufacturing. Perhaps ask yourself "Why did GM revise the lower intake gaskets?" If you start rereading your own thread, how many users have steered you to GM 89017825 to use for new gaskets? Why would we all try to steer you wrong and yet in the exact same wrong direction? The answer sir is that several very knowledgeable and capable (NOT ME) users are very much attempting to HELP you. Trav, doublebase, and Lubener are assets on this board.
If you're under the hood, look at the engine on the driver's side, just above and to the left of where the coolant temp sensor is...the lower intake gasket is visible right here at the corner (about a half inch to the left and below the thermostat housing). Clean the gasket here with some carburetor cleaner. If the cleaned gasket is black, it's OEM and failure waiting to happen. If it's grey, it's aluminum and has already been replaced with GM 89017825.
Watch this guy do it from beginning to end in just over 20 minutes:
Then you can search for the operation on Youtube and there are myriad videos, this is a known common problem: https://www.youtube.com/results?search_query=replace+gm+3800+lower+intake+manifold+gasket

Well... forgive me if I came-off as sounding like I was disregarding everyone's advice and expertise. On the contrary, I highly regard the help and opinions on this board and that's why I've been a member for a long time. I am very happy I can post a question here and have so many wonderful and experienced people advise me. (So THANK YOU everyone that shared their opinions and advice with me!) Ihatetochangeoil - Thank you for writing and your comment: "You're avoiding a distinct possibility of hydrolock and wasting an engine over a KNOWN defect in manufacturing." really hit home. I thought about it and well.... makes complete sense!! As far as the car having the newer improved gasket? I don't think it does. ( I will check later when under the hood). Reason being - It's been in the family since new and purchased in 2001. Would the factory have done this in those early years? It would have to have been modified since day#1 since no one else has touched it.

My "leave it alone" thoughts were strictly based on the low $50k mileage. I was thinking I would just replace the metal elbows, add coolant, and be done with it. Now, based on what everyone is telling me is that there is a distinct possibility I will be facing a future gasket failure on this engine. This made me reconsider going deeper, biting the bullet, and replacing the lower intake gaskets. (Which after much thought, seems like the right thing to do.)

So.... I give credit to you for explaining it in this fashion. I would imagine a failure could happen at 60k or 100k...but why gamble with such a nice car?

Plan of action:

1. Replace the lower intake gaskets with the newer metal version GM 89017825. (Question - Would the Fel-Pro be an equivalent?) - https://www.amazon.com/dp/B002LWL3X...colid=RF1JGLDS5LPM&psc=1&ref_=lv_ov_lig_dp_it

2. Replace the upper Intake with ATP unit. - https://www.amazon.com/dp/B000C8T7X...colid=RF1JGLDS5LPM&psc=1&ref_=lv_ov_lig_dp_it

3. Metal elbows with GM O-rings.

Obviously drain and flush coolant... (Most likey just use DexCool again as it looks like Gaskets were not designed properly.)

Hopefully... this will take car of "Everything". Thank you very much for your opinions guys!!
 
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