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1997 Buick 3800 series two

Discussion in 'Non-Mopar Tech Support' started by Rickorino, Aug 4, 2016.

  1. Rickorino

    Rickorino Well-Known Member

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    I recently had an oil analysis on my 97 Buick Lesabre and got the news of a small coolant leak into the engine oil. I have had to add very small amounts of coolant recently which prompted me to check further.It has 45k miles and betting on the plastic upper intake manifold and gasket. I have learned that this item was bad from day one and want to replace it and gaskets for the lower manifold as well. Can anyone suggest which "improved" manifold and gaskets to get so I do not have to do this again.
     
  2. ImperialCrown

    Level III Supporter

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    I have read on discussion boards and forums about these GM plastic intake issues. Dorman may make one? I think that any new part stock source would have the improved version. Stick with brand name OEM-style, even if they are made in China.
    Being 20 years-old, it may have simply warped or the gasket failed. I have done numerous GM V6 (3.1L/3.4L) intake gaskets and 3.8L plastic heater fittings because of internal and external coolant leaks. Dexcool is blamed for a lot of failures also.
    P.S. - I have read about hot exhaust EGR gases melting through the GM plastic intakes.
     
  3. Rickorino

    Rickorino Well-Known Member

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    Yes, those plastic coolant elbows are another engineering marvel. I do miss my Spirit, to me there is no comparison between those and the GM products.
     
    JA Cumbo likes this.
  4. peterjon1

    peterjon1 Well-Known Member

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    I think Dorman may make a replacement aluminum intake manifold. I know someone does.
     
  5. Rickorino

    Rickorino Well-Known Member

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    I checked all over and the lower manifold is the only one available made of aluminum. I would go that route if I could.
     
  6. peterjon1

    peterjon1 Well-Known Member

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  7. Rickorino

    Rickorino Well-Known Member

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    After a lot of research, I went with ATP's manifold because of the fitted steel sleeve in the EGR passage that the Dorman didn't have. Also got Felpro's " improved" problem solver lower intake gasket set. It's made of metal and should last a long time. I am still going to stick with the Dexcool, even after reading about some issues some have had. I believe it probably was left in there way too long. Will be tearing things down soon and will be replacing those silly plastic coolant elbows with Dormans aluminum ones.
     
  8. Locodave

    Locodave Member

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    I replaced the whole upper and lower manifold gaskets on my 2000 Lesabre 3800. 2 years ago. As I was loosing coolant the same as you.

    I went with the Dorman upper plenum. Fel-pro lower. Fel-pro makes 2 types. The one you want is the Felpro MS 98014, not the Fel-pro MS 958091. I also went with the aluminum elbows.

    If your going to keep the car a long time. While you have it apart. Swap out the valve cover gaskets, put new plugs in. Wires if needed. Those back 3 plugs are easy to get at when you have the intake off. Months later, I had the water pump start leaking. Wish I would of put in a new one, when I had it apart before.

    Your throttle body is going to be really carboned up. If I remember right. When you unbolt the T/B. There is a bracket attached to one of the bolts. Thinking lower front bolt. Take the bolt out and bend the bracket down-> Back? To remove the T/B. The metal flex pipe for the EGR, be care full not to bend it too much. So it will replace with ease on the lower.

    Yes there are hidden bolts on the lower. If the plastic coolant elbows break off and leave a piece inside when removing the alt bracket. Use a stiff wire with a V-J or L bend on the end to pull out the piece. The O rings on the L get kinda glued to the cyl wall. Plastic gives out and breaks. I used a dremmel with a brass wire wheel to clean out the crud on all 4 pockets.

    I think the biggest pain was going around with my inch lb torque wrench in sequence for the upper. If you need specs let me know. I never removed the exaust cross over pipe. No need. Lower manifold taken off, put towels or a rag in the valley to catch any gunk when cleaning it up. A link with pics below.

    -> Change Upper Intake Manifold & Lower Intake Manifold gaskets : Engine
     
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  9. Rickorino

    Rickorino Well-Known Member

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    Thanks for the reply. I read that the head of a gutter spike works good for removing a broken elbow. I might replace the water pump as you suggested. The car has only 45k miles but is 20 years old. I would appreciate the torque specs. I believe the plenum is 88 inch lbs but don't know the lower unit.
     
  10. ka9yhd

    ka9yhd Active Member

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    My mother has a 1999 Olds 88 with the 3800 v6 and it is starting to leak coolant again, but not into the oil. It is leaking into the cylinders and burning it.
    The last time it was leaking my brother replaced the gaskets and followed GM's recommended use of the stop leak tablets in the coolant. Which with the Dex Coolant the coolant turned into looking like old waste oil and sludged up everything.
    I flushed out the coolant system the best I could and refilled it with fresh Dex Cool and now the coolant is staying a bright orange, but it is starting to leak again and is using coolant.

    This is what the coolant looked like before I flushed the system.
    [​IMG]
     
  11. Rickorino

    Rickorino Well-Known Member

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    GM didn't take good responsibility for this defect and came up with a schmuck type resolution.If he only replaced the gaskets, the plastic upper manifold likely is bad. The aftermarkets are improved to lessen the chance of a burn thru at the EGR pipe area. If you do not replace the upper unit, changing gaskets is only a band aid fix. Also, if the new lower manifold gaskets were not the improved metal versions and were the plastic ones, they could be leaking again. I would stop driving it till you fix it because if you hydro lock the engine, it can bend a connecting rod.
     
    #11 Rickorino, Aug 18, 2016
    Last edited: Aug 18, 2016
  12. ka9yhd

    ka9yhd Active Member

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    The coolant is not pouring into the cylinders. I need to refill the coolant over flow container once in three weeks.
     
  13. Rickorino

    Rickorino Well-Known Member

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    That is how it starts. Then it will get worse. Your losing coolant at a faster pace than me. Unless you get an oil analysis, you don't know if it getting ion the oil too. That milky appearance will be present on extreme seepage.
     
  14. ka9yhd

    ka9yhd Active Member

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    No milky appearance in the oil.
     
  15. Locodave

    Locodave Member

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    11 ft lbs or 132 inch lbs for the lower, 7.2 ft lbs or 89 inch lbs for the upper plenum. Link below is the order.

    -> Fix Your Chevy With Your Own Hand

    ka9yhd,

    When I did mine. I had no coolant in the oil. Your egr pipe that goes thru the upper. Thats where coolant is being drawn into the intake and burned. ( Take off the throttle body and peer into the port. You won't like what you see. ) Repair it soon. Coolant and the cat don't like one another. I had to replace my cat. Hope he used the metal Fel-pro gasket on the lower. If not, or dosen't remember. Swap it out. For what it's worth. Trying to remember where I bought parts. I did buy the Dorman upper. Good design. Think I ether bought from am-autoparts or amazon.

    I'm going to see if I can find pics and post here.
     
  16. Locodave

    Locodave Member

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    Trying to put pics in.

    upload_2016-8-19_11-48-51.jpeg



    upload_2016-8-19_11-50-41.jpeg


    upload_2016-8-19_11-51-34.jpeg



    upload_2016-8-19_11-52-36.jpeg
     
  17. Locodave

    Locodave Member

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    Last file was too large to see the inside of the T/B. Thats the pic of the old plenum.

    See the dif between the old and new gaskets? The Dorman has the base for the egr fit the hole. But the metal pipe going up is smaller and dosen't touch the upper plastic.
     

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