When do they fail?
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When do they fail?
Anybody know the approximate average mileage or age that a Series II'* intake plenum usually starts leaking? I ask because I'm currently looking at both a '95 Olds 98 Regency and a '95 Buick Park Avenue, with 101k and 107k, respectively, and both cars cost enough, even factoring in haggling, that I wouldn't be able to afford having that problem for a while. At the very least, given that I do already know this problem is hard to predict with any certainty, does anyone have any advice for spotting this problem? And if I do find one (or both) of them has it, how much should I try and talk them down on that one point based on the potential repair costs? Thanks in advance to everyone for the help 
And for dealing with another one of my car questions 
And for dealing with another one of my car questions
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Ok one thing you need to know is weather or not the upper plenum has been replaced... If it has been replaced than this car has either had the leak/rupture of the upper intake...
Go here, this willl show you how to read the dates on the upper intake...
http://www.bonnevilleclub.com/forum/...d03bd05be1d3ca
What you will do is twist off the lower portion of the oil cap, there will be a 1.5 spacer under the oil cap, thats what you will want to twist off... From there all you have to do is lift the cover from the front, pull almost all the way up and the cover should come out of its holder... Then you will be able to read the date...
Its possible for these cars to have an upper intake that was manufactured at the end of 94, so don't be supprised if the upper intake from the 95 has 94 on it... Simmilar for the other car as well...
Possibily as a bargining chip, you could explain that the upper intake is very proned to failing at the milage, and will soon need to be replaced, thats if it wasn't done already... It will cost roughly $700-1100 or so at a dealership depending on weather or not the lower intake has to be replaced... In some cases its required..
Chances are pretty good that both of these cars have had the upper intake replaced, just check the dates on both cars...
I'm at 138,000 miles... With no further issues form 5.5-6 years ago...
If you do buy one of these cars I will highly reccomend that you change to a 180F thermostat..
Good Luck Kyle and let us know what happens
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Go here, this willl show you how to read the dates on the upper intake...
http://www.bonnevilleclub.com/forum/...d03bd05be1d3ca
What you will do is twist off the lower portion of the oil cap, there will be a 1.5 spacer under the oil cap, thats what you will want to twist off... From there all you have to do is lift the cover from the front, pull almost all the way up and the cover should come out of its holder... Then you will be able to read the date...
Its possible for these cars to have an upper intake that was manufactured at the end of 94, so don't be supprised if the upper intake from the 95 has 94 on it... Simmilar for the other car as well...
Possibily as a bargining chip, you could explain that the upper intake is very proned to failing at the milage, and will soon need to be replaced, thats if it wasn't done already... It will cost roughly $700-1100 or so at a dealership depending on weather or not the lower intake has to be replaced... In some cases its required..
Chances are pretty good that both of these cars have had the upper intake replaced, just check the dates on both cars...
I'm at 138,000 miles... With no further issues form 5.5-6 years ago...
If you do buy one of these cars I will highly reccomend that you change to a 180F thermostat..
Good Luck Kyle and let us know what happens
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Originally Posted by 95naSTA
My original 95 upper intake showed no signs of failing when i had my engine rebuilt at 9x,xxx.
I have seen too many 3800II'* at the dealership for an upper intake replacement... It was like the Buick 3800 L36 Palgue... I have also looked at many GM cars with the L36 and just about every one, 95,96,97 Had their intakes replaces 4-5 years later... There are some that make it a long ways.... No one knows for sure why... I made almost 88,000 miles when mine finally decided to go..
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Originally Posted by L27Buick
ill have to try that date thing maybe tomrrow if it aint rainning ill look at it cuz id really like to know if it was ever replaced.
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Well, the Buick guy said it never had been, and the Olds guy didn't say. Guess I'll have to check, then... Is it true I can also tell if the water resevoir is low?
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Originally Posted by Krazy Kyle
Well, the Buick guy said it never had been, and the Olds guy didn't say. Guess I'll have to check, then... Is it true I can also tell if the water resevoir is low?
I would count on having to replace it on either car. Like said, they can fail after only 40,000 miles or go to 140,000 miles. Really hard to tell. If you plan on keeping the car, plan on replacing it.
Furthermore, even if the UIM is fine, you should really plan on replacing the lower intake gaskets regardless. I replaced mine at only 77,000 miles and they were severly deformed. Once the UIM is removed, removing the lower intake is not too much extra work to get access to the gaskets.
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Jeez, a LOT of work... that Olds is $3000
...and the PA is $3400! WAY too much work for all that money up front...
Guess that'* that... What is that, thousands of dollars in repairs? I guess it'* back to Series I-only shopping for me...
...and the PA is $3400! WAY too much work for all that money up front...
Guess that'* that... What is that, thousands of dollars in repairs? I guess it'* back to Series I-only shopping for me...