The Dreaded Upper Plenum Coolant leak. - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


Oldsmobile When starting new posts, please specify YEAR, MAKE, MODEL, ENGINE type, and whatever modifications you have made.

Reply
 
 
 
Thread Tools Search this Thread
Old 06-13-2006, 12:51 AM   #1
Member
Posts like a V-Tak
Thread Starter
 
grtpumpkin's Avatar
 
Join Date: Nov 2005
Location: Hooksett NH
Posts: 58
Thanks: 0
Thanked 1 Time in 1 Post
grtpumpkin is on a distinguished road
Default The Dreaded Upper Plenum Coolant leak.

I wasn't sure where I should post this but this section seems fitting. I'm bringing up an old discussion here. I got the dreaded phone call friday night from my wife who said her car would not start. 1996 Regal w 3.8k.

I thought for sure it was a dead or weak battery so I told her to go and turn the lights on and call me back to let me know. When she called back she said the car just started but a huge amount of white smoke was coming from the back and it had a sweet smell to it. I told her not to drive it or start it again.

Oh no. I had changed the lower intake and upper plenum gaskets at 83,000 miles. Now it has 168,000 miles on it. It was running like a top, then all of a sudden this happens. I figured for sure it was the plenum or the gasket as I had sold a lot of them when I was working at a GM dealership. I was right. But what I did not know was the fact that all these 3800 seem to do this. the EGR stove pipe burns through the plenum. What a stupid design. I always thought the problem was with the gaskets. This blows. I must have spent 2 hours perusing this site and was totally amazed by all the knowledge on this site on just this topic alone. Thank you gentlemen.

I like the idea of the repair kit that'* offered but I don't want to wait so I purchased a new one from the dealer. $88.00 plus $21.00 for the gasket. It'* nice to know people. Now this new plenum looks exactly like the old. No new design. And yes the old one was the original with a date code of 10- 15- 95. What a shame.

Now what I propose to do is grind off some material on the EGR stove pipe in order to give some added clearance between the pipe and the plastic plenum. Hopefully this will aid in it'* longjevity by keeping some extreme heat away from the plastic surface.

I also retourqed the lower intake and was surprised at how loose a few were. Even though I used locktite previously. I know I should replace the lower while I'm in there but the car is 32 miles away in a driveway. It'* tough remembering to bring every little tool needed to do a job.

It should be good to go as it doesn't appear to have any coolant in the crankcase and all the spark plugs look good. Thank god she called me and did not drive it.

I just felt like bringing this old topic up as I found it very interesting.

Wouldn't it be nice if cars didn't have EGR valves. I've always hated those things.
grtpumpkin is offline   Reply With Quote
Old 06-13-2006, 02:14 AM   #2
Senior Member
True Car Nut
 
Join Date: Jun 2003
Location: Climax Springs, Missouri
Posts: 2,493
Thanks: 0
Thanked 0 Times in 0 Posts
LittleHoov is on a distinguished road
Default

a member here, Bob Dillon, has started repairing broken UIMs by putting a metal sleeve inside the stovepipe, the pictures explain it better so here are a couple links:

http://www.bonnevilleclub.com/forum/...=340444#340444
http://bonnevilleclub.com/forum/viewtopic.php?t=50711

There are several members here running them with no problems at all, even though you just bought a new part, he could still do it to that.

Or you could return the part you just bought (since you know people) and get your old intake sleeved for half the price.

Or if nothing else you can send Bob Dillon your old UIM so he can fix it up and help someone else out later.

ALSO IF YOU HAVENT ALREADY GET THAT OIL OUT OF THAT ENGINE!!! the oil/coolant mix is eating away at your lower end bearings, so if you dont get it out of there pronto its going to be bad bad bad.
LittleHoov is offline   Reply With Quote
Old 06-13-2006, 08:59 AM   #3
DINOSAURUS BOOSTUS

Expert Gearhead
 
BillBoost37's Avatar
 
Join Date: Mar 2005
Location: Enfield, CT
Posts: 41,391
Thanks: 0
Thanked 0 Times in 0 Posts
BillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of lightBillBoost37 is a glorious beacon of light
Default

Sorry to hear it happened. Glad to hear you were able to fix it in a parking lot? That'* a good thing there.

On the oil, it is suggested that you change it a couple of times in tne next week or so.

I've pulled a pan before and there is about 1/4" of fluid below the oil plug. When we think about that and that any water or moisture would sink..that leaves the possibility that some is in the crankcase.
BillBoost37 is offline   Reply With Quote
Old 06-16-2006, 05:13 AM   #4
Senior Member
Posts like a Camaro
 
Join Date: Dec 2005
Location: Clovis, CA
Posts: 851
Thanks: 0
Thanked 0 Times in 0 Posts
MACDRIVE is on a distinguished road
Default

From what I understand, the Dorman UIM'* are supposed to have the revised EGR tube.


MACDRIVE is offline   Reply With Quote
Old 06-16-2006, 07:42 AM   #5
Member
Posts like a V-Tak
Thread Starter
 
grtpumpkin's Avatar
 
Join Date: Nov 2005
Location: Hooksett NH
Posts: 58
Thanks: 0
Thanked 1 Time in 1 Post
grtpumpkin is on a distinguished road
Default

I finally got it fixesd and was able to drive it home. It took a good 15 - 20 minutes before the white smoke finally cleared out after start up. I guess it was all in the exhaust and cat. What a stressfull 20 minutes. I mean white smoke continued to billow out like there was no tomorrow. After the fisrt minute though, it was purring nicely. Big sigh of relief. Oil in crankcase looked good. I had just changed it only 5 days prior to this failure.

Ready for another hundred thousand miles? I hope.

I need Bill boosts address so I can send him my old one.
grtpumpkin is offline   Reply With Quote
Old 06-16-2006, 01:39 PM   #6
BANNED
 
Join Date: Aug 2002
Posts: 0
Thanks: 0
Thanked 0 Times in 0 Posts
banned3800 is on a distinguished road
Default

Did you just do the upper while you were there?

The gaskets for that upper being so new can be reused if you decide to do the lower gaskets... I say this as the gaskets are brand new....

With the miles you have the lower would be on the list, and we have found that GM has a new alluminum lower gasket design...

And yes the upper intake suck... sorry that had to happen to your wife... But it looks like you got it taken care of...

Now please please please change the oil for us... Even tho you had just changed the oil that was a lot of moisture that got forced into the system...

Good work BTW

My 95 Bonneville killed an intake in 99, and I replaced it again in 05( it was ready to pop ), the replacement was a Dorman unit with all new lower intake gaskets...

__________________
Best Car Insurance | Auto Protection Today | FREE Trade-In Quote
banned3800 is offline   Reply With Quote
Old 06-16-2006, 05:04 PM   #7
Member
Posts like a V-Tak
Thread Starter
 
grtpumpkin's Avatar
 
Join Date: Nov 2005
Location: Hooksett NH
Posts: 58
Thanks: 0
Thanked 1 Time in 1 Post
grtpumpkin is on a distinguished road
Default

Yes I did just the upper. I Know I should do the lower but it was a pain to do any work to it because of where it was and time wise. I did retourque the lower while I was in there and was surprised how a few bolts were loose. I guess loctite is a waste of time for this application.

I changed the oil and did not find a hint of water in it. I let the oil sit in a clear plastic bottle overnite and found no water in it. Wicked cool.

This thing runs so sweet it'* as if nothing ever happened. I feel confident in letting my wife commute with it again. I've already shippid the oold UIM to Bob Dillon.

Bob Dillon the Musicion????
grtpumpkin is offline   Reply With Quote
Old 06-16-2006, 11:53 PM   #8
Junior Member
Posts like a Ricer Type-R
 
Join Date: Mar 2006
Location: NJ
Posts: 15
Thanks: 0
Thanked 0 Times in 0 Posts
inthedirt is on a distinguished road
Default

Dumb question..........

Has anyone ever experienced a vacuum leak instead of a water leak with this condition? ....or even a vacuum leak at the EGR with the distortion of the manifold?

I'm convinced my '95 should have more [email protected]
inthedirt is offline   Reply With Quote
Old 07-14-2006, 03:11 AM   #9
Senior Member
True Car Nut
 
Join Date: Mar 2004
Location: Ames, Iowa
Posts: 3,066
Thanks: 0
Thanked 1 Time in 1 Post
bill buttermore is on a distinguished road
Default

Quote:
Originally Posted by inthedirt
Dumb question..........

Has anyone ever experienced a vacuum leak instead of a water leak with this condition? ....or even a vacuum leak at the EGR with the distortion of the manifold?

I'm convinced my '95 should have more [email protected]
Not personally, but looking at some of those throttle body seals, some of them must be suckin' air.

However...one of the longest running posts ever ended up to be a vacuum leak at the lower intake manifold gasket. This was not on a Series II, but an L27 92 olds 88.

http://www.bonnevilleclub.com/forum/...487&highlight=
bill buttermore is offline   Reply With Quote
Old 07-14-2006, 07:41 AM   #10
Junior Member
Posts like a Ricer Type-R
 
Join Date: Jun 2006
Location: Montana
Posts: 16
Thanks: 0
Thanked 0 Times in 0 Posts
bigsky is on a distinguished road
Default Vacuum Leak

Have recently finished the process of having the upper intake replaced (Dorman/97 Park/120k)(btw, 3rd one on this car). Also, Ken-Co kit installed and lower intake gasket replaced (about a month later following advice found on this site). Car running best since my ownership at 75k. Mechanic said that maybe a vacuum leak had been fixed. And for more good news...32mpg on a tank that was mostly (but not all) highway miles. But...a downside....Mechanic showed me the sludge forming in the intake valley...and his prognosis was 20k or so left on the engine. I'm getting ready to try the "Auto RX" additive.
bigsky is offline   Reply With Quote
 
 
Reply

Related Topics
Thread Thread Starter Forum Replies Last Post
My upper plenum John01 Buick 6 07-05-2015 10:32 AM
Feared and dreaded Upper Intake dieselK 1992-1999 11 11-28-2005 09:45 AM
Is it hard to remove the upper intake plenum ? Performance, Brainstorming & Tuning 10 09-28-2005 12:12 PM
Intake Upper Plenum Manifold replacement found glorkar General GM Chat 7 04-05-2004 12:25 AM
upper intake plenum 95 and on.. Custom88 General GM Chat 28 01-07-2003 06:52 PM


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -4. The time now is 10:09 PM.


We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.