coolant leak around intake manifold? - GM Forum - Buick, Cadillac, Chev, Olds, GMC & Pontiac chat


1992-1999 Series I L27 (1992-1994 SE,SLE, SSE) & Series II L36 (1995-1999 SE, SSE, SLE) and common problems for the Series I and II L67 (all supercharged models 92-99) Including Olds 88's, Olds LSS's and Buick Lesabres Please use General Chat for non-mechanical issues, and Performance and Brainstorming for improvements.

Closed Thread
 
 
 
Thread Tools Search this Thread
Old 10-25-2004, 08:20 PM   #1
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Jun 2004
Posts: 38
Thanks: 0
Thanked 0 Times in 0 Posts
commo is on a distinguished road
Default coolant leak around intake manifold?

99 Bonneville, 3.8 non supercharged, 55,000 miles.

Took girlfriends car into shop for oil change, coolant flush and tire balance and rotate.

Picked up car, shop said coolant was pretty low, and to watch for leaks.

Drove it home, parked it for 2 days.

Yesterday noticed a small puddle of coolant coming from drivers side of engine. Opposite water pump. ( I had noticed a few occasional drips from that area in the past, but it was only occasionally and nothing that seemed to be getting worse or happen all the time.)

Opened up hood, popped off plastic cover and noticed coolant pooled up on exhaust manifold and all around intake manifold gasket area. Area right where thermostat is located is dry.

Went back to shop to ask if they noticed anything weird and they said no, just that it was low on coolant, told them what I found and they said it was a common problem for the intake manifold gasket to start leaking on the smaller engines and occasionally on the 3.8'*. Asked for a quote on what i described and I got $320.

Questions:

1. Has anyone else had a problem like this or heard of it? I've never seen water leaking from around bottom of intake manifold.

2. It looks like a pretty straight forward job to replace myself. Is it fairly simple and is there anything I should be aware of before I start?

Thanks!
commo is offline  
Old 10-25-2004, 09:03 PM   #2
Senior Member
Certified Car Nut
 
Join Date: Oct 2003
Posts: 19,756
Thanks: 0
Thanked 0 Times in 0 Posts
1993 SLE is on a distinguished road
Default

it could be one of two things the T/B gasket could have started to leak or the Upper intake has failed.

DO NOT DRIVE THE CAR.

If the upper intake has failed and you try and start the car, and drive it or ever let it idle, it is bad very bad. The T/B gasket change is a rather easy and simple replacement feature. Could you please describe or give any more info that you have to fruther diagnose the loss of coolant issue

does it look like there is coolant dripping down from the throttle body area or does it look like there the coolant is leaking ontop of the block??
1993 SLE is offline  
Old 10-25-2004, 10:21 PM   #3
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Drain the oil immediately. Like right now, even if it'* 2am. If the upper intake manifold has failed, and coolant has entered the oil pan, it can rust the bottom internals in the engine.

Does the oil on the dipstick after running look contaminated? Milky? Read the Vin K Techinfo articles.
willwren is offline  
Old 10-25-2004, 11:12 PM   #4
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Jun 2004
Posts: 38
Thanks: 0
Thanked 0 Times in 0 Posts
commo is on a distinguished road
Default

Those vin k articles are great! thanksonce again

the oil is brand new and looks fine, they just changed it same time as coolant flush about 3 days ago.
I drove the car max 2 miles home from the shop and it has not been started since.
mechanic said nothing about oil looking milky or anything.

I borrowed your engine picture to show where moisture is, just keep in mind, I don't have the turbocharger, just a black plastic cover covering the throttle body that bolts to intake manifold. Most of the coolant is in the back corner nearest drivers seat on the exhaust manifold.

commo is offline  
Old 10-25-2004, 11:37 PM   #5
Senior Member
Certified Car Nut
 
Join Date: Oct 2003
Posts: 19,756
Thanks: 0
Thanked 0 Times in 0 Posts
1993 SLE is on a distinguished road
Default

that is most likely the T/B gasket leaking. It is a simple fix, If you do a search you should find some good info
1993 SLE is offline  
Old 10-25-2004, 11:53 PM   #6
Senior Member
Posts like a Turbo
 
Join Date: Jul 2004
Location: Woodstock Ill.
Posts: 214
Thanks: 0
Thanked 0 Times in 0 Posts
Ranger is on a distinguished road
Default Re: coolant leak around intake manifold?

Quote:
Originally Posted by commo
they said it was a common problem for the intake manifold gasket to start leaking on the smaller engines and occasionally on the 3.8'*.
Occasionally?? From what I learned on this forum a 3800 might occasionally not leak. That is a pretty common problem from what I have learned. I just did mine a couple of months ago, but I had twice your milage. I replaced the upper plenum and gasket as I assumed the plenum was a victim of the infamous EGR "stove pipe" burn through. As it turned out it was not too bad. I machined a new stove pipe with a .050 clearance so it no longer touches the plenum and sleeve to prevent the problem in the future. The biggest problem I found was the TB gasket that is molded to the plenum was pretty flattend and was leaking much like yours is. The one bit of advice I can give you (if the '99 is like the '96) is don't even bother trying to remove the TB from the plenum til after you remove the plenum. You'll see why.
Ranger is offline  
Old 10-26-2004, 12:22 AM   #7
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Jun 2004
Posts: 38
Thanks: 0
Thanked 0 Times in 0 Posts
commo is on a distinguished road
Default

man the more i read the more i want to puke.......

i see no signs of breakdown on the outside of the plastic, looks strictly gasket to me, but will only know when i get it off.
commo is offline  
Old 10-26-2004, 12:28 AM   #8
Senior Member
Posts like a Turbo
 
Join Date: Jul 2004
Location: Woodstock Ill.
Posts: 214
Thanks: 0
Thanked 0 Times in 0 Posts
Ranger is on a distinguished road
Default

You won't see any signs externally. I don't think you have enough miles for that though. yours sounds more like a TB gasket. I stopped mine for about 6 months and then slowed it to a trickle with the GM cooling sealer suppliment tabs. 4 tabs in the radiator will buy you time if you need it.
Ranger is offline  
Old 10-26-2004, 12:30 AM   #9
Junior Member
Posts like a Ricer Type-R
 
Join Date: Aug 2002
Posts: 10
Thanks: 0
Thanked 0 Times in 0 Posts
willwren is on a distinguished road
Default

Ok, let'* clarify a few points. First of all.....SUPERcharger.

Second, Bonnevilles aren't prone to leak in general. The 95-98 non-supercharged engines are prone to failure of the upper intake in the EGR inlet port area. It'* rumored that 99 had an updated design, but keep an eye on it anyway. Yours does thankfully sound like a TB gasket leak. An hour fix for 10 bucks. Use an inspection mirror to see if it'* dripping off the bottom of the plenum/TB union while idling hot.
willwren is offline  
Old 10-26-2004, 12:37 AM   #10
Member
Posts like a V-Tak
Thread Starter
 
Join Date: Jun 2004
Posts: 38
Thanks: 0
Thanked 0 Times in 0 Posts
commo is on a distinguished road
Default

ok, thanks again and sorry about the turbo charger slip....

will let you know what i find.
commo is offline  
 
 
Closed Thread

Related Topics
Thread Thread Starter Forum Replies Last Post
Intake manifold leak? Abbby 2000-2005 11 01-25-2010 07:20 AM
98 Grand Prix coolant leak around UIM chantspel Pontiac 22 12-04-2009 10:26 AM
Newcomer with coolant leak near upper manifold 96 Bonnevillese 1992-1999 3 11-15-2005 09:31 PM
'94 SSE Series 1 Intake Manifold Oil Leak dougworner 1992-1999 7 03-19-2004 02:40 AM
97 SSE - LOWER intake manifold coolant leak j_ozolins 1992-1999 4 02-11-2004 11:53 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 05:22 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.