How to detect Lower Intake Manifold Gasket Leak ???

2002 Monte Carlo 3.4 57K miles
I've been losing coolent for about two weeks now... but I can't find the leak..
I can smell the antifreeze and the coolent level is dropping.
I did a cooling system pressure test. Cooling system held the pressure and nothing was dripping on the ground. Also nothing drips while the car is stopped in operation so I'm assuming this is burning off.
There MIGHT be a hint of white smoke coming out of the tailpipe...not real sure at this point.... might have been early morning condensation as I saw a slight bit and then it stopped.
Did an oil change... oil looks pretty good so no indication there.
Okay... so where is the inner manifold gasket leak normally detected. Where do you look, front of the engine or back and in which area.
I've been searching the internet without any success. Can someone supply a URL listing procedures to identify the leak and perhaps a procedure list to replace the gasket.
thanks !!!
Peter
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
It can leak externally in the corners for example, internally into the intake passages and internally into the block area. If no external leaks do the lower intakes, goin' need at some point anyway.

----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.pronews.com The #1 Newsgroup Service in the World! >100,000 Newsgroups ---= - Total Privacy via Encryption =---
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Peter wrote:

Gee that sounds just like a gasket leak that is dropping the coolant into the intake runner.
The most common external leak will be just above the area where the head and intake mate up to the block.
The next most common is a leak internally that drops coolant into the oil. And the last is the internal leak into the intake tract. The way to see if that is the problem is to pull the plugs and look at them. It will show up as burnt on deposits on the ceramic and the electrode may even have crud built up on it.
I wish I had saved the page that Ian posted a while back. It showed the gaskets and the failure area.
Here are a couple sites that show the failure mode. Just not the 3.1/3.4 engine.
http://www.dsengine.com/gmgasket/index.html
This one shows a 3.1 and even has a video showing replacement. http://www.denlorstools.com/home/dt1/page_6822 /
--
Steve W.
Near Cooperstown, New York
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Mucho Thanks.... I'm going to pull the plugs tomorrow and see.
Also noticed that denlorstools has a Cylinder Leak Down Test Kit. I probably should take a few extra minutes and verify that the head gaskets are prime and rule out any other components. The engine's being partially disassembled anyway. Never did one before... it should be fun.
I'll have D&S Engine ship the replacement gasket set and replacement manifold bolts. Theirs look pretty heavy duty.... I'm concerned that the dealer parts department may try to ship outdated products to get them out of inventory.
Spoke to two dealers today... first one said... If there's a settlement that's between you and GM. It will cost about 600. - 700. to replace the gasket, not including shop charges of $50. and 6% tax.. Plan on renting a car for one maybe two days. That's fair.
The second dealer's service dept... said " We don't know anything about 'good will' programs or assistance to GM customers. Can't give you a ballpark price until you bring the car in and we take it apart...at which time we can tell you approx what the price will be" He honestly did say that !!! So I said... " well, I've gotten ballpark estimates between 300.00 and 800.00. He calls me back and says... yupp about 800.00 or so. Maybe his service department doesn't do enough of these to whip out an instant price...or maybe he's just cautious and doesn't want to do a ballpark estimate for a lower manifold gasket sight unseen. Just seems to me there's a pretty big opportunity for getting screwed by getting a price after the car is in the bay and partially disassembled.
Thanks again for your help. I enjoyed browsing the Denlors Tools site... plenty of nice toys !!
( I gotta DIY, how else can I afford all those tools )
Peter
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
All shops and dealers work on a book time to do the lwr gaskets, aside from incidentals and labor rate, the price should have only minor variations. <Peter> wrote in message

----== Posted via Pronews.Com - Unlimited-Unrestricted-Secure Usenet News==---- http://www.pronews.com The #1 Newsgroup Service in the World! >100,000 Newsgroups ---= - Total Privacy via Encryption =---
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
snipped-for-privacy@spamtrap.net says...

Sounds like a head gasket or cracked cylinder head. If you can't detect an external leak, usually that means an internal leak. Since you say you smell it, what about a heater core? Do you see any green fluid on the passenger side floor? You say that there might be white smoke coming out of the exhaust. That's not good. I've had 10 or 15 cracked cylinder head/head gasket problems in my life. I burn propane, which is very hard on the heads. Anyway, here are the symptoms! 1: Loss of antifreeze with no external leaks 2: White smoke coming out of the tailpipe 3: Antifreeze in your oil..."this will give your oil a milky look" 4: Bubbly coolant.."your coolant looks like a bubble bath" 5: Your overflow reservoir might be getting full, and might be overflowing on to the street. 6: One of your spark plugs might look funny 7: You might have hydrocarbons in your coolant. This can be detected by a radiator shop with a very cheap hydrocarbon detector. 8: If you just have one of these symptoms, I would lean towards a head gasket... :-(
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
b wrote:

On many cars you would be right, but on the GM 3.1/3.4 engine line it is almost always the intake manifold gasket which has failed as the cause of these symptoms.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Then why did you suggest the oil analysis?
--

-Mike-
snipped-for-privacy@alltel.net
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike Marlow wrote:

Because I have experience with this problem and know what I am talking about.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Peter wrote:

The most sensitive way at a decent price is to take an engine oil sample and have it analyzed. Costs around $25.
I had mine done by www.blackstone-labs.com . It showed the characteristic contaminants in the oil long before a pressure test showed anything.
Note that there is a class action settlement on this which should cover you if you need the repair.
John
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

No - the most "sensitive" way would be to inspect the engine for the telltale signs of intake gasket leaks. Pay no attention to John's advice - he is only here to critique GM in the worst possible way. His technical awareness is somewhat below that of a stone.
--

-Mike-
snipped-for-privacy@alltel.net
  Click to see the full signature.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Mike Marlow wrote:

Oil analysis did in fact catch the intake manifold gasket leak problem on my Olds Silhouette when the dealer's pressure test didn't. After I took them the analysis report they looked harder and agreed to fix it.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.