Found the leak

**Conflict** · 12-16-2009, 12:32 PM

Well I finally got a pressure tester and did the test. I see spraying coming from above or around the Alternator. Its a big mist and it loses pressure fast. So far my idea is it is the intake manifold or the heater core... anyone have a similar experience? Ideas maybe, any help please!

V6 3.8 L 5-speed

**0rion** · 12-16-2009, 01:42 PM

my money is on the intake gasket.

**Conflict** · 12-16-2009, 04:47 PM

well now I took off the Alternator and the leak is shooting across the engine... I'm getting so frustrated. I really wish I could find it

**Smittro** · 12-16-2009, 04:52 PM

Yup intake, as I mentioned in your other thread it's common on the 3800, and in that spot is too.. If you're running dexcool get rid of it. It's been said that its hard on everything..

**0rion** · 12-16-2009, 05:45 PM

Originally Posted by Smittro

Yup intake, as I mentioned in your other thread it's common on the 3800, and in that spot is too.. If you're running dexcool get rid of it. It's been said that its hard on everything..

I think we've had this discussion before but I disagree with that. The 3800's and the 4.3's would leak at that intake gasket if you were just running water in there I bet.
To the original poster....the good news is it's not that bad of a fix. Just a little time consuming but if you got the alternator already off you're halfway home.

**Wesman** · 12-16-2009, 06:14 PM

Originally Posted by 0rion

I think we've had this discussion before but I disagree with that. The 3800's and the 4.3's would leak at that intake gasket if you were just running water in there I bet.
To the original poster....the good news is it's not that bad of a fix. Just a little time consuming but if you got the alternator already off you're halfway home.

I tend to agree with this. Plenty of other GM engines run Dexcool without any problems, and many of the foreign cars run coolant that is a similar formulation as well. Dexcool only becomes a problem when its exposed to air or mixed with other types of coolant, which can cause it to become acidic or sludge up.

The 3.8's, 4.3's, and 5.7's just have shitty intake gaskets from the factory. They run hot coolant through the gaskets, as well as very hot EGR gasses. On the bottom sides of the gaskets is the engine valley, which exposes the gaskets to oil. When the gaskets get old, they start to leak. My 3.8L gaskets were actually melted and sagging, very bad. Thats was with 152K miles of course, but just the same, it was bad. I replaced them with the updated design from GM, which replaces the original plastic gaskets with aluminum ones. Those seem to be much better.

Here's what my original gaskets looked like when I removed the manifold:

**Cutlass** · 12-16-2009, 07:09 PM

I'm not so sure 3800 intake gaskets leak externally. I've never seen it. If you look in the above picture, the 3800 coolant passages are inboard of the outer intake air passages and the coolant passages are located low closer to the bottom of the head.

**Smittro** · 12-16-2009, 09:24 PM

Originally Posted by 0rion

I think we've had this discussion before but I disagree with that. The 3800's and the 4.3's would leak at that intake gasket if you were just running water in there I bet.
To the original poster....the good news is it's not that bad of a fix. Just a little time consuming but if you got the alternator already off you're halfway home.

No sir.. Running only water would be rediculas.. GM released a Technical Bulletin (TSB) 04-06-01-017 and there's more...

http://www.lemonaidcars.com/pdf/GMIM...lbulletins.pdf
The coolant leakage problem has been blamed on a number of factors, including coolant neglect and a less-than-robust OEM intake manifold gasket design. Though Dex-Cool is supposed to last up to five years or 150,000 miles, some say changing the coolant every two years can avert many of the problems that occur with aging coolant. Also, if the coolant level gets low, oxygen mixes with the coolant, which tends to cause problems with Dex-Cool.

http://www.underhoodservice.com/Arti...6_engines.aspx
Another coolant leak problem prompted GM to issue a recall on certain 2000-’03 model year Chevys, Buicks and Pontiacs with the 3800 engine. The coolant leak on these engines was at the gasket between the intake manifold and throttle body or, in some cases, between the upper and lower intake manifold. The recall involved replacing the three throttle body fasteners, applying sealer to the threads, and dumping some sealer pellets into the cooling system reservoir. Recall 03034 was issued in July, 2003, but was only good until July, 2004. If a vehicle was repaired under this recall, there should be a GM recall decal affixed to the engine or under the hood.

http://www.underhoodservice.com/Arti...econd_Gen.aspx
Abnormal Engine Coolant Consumption or Coolant Leak
Models: 1995-’97 Buick Riviera; 1995-’99 Buick LeSabre, Park Avenue; 1996-’99 Buick Regal; 1998-’99 Chevrolet Lumina, Monte Carlo; 1995-’96 Oldsmobile Ninety-Eight; 1995-’99 Oldsmobile Eighty-Eight; 1998-’99 Oldsmobile Intrigue; 1995-’99 Pontiac Bonneville; and 1997-’99 Pontiac Grand Prix with the 3.8L engine.

Note: This bulletin, issued in September 2007, is being revised to add to the 1999 model year. You should discard the previous GM Corporate Bulletin Number 01-06-01-007B (Section 06 - Engine).

Condition: Some customers may comment on excessive engine coolant consumption, or an engine coolant leak near or under the throttle body area of the upper intake manifold.

I can post more as per request.. The Doc is in.....

**Wesman** · 12-17-2009, 08:10 PM

Originally Posted by Cutlass

I'm not so sure 3800 intake gaskets leak externally. I've never seen it. If you look in the above picture, the 3800 coolant passages are inboard of the outer intake air passages and the coolant passages are located low closer to the bottom of the head.

You wouldn't think they would, but thats how I first noticed that mine were leaking. Coolant was pooling on top of the lower intake runners. At first I thought it was oil because it was so dirty, but upon further examination I determined it to be coolant.

Here is what it looked like:

**0rion** · 12-17-2009, 08:16 PM

my 4.3 leaked out of the front of the intake and that stock gasket design sucked. iirc the portion over the valley had little to no gasket on the corners.

**0rion** · 12-17-2009, 08:19 PM

Originally Posted by Smittro

No sir.. Running only water would be rediculas.. GM released a Technical Bulletin (TSB) 04-06-01-017 and there's more...

http://www.lemonaidcars.com/pdf/GMIM...lbulletins.pdf
The coolant leakage problem has been blamed on a number of factors, including coolant neglect and a less-than-robust OEM intake manifold gasket design. Though Dex-Cool is supposed to last up to five years or 150,000 miles, some say changing the coolant every two years can avert many of the problems that occur with aging coolant. Also, if the coolant level gets low, oxygen mixes with the coolant, which tends to cause problems with Dex-Cool.

http://www.underhoodservice.com/Arti...6_engines.aspx
Another coolant leak problem prompted GM to issue a recall on certain 2000-’03 model year Chevys, Buicks and Pontiacs with the 3800 engine. The coolant leak on these engines was at the gasket between the intake manifold and throttle body or, in some cases, between the upper and lower intake manifold. The recall involved replacing the three throttle body fasteners, applying sealer to the threads, and dumping some sealer pellets into the cooling system reservoir. Recall 03034 was issued in July, 2003, but was only good until July, 2004. If a vehicle was repaired under this recall, there should be a GM recall decal affixed to the engine or under the hood.

http://www.underhoodservice.com/Arti...econd_Gen.aspx
Abnormal Engine Coolant Consumption or Coolant Leak
Models: 1995-’97 Buick Riviera; 1995-’99 Buick LeSabre, Park Avenue; 1996-’99 Buick Regal; 1998-’99 Chevrolet Lumina, Monte Carlo; 1995-’96 Oldsmobile Ninety-Eight; 1995-’99 Oldsmobile Eighty-Eight; 1998-’99 Oldsmobile Intrigue; 1995-’99 Pontiac Bonneville; and 1997-’99 Pontiac Grand Prix with the 3.8L engine.

Note: This bulletin, issued in September 2007, is being revised to add to the 1999 model year. You should discard the previous GM Corporate Bulletin Number 01-06-01-007B (Section 06 - Engine).

Condition: Some customers may comment on excessive engine coolant consumption, or an engine coolant leak near or under the throttle body area of the upper intake manifold.

I can post more as per request.. The Doc is in.....

I'm not disputing that they leak ( and the water comment was not serious). I'm disputing that dexcool is behind the leak. I think it's a combination of a shitty design, poor maintenance, and little/no knowledge of the difference in antifreezes. If air, oil, or regular green get mixed into dexcool that's where the coolant problems start. The root cause though isn't necessarily the coolant but the fact the gasket failed. Look at the LSx cars. How many 100k mile cars are floating around the site and very few if any have gasket issues and therefore no coolant issues.

**Smittro** · 12-17-2009, 08:26 PM

Originally Posted by 0rion

I'm not disputing that they leak ( and the water comment was not serious). I'm disputing that dexcool is behind the leak. I think it's a combination of a shitty design, poor maintenance, and little/no knowledge of the difference in antifreezes. If air, oil, or regular green get mixed into dexcool that's where the coolant problems start. The root cause though isn't necessarily the coolant but the fact the gasket failed. Look at the LSx cars. How many 100k mile cars are floating around the site and very few if any have gasket issues and therefore no coolant issues.

I gotcha now.. My bad. I really don't have to much data on the dexcool issue I'd mentioned but more often than not I'd heard folks telling others to get rid of it guess I followed suit.. I flushed my 3800 out and refilled with regular old coolant. Now that I've done that I'm hearing conflicting things about dexcool, some say it's bad others say it's fine with no trouble. I dunno I guess I was'nt taking any chances one way or the other as precaution...

**Conflict** · 12-18-2009, 01:01 AM

well I decided to take it to my dads shop, I'm done trying to mess with it... O well I hope I get it back soon

**Cutlass** · 12-18-2009, 03:38 AM

Originally Posted by Wesman

You wouldn't think they would, but thats how I first noticed that mine were leaking. Coolant was pooling on top of the lower intake runners. At first I thought it was oil because it was so dirty, but upon further examination I determined it to be coolant.

Here is what it looked like: