Members Login
Username 
 
Password 
    Remember Me  
Post Info TOPIC: 3800 V6 3.8 GM Series II Intake Manifold coolant leak causing hydro lock.


OUT-OF-HAND

Status: Offline
Posts: 8024
Date:
3800 V6 3.8 GM Series II Intake Manifold coolant leak causing hydro lock.


Well it would seem that 3800 come in pairs... After my last 03 Impala with the Series II 3800 engine leaking coolant out of the elbows I had a 1999 Buick Lesaber come in with complaints about sweeping engine tempratures and loss of heat during said sweeps.

First thing I do is check out the coolant level and sure as $hit, it's low. I topped off the system with DexCool and heat returned but engine tempratures were still sweeping. 

Since it was cheap enough I decided to install a thermostat figuring the spring was at fault as there really was no pressure build up.

Then what happend is for the history books... Upon restarting the vehice and refilling the coolant the engine began to run funny and sucked the entire contents of the coolant bottle into the radiator! The engine ran a little funny as the computer spit out a code for cylinder misfire in cylinder #5! Upon trying to re-start the vehicle it would no longer start! Seemed like it was locked up! So I pulled cylinder #5 and antifreeze come pouring out! At first thought it was a head gasket but I had never had anything like that happen. Next step was to start tearing it down, as I would soon learn about the dreaded 3800 Series II plastic intake weakness...

First on the docket was the upper intake manifold...

And look at that! FULL OF DexCool! To the brim! LOL

So here is what causes this problem, and trust me when I say many web sites give little information on the problem

As you can see the EGR port heats up the plastic intake that also carries coolant into the throttle body. This area disinigrates and it literally sucks coolant into the intake track. Some people get by for a long time with low coolant, but there was reports of the customer thinking he smelt antifreeze in the past. Anyway, to make a long story short, if you have a 3800 engine that is sucking in antifreeze into the engine it's a good chance the intake manifold needs to be replaced. In the event the engine hydro-locks I would suggest doing the head gaskets to clean things up and ensure everything is in order.

Here is a look at the tube on the intake from the factory that slides into the intake manifold.

And this is the new one that gets installed with the new intake kit shown below offered by Dorman



__________________

State of Michigan Certified Master Auto Mechanic +2

Specialty Certified Since 1994



OUT-OF-HAND

Status: Offline
Posts: 8024
Date:

So now, since it's hydro-locked I am stuck pulling off the heads to ensure she is worth putting the money into...

So here above you can see how the intake manifold gasket is also a problem area... They do sell these made out of aluminum but I have yet to see anyone local that stocks them. Most of the problem comes from the intake, but if you have a supercharged version of this engine I would go the performance route due to boost factors.

Here you can see the nastyness as I call DexCool! I tell you this stuff gets toxic because people forget it's 100,000 or 5 years... So they go 15 years before they get to 100,000 miles and well... This is what you get.



__________________

State of Michigan Certified Master Auto Mechanic +2

Specialty Certified Since 1994



OUT-OF-HAND

Status: Offline
Posts: 8024
Date:

So with my trusty Rol-Loc pad and die grinder in hand I work some "Magic" and bring them nasty looking heads, block and manifold back to life.

Ohhh.... Ahhhhh... So clean! PowerStroker would be jealous to know I did this by hand!

Now it's up and running like a champ! Heat is awesome, like a LeSauna in there! LOL!  Runs at a steady 190 as it should and everything on the lower end was happy.

Now it's time to put the Auto-Trend "glow" on it...

All DONE!



__________________

State of Michigan Certified Master Auto Mechanic +2

Specialty Certified Since 1994



FAR BEYOND DRIVEN

Status: Offline
Posts: 3048
Date:

By "auto trend glow" I take it you hose the engine down with a thick coat of n%##@r gel?

__________________

~ Ford Senior Master Technician

~ 2 "mandatory vacations" from this site for being way too qualified

~ Is America whi... I mean great again yet ???



OUT-OF-HAND

Status: Offline
Posts: 8024
Date:

Whale sperm... lol j/k

No it's a silicone based product. Good for the ruber and plastic parts.



__________________

State of Michigan Certified Master Auto Mechanic +2

Specialty Certified Since 1994



Member

Status: Offline
Posts: 1436
Date:

SOUNDS LIKE A UMNEY HOMEMADE VERSION OF DA KY JELLY!!!!!!!!!!!!!!!!!!!! AHAHAHAHHAHAHAHAHHAHAHAHAHAHHAHAHAHHAHA!!!!!!!!!!!!!!!!!!!!!!!!!!

__________________

 

 



FAR BEYOND DRIVEN

Status: Offline
Posts: 3048
Date:

I wonder if using green coolant would have prevented that problem? I've heard nothing but bad things about Dex Cool.

__________________

~ Ford Senior Master Technician

~ 2 "mandatory vacations" from this site for being way too qualified

~ Is America whi... I mean great again yet ???



OUT-OF-HAND

Status: Offline
Posts: 8024
Date:

I think DexCool, changed at regular "green" coolant intervals would prevent this problem.

I have found that 10 year old DexCool is the most corrosive coolant I have ever seen. I have heard stories that GM was sued over DexCool, however in almost every case where DexCool becomes corrosive it's because people try and get over 5 years out of it.

Still, the fault is mostly with the intake manifold in this case. The design with the EGR being pumped into a plastic intake, followed by coolant circulation around the area is what really causes these things to "pop". In this case.

In other cases of the Vortec v8's with high miles, I see DexCool eats pits in aluminum manifolds and such all the time. Then again this has happend with Green coolant in days past with cast iron.  



__________________

State of Michigan Certified Master Auto Mechanic +2

Specialty Certified Since 1994

Page 1 of 1  sorted by
 
Quick Reply

Please log in to post quick replies.



Create your own FREE Forum
Report Abuse
Powered by ActiveBoard