First off I would like to say that this is a great forum, Keep up the good work. I hope to contribute as much as I can.

Now my story, After doing my annual tranny filter change I took it for a test drive - shifting through the gears manually to get the fluid moving I got about 3 blocks down the street when the engine died, I pulled her over and tried to start it again, it turned over a couple times and then locked up. I popped the hood and noticed the antifreeze overfill was empty. I then knew what happened. Got her home and pulled the spark plugs and sure enough yellow juice flowed out. So far I have pulled the the upper and lower intake and am cleaning stuff up. There sure is a nice hole in the upper plenum where the EGR stack sticks up (failure point). I have some nice pictures if anybody is interested.

I just hope that nothig else happined because of the hydolock. Im thinking since it only hydrolocked when I was trying to start it I may be OK. What do ya think?? It may be just hopefull thinking. I know she has a lot of rounds on her but she was running strong (mostly highway miles). I am going to do a compression check on it and see what they are at. Any idea what they should be at?
I am getting ready to buy all the stuff if the compression looks good. I need to decide where I am going to buy from, I have been very happy with gmpartsdirect website. I bought my struts from them last year.

What really pisses me off is that I was going to do the plenum back in Dec when I noticed my antifreeze was about an inch low in the overfill after filling it a couple weeks previous - but then it slipped off my priority list. Oh well if you can only turn back time.

Sorry to hear about the troubles.

As long nothing has cracked or broken you should be alright. The compression will help you decide. If its low pump a few shots of oil from a can in the cylinder and try again, this will rule out valves/heads.

I think you are in good shape. You may look at my message posted on August 5 (Intake failure in Puerto Rico) to see the similarity between your case and mine. Today my friend just finished installing the plastic intake and the car is back to normal.
I bought the Dorman intake from Northern Auto Parts thrue Internet and it cost only $158 delivered on 2nd day to Puerto Rico via UPS. This price included the gaskets. I did not remove the lower intake at all. I did an oil-filter change before starting the car. Also put a new PCV. Had a hard time starting the car, but it seemed to be that the spark plugs I had installed a few days ago were no good. Put a new set of plugs and it started. A lot of white smoke came out the exhaust for a while. Itt even stalled a couple of times but after erstarting and after a few minutes of the engine running (5-10 ???), the white smoke disappeared and it has beed doing fine since. Most probably I will do another oil change in a couple of days, and also may even change plugs again since i used cheap ones to see the engine would run OK. It looks nothing was bent or broken inside the engine. Thanks God.
I think you are even in better shape simce you do not emntion any heating up of your car. Mine heated up pretty bad. So good luck.By the way: my car is a97 SE.

Drain your oil immediately. Several of these failures have caused bottom end bearing failures within 6-12 months of the upper plenum failure. Due to rust on the lower block engine components.

I agree that you'll probably be fine, but I'd do at least a dry compression check just for the peace of mind.

Drain your oil TONIGHT.

Hey, Thanks for the replys.
I forgot to mention in my post that right after i pulled the plugs I drained the oil, because when i pulled the oil dipstick I seen that there was moisture on it, and yes when I drained it, first out came the oil then the antifreeze came out. It wasnt that much but it was enough for me to decide that i was going to replace the lower intake gaskets. I hope that what you say willwren wont happin to me - cross my fingers.

I think I will put oil in her before doing the comp test, it bothers me turning it over without oil in it. Thanks for the oil tip potiacdad. I recall doing that with my old pickup which i knew had bad valve seats it worked like a charm, finding the bad piston ring.

I am going to replace just about everything including the plug wires, I think they are original. What gives this away is the numbers on them for each cyclinder. I recall when I first bout the car I was going to change them and all I could find were 7mm wires local unless special order. The ones on there are 8mm. So i ddnt get any. Now im am going to buy, anyone know if I can get 8mm wires for this without breaking the bank. Again I think I will check gmpartsdirect. By the way when i bout this car from my boss it had 100,000 rounds on her - he was worried about the engine dying. He regrets it now after I put 70,000 more on her. In that time this is the worst thing that has happined, not counting the water pump last summer(bearing went out - it still pumped but very loud)
My point being she never left me on the side of the road.

Here'* my buy list:

lower Intake gasket kit
Upper plenum+gaskets
Valve cover gaskets
Plugs + wires
Tstat + Cap
PVC valve
EGR gasket

What am I missing, Hmmm.

Sorry to hear about the failure.At least yours went longer than some others before happening.------Regarding 8MM plug wires,I bought a set of BORG WARNER SELECT for my last car( 3800 series 1) at Pep Boys. I'm very sure they were 8 mm.Nice quality construction,wire wound center conductors and silicone jackets, and cost about 27 bucks.There was also a lower priced/lower quality Borg Warner wire available but the "SELECT" were real close to the factory wires.Never had a problem.Good luck.

To your "buy list" you might want to add : Ultra Black or some other good silicone sealent for the corners of the lower gaskets end seals.Loctite blue for the bolts.New injector o-rings.Any water pump bypass hoses or elbows that might need replacing.Motor manual with torque sequence and torques.---NOTE--- anybody heard about GM issuing new torque sequence and torques for the lower manifold?

FYI check out my post on the job I did last week.
http://www.bonnevilleclub.com/forum/...ic.php?t=22897
Seriously consider changing the $8 lower intake coolant elbow too.
This little part will get you stuck on the road if it fails.....

Say, is this a dealer part or would napa have something like that.

I agree to replace that. It would be a bear if it failed. Has anyone had it happin?

It'* a dealer part. Or, you could get it from gmpartsdirect.com.