An engine hydrolocking at speed lunched something, most likely a rod bearing, the weakest part of the system. You can fix it and see what happens, but I don't think you're going to get lucky.

Remember, you had probably 80-100 pounds of metal spinning at several thousand RPM. That'* an enormous amount of kinetic energy. I would suspect that the head gasket blew out, as well as one or more connecting rods bending, and maybe even lunching a crankshaft throw, and you can't check those out without tearing it down.

If you're keeping the car, I think it'* either rebuild or used engine time.

As I read your description, it does not sound like the car was running when it suddenly stopped due to hydrolock. Rather, the coolant stalled things out, then the starter broke when it hydrolocked, so I'm thinking your rods may be OK. I'm not sure, but I don't think the starter may have enough oomph to bend a rod, unless at least one or more other cylinders fire as the piston is coming up trying to compress the liquid.

Also, the condition of your bearings will depend on how long (if at all) they have been exposed to coolant. If the rupture in the UIM or LIM gasket was sudden, maybe the bearings are OK too. That'* why you need to get the coolant away from the bearings ASAP.

I was thinking about Technical Ted'* idea of draining all the coolant and starting it up for just a few seconds to see if you have a god-awful knock that might be a bent rod.

Something else you may want to try would be to pull the plugs, refill the crankcase with cheap oil and just run a compression test. If you hear a horrible knock, you'll know something is bent or busted. If the compression readings are normal, that would be a good thing. If a rod was really bent, the compression would be a lot lower in that cylinder. You could squirt in a couple of teaspoons of oil into each cylinder as we normally do for the "wet" compression test, and help to prevent any rusting that might occur due to the exposure to coolant. This might actually be a place where WD-40 would be useful. It is supposed to displace water, so maybe a good WD-40 bath sprayed in the plug hole would help minimize any rust.

I would think Ted'* idea would be OK if you only run it for about 15 seconds. With only the cylinder wall and air on the other side, things are gonna get very hot, very fast in the combustion chambers. But, I agree with Don that you should flush it out with some cheapo oil before starting it at all. Maybe even twice. And use really light oil, like 5W-30.

If you pull all the plugs, jack it up and remove the RF wheel and splash shield, you can put a huge half-inch drill on the crank nut and spin the engine to run the cheap oil through the oil gallery. I use a cheap 1/2" drive extension with the female end cut off and ground with three flats to fit the drill. This is how I prime 3800s that I have rebuilt to get oil circulated throughout before firing them.

Please make sure you read Techinfo article 38. http://www.bonnevilleclub.com/forum/...e=article&k=38

Bill, that sounds like really good advice...You are correct, the engine did not hydrolock while it was in operation, it was only when I was trying to crank it, so I may be in luck there.

Also, there was only maybe a 1/2 cup of water that came out of two cylinders, the others appeared to be "dry" so the engine wasn't 'flooded' with coolant....
With these conditions, maybe I've lucked out...

With the intake manifold still cracked I'm concerned about pulling more coolant into the engine while I'm trying to crank it. I may drain the coolant before I try and turn it over to prevent this.

Here'* what I'm going to try this morning:
1) Take air hose with nozzle & tube and attempt to 'blow' the remaining water out of the cylinder through spark plug hole

2) Inject oil into each spark plug hole as a lubricant

3) Fill the crankcase with oil

4) Manually rotate the engine around a few time to listen for bad noises.

5) I'll perform a compression test; although because of the oil it may be somewhat invalid..

After this, I'll re-post.

I've got a new intake manifold on order, it should be at the parts store at 9AM today. It'* one of the dorner replacement units that I've read about on the site. Of course, I don't want to go through the labor to mount this, if the engine is shot...

Absolutely, drain the coolant before turning over the motor. That was what Ted had in mind:

And, the more I think about running it without coolant, if you try that, I would limit the time it runs to maybe 8-10 seconds. That should be enough to get oil pressure up and let you know if you have a horrible problem.

I think your plan of attack is a good one. Do start, as you mentioned, by draining the coolant. And the compression test should still let you know if a rod is bent really badly. Even with oil on top of the piston, if the rod is bent, the piston will be lower in the bore and unable to produce its normal compression. Remember to block open the throttle plate when you run the compression test.

You are planning to replace the lower intake manifold gaskets while you're in there, right?

Yes, please do seriously consider doing the lower intake gasket, also. You may as well get both common problems taken care of at the same time. You're just a few bolts away, anyway.

Bill, as he went with the Dorman UIM, maybe one of your sleeves would be a good idea for some extra protection?

Great idea, and use a 3/8" drill bit to remove the casting flash from the UIM coolant passages.

Since you chose a Dorman replacement Upper Intake Manifold, and your car is 95-98, it would be fairly easy for you to install a shielded stovepipe. This involves pressing a thin, .125 h x .620 ID x .750 OD ring onto the shoulder of the little aluminum stovepipe that will come in your Dorman kit, so that it can be installed in your lower intake manifold, and installing a thin-wall (.750 x .710 x 1.0 h ) stainless steel sleeve on top of the ring in the LIM bore. A nut, bolt, and two washers can be used to press the ring on the pipe. This modification will provide you with a .100" insulating gap around the hot pipe and a heat shield to prevent deterioration and ultimately perforation into the coolant passage of the UIM.

If you re-use your stock .750 stovepipe with the new Dorman, you will be putting the hot pipe against the new plastic so the deterioration can begin anew. Although, to be fair, this is the same situation your car was in when it drove off the showroom floor. (!)

Or, if you are able to wait a few days for a better fix, consider cancelling the Dorman order and instead ordering the APN UIM kit that is mentioned in Techinfo article 38 linked above. The APN kit comes with a reduced diameter stovepipe that will fit right into your LIM, and the upper has a factory installed steel heat shield. An added benefit - the APN kit costs less than the Dorman. This will give you a .125" insulating gap and a heat shield for the upper.

If you want to adapt the Dorman pipe to your LIM and add a heat shield, I can mail you the parts for $10. Send me a PM if interested.

Since you chose a Dorman replacement Upper Intake Manifold, and your car is 95-98, it would be fairly easy for you to install a shielded stovepipe. This involves pressing a thin, .125 h x .620 ID x .750 OD ring onto the shoulder of the little aluminum stovepipe that will come in your Dorman kit, so that it can be installed in your lower intake manifold, and installing a thin-wall (.750 x .710 x 1.0 h ) stainless steel sleeve on top of the ring in the LIM bore. A nut, bolt, and two washers can be used to press the ring on the pipe. This modification will provide you with a .100" insulating gap around the hot pipe and a heat shield to prevent deterioration and ultimately perforation into the coolant passage of the UIM.

If you re-use your stock .750 stovepipe with the new Dorman, you will be putting the hot pipe against the new plastic so the deterioration can begin anew. Although, to be fair, this is the same situation your car was in when it drove off the showroom floor. (!)

Or, if you are able to wait a few days for a better fix, consider cancelling the Dorman order and instead ordering the APN UIM kit that is mentioned in Techinfo article 38 linked above. The APN kit comes with a reduced diameter stovepipe that will fit right into your LIM, and the upper has a factory installed steel heat shield. An added benefit - the APN kit costs less than the Dorman. This will give you a .125" insulating gap and a heat shield for the upper.

If you want to adapt the Dorman pipe to your LIM and add a heat shield, I can mail you the parts for $10. Send me a PM if interested.

OK, here'* the results:

I performed the steps that I described in my post, and when I turned the engine over by hand (Turning it with a ratchet as fast as I could go). The engine rotated freely and made no unusual noises.

I then "bumped" the engine with the starter a few times until I saw oil pressure show up on the guage, then cranked it freely and no unusual noises, oil pressure good, all seemed well.

Here are the results of the compression test:

#1: 205
#3: 185
#5: 180
#2: 185
#4: 205
#6: 170 * Very litte oil added to this cylinder

The numbers are slightly out of the 10% spec, but given the fact that each cylinder had varying amounts of oil added, and the vehicle has 240K miles on it, I think that the results are good...

What should I do from here? The intake manifold kit comes with all required gaskets for re-installation. Should I use those or step-up to a fel-pro set based on other people'* experience?

Also, I originally intended on replacing the timing chain soon, and I was thinking about doing it now, but I think that I won't for two reasons:
1) If the engine does have bearing problems I don't want to sink any more money into it than I have to. I want to watch it for a while, and if it looks good after a month then I'll go back and replace the chain.
2) I diddn't want to create to many potential problems at the same time, when then complicates the troubleshooting process (ie: rough running engine - is it a vacuum leak, timing off, cam/crank position sensor problem, etc etc )

What are your thoughts?