Hydrolocked from melting snow??????

[Z28dryva]

That's the only explanation I can come up with. Now the back story: Parked my 01 Z28 due to bad weather. Thought I'd take advantage of the down time a few days later and put a tranny mount in it. I went to start it and the starter breaks off the engine. Mind you the car ran perfectly when it was parked. I order a truck starter with the stouter mounting points and instal it about a week later. The engine turns over like the battery is dead so I jump start it. I starts but knocks like the end of the world. I see water dripping from a leak in the exhaust pipe on the passenger's side and decide I must have cracked a head or block with bad antifreeze and cold weather and prepare to put and engine in it. 1 week later I decide to tear into it. First I test the antifreeze and find that it passes to - 40 degrees. I pull the plugs on the passenger's side and find #6 and #8 look like swamp things. I then assume the head gasket is bad and decide to pull the head off. I pull off the intake and it pours out at least a glass full of straight water from the throttle body. Over 3 weeks have passed since the car has been parked and that much water was trapped on inside of the plenum just inside of the throttle body even though the engine has been started 3 times. Aside from assuming somebody broke into my car unnoticed, took my intake boot off and sprayed water into my engine or the back of the intake has a small leak and snow melting off the windshield has somehow made it's way into the leak and accumulated that much water within it. The MAP sensor sits kinda loose in it's hole and the round piece at the back of the intake that the MAP sensor and the vacuum tree mount to also seems to have a little free play to it. I'm kinda baffled at this point so if anyone has any ideas please fill me in

[2002ssslp]

you are 100% sure it is water and not gas right.

[Z28dryva]

Yep. Fuel came out the rail inlet and non evaporating nasty ass water came out the throttle body hole. Not antifreeze either

[SMWS6TA]

not saying it's impossible but it would have to have a serious crack or opening to accumulate that much water.


Only possible scenario I could see is that water accumulated on the map sensor and froze again. When it froze it expanded the crack/opening enough that when it thaws out it melts into the intake.

Post a pic of the intake with the map sensor.



Is this a LS1 intake?

[jrbonds]

I thought you already figured this out?

[Z28dryva]

Maybe I want a slightly more expert opinion Jodi. It's a LS6 intake and I made a video demonstrating how easily the MAP sensor wiggles in it's grommet and how loose the vacuum tree sits in the hole. If I ever get the video to upload I'll post it

[Z28dryva]

This damn video won't load so I'm sending it to youtube and linking it momentarily

[Z28dryva]

Ok as you can see, the MAP sensor seems to want to wiggle the same direction though I try to wiggle it other ways but this just seems WAY too loose to me. It seems the tree doesn't sit that loose in the intake when the engine is running since vacuum pins it against the hole it's sitting in. Seems a legitimate way for water to get in

[35th-ANV-SS]

You have a very odd problem on your hands. First-time seeing this one. Watched the video. Not sure, man. That's a lot of water to soak through that area.

[Z28dryva]

Indeed it is an odd problem. I just don't want it happening again since I'm putting a nice LQ4 in it that I don't want to kill

[SMWS6TA]

Wow a lot of play there, it made me go look @ my LS1 intake and check out how much play the map on it had. It didn't move much at all.


Have you tried using another map sensor?





Also I could see any cracks, mostly because the camera view. Does it have any around the map sensor or any where else?


how is the seal between the TB and the intake?

[35th-ANV-SS]

I would take a hose, glass of water, or whatever and pour it around that area and see if you see water coming through.

[0rion]

*normally* water gets in there by dripping past the cowl and leaking around an injector seal. I don't see how that much water could get through that map no matter how loose it is. I'm also wondering if it's all just coincidence and you spun a bearing and not hydro'd the motor. Normally the block gets vented on a hydrolock. Water dripping from the exhaust means nothing on a car that's been sitting in the cold and then started up....it's just condensation and they all do it. My GTO would piss out the exhaust pipes for an hour after it sat overnight when it was cold. The bird does the same thing but not quite as bad. I'm also wondering if the water in the intake was condensation but it sounds like you're describing a ton of water.

[Z28dryva]

All the TB gaskets seem good to go. It was a "ton" of water. Like over 2 cups at least. The only way water can get in that area is through the TB or the vacuum tree. Coming in an injector hole defies gravity

- - - Updated - - -

I'm gonna try the water hose trick today when I get home

[Firebirdjones]

*normally* water gets in there by dripping past the cowl and leaking around an injector seal. r.

^^^^This.

If the car was just sitting, it's been an issue that water can leak through the cowl and drip on top of the intake, and slip past an injector seal filling that cylinder with water. But like Orion said, when this happens you almost instantly ventilate the block, bend a rod etc...
Also, in this instance water wouldn't be in the throttle body as you described. Only easy way to get water up there is through the intake track and you would have to be driving the car through some seriously deep water. Since the car was sitting I'd suspect you have some other strange issue going on.

[0rion]

that much water is hard to account for really......my gut tells me it's condensation but that's a ton of condensation. There's just really no easy way to account for that much water in the intake. I really doubt it came from the map being loose.

[Z28dryva]

Ok update. I put the car back together a few weeks ago using a LS6 out of an 01 Vette. The injector O rings were all good but I replaced them anyways. After getting the car back together, I washed it and observed water dripping on the engine from the windshield cowl. Not from the weather stripping sealing it off to the hood, but rather the weather stripping on the bottom of the plastic sealing it off to the body of the car. It was all screwed up and torn and allowing water to pass right through it. I put about a 3/4" bead of bathtub caulk along this area and used bolt instead of the cheap plastic pop rivets that hold this thing down from the factory. My theory is that the intake was not torqued down properly and water leaked past it into cylinder 6 and the reason there was so much water in the intake (defying gravity) is because I cranked the engine over by hand backwards and the piston shoved it up in the intake.

It was a costly freak accident, but I fixed numerous problems the car had in the process of gaining 50hp from an engine swap. All in all, I'm glad it happened as I would probably be procrastinating all the stuff I needed to fix on the car and would probably never get to it

[SMWS6TA]

congrats......

[RockinWS6]

Actually what happened to you is very common, open your hood after its raining and you will be treated to water dripping onto the intake from the UNSEALED factory cowling around the WS. All it takes is loose intake bolts and the water leaks right in. I've seen it happen a bunch of times. !st thing I do to every LS1 car I've owned is silicone the cowling around the WS to stop this from happening. Another problem with these nylon intake manifolds are forever shrinking causing the bolts to come loose. Becha I tightened mine 5-6 times over a few weeks time before they stayed tight at 89 inch lbs.