Good luck 
Loud Knocking After Ingesting Water?
Thread Starter
Joined: Sep 2004
Posts: 6,814
Likes: 3
From: Hou. TX.
Loud Knocking After Ingesting Water? Hey guys, we had a big flood here in Houston yesterday and I got caught out in it. It was raining so hard I never saw the deep water. I was driving slow, but still got a little water into the intake. I kept the engine running so it never hydrolocked. It was sputtering as I backed out of the water. Once out, the sputtering smoothed out, but I have a real loud knocking sound.
No water or foam in the oil.
The sound seems constant and gets faster with the rpm.
Bearing?
Bent pushrod?
Would the MAF have gotten damaged?
There is no SES light or any other warning light.
I'm stumped. You guys have any idea what it could be or what I could check before I'm forced to go through my insurance?
No water or foam in the oil.
The sound seems constant and gets faster with the rpm.
Bearing?
Bent pushrod?
Would the MAF have gotten damaged?
There is no SES light or any other warning light.
I'm stumped. You guys have any idea what it could be or what I could check before I'm forced to go through my insurance?
Ive redone 3 motors this year from this. They ended up having bent connecting rods. You can take a look at your pushrods but I doubt that will be the cure. I would not run it anymore untill you tear it down and properly inspect it. It could be alot of things. 
water won't compress....if it's a knock (sound deep, not like a lifter ticking which would make valvetrain problem more likely) then I'm guessing a bent rod....hope I'm wrong though.
Thread Starter
Joined: Sep 2004
Posts: 6,814
Likes: 3
From: Hou. TX.
I just pulled the valve covers. I rotated all the pushrods while still in place just to see if they would turn or not and they all did. So if one is bent, it's not bent very much. I'm not real sure how it would get bent in the first place, but I want to check all the stuff I can.
It does sound like it's deep in the motor as opposed to the valve cover area. Now what happens with a bent rod? Does it bend front to rear or side to side? Is it the rod itself hitting the block that makes the noise?
If I let the clutch out slow and let the revs drop to about 500 the sound will go away which is strange to me.
I'm not going to tear down the motor or pul the oil pan. If it seems internal, like a bent rod, I'll just fork over the $500 deductible to the insurance and let them get it fixed. It's just that I would be so pissed if it were a cheap simple fix (like replacing a few pushrods) and I wasted a lot of money. Know what I mean?
It does sound like it's deep in the motor as opposed to the valve cover area. Now what happens with a bent rod? Does it bend front to rear or side to side? Is it the rod itself hitting the block that makes the noise?
If I let the clutch out slow and let the revs drop to about 500 the sound will go away which is strange to me.
I'm not going to tear down the motor or pul the oil pan. If it seems internal, like a bent rod, I'll just fork over the $500 deductible to the insurance and let them get it fixed. It's just that I would be so pissed if it were a cheap simple fix (like replacing a few pushrods) and I wasted a lot of money. Know what I mean?
Thread Starter
Joined: Sep 2004
Posts: 6,814
Likes: 3
From: Hou. TX.
I'm thinking of pulling the plugs and seeing if any water is trapped in there. I would assume there's not since the engine is running. Wouldn't any small amounts of water in the cylinder drain past the rings overnight?
Thread Starter
Joined: Sep 2004
Posts: 6,814
Likes: 3
From: Hou. TX.
Maybe I should just drive it. If it breaks completely the insurance would probably replace the engine. Right now they may just replace the one rod, assuming that's what's wrong. I don't know, it's a thought. I have the weekend to decide.
Trending Topics
That happened to me a couple of weeks ago. There were no rpm's at all and it turned out that i broke one of the rods and damaged a valve. The insurance took it to a local dealership and just from the knocking they figured it might be a blown piston so they ok'd a new motor. I asked the insurance if i could take it to a shop of my choice. They cut me a check and im having them rebuild the motor but with some goodies with money to spare...
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Verdad Gallardo
Awesome K5 Blazer Restomod Comes With C7 Corvette Power
Verdad Gallardo
10 Camaros You Should Never Buy
10 LS Engine Myths That Refuse to Die
Verdad Gallardo
A guy just did this on base yesterday, only it was a C6 vette. He had water all in his intake. I felt bad for the guy. Its still sitting here. Dont know what hes gonna do with it. I told him to have it towed to the dealer and let them diagnose it. The card wouldnt even turn over anymore.....
Thread Starter
Joined: Sep 2004
Posts: 6,814
Likes: 3
From: Hou. TX.
You'll just have to use your imagination.
About the rods, since I usually hear about them puching out the side of the block, I'm guessing they tend to bent to side to side and not front to rear. I was thinking maybe it was the bearing that got damaged since it is a softer metal. If the bearing got squished the clearance would be huge and cause the knocking. Is that a possibility?
About the rods, since I usually hear about them puching out the side of the block, I'm guessing they tend to bent to side to side and not front to rear. I was thinking maybe it was the bearing that got damaged since it is a softer metal. If the bearing got squished the clearance would be huge and cause the knocking. Is that a possibility?
its not a bearing,your definetly bumming and it sucks but i agree call insurance they will have a dealer look at it and probably cut you a check for repairs since the block is hopefully not damaged yet you may be able to upgrade a few internals during the fix,GOOD luck sorry.
She looks familiar and it's driving me nuts! 
Originally Posted by deathtrap
in march i went through some water and shot a rod through both sides of my block. call your ins and put it all back stock before you do it. mine paid 8000 for a 01 z06 so you should have some mod money left over
Thread Starter
Joined: Sep 2004
Posts: 6,814
Likes: 3
From: Hou. TX.
Just an update. The engines power seems fine. I got up the courage to step on it and bring up the revs to about 5K under load and it's boogying. Still not a single SES light.
Here's 2 new things. The idle speed is now either 1300 or 2000. Wierd. Maybe something to do with the MAF?
I can also feel the vibration some what when I press the clutch in a little. Would that be a normal transfer of vibration from the engine? Why wouldn't I feel it with the clutch pedal fully out?
It seems the source of the knocking is around the number 7 cylinder right by the oil filter. It may be, dare I say, something with the clutch or trans. The sound is really close to the back of the engine.
I don't know. I'm going to let the dealer look at it and maybe the insurance if need be.
Here's 2 new things. The idle speed is now either 1300 or 2000. Wierd. Maybe something to do with the MAF?
I can also feel the vibration some what when I press the clutch in a little. Would that be a normal transfer of vibration from the engine? Why wouldn't I feel it with the clutch pedal fully out?
It seems the source of the knocking is around the number 7 cylinder right by the oil filter. It may be, dare I say, something with the clutch or trans. The sound is really close to the back of the engine.
I don't know. I'm going to let the dealer look at it and maybe the insurance if need be.
Last edited by JasonWW; Aug 20, 2007 at 05:16 AM.
