Jump to content

Possible Hydrolock

Chrisgreenm
 Share

Recommended Posts

Chrisgreenm Enthusiast

Chrisgreenm

Posted
Posted

I own a 2006 sierra denali with the 6.0 gas. A few days ago I drove through a pretty deep puddle (I know the danger now) and immediately after my engine started knocking. It never stalled, never died or stumbled while in the water. I pulled my intake and it was full of water, filter was soaked. I let it dry while I worked, and let the filter sit in the sun for a bit. Put it all back together and on startup and at idle it did not knock. I could even raise the rpm's and it wouldn't. However once I got about 60 seconds into my drive it started again. Same thing today, it didn't do it on startup or revving at idle but once I put it in drive and went it came right back. I know the obvious answer everyone's gonna say is I bent a rod when I hydrolocked a cylinder, but wouldn't that make noise consistently? And raise with rpm's? Looking for if anyone knows any other possible reason as to why it's knocking or what I'm missing here

  • Like 1
richard wysong Senior Enthusiast

richard wysong

Posted
Posted

Try it without the air filter and see if that helps. The water may have damaged it

Chrisgreenm Enthusiast

Chrisgreenm

Posted
  • Author
Posted
16 hours ago, richard wysong said:

How's the oil look?

Oil is clean. Changed it a little bit before the incident and it's still clear clean looking oil, not milky.

  • Like 1
Silverado4x4 Senior Enthusiast

Silverado4x4

Posted
Posted (edited)

With the airbox soaked with water the water may have damaged the MAF sensor and screwing up the air/fuel mixture.  You don't have any codes? I would try and disconnect the battery for about 15min or longer to reset the computer as this could have screwed up the readings for the computer. Yeah definitely not hydrolocked. 

Edited by Silverado4x4
  • Like 1
Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted
15 hours ago, Silverado4x4 said:

With the airbox soaked with water the water may have damaged the MAF sensor and screwing up the air/fuel mixture.  You don't have any codes? I would try and disconnect the battery for about 15min or longer to reset the computer as this could have screwed up the readings for the computer. Yeah definitely not hydrolocked. 

 

Good thought! 

PunchT37 Enthusiast

PunchT37

Posted
Posted

Is all the water out of the intake? Some are almost impossible to get all the water out. It will sit in there till revved. Then, boom.

Chrisgreenm Enthusiast

Chrisgreenm

Posted
  • Author
Posted
On 6/13/2025 at 5:53 PM, Silverado4x4 said:

With the airbox soaked with water the water may have damaged the MAF sensor and screwing up the air/fuel mixture.  You don't have any codes? I would try and disconnect the battery for about 15min or longer to reset the computer as this could have screwed up the readings for the computer. Yeah definitely not hydrolocked. 

I do have codes like p300 and lean fuel on bank 1 but I had that before. No new codes. I pulled the tube off from the box to the throttle, should I pull the throttle and intake manifold too? Maybe waters stuck in the manifold and causing noise?

Chrisgreenm Enthusiast

Chrisgreenm

Posted
  • Author
Posted
On 6/13/2025 at 10:14 AM, richard wysong said:

Try it without the air filter and see if that helps. The water may have damaged it

Without the filter it makes the same noise

Chrisgreenm Enthusiast

Chrisgreenm

Posted
  • Author
Posted
On 6/14/2025 at 8:55 PM, PunchT37 said:

Is all the water out of the intake? Some are almost impossible to get all the water out. It will sit in there till revved. Then, boom.

Up until the throttle yes, I didn't go further than that. Would it get past the throttle and stay there?

PunchT37 Enthusiast

PunchT37

Posted
Posted
40 minutes ago, Chrisgreenm said:

Up until the throttle yes, I didn't go further than that. Would it get past the throttle and stay there?

On many modern engines, once a liquid gets in the intake, it`s a good idea to change it. You can`t just pour it out. It will stay in the bottom of the long runners. Then, with enough air velocity, it will make it to the cylinder. Then, a bent or thrown rod. Maybe not your particular intake but, something to think about. I would at least pull it and see if water is in it, and if you can get it all out.

Chrisgreenm Enthusiast

Chrisgreenm

Posted
  • Author
Posted
On 6/16/2025 at 9:17 AM, PunchT37 said:

On many modern engines, once a liquid gets in the intake, it`s a good idea to change it. You can`t just pour it out. It will stay in the bottom of the long runners. Then, with enough air velocity, it will make it to the cylinder. Then, a bent or thrown rod. Maybe not your particular intake but, something to think about. I would at least pull it and see if water is in it, and if you can get it all out.

So I finally got around to pulling the manifold. There was a decent bit of water in there mixed with oil. Got it all out and dried it, reinstalled and the noise is still there. 

Chrisgreenm Enthusiast

Chrisgreenm

Posted
  • Author
Posted

Anyone have any ideas what could be rattling around? I've checked it over and over and I don't see anything. Maybe it warped something like my exhaust? Did hit the puddle right after coming off the highway so it was definitely hot

PunchT37 Enthusiast

PunchT37

Posted
Posted

If it`s not the engine, then maybe the cat core is broken and rattling around. The cat is usually very hot and driving through cold water shocks the ****** out of it.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.5k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,894
    Total Members
    8,960
    Most Online
    TopBo
    Newest Member
    TopBo
    Joined

  • Who's Online   4 Members, 0 Anonymous, 1,185 Guests (See full list)

  • Latest Articles

  • Posts

    • 81mmcat
      Higher oil pressure after DFM shut off

      By 81mmcat · Posted

      Can anyone explain why the oil pressure runs higher after the DFM is shut off?  just installed the Pulsar Lt.
    • fm2176
      New to Me 2010 SLE (Quirks, Issues)

      By fm2176 · Posted

      Thanks!  I figured as such; GM and other manufacturers have used standard parts and harnesses across trim levels and such for decades.  I pulled the blank accessory cover off of my commuter van (a 2016 or so Chevy 15-passenger) years ago and found the plug for a USB outlet.  It wasn't connected to anything, though (I tried swapping in an outlet from another van).  I was a GM Tech years ago (late-90s) and was pretty familiar with my 2006.  I might be wrong, but I view newer vehicles (pretty much anything made in the past 20 years) as being a lot more plug and play.  Meaning, more unused wires and plugs unless you have the Mack Daddy of vehicles.    
    • Coastie05
      It's Been a Long Time...

      By Coastie05 · Posted

      Welcome back!
    • davester
      New to Me 2010 SLE (Quirks, Issues)

      By davester · Posted

      not all plugs will be used.  gm uses more generic harnesses that support most/all options, and if your truck doesn't have a specfiic option, the plug won't be used (commonly will have a dummy insert in the plug , or it'll be taped up, but some may just be left as is).  But it's sldo possible some p.o. has installed the wrong/cheaper parts that aren't correct for your vehicle...
    • fm2176
      New to Me 2010 SLE (Quirks, Issues)

      By fm2176 · Posted

      First off, I'm not trying to just get easy advice/fixes for the issues I've noticed so far.  I'll be combing through the site via searches and such, and if past experiences are any indication, should find what I need.  For the sake of conversation, though, I figured I'd post the handful of things I've noticed in the 12 hours since buying my 2010 SLE CCSB.     Indicator lights: Airbag and TPMS.  The tire pressures aren't reading for any of the wheels, so I'm pretty certain the sensors were either removed, are damaged, or are otherwise inoperable.  I used to mount and balance tires 25 years ago but am pretty much ignorant when it comes to TPMS.  My 2006 didn't have the sensors and this might be the fourth vehicle I've owned that does.     Radio: Rear speakers aren't working.  I removed the driver's side rear door panel and checked the speaker and wiring.  I also removed the sill and b-pillar covers to check the wiring.  A few minutes of Google Fu showed that this is potentially a head unit issue.    Switches: Power mirrors don't turn left/right.  I ordered replacement driver's door switches that should arrive tomorrow.  The windows and locks work but it was only about $20 for all of them.  The driver's side rear window switch lets the window down but won't put it back up.  I think the passenger rear doesn't work at all.  In the coming days/weeks, I'll break out my multimeter to check all of that.   Unknown wiring harness: There's a box attached to the front driver's side of the engine compartment, right where the second battery shelf is located.  There are three plugs, one of which looks like it fits a standard headlight-style bulb (9007 or similar).  It doesn't look like it's plugged into anything.  I'll do some digging and if I don't see anything elsewhere on the site, post some pictures here.   Unknown plugs on brake booster: There are at least two female plugs on the brake booster that aren't being used.  I think it might be a replacement/aftermarket, so maybe those are used for a different application, as there don't seem to be any unplugged harnesses and no indicator lights are on.   Little squeaks when turning: Sounds almost like a bushing around the bed of the truck.  I'll have to pay close attention as I get more familiar with the truck.   Clunk on acceleration: possibly the infamous drivetrain clunk.  My 2006 had it and I'm just not familiar enough with this truck yet to fully grasp what it is.   Anyway, my apologies for the vague and all over the place post.  This truck is new to me, and it's been four years since I drove my 2006.  With 200k miles, I know I'll need to learn this truck quickly to avoid having any major issues, despite being confident it's got much more life to it.  My 2006 had nearly 320k on it when I parked it (nearly 300k of which I put on the truck), and it was still drivable then, though I suspected the head gasket might have blown.  I'd hoped to have that truck back by now, but it's gone forever, as I detailed in my reintroduction thread.  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...