Jump to content

Water Slushing sound on startup

Gangly
 Share

Recommended Posts

Gangly Senior Enthusiast

Gangly

Posted
Posted

If I drive my truck for a good bit then let it sit for an hour or so, I will sometimes hear a water flowing sound from what I believe is the heater core immediately upon restarting it after sitting.  Like its sucking water up or something.  It last for about 1 second, immediately on startup, then I never hear it again, regardless of how long I drive.  It only occurs on startup, and is random at that.  Is anybody else familiar with that sound?  It has done it since day one and it never bothered me since I thought it was normal, but I just want to see if I am along in this or not.  I just hit 36k miles too...hope its nothing.

Gangly Senior Enthusiast

Gangly

Posted
  • Author
Posted

Funny how just reading your comment makes me feel better, at least I know I'm not alone :)

Skirtbag209 New Member

Skirtbag209

Posted
Posted

I had a 96 Silverado that would make randomly make the same sloshing noise. After owning it for some time I eventually had to replace the heater core. I can't recall if I started hearing the noise before or after it leaked/replaced. 

 

Currently, my 02 escalade started sloshing for the 1st time (in the 3 years of owning) a few days ago. 

mrtizzom Enthusiast

mrtizzom

Posted
Posted

Mine does it also. Come to think of it, the last couple trucks I've had did this. I'm so used to it now that it doesn't bother me anymore lol

  • 3 years later...
JCantu23 Enthusiast

JCantu23

Posted
Posted

Has anyone found the reason why this is happening? I just noticed my truck doing the same thing. 2021 Chevy Silverado with about 37K miles on it.

  • Like 1
GMCustomerService Senior Enthusiast

GMCustomerService

Posted
Posted
On 2/3/2025 at 6:05 PM, JCantu23 said:

Has anyone found the reason why this is happening? I just noticed my truck doing the same thing. 2021 Chevy Silverado with about 37K miles on it.

We understand how this concern with your Silverado has been worrisome and we would like to investigate deeper on our end. Kindly send us an email to [email protected]. Be sure to include your Username and Forum name in the subject line with additional details. Our team looks forward to hearing from you. 

Shall36 Enthusiast

Shall36

Posted
Posted
On 2/3/2025 at 6:05 PM, JCantu23 said:

Has anyone found the reason why this is happening? I just noticed my truck doing the same thing. 2021 Chevy Silverado with about 37K miles on it.


I had the same thing. Top off your coolant reservoir. 

Gangly Senior Enthusiast

Gangly

Posted
  • Author
Posted

Yup.  My solution was to top off the coolant reservoir a half inch or so above the "MAX" line, and run the truck on a slight incline for a few minutes at full temperature.  

Gangly Senior Enthusiast

Gangly

Posted
  • Author
Posted

Unfortunately, I don't remember for certain.  If I am remembering correctly, the first time I left the cap off, and the second time I placed that cap on.  Both times the issue was solved.  I know each time I performed that process, it worked for about 40K-50K miles before hearing it again.

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

  • Latest Articles

  • Posts

    • Atlas
      Wow I'm in a pickle. (Broke down truck) and a story.

      By Atlas · Posted

      While waiting for parts I have been working on installing the AC compressor, new accumulator, and orifice tube. Also changed out the high side ball valve (original). The orifice tube that was in there wasn't too bad. Slightly dirty, a little bit of junk, but not blocked. Glad I changed it out.   The accumulator, which should have been a 5 minute job, may have just burned $50. Put some PAG in it, wrote the date and mileage on the side, fresh o-rings and gooey'd up the threads and rings with Nylog. Got everything connected and snugged and was going to vacuum down the system, and....   My manifold gauge won't fit on the port. It's not an R12 service port. It LOOKS like an R134 service port but the diameter is a hair too large. There's a sticker on the accumulator that says it's designed to be used with R12 and R134a systems only. So it's not R1234yf. Even if I reduced the diameter slightly with a file, the shoulder on the port is too large so the quick-connect valve won't lock on. I'm stumped. It's going back, and 50/50 on if they'll give me a refund.   Also, I did a fuel pressure test.... Key on, the gauge spikes to about 60psi and quickly bleeds off, like 2psi per second. The fuel isn't going into the plenum, no smell, starts fine, so I'm guessing there's a bad check valve in the pump and the fuel is just draining back into the tank. oh, hell. But, it shouldn't be a problem, pump primes just fine and the truck starts right up. It just means I can't really ever use fuel pressure to verify a leak at the injector or intake.
    • No F-bdy Bs
      SERCICE ESC message?

      By No F-bdy Bs · Posted

      Got this yesterday out of nowhere. Truck is a 25',6.6 gasser with 8k miles.  Only semi anomaly is that the truck had been sitting, uncranked for 6 days. Elec Stability Control showed immediately upon cranking, not while driving. No drivability issues, just the message. Battery didn't seem to be weak when cranking over.  I drove it, killed it, let it sit a few hrs with no avail.  Truck is 100% stock. No damage. 
    • newdude
      on-wheel cellphone control: 2026 1500 WT (2.7L 4WD std cab)

      By newdude · Posted

      This can be done.  It is not cheap and requires an instrument cluster swap with custom programming, new steering wheel with the controls on it, and a special jumper harness.   The cluster upgrade - 12.3” Digital Cluster Upgrade – 2022.5–2026 Silverado / Sierra (T1 Refresh Pickup) - WAMS   The wheel upgrade - Steering Wheel Upgrade Kit – 2022.5–2026 Silverado / Sierra (T1 Refresh Pickup) - WAMS   The column harness upgrade - 2019 - 2026 Silverado / Sierra: Steering Wheel LIN Bus Harness - Harness Dr. - DIY Done Right     The problem with doing all of this?  You pretty much can't have any programming done to your truck that involves the cluster ever again.  The dealer won't be able to program the cluster as GM's system will only pull data for the cluster the truck came with.  So it would be advised also to turn off over the air updates.   TLDR;  Should have bought an LT double cab?  You'd have a power seat, the wheel controls, the cluster, all things that you've been seeking in your various posts so far about your new WT regular cab.  
    • dna9656
      New to Me 2010 SLE (Quirks, Issues)

      By dna9656 · Posted

      I was unaware of that, thanks for updating me.
    • newdude
      2026 TurboMax L3B 2.7L: AFM/DFM present/disablable? [2026 Silverado 1500WT: 4WD RC RB 2.7L]3GCNKAEK9TG345558

      By newdude · Posted

      Yes.  The 2.7 Turbomax has Active Fuel Management.  It is NOT the same as the V8s.  Totally different system.     Here is an article from GM when the 2.7 came out explaining the cylinder deactivation and the valve lift system.  Starts at the section called "SCS Valvetrain":   New Turbocharged 2.7L 4-Cylinder Engine Powers Full-Size Trucks – TechLink         This is an internet myth going around.  It was alleged that some 5.3s had this mystical 8th digit of the VIN as an "E" which somehow meant it had a new one year only 5.3 that didn't have DFM.  The writer of said article and the person that made the claim conveniently can't count because they posted the VIN.  The 8th digit was a "D" which meant its still the 5.3 with DFM.  The 9th digit of the VIN was an "E" and the 9th digit isn't the engine code.  At all.  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...