Liquid Sound then "Ka-thunk" Noise from Engine

[4Runner_Steve]

I have a 2002 4Runner Sport Edition that makes some noises that really concern me.

Basically, when driving around town I notice an intermittent (yet frequent) "ka-thunk" sound coming from the engine compartment, probably more on the passenger side of the engine. This sound often happens when I get to stop signs or am accelerating slowly away from them.

Sometimes, before the "ka-thunk" sound there is a clear sound of liquid rushing through pipes, with the "ka-thunk" ending the liquid sound.

I have brought the truck into the dealer three times for this problem with no avail. Once I even rode around town with the mechanic and it didn't happen -- it was SO frustrating! (it happens so much to me and my wife)

Should I be concerned? What could this sound be?

 

[loner]

Here's a guess -

Often Toyotas of that vintage would have the sunroof drains that exited via the rocker panels. The drains slots in the panels would become clogged and water would accumulate inside the rocker panels.

Perhaps you're hearing ice chunks (you're in CT, right?) and water sloshing around in your passenger side rocker panel.

Best way to tell is to look under your rocker panels and make sure the drainage slots are clear. There are subtle little slots that you can clear with the end of a zip tie. These should be located along the pinch weld seam. Also, there are probably plastic plugs you can pull out.

Good luck!

 

[4Runner_Steve]

Thanks for the message loner!

Actually, what you are describing is a very familiar situation for me -- I have had that problem with the rear passenger door on my 1997 Toyota Avalon. At times, it has seriously had gallons of water in it, something which was very disturbing to me at first. Unclogging those drain slots definitely does the trick.

As for this post about the 2002 4Runner, I was thinking that the noise could better be described as a clucking noise -- one loud metallic cluck (as opposed to a ka-thunk). A clearly audible liquid noise precedes the cluck approximately 20% of the time.

It's so troubling because I know that something is wrong and I have spent so much effort selling my wife on Toyota quality -- my 166,000 mile low-maintenance Avalon is another testament of this quality to a family of Toyotas that my side of the family has owned. One of these days this cluck, or clunk, or ka-thunk is going to spell big repairs... I have a bad feeling about it. Otherwise, I absolutely love the truck...

Thanks again for the message!

 

[kvanderploeg]

I hear something similar in my 2001 Sport. I can't say that I hear any liquid rushing, but I was always under the impression it was the pump that pushed washer fluid to the back window wiper/washer resivoir. I believe that the hoses for this do run inside the passenger compartment. Just a possibility.