Some of you may know I swapped engines in my Dak little over a month ago.

I've noticed that I now have a pretty loud gurgling/bubbling noise coming from behind the dash... not sure if I'm being paranoid but I don't remember having this problem with my old engine.

I noticed that it will gurgle and bubble regardless if the heat and fan are or off.

If you turn the truck off you can year it still bubbling if its warm for about 30 seconds.

Also, I've got a large evap leak somewhere. All hoses look fine and I know I didn't forget about any. Gas cap was replaced a year ago and is a PITA to put in the filler neck. Once u put it in it stays locked though.

Any ideas?

 

I forgot to mention... I thought it was possibly air in the cooling system but I made sure to burp it. I ran the engine with the rad cap open while adding fluid as air bubbles surfaced. Repeated this process until no more air was coming out.

 

Bubbles make me think of the heater core and air in it.

 

Did you ever flush out the cooling system in the new engine?

Also I suggest an engine flush to get any sludge out of the oil system.

An engine that may have sat around for a few years can develop sludge in the oil and cooling systems.

Did you check/change the cooling stat on the engine?

Is the cooling fluid antifreeze at the correct % if too much water it will do that.

 

can you pinpoint where behind the dash? May be heater core/coolant system, would be my guess

 

Good suggestions thanks guys.

I was also thinking air in the heater core so yesterday morning I burped it again, this time I jacked up the front engine and burped it and I actually got a tiny amount of air come out of the system.

The level dropped a tiny bit so I must have added another 1/4 cup of fluid... burped it for a while till the fluid level didn't move at all.

Never flushed the coolant, but I did swap waterpumps and timing cover so I made sure to get most the coolant that gets stuck in the engine.

Didn't flush the engine itself, but I put in fresh oil, drove for 2 weeks and changed it again. The engine was date stamped Feb 2013 so it only sat for 6,7 months or so before I got it.

Tstat is about a year old, had to replace it on my old engine so I just swapped it over.

I bought 2 jugs 3.8L of Zerex G-05 coolant (non-premixed) and 2 jugs 3.8L of de-ionized water, mixed it all together in a big bucket, then took one of the jugs and filled it up and repeated this process till the coolant was full.


About my code... I am certain its my damn gas cap area OR.... My neighbour said he had a problem on his 06 Impala where there is actually a sensor in the filler neck... the dealer told him it was his gas cap and after replacing it twice he found out it was a sensor... he wasn't sure if my 02 Dakota has this too, or if it would be too old.

Does anyone know of some type of sensor in the filler neck, or is the code truly being thrown because of my gas cap.

Thanks