Hi everyone.

I have a 99 4runner 5 speed with 430000km on it.
I've noticed a strange gurgling sound coming from the engine but only when the car has been idling for 5-10 min. Right after that, under load/throttle there is a diesel gurgling sound coming out.
If i don't let the car idle for long times, the sound is not present.

I also have a check engine light p0171 that I have been trying to diagnose. I cleaned the MAF sensor, replaced a few cracked vacuum hoses and also the CAT due to a leak but the code keeps coming back. I am not sure if the code is related to this diesel gurgling sound issue.
I have also replaced the o2 sensors a while back.

Any recommendations to diagnose this issue? I just took it to a mechanic shop regarding the noise, he said it might be a timing issue and to run some premium fuel and see how it goes.

 

Bump....

Had the shop perfrom a smoke test. Found one bad hose and replaced it. Cleared the code and came back on 2 days later.
Still have the diesel gurgling noise under load when car idles for 5-10 min.

Can anyone chime in? Could this be injectors? Do all of them need to be replaced or how to tell which one is bad?

Thanks

 

I'd say I hear the same on mine. I think its air bubbles being pumped around in the cooling system. May need to bleed the air out of the hoses whenever you're due for your coolant. Thats of course a guess. "Under load and idling" dont usually occur unless foot is pressing on the gas pedal while in park/neutral. Idling alone does not put any additional load on the engine.

Elusive P0171.
How clean is your MAF? If the sensor wires inside aren't shiny metal you may have caked on dirt. I had to carefully pick mine off the delicate wires after spraying the cleaner. I have a pic on one of my posts here.

Do you have a scan tool that can tell you the MAF readings? That can be helpful in your troubleshooting before and after cleaning.