Rattling / tikking noise under load

 Hi, I have 2009 jimny with M13A engine, automatic,145000 km, it works great and I don’t feel any power loss. However, lately, I noticed that under load, in any gear, at 2500-3100 RPM and especially when it’s warm outside the engine make rattling/ tikking noise. When I let go the pedal its stops right away. I uploaded an audio with the noise , you can really notice it towards the end .



I did the following but without any outcome:
- clean MAF, TPS, MAP.
- used 98 fuel 
- changed knocking & crankshaft sensors 
- used colder spark plugs (7).
- checked the catalytic converters.

The little jimny runs really great but that sound makes me cringe..

I saw a lot of topics that mentioned knocking noises under the same conditions but without any outcome.

Any ideas what it could be?

Thanks!

I listened to your recording but couldn’t hear the rattle you refer to. There was a slight whine towards the end, but it just sounded normal transmission noise to me.

All sorts of things rattle and it might just be an exhaust heat shield that hits resonance at the rev range or something else loose.

Under load the engine moves slightly on the mounts so something can rattle under load and not when in neutral at the same rev range. Have you checked in neutral with the bonnet up?

As regards pinking, what did the plugs look like, did they show pre-ignition?

I don’t know if the timing chain on this engine rattles, but I would have thought that would rattle even in neutral.

If everything in the engine looks fine, I would check for something loose. One further thing that does rattle is the dashboard, it’s held on with three screws under plastic covers and they come loose, I know from experience that a loose dashboard can sound like a rattle from the engine.

Robin

Hi Robin! Thanks for the reply.

It’s hard to record and catch the rattle noise from all the background noises.
The whining sound is the reduction ratio in the T-case.
Turn the volume up and you will hear it around the middle of the audio.

I can’t hear that in neutral , only under load when while driving.
The spark plug looks good, no oil or white residues.

I looked into the combustion chamber and there is small amount of carbon, not something that should cause detonation or pre ignition.

I also thought it can be the timing chain but it shouldn’t be noisy while starting the engine as well?

I will also look for loose bolts at the dashboard.

Appreciate the help 

Agreed I'm struggling to hear anything ominous from the recording. Once you've got the noise to manifest can you sustain it eg keeping the revs constant on an incline?

Alright… so I grabbed a rubber hammer and started tapping around the engine, trying to track down any rattling noises.
Found out that a piece of metal touching the extended panhard mount—fixed that.

Then I poked around with a flashlight and spotted something sticking out from the engine mount bracket… and it was a tiny stone hiding in there! Pulled it out, went for a test drive, and now the engine is quiet as ever 😃

I’ve been chasing this noise for 2 months! Along the way, I found out the knock sensor and crankshaft sensor were bad, cleaned carbon off the pistons, and went through every sensor in the car.
In the end, it turned out to be a good thing, thanks to this little stone the jimny feels like a brand new ride now 😎
(until next time..)

Thanks Robin and Lambert—really appreciate the help!
– Meir

We have all been there chasing a rattle that turns out to be a couple of coins in the ash tray.

Good news you found the problem and think of all of the experience you have gained cleaning and looking at plugs, MAF sensors, etc.

I went through something similar with my other car (not a Jimny) trying to fix a random misfire, replaced plugs, coils, MAF sensors, cleaned the throttle body, new air filter, etc, etc, only to find it was a weak battery which was strong enough to start the car, but too weak to keep it running at low revs.

Robin