2011 FX50 piston slap?

skynet

Member
Car
2011 FX50 AWD
Name
Laszlo
Hi,

I have a 2011 FX50 with only about 78.000 miles according to the dash. I've checked with the local Infiniti dealer and seems accurate, the car was used in Italy until cc 50.000 miles and then was sold to Lithuania in 2015. Just to prove - to myself also - that the car seems to have a normal mileage (about 10.000 miles per year), this is not an engine with a bazillion miles in it.

So the symptom is: transmission is in P (I mean: I don't have to drive the car uphills to give some burden) and when revving up the engine, from cc 2000 to 3000 RPM there is a rattling sound, and when stepping off the gas, and leaving the engine slow down, when I step on the gas again, at about 1500 RPM the rattle comes in again and continues to 3000 RPM.

See attached videos, the first one is outside the car so you can easily hear the rattle, the second one is inside showing RPMs but in this case the engine can't be heard so well.

You can see on the dashboard the engine is hot, or to be more exact, at normal operating temperature. The rattle sound does not get worse when the engine is cold, and there is no rattling when starting the engine, only between the above mentioned RPM's - or at least I can only hear it in this range.

Please anybody can confirm if this is piston slap? My mechanic insists it is.

Another possible cause for this rattling might be that the cats are not in a good shape; I had P0420 and P0430 (left and right cat efficiency not OK; the previous owner had them too because I could see he cleared them 300 miles ago before I bought the car) so first I'll go and have them checked: if the cats exist at all. The smell coming from the exhaust is quite bad, I'd say it's like the smoke of an old car without a cat, but my mechanic says it's like the car's burning oil.

I'll also drive the car for some hundred miles and check if it's consuming oil.

But until then, maybe somebody can tell now if it's piston slap or not.

Outside, loud, listen to this first and turn up the volume for the next one:

Inside, silent, be sure to turn down the volume if you switch back to the outside vid:

Thanks for everybody for reading ;)
 
It sounds more like a loose heat shield or bracket on the exhaust. You could take the video with the bonnet open and have the mike close to the engine to give a better idea where the sound is coming from. I really do not think this is an engine noise.
 
Thanks, Denis! I took the car to another mechanic and he said it was rod knock. I can make a better video when rain stops (I'm not in England but it's been raining since Saturday).

So now I'm confident that the engine has to be disassembled and then I'll know for sure (3 days' labor, which only costs $500 here).

I bought the car from a Russian guy and he must have omitted oil changes and it killed something in the engine; oil was black but there were no metal chips; he must have put something like Kleen-Flo | Products - Oil Treatment into the engine to silence the rattling (and to hide the smoke) temporarily.

I'll post back when the engine is disassembled (beginning of December).
 
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That sucks about the engine. If possible, try to get a few pics of the engine when is opened up, especially any damaged components. That is an amazing price for 3 days labour. Hopefully the problem is relatively minor.

Best of Luck
 
So it took some time but now the engine has been replaced. I bought another car with a burned out dashboard but with an engine that has only 12.000 miles in it.
The whole thing (another FX50 + shipping + labor) costed about $13,000 and took about a month's labor net.

Now the engine run as smooths as a new one (no wonder) and I'm trying to sell the other car.
 
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