Hi there, 

I’ve just taken my Jag 2.5 V6 out for a drive. And I’ve noticed in certain gears that the engine is making a slight rattling noise but only in certain gears. I could be driving slow and accelerate and no noise. And then when I’m accelerating what feels like a wring I get this rattling noise coming from what sounds like engine. Earlier I noticed the noise When going up a slight incline hill so I accelerated more and the car changed gear and the noise fadded. I noticed it only does it around the 1,500 when the engine is a bit sluggish. If I accelerate at that RPM I can hear a rattle like something loose in the engine. It doesn’t do it when Rev stationary. 

Does anyone have any ideas? I’m anxious and worried about this quite a lot as I suffer from anxiety too! So I’m really stressed 

Update** this morning on cold start I had the oil cap off wondering if it’s engine or gearbox. I think it’s engine because I could hear the noise either from the engine bay or through the oil cap.

 

From your description, i'd say the little ends are shot. Could also be piston slap but that's usually more obvious when it's cold going up a steep hill in a higher gear than you should.

When did it last have an oil/filter change?

Could be pinging  

Just now, sosmotorcyclerecovery said:

Could be pinging  

If its getting worse under load 

5 hours ago, sosmotorcyclerecovery said:

If its getting worse under load 

Not likely, the timing is controlled by the engine management ECU/PCM and therefore shouldn't allow pinking/pre-ignition/detonation/pinging unless the EML/MIL is lit in which case the codes need to be read and the cause investigated.

If it is the little ends as i suggested, it is often worse on cold start (and cold engines shouldn't be revved hard anyway) and either way, worse under load. Piston slap is more of a knock than a rattle too.

On 8/4/2022 at 7:39 AM, LairdScooby said:

Not likely, the timing is controlled by the engine management ECU/PCM and therefore shouldn't allow pinking/pre-ignition/detonation/pinging unless the EML/MIL is lit in which case the codes need to be read and the cause investigated.

If it is the little ends as i suggested, it is often worse on cold start (and cold engines shouldn't be revved hard anyway) and either way, worse under load. Piston slap is more of a knock than a rattle too.

ahh see us old uns are not used these new fangled computer controlled thingys ..lol

Tell me about it.

 

Regards, John