Engine Noise at 3500RPM

[CMF_Toppersutz]

My 1999 1.3 SI as developed a strange engine noise at 3500 RPM. Under load and in any gear at 3500RPM the engine produces a “war, war, war” sound. Going beyond 3500RPM the noise stops. Idling at 3500RPM does not produce the sound.

Does this sound familiar to anybody? Can anybody suggest an explanation and cure?

Thanks – Toppersutz.

 

[CMF_Yom]

Visiting a mechanic will be a better idea than asking the forum. Unless you can get a clear recording of the sound there's not much we can do unless someone else thinks they may have had the same noise.

I mean, it could be just a resonating frequency through the car body - mine gets all sorts of weird noises through the cabin at various RPM (i've got a shagged engine mount somewhere - gearstick moves a bloody inch when i take off!!) and the fact that it doesnt happen past 3500rpm and I'm assuming that there are no other strange feelings through the cabin, pedals or steering wheel tells me that its probably not a serious issue.

Good luck with it.

 

[CMF_Toppersutz]

Thanks for the reply Yorn

My local mechanic is my mate – but he’s no idea!

I’ll try and get a recording of it – but not sure how just yet!

I’ve eliminated all other noises (lots from the exhaust shielding!) leaving just this one. No other issues through the cabin, steering or pedals.

 

[CMF_kneival]

Could it be a bearing in the water pump or alternator going?

A good way to tell where the noise is coming from is to get a pole and put it on an item then put your ear on the other end.

 

[CMF_Toppersutz]

The big problem here is that it only happens at 3500RPM under load – not while idling – so recording the sound or listen through a pole is going to be difficult – 3500RPM in 5th is around 140KPH!

 

[CMF_Yom]

You sure?

Memory says its about 120/130km/hr in my car.

 

[CMF_micra-man]

Either way it's a bit fast to be hanging off the front bumper with your head under an open bonnet!

 

[CMF_Toppersutz]

Sorry Yorn – you’re probably right – it’s about 78 MPH – but I wanted to translate it into KPH. Either way, still too fast to be hanging from the bumper.

I was wondering if it might be some sort of standing (or almost standing) wave in one of the timing chains? What do you think?

Regards - Toppersutz