Could even be a bit of trim loose on outside of Motor Home.
Technical 2.8 2001 whistle
- Thread starter Adie1023
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Technical 2.8 2001 whistle
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Adie1023
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Still got this issue had it in the garage they said they did a smoke test but could not find anything leaking could hear the noise but not find it what a bugger was there 3 days and the kept looking at different times.
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Adie1023
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Hi yes it comes on only in 3rd 4th and 5th gear at 2100 revs till 2500 and if you lift accelerator slightly it disappears even at them revs and if you let the engine do the work but as soon as touch the accelerator a bit it comes back. Not tried heater yet will do thanks.I agree, when in vehicle you can test for many things, unlike video.
For instance if air vent noise does putting heating onto recycle (not external air source) turn heater fan off, re brakes does a very light brake pedal pressure whilst still driving with accelerator and engine noise does sound change, does noise come on at different engine rpms when in different gears, does fractionally relaxing accelerator when noise apparent change/stop the noise whilst road speed the same, will noise come on at same speed when coasting down hill?
There are so many ways that noises can alter, so many tests required.
Many years ago we had brand new Mazdas making a noise when slight turn of steering, we located the source as the factory pressed stainless steel wheel trims with vents in them.
From what you are saying I would still go back to the turbo side/hoses/intercooler leaks etc.
Just to test that theory is it possible to disable the turbo side?
Not sure if easy on your age of vehicle as may not have an easily accessible vacuum pipe to turbo actuator, instead you may have to simply remove the turbo intercooler hose with big jubilee clip, this may make a blowing noise and will result in loss of power whilst testing, but may affect the noise that you have been experiencing and so point in a direction of diagnosis.
Normally I would have expected a garage smoke test to show if any leak there.
Another test like that is using blanks and a pressure test to the pipes from turbo through intercooler and ontowards the inlet manifold.
I did this on a 1.6 Fiat Doblo and found some hose clips that were not doing their job, the test is around 20 psi.
Given that it is happening when engine working hard , so under boost conditions and less dependant on road speed my thoughts are in that area.
Have you carefully checked all pipes and intercooler after the turbo for even slight signs of oil stains as it may point to a suspect area. Oil is not meant to be there , but often breathers from the engione allow a mist of oil through the turbo.
Hello @Adie1023
The video you post sounds like either an oscillation vibration or a dry bearing on the cusp of failure, not the whistle of gases escaping from an insecure pipe, aperture or component.
This fits with it being dependant on engine rpm, engine and transmission load according to specific gears selected along with road speed.
For the dry bearing scenario, things to try would be a very short run with drive belts removed so that components such as alternator/water pump/ AC pump/power steering pump are static.
Also try resting on the clutch pedal in the unlikely scenario it’s the clutch release bearing.
Personally I think it sounds like oscillation vibration, ie two components rubbing very fast together, like a finger on a wine glass rim - if you listen carefully you can hear the oscillation in the noise as it peaks and troughs.
It may be worth having a look for rub marks on exhaust pipes & shields, engine pipework, brake back plates, components under the dash that have come loose. Are your engine mounts in good order or is the engine shifting at that road speed and engine rpm? Could it be under the wheel arch? Are your wheels properly balanced? Move wheels around to eliminate an out of round tyre causing issues.
Are any body panels loose and rubbing together at that speed.
I’ve had my own experience with noise travelling on a Volvo XC70 - an almighty creaking noise with every uneven surface that sound like a suspension component - for weeks I chased it with silicone lube to find it was the headlight levelling sensor on which the pivot joint attached to the suspension was virtually seized but the noise was travelling through the body and emanating from the lower bulkhead.
It’s a shame you’re not nearer, I’d have a look with you, there’s nothing worse than a noise you can’t identify. Very distracting.
The video you post sounds like either an oscillation vibration or a dry bearing on the cusp of failure, not the whistle of gases escaping from an insecure pipe, aperture or component.
This fits with it being dependant on engine rpm, engine and transmission load according to specific gears selected along with road speed.
For the dry bearing scenario, things to try would be a very short run with drive belts removed so that components such as alternator/water pump/ AC pump/power steering pump are static.
Also try resting on the clutch pedal in the unlikely scenario it’s the clutch release bearing.
Personally I think it sounds like oscillation vibration, ie two components rubbing very fast together, like a finger on a wine glass rim - if you listen carefully you can hear the oscillation in the noise as it peaks and troughs.
It may be worth having a look for rub marks on exhaust pipes & shields, engine pipework, brake back plates, components under the dash that have come loose. Are your engine mounts in good order or is the engine shifting at that road speed and engine rpm? Could it be under the wheel arch? Are your wheels properly balanced? Move wheels around to eliminate an out of round tyre causing issues.
Are any body panels loose and rubbing together at that speed.
I’ve had my own experience with noise travelling on a Volvo XC70 - an almighty creaking noise with every uneven surface that sound like a suspension component - for weeks I chased it with silicone lube to find it was the headlight levelling sensor on which the pivot joint attached to the suspension was virtually seized but the noise was travelling through the body and emanating from the lower bulkhead.
It’s a shame you’re not nearer, I’d have a look with you, there’s nothing worse than a noise you can’t identify. Very distracting.
Noises can be subjective, often a different set of ears can listen and pin point it straight a way.
Pity garage unable.
Pity garage unable.
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Adie1023
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Where are you based ?
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Adie1023
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Thanks will have a look but my mechanical knowledge not the best.
J29 ish of the M1
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Adie1023
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Not too bad on a nice day for a drive out can pay for your time too
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Adie1023
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An hour away roughly
Wouldn’t need payment and you’d be more than welcome to drop by although my availability is limited each month due to work and family commitments….
Yes, they are definitely subjective.Noises can be subjective, often a different set of ears can listen and pin point it straight a way.
Pity garage unable.
If we go back to Adie’s first request for help, the sound was described as a whistle, and whilst this is no criticism of that description, that is where the quest inadvertently went down a rabbit hole with the subsequent inspection by the garage mostly likely following the same thought pattern and coming to a dead end because in my opinion based on the video recording, there isn’t a whistle….but as you say it’s a pity the garage weren’t able to consider any other options.
Don’t do yourself an injustice, subconsciously you have already begun your diagnostic career.
Think about it, you’ve identified that the noise is engine rpm, gear selection and road speed dependent.
Next step is to identify what components are affected by these specific conditions.
A consideration is drive train - is there a driveshaft support bearing on the offside like what I’ve circled in the attached image?
If this is failing or the driveshaft joints are failing causing stress on the bearing all manner of noises could present themselves. You could jack the vehicle up and grab the shaft to see if there is excessive play.
…..but so you don’t end up down that rabbit hole remember there are other components that can be affected such as, is the front shocker strut top mount worn and oscillating at that speed and perhaps that’s why the noise appears to be emanating from the dash vent?
There’s two items you can add to the diagnostic consideration list….
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Adie1023
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Taped phone in engine bay first bit of noise from drivers side phone taped to battery second is with phone taped to airborne.
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Adie1023
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Meant Airbox
The noise exhibited in your original clip does not appear to be present in those locations, albeit cam train noise is the bulk of the audio.
Perhaps a cheap wireless microphone could be deployed in different locations - the below is only a tenner on a well known vendors site named after a famous rain forest…
It is my lowly opinion that you need to focus your attention away from the main engine bay.
Is the off-side strut top accessible with a lower dash panel removed?
Whilst I wouldn't dream of discounting the suggestion of drive shaft support bearing as one thing I have learnt over the years is with all the parts of a motor vehicle there can be even more possible solutions.
The drive shaft bearings I have been involved with when noisey, have increased with road speed regardless of which gear or loading of the engine.Also I agree the original sound recording appears different to the latest one.