Sounds Like Dry Alternator But Isnt!

[Sher]

I been away caravaning for some months since obtaining my new 1.9 TDi 115 Ghia last October.

One morning starting from cold 2C I trundled through the campsite at tickover and just as I reached the exit I started to hear a noise I was familiar with in my early 20's, or so I thought, dry alternator bearings. I revved the engine slightly but the sqeal did not rise in frequency or go away.

I proceeded to drive away briskly, it did not rise in frequency, so it wasn't a wheel bearing and the noise disappeared after some seconds more as obviously lube arrived somewhere.

Disconcerting on a new car.

This happened a couple of times more before I realised that idling the vehicle along the roadways through the campsite was the cause and since then I have always blipped the accelerator to raise engine revs after starting up in the morning.

The noise came from the front right hand side when facing the open bonnet. Perhaps behind the engine itself.

I have suspisions that it may have been a slow running turbo as another camper speculated to me but have had no luck with the local Ford dealer.

Anyone anything similar?

[Guest martinkerr]

sounds like the secondary air pump, when cold (usually in winter time) it runs between 30 sec and 3 min to warm up the cat, the cat dosent work right when its cold

 

It is front roght od the engine, to the left of the battery (on my gal)

 

It is a normal part of the car and unfortunatly quite noisy

 

Martin

[Sher]

Can't be secondary heater, as bad luck would have it, it started the noise again today on my street when it was 15C.

Does this air pump run at Constant speed? Do you know if raising the engine revs does away with the need for this air pump?

Local Ford Dealer wants to keep it overnight.

I am not so happy with them at the moment. At 2 nd service inside warranty they used 5W-30's oil. Book says min 5W-40's. I'm going to get them to change it next week when it goes back to replace a noisy driver's door seal. Would normally have done it myself but inside Warranty feel nervous about it at Moment.

I prefer fully synthetic 5W-40's. I've done 18000 miles in 9 months pulling a Caravan 5000miles and in some low(-2C) and high temps(39C)

This car has to last me!! Milage averagig 25000/year but is reducing now. I expect only 4000 in the next 3 months.

[Ivor_E_Tower]

If book says min 5W40 and they have used 5W30, they have used better than book, so don't complain! The lower the second number, the more viscous the oil is at high temperatures - i.e. the easier it flows.

Can't help you on the noise though; may be best to leave the car with dealer overnight, especially as they've offered...

[Sher]

As regards Oils I can see this is going to get technical. (Viscous=thicker?)

All oils get thinner as they get hotter, even multigrades.

They were introduced to prevent the oil from becoming too thin at higher temperatures and to maintain at least Boundary layer lubrication between sliding metal parts under more extreme conditions.

A straight 5's oil will get thinner as the temp rises.(Maybe too thin when hot.)

A straight 30's oil will get thinner as the temp rises.

A straight 40's oil will get thinner as the temp rises.(Too thick when cold)

But the 40's will always be slightly thicker at higher temps.

The problem with the straight 40's oil is that is also thicker when cold and lubrication is a problem when starting.

Intro Multigrade 5W-30's.

Thin in (Winter) or when oil is cold. When hot(100C ?) has better lube properties of the 30's oil.

5W-40's Thin when cold has even better lube properties of the 40's oil when hot.

Mineral oils achieve this by better refining and use of additives but degrade with use.

Fully synthetic oils are synthesised from a purer material posssibly Natural Gas to give a controlled base oil which resists degradation better and should be able to be left in the car for extended miles ( + additives of course)

I swear by straight synthetics.

[dulux72]

This may be a red herring but our sharan sometimes suffers from a similar noise which I have tracked to the right hand cooling fan. The bearing must be wearing and it squeals like you have described. Revving the engine makes no difference to the pitch. A quick spray with WD40 soon shuts it up :)

[Guest martinkerr]

if it is the 2nd air pump it wont be affected by the revs, its electric

 

martin

[Sher]

It may be that. I would presume that it runs at constant speed. But I wonder if the actual pump mechanism takes lubrication from the crankcase? Will try and locate and view.

Noise continues to happen in a sporadic manner, however, 2 days ago 250 yds with light throttle.Stopped at lights and I could here it as the noise level rose with lack of lub. Not able to raise bonnet at that moment as I drove away noise level went down and never came back.

At agent at service over a week ago they must have left it running for nearly 2 hrs but could not hear it. Only from cold. They also changed the 5w-30's oil for my own 5W-40's fully synthetic Shell Super Helix (28 Euro's)