High Pitched Whine That Increases With Engine Speed

[stuzbot]

OK. Before you point out the obvious, I know it's almost impossible to describe a sound and I did try and get a recording of this on my phone, but the damned thing didn't pick anything up. I'll try again and post a recording here when I get it. In the meantime, I'm just looking for some possibilities:

Last week I was driving the van home from a few miles away when, after about 10 - 15 mins driving, I suddenly heard a high pitched kind of whining sound coming from the rear. The sound wasn't overly loud, but loud enough to hear over the [already quite noisy engine] and loud enough for me to have a "WTF?!" moment.

When I let up on the accelerator, the whine stopped and then started again when I accelerated again. This it continued to do for the rest of the [thankfully short] drive home.

Yesterday I was going to do an oil change. So I took the van out again fro a short 10 minute spin to warm up the oil [the first time I'd driven it since that incident]. After about 5 minutes, the whining noise started again. As the noise only happens when accelerating, it's going to be a bugger to diagnose, as I can't listen for it with the vehicle stationary and because *everything* is behind you in these vans, I can't even tell whether it's coming from engine, gearbox, or wheels ,while I'm driving along.

One of my initial thoughts was it might be turbo whine. This is the first engine with a turbo I've ever driven, so I'm not overly familiar with them. But I've never noticed any noise form the turbo before, so that seems unlikely unless it's suddenly making more noise because it's about to blow up.

So, any thoughts on what else I should add to my list of possibilities that it might be? And, any tips on diagnosing any of the potential candidates?

Like I said, I'll try and get out in it in the next few days and see if I can get a decent recording. But, in the mean time, fire away with suggestions.

Oh. About the same time this was happening, I was having a few problems getting into second gear. One change it would work fine, the next the gearstick would just not move back past neutral at all and I'd have to wiggle round a bit a couple of times, before eventually finding 2nd, when it would go in easy as pie, as if nothing had happened.

I don't know whether that's related to the noise or not. I've recently overhauled the entire gear linkage including new selector fork plastic tips, which are still a bit 'square edged', not having rounded off with wear yet. So the gear change isn't the smoothest at the best of times. But I've always had the feeling that the 'notchiness' was at the front, in the area of the selector fork & gate, rather than in the box itself. I thought I'd throw that into the mix though, just on the off-chance it could be related to the whining noise.
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1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
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[E1]

May be totally unrelated, but if it completely stops when dumping the clutch, that's just what ours did before rebuilding our transmission.
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‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[jimf909]

E1, did yours whine in every gear and was a there a suggestion from your rebuilder on the cause of the whine after the rebuild?

I ask because I'm beginning to hear a whine in second gear only.

Thanks.
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- Jim

[E1]

Jim, 3rd and 4th only in our case. Not bad when cold, more after, a ton more when heat-synched, downright "pull over" if heat-synched and a hot day.

The rebuilder told us he'd never seen a tranny like ours that still functioned. But he refunded our core anyway. I think it was either a slider or a bearing, sorry to not be sure.

We first heard it when closely-paralleling a concrete construction wall on the Blue Ridge (window down), was pretty loud by Savannah, unnervingly-louder by Miami, added oil in Sarasota, still more noise by Biloxi, pulled over with fear over sounds of an immediate rebuild in Galveston, had a beer, carried on to Parker with a side-trip to Buses by the Bridge (seemingly only to back the van into a pickup, knowledgable party Ssshhh!), and on to San Diego and Santa Cruz, to install an awaiting, rebuilt trans by Arizona Transaxle.

It'll tell you when you're asking too much, and then until you really are. In our case it went like 5,000 miles and didn't implode. If happening again, I'd have put 85/140 synthetic to increase the odds of seeing the Pacific.
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‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[Sodo]

In your transmission there are two shafts that spin on bearings.

1) whenever your clutch is out, the mainshaft spins at engine rpm. Even in Neutral. Whenever your foot is OFF the clutch, the mainshaft is spinning the RPM that’s indicated on your tachometer.

2) the other shaft is the pinion shaft. It spins at wheel speed. Actually 4.86 times your wheel speed. But anyway its at zero RPM when you’re stopped, and it goes to about 3000 rpm at 70 mph.

There are several items on the engine that spin with engine RPM. The alternator, the power steering pump, A/C pump.

And theres the turbo too, which the RPM is dependent upon exhaust pressure. There’s more pressure when the engine is working hard, and the turbo will spin faster.

Well anyway theres some candidates for whines, I hope this helps. It could be your checkbook whining....
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'90 Westy EJ25, 2Peloquins, 3knobs, pressure-oiled GT mainshaft, filtered, cooled gearbox
'87 Tintop w 47k 53k, '12 SmallCar EJ25, cooled filtered gearbox
....KTMs, GasGas, SPOT mtb

[DuncanS]

I think you have worn gears with back lash. The fact that you only hear the noise when you're on the accelerator tells me the problem occurs under load. I think you need a tranny rebuild and it sounds like your 3/4 slider is failing also. My tranny makes the whining sound in all gears and has all the same symptoms yours has. Figure the PO at some point ran the tranny a bit dry. It sounds like a Provost bus. Just gonna keep going until it doesn't.

[Waldi]

Could be your turbo.
Starts ho whine high when pressure builds up on accelarating.

Edit:
you dont have the whine if you rev your engine without driving, as you have no trubo pressure (just a little) without load.

[stuzbot]

Thanks for the replies, folks. That gives me plenty to think about.

Unfortunately there seems to be a bit of a consensus that it's a transmission problem. I'll be pretty gutted, if that's the case.

As mentioned in various other threads, I had a problem after I collected the van with it jumping out of fourth gear around 50mph, after I'd been driving it home for about an hour on the motorway. Also the gear-change was all over the place, so much so that it would go into 3rd instead of 1st most of the time and reverse was almost impossible to find.

I've since stripped down and replaced all the moving linkage parts from the gearstick right back to the gearbox, as well as flushing and replacing the gearbox oil [minimal shrapnel on the drain plug] and had taken it for a brief spin up the motorway a week or so ago, when I had it up to 70, without any jumping out of gear nonsense. Also gear-change had been a lot more precise.

So I had been beginning to dare to hope that the transmission was going to be OK after all and I had dodged a bullet on that front. Now I'm starting to get that sinking feeling again. If it does turn out to be a tranny-rebuild level problem than I'll definitely have to sell the van as that would put getting it roadworthy way over my skill level and budget. So here's hoping for a miracle!

I''m a bit snowed under with other work at the moment, so I'll likely not be able to get a recording of the mystery sound until the weekend. But I'll keep youse posted.
_________________
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Click to view image
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1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
*****************************

[E1]

Full rebuilds start at just over a thousand bucks. Make sure it has enough and/or good, clean oil before doing anything rash!
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[stuzbot]

[E1]

If you're thinking of unloading a Syncro for want of a tranny, start the bidding here.
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[jberger]

[E1]

A thought on the theory of the whine being the turbo...

When our tranny whined, if I pushed in the clutch pedal and revved it, there was no whine.

If yours still does, with the clutch in and in time with the engine, then it may not be the tranny, and could be the turbo -- and an excuse for you to ship beer here:
Samba Members
111 Beverage Avenue
Dizzyville, USA
66666
_________________
‘84 Westy, 2.1L with Digijet, 5.43 R+P, GT Gears
"Adding power makes you faster on the straights.
Subtracting weight makes you faster everywhere."
— Colin Chapman

[snowsyncro]

[Waldi]

If the pinion bearing is worn out you should also hear a whine while deselarating or engine breaking driving downhill.

If the whine comes from the turbo, ofc it will also go away if you press the cluch.
How about to check your tube between turbo and inlet manifold and your exhaust system ?

If i could hear "your" whine i could tell you for sure if it comes from turbo or box

Why i come first to the turbo ? Bcs of "high pitched" whine.

[DuncanS]

My "whine" is like snow tires on smooth pavement whine. But more, it sounds exactly the way our '35 Ford Phaeton sounds in non synchromesh gear when starting off. Or reverse used to sound in the old days, or my '57 23 window sounded in first--in other words gear noise.
And mine only occurs under load. If I let up on the gas, it stops. So I need to have someone tell me is isn't gear backlash and what I might do other than a complete rebuild. I have a '91 with the semi decent 3/4 slider and would want to either keep it or upgrade to some of the super sliders guys have posted about. I remember a thread called "84 Vanagon stuck in gear" which had really good information.

[stuzbot]

Well, ain't that fecking typical!

I roped in the missus to help with a bit of sound recording today. So, off we set with her in the back of the van leaning over the engine compartment, ready to record the whining sound, when it started....

And, of course, the sound didn't manifest itself. I must have driven for about 45 mins, up and down through all the gears, giving it some really high revs in the lower gears and not a bloody whine to be heard.

Since reporting the whine issue originally, I've done an engine flush and oil & filter change. I found that the oil in the engine seemed to be about a litre short of what the manual says should be in there, even though it looked fine on the dipstick. I've now filled it with the proper 4,5 litres and it's showing slightly over the max point on the dipstick, which makes me wonder if the dipstick is not original.

I've also injected some CV grease into the rear CV joint on the driver's side as, when the whine happened originally, I thought it sounded like it was coming from that side of the van, at the rear. Although chances are that was probably just because I was sitting in that side of the van with the window open, so any sound would seem to be louder there.

Anyway, I thought I'd give the CVs in that corner a bit of a grease 'just in case' although subsequent reading suggests a dry CV joint would be more likely to clunk or grind than whine.

Anyway, I can't really see how either of those to things would have made a difference, given the consensus seemed to be that it was likely a transmission or turbo issue. But I thought it best to mention them for reasons of "things which are not now as they were then" elimination.

Of course, although I was relieved the whine didn't happen today, it's not really left me any the wiser. Is the problem [whatever it was] fixed? or will it rear it's ugly head again when some random alignment of the galaxies comes into configuration? Who knows? I think I'll just have to keep taking him out for a drive round every day and see what happens.

The annoying thing with all this uncertainty is that I'm going to visit a mate late next week who has a farm. So I was hoping to take the Syncro and have a play with the 4WD in one of his fields. But he lives about 120 miles away, so I'm a bit loathe to risk that long a journey with the possibility of a scary "this sounds like some kind of a bearing somewhere is about to seize" problem raising its ugly head when I'm a long way from home.
_________________
*****************************
Click to view image
*****************************
1992 VW LT35 2,4D [SOLD]
1993 VW LT35 2,4D [SOLD]
1992 VW T3 1,6TD Syncro [SOLD]
*****************************

[Ahwahnee]

You might try again with the headlights on. In fact, have them on for about 15 minutes before starting the engine.

[stuzbot]

[Pcforno]

My weddle fourth gear has a distinctive whine. Only 4th, no other gear