Hi,

For awhile my 72 kombi has been making some strange noises.

Firstly, under acceleration there is a high pitched past paced rattling type sound coming from the rear somewhere, almost like a mosquito on speed.

Secondly, there is a sort of slower but more constant rattle coming from the front of the bus somewhere. It also happens only under acceleration. I have looked everywhere for loose stuff but can’t find a thing!

Anyone have any ideas?

pinging????

does a 72 have an internal engine acess cover??

get some one to sit in the back while you drive and try and track it down

Does it only do it under load or can you do it when you a reving it???

If under load only i suggest it is pinging

wesley check that the engine fan hasnt sucked some paper or wrag/leaves etc as this gives the impression with the mozzy on speed? a thought to check out.cheers dsk steve

...also consider the shift rod rattling...usually heard from up the front - can usually be stopped (temporarily) by placing pressure on the shifter with your hand and pushing it left or right - shouldn't need a lot of pressure though.

My Brothers splitty used to do this, and my parents 411 does it all the time (bloody annoying too :bounce )

Rattle from back does sound like pinging - try using premium unleaded (if you are not already) and see if this reduces the noise from the back...

Very hard to diagnose noises over the internet!

R

Thanks for the reply's fellas, I don't believe it's pinging, as it happens when the revs are high, in fact it seems to disappear when I am actually going up a hill!

Doesn't appear there is anything stuck in the fan, but I will have a closer look.

The rattling coming from the front of the vehicle is a complete mystery still. That is happens at high revs is also confusing, could it be something eletrical? As I think I only noticed it after my stereo was installed?

Cheers

I am using premium unleaded always, although I might try an additive to see if it helps.

The shift rod coupling was replaced just recently, but I will try that trick next time I hear it.

Yes, the internet is certainly not the best medium for diagnosing noises! Maybe I will get a recording...

Speedo cable rattling :thumb

Ok I think the noise from the front is to do with the shift coupling thing, as when i move the stick around while in fourth, the noise stops...

WOOHOO

As for the noise from the rear, I'm still stumped...

Thanks for the help fellas..

simple solution - turn the radio up and the noise will magically go away!

Has anyone found definitive fix for the gear shift rattle other that just putting a hand on it. It gets tiring after a while....

New bushes are the usual fix

Hey come along to some event sometime, I'm sure someone will be able to help. I'm in Melb, south east area near chaddy, you 'round here? My bus can be made to ping, but it's not nice to do that so I avoid it - but I know what it sounds like.

Good luck dude, Aurel ('74 1800)

good luck with that. hopefully it's only something minor. I'm no stranger to major engine problems unfortunately.

The mozzie noise at high revs or does it pulsate? If it pulsates it could be a leak. like from a head gasket, an inlet manifold or the exhaust.....When was the last time you checked your fanbelt?

Yeah the mozzie noise does not pulsate, it's constant when at high revs, but as soon as I'm off the gas it goes away.. it's starting to worry me a bit..


Aggri1 sounds like a great idea, I'm around the Fitzroy area but my folks live out at Dandy, so I go past chaddy quite regularly. I will U2U u.

EDIT: I will most likely be at the Herbie thing at the Coburg drive-in, not to sure if the management would be happy with me fanging round' the carpark checking for noises.. hehe

[Edited on 3-6-2005 by wezley]

how many ks on the mtr
the cam gear /ring and pinion under load may be the noise as the hardening could have worn off. try molybond additive in your oil

I also know of annoying noise from the spring-loaded carbon button inside the dizzie cap
check that may be worn or the spring could be stretched (although I'm not sure if your dizzie has one.
give it a go

Hope yo find the problem. I'm really interested in this!

My beetle had a whistling noise. It started after I put a new transmission in. Turned out to be normal fan noise. I was sooo used to the horrible grinding noise from the collapsed main bearing. I know it's off topic.

I not sure how many k's are on the motor to be honest. I'm not even sure what distributor I have. I will have a look tonight and take a photo.

I took the bus for a drive the other night in an attempt to record the noise with my phone. It was pretty damn cold here at night in Melbourne and the bus drove great.

The noise for the most part wasn't even there, I notice it mostly above 55mph, but I could hear nothing cruising at 65mph!

The bus was seemed to be running better than I have noticed. For example I was going about 60mph and a large truck was tail gaiting me. (I was in the left hand lane) and I decided to accelerate. I was going up a slight hill on the freeway and the bus pulled away to 75mph leaving the truck in my dust muahahaha.

It all seemed very strange because every time I have taken the bus out prior to this the mosquito noise had been very present....

I will keep you all updated with the progress.

Ok I have found a pic of the engine bay, not sure if you guys can tell what dizzie from the pic?



[Edited on 7-6-2005 by wezley]

Hmmmm.... Ambient temperature related?

Shame you don't have a temperature gauge on the motor...or do you?

Trying to think. usually noises stop as the motor gets warmer, not the other way.

Try to take it for a spin in the warmth (ha!) of day and in the night/early morning. I just want to know if the noise is consistent with temperature.

Keep us posted.

No, I have no temperature gauges..

I'm going on a bit of a cruise down the peninsula this weekend so I will keep you peeps posted about the progress...

Thanks for the help so far, very much appreciated!

maybe a rock or something sitting on the tinware that rattled loose? maybe a loose exhaust mount?

that rusty spring could be creating harmonics with the engine under load.
Harmonics are when 2 or more sound waves clash they create a new sound
-can be horrible.
A beaut vase of my mums started to crack as it was sitting on the radio for months.
We used to have it on the ABC all the time (until then)

Never thought of that. A standing wave in my beetle used to get me at about 57km/h. I had to avoid driving at that speed.

sounds like an early beetle story with the fan harmonics sending drivers to sleep. 36 hp fans were better replaced by 40hp as they had some more blades and less harmonics and whine....

Have you found the problem yet? Hope so.

Karmen, never knew that one. What a scary problem. But I guess there are just some tones that do it to people. There was an old bar fridge at a place I lived that did it to me every time.

might a been the contents of the bottles or cans IN the fridge lol..

sorry fellas I have been away on business this week, I will put my detective hat on once again this weekend in hope of finding the problem.

Interesting post about the harmonics, not sure if this is the case as it did not used to make this noise; however I am not ruling this one out.

As for loose nuts / beer cans etc I'm not sure. The sound is so predictable and constant when I am at high revs that I find it hard to believe it could be a nut or a rock. Surely if this was the case it would cut out or stop at random points? It certainly sounds metallic though.

My initial attempt at recording the sound was a dismal failure, but I am going to borrow some recording apparatus from a mate at work.

Cheers for all the ideas and solutions, they are much appreciated. I will fill you guys in when I find out what the heck is going on.

I will check out the exhaust studs thing, I will have to look at the Bentley to work out excatly what that means.. hehe but thanks for the advice.