help my engine is making a lot of noise!
 

i recently bought a volvo 340 dl automatic because i was impressed with the cvt....it only has 57000 on the clock and was running fine for about 2 weeks now all of a sudden the engine is making loads of noise....sounds like its reving its nuts off whenever i go over 15 mph....i first thought that the low gear hold was stuck on but closer inspection revealed that this was not the case......has anyone heard of or come across a simlar thing before any ideas??
please help!

Hi there Spike,

Hopefully someone will be along here shortly with some useful advice but it's probably worth trying the good folks on www.volvo300mania.com too. These Volvo forums are great but there's a different specialist 300 people there - some of us use both forums too.

Pete

There could be a number of things causing the same problem . Once you get up to 50 mph it should change up with the aid of the centrifugal weights in the primary unit and rpm reduce is this the case?

The cases with probability first assuming it was working properly before this fault developed ..
1 . Broken air valve head in Vacuum 4 way valve , There are two rubber valves in this , one at each end , if you dismantle and find one broken it can be superglued back on and you will get another year or two of extra useful service from it ..
2 , Accelerator kickdown switch on cabe faulty ..
3 , brake switch stuck on , on master cylinder .
4, Vacuum pipe seals where the 2 pipes enter the centre of the primary unit drum
5 , Primary unit diaphragm hole
6 Tachometric relay faulty near brake servo
7 , Have you had some welding done ? Melted front to rear vacuum pipes inside inner chassis members ..

This is really a specialist job , if there are any people left who can remember how they work ! A DAF specialist would be a good first stop ..

i dont know what it will do if i take it to 50mph....40 is as high as i have had it since this problem started anything above that and it is screaming its head off ...hard to describe the sound...i would say it dosent sound so much like theres something wrong with it as much as it just sounds like it is going a hell of a lot faster than it is....if you know what i mean....allso i have noticed that since this began too happen i have been unable to start the engine without using the choke...

ahh have a look at vacuum pipes coming from the inlet manifold one could have perished or cracked which would upset the idle of the engine too . Whatever happens to the vacuum overdrive upchange mechanism the revs should go down with mechanical action over 50 mph ...

hi there

are you anywhere near manchester? I've just met a chap who used to work for Daf and then for volvo and used to train volvo dealers how to service Daf vehicles. Im sure he'll be happy to help!

alternatively, there are some CVT experts on volvo300mania.com but most of those guys frequent these forums too.

Clan, you're based at a volvo dealer so you're in the CVT expert team too!

Wasn't it the case that the drive band was only good for about 20000 miles at the most and needed to be replaced regularly. And as it did wear out then the engine would scream its head off before the transmission caught up?. Just what I'm trying to remember through the mists of time but I may be completely wrong!.

Yes the belts ( a pair working in tandem to spread the load ) lasted from 25000 to 35000 miles normaly but never affected the gearing , you would get a vibration when they were near the end as chunks of tooth came off , but you have them checked at service and changed before this happened of course when the cracks were more than 60% through ...

hmm...nothing wrong with the vacuum pipes and the ideling of the engime is fine.....just seems to be that whenever i go over 15-20mph it starts making loads of noise and i have just noticed some increase in vibration when this happens.....beats me.....may have to resort to going to a mechanic

okay ...tried talking my 340 dl to a mechanic and without even looking at the car he told me it needs a new gearbox.......not trusting him i checked under the car....and there seems to be a slow leak from the transmission.....does anyone know if this could be the cause of the car sounding too loud?.....if so could someone could let me know how to rectify this that would be much apreciated as i know exactly zilch about cars....

is it a grinding noise as if a bearing has worn, or just noisy due to high engine speed? Its not unusual for the units to be damp ! At least check the oil levels ...
Maybe he doesnt understand them ..( i'd put money on it that he doesnt )

I just replied to your other thread, but this one is more active! The CVT boxes are notoriously tricky when it comes to finding competant mechanics to work on them. If your man has told you you need a new box without even looking at it...he's almost certainly wrong. The number of CVTs which get written off because mechanics do not understand them is frightening.

Given that you have (or had? has it gone away?) the cold-start issue, I strongly suspect that you have a vacuum problem...vacuum being critical to the operation of the CVT box (unlike on a normal car where a vacuum leak simply makes the engine run badly).

cheers

James

there doesnt appear to be any problem with the oil in the gearbox as i suspected earlier....found a mechanic who understands cvt's :) he hasnt seen the car yet but reckons it may be a belt slipping or wrongly alighned...i suspect he will try to tell me it needs new belts....anyone know if this is likley to be expensive?

I refer you to my post#3 above .. but as you say you need more choke since this happened you need to look at the black vacuum hoses coming from the manifold , Even a cracked breather hose would lower the vacuum avaailable but this would also cause a rough , slow idle ...
Yes belts are expensive , i can remember when they were £30 a pair but probably £150 a pair now ..

hi the fault has now been traced to the vacuum valve thingy ...aparently i need a new one....any ideas where i can get one...cant find em anywhere

obviouse
 

Why didn't anyone think abouta vacuum based fault? its so obviouse now i know.

finaly got my hands on a replacement vaccum valve...much better now.....still a noisy lil bugger tho not worried this time tho am certain that this is down to the absence of soundproofing anywhere in the car lol.....was curious if anyone knows.....were they built like this or is it likely someone has stripped it for some unknown reason?

They were fitted with quite a bit of soundproofing at the factory...so I'm not quite sure why it would have been removed.

cheers

James

hmm....god knows......maybee had problem with water getting in in the past or sumfin? ...have heard that can cause people to remove it (would find it hard to beleive tho...not a spot of rust anywhere on the whole car) its a mystery that i will most likely never solve ....... ....so would that prehaps explain why the car seems so noisy whilst driving?

It certainly would. A friend had some welding work done to his floorpans, and they didn't replace the soundproofing. It's a lot noisier than an original 360 at high speed...although at least it's not rusty :)

cheers

James

right ...looks like i will be having to replace the soundproofing.....any idea what is best to use?

You can get off-the-shelf soundproofing from various sources. I imagine it might be something that frost (www.frost.co.uk) do.

cheers

James

Hello,have you tried turning it off?

grrr.... over reving problem is back :S ! ...

ive tested the vacuum valve with wires direct from battery..... its mechanicaly functional,

however following green books ive done some checks and the current to the vacuum valve never moves from the low ratio side to the overdrive side


im thinking that this is a microswitch fault stopping it changing up

at the moment im having to put up with revs around 40000 when traveling at 30mph... not good

ive had belts checked (good)

clutch clearance (good)

4 way vacuum valve seems ok will probably change it to be 100%

microswitch,,,, pretty sure its not working right will change it as soon as i source a replacement..

any ideas what to try next if changing the valve and microswitch makes no difference ??????

tachometric relay by the master cylinder ? you should hear it click when rpm gets near 2000 rpm when you listen under bonnet .

Vacuum leak from the plastic lines which go through the chassis , welding tends to melt them!

The rubber Diaphragm in one side or other of the primary unit drums can perforate .

The seals which seal the rotating union which let air in and out of the drums in the centre of the Primary unit drums can wear .

the vacuum 4 way valve may well click , but the head of the rubber valve inside tends to fall off ! easy to dismantle and bond back with superglue , it gives you another 18 months of life from it ..

Broken diaphragm springs in secondary unit ..

etc etc . there are a LOT of things which can cause your problem ...

bad animals are in your engine

It is actually the vacuum side of the system that you need to check.
Have you already gone through this article yet? http://www.volvo300mania.com/forum-u...hp?f=6&t=12314
It actually describes how to investigate vacuum problems.

Since a couple of years you can get an overhaul kit for the 4 way vacuum valve.
Just have a look at article 3291047-R on http://www.born-built-beauties.eu/ht...n_par.html#CVT