What to do with strange noises and vibrations on the Volvo 960?
This guide has been written as a supplement to an earlier guide at http://reviews.ebay.co.uk/Volvo-960-Automatic_W0QQugidZ10000000003233806 It has been written as response to a number of emails from Ebayers who own, or have experience with Volvo 960s.
1. Squealing noise at start up which disappears after a while
Probably the belt that drives the alternator/power steering/air conditioner pump. Check the belt for 'cracking/splitting' and wear. a 'shiny' belt is probably worn. They are a service item that are supposed to be changed regularly (but never are ..). If it looks 'cracked/split' or excessively shiny - change it. A very easy job. Just force the belt tensioner to one side with a big screwdriver, remove the belt and put on a new one. (The camshaft timing belt is unlikely to make a noise).
Before turning on the engine, lightly smear some oil on the inside of the belt. Switch on .. and see if the squealing noise has disappeared. Be aware - the metal pulleys that the belt goes around can wear. Though to be honest, this is quite rare these days.
The other source of squealing/screaming at start up may be the belt tensioner (at the top of the engine). With the engine running, gently put some fore-and-aft pressure on the tensioner. If the squealing stops, the tensioner is the culprit. Try squirting some WD40 into the housing to lubricate the bearing.
At start up it sounds as though crabs are tapping their claws on a biscuit tin
It sounds like a camshaft problem. Though it could well be a 'lazy tappet/lifter'. The hydraulic tappets/lifters control the valve clearances. They work on oil pressure. With age and mileage they can stick and become lazy ... causing a clicking noise and maybe loss of performance (such as reluctant to pull away in low gear .. though this symptom can also be attributed to a blocked auto gearbox filter/gearbox fault).
Start with the cheapest option. Go to your local car accessory shop and ask for something that will fix sticking/lazy hydraulic tappets. It's an oil additive - just pour it in - but it's not actually an oil. It will free and quieten hydraulic lifers and valve trains. This symptom usually occurs on cars that do short trips. It worked on my wife's 200, 000 mile 960 which had been making 'ticking' and 'clicking' noises.
There's a knocking noise from the engine at start up which soon disappears
A 'deep' or rumbling knock that seems to come from the bottom of the engine at start up .. may well be the big end bearings.
Overnight, oil drains from the engine back into the sump. At start up there is a 'gap' between the )worn) big end bearings and the crankshaft. The piston - via the big end bearings - 'bounces' on the crankshaft, causing the deep rumble/knocking noise until the oil is pumped into the 'gap' and quitens things down. However, this is symptomatic of a more serious problem that should be dealt with. Expensive ... Starship mileage cars andcars that have not had regular oil changes can exhibit this problem.
Identify where the clicking (top end) or 'rumble'/knock - bottom end .. is actually coming from.
My car vibrates but the tracking and wheel balancing is ok
Put the car into gear. Lean underneath and try turning the propshaft in a clockwise/anti clockwise direction. There should be almost no play. If you can move the propshaft and feel it 'jerk' slightly ... it may be that the bolts need tightening, or, more than likely, the 'knuckle' in the propshaft has worn.
A worn knuckle (or CV joint..) in a propshaft can cause severe vibrations .. enough to rattle your teeth at times. The whole car vibrates as does the steering wheel. If replacing parts yourself, eithr buy a 2ndhand propshaft or take the original along to a workshop to have a replacement 'knuckle' fitted. (or look in acar mag/phone directory for 'prop shaft services')
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