Hi Guys, I have a 2002 V40 with a B4184s2 Engine, I have been plagued for several weeks by an intermittant chattering noise coming from the top of the engin, the car even went through its MOT and the garage mechanic didn't know what the noise was, but he said it didn't sound like an "engine" noise. Today armed with socket set, tool box and several cups of tea I set to work and traced the racket to what appears to be some kind of auxillary oil pump activated by a solenoid on the top left of the front camshaft.

My workshop manual doesn't cover this engine. Does anyone know what this device actually is? and anyone had a similar problem? and of course best place to get a replacement?

By the way, I have recently replaced a rear coil spring and took photographs if anyome would like to a description with photo's I'll put them on my website... Just let me know.......

Update......... I've discovered that this "thingy" is a Variable Valve Timing solenoid, and this particular fault is associated with the camshaft pulley which I'm told has some vernier scale mechanism for varying the valve timing. Some people say it's the pulley thats rattling and some the solenoid. Everyone seems to agree that this problem is caused by infrequent oil changes. Except that I change my oil every 5K miles, and always have. I've priced up both parts, the solenoid is £95 and the pulley £150, both plus the VAT of course, so my next problem, is how do I know which bit isn't working? I've taken the solenoid to bits, there's no wear and all the small oil holes are free from gunk, when I apply battery voltage across the terminals the solenoid operates as it should, and I don't want to spend over £100 if the original part is ok. Any further testing procedures I can do? Now for the pulley, I can't find a detailed description anywhere, or exactly what it does, does anyone know how to check it for wear? Of do I just pull the electrical connector off the solenoid and do without the VVT, but have a peacefull quiet engine again?

I have had a similar problem on my 2004 Volvo S40. Volvo dealers had a look at it and said it would cost £700 to repair (I'm no mechanic). They also said it was probably an oil issue - they had only seen it happen on Volvos that had not been serviced with them, possibly because of using poor quality oil. (I had the first out-of-warranty service carried out by a reputable local garage in May 08 - when I told the head mechanic there what Volvo had said about the service and oil issue, he said he was talking rubbish, since they only use the best synthetic oil.)

Anyway, he quoted me £480 insted of £700, and had the car in for 2 days. He phoned me yesterday to tell me the car was losing compression after the repair. They've put an inspection device into the engine, and two of the valves appear to be hitting the pistons. He's got to open up the engine again to investigate the problem. He's now estimating £850 for the repair.

He couldn't understand why an four year old engine with only 29000 miles on the clock would have this problem. Sorry I can't help with the technicalities, but I was interested to hear of someone else having the same problem. H0pe you can sort yours out more cheaply than mine!

Hello Peatones,

thanks for your reply, this problem seems to be more common than I thought, I had a word with a Volvo mechanic who said that VVT on the inlet cam should not be operating when the engine is idling, hence the chattering noise, and that pulling the electrical connector off the solenoid would not do the engine any harm at all, there just wouldn't be any VVT. Fuel consumption may be a little higher and there may be a slight drop in power. With this in mind I ran the car yesterday for more than 60 miles and I never noticed any difference, other than peace, perfect peace!

He also suggested that as my car has done almost 60K miles that I should consider replacing the cam belt and at the same time remove the camshaft pulley for assessment and possible replacement. This seems like a reasonable plan, even though the belt is £50 and the pulley is £150. I guess I'll just have to bite the bullet, at least I will know which part definitely needs replacing. According to my Volvo mechanic friend, replacement of the pulley is simple, "just unbolt it and put a new one on" The Haynes manual doesn't describe the procedure quite like that but I'm a competent mechanic and an optimist!

As for your little twist on this problem, the camshaft pulley is not keyed or fixed, other than by tightening the fixing bolts, getting the timing right I have read can be difficult if you're not careful. Get it wrong and yes I suppose the valves could hit the pistons, but when this happens the resulting damage is usually catastrophic. I'd be interested to know what the "inspection device" is, never heard of that one before. I think I may take step by step photographs, and post them here for anyone else who experiences VVT clatter, at the very least if I **** it up you guys will know what not to do.

The car was running fine even with the VVT chatter (only happening when idling with engine warmed up). Do you reckon the subsequent valve / piston issue is likely to have been caused by the garage not getting the timing right after replacing the VVT?

Well, if the cam is opening the valves too late or too soon then there is likely to be contact with the top of the pistons...... And the engine would run badly. Think about it logically, if your engine was behaving exactly the same as mine, i.e. noisy at idle only when the engine is warmed up, but no other problems, and running fine, apart from the noise, mess about with the cam pulley and now the valves are hitting the pistons? Then I would suspect that the garage has not put things back together properly. Don't get me wrong I'm not an expert on VVT and I haven't taken my engine to bits yet, so I'm basing my comments on other engines I've worked on, but I think that the possibility exists that they got it wrong.

But.... If a valve hits a piston, usually something bends or breaks and the engine stops running very quickly, as it does with a cam belt failure, and I've had a fair bit of experience with cam belt or chain failure. If I were you, I would be tempted to err on the side of caution and get another opinion from another garage

Another update...... The car has now done 200 miles with the VVT deactivated, engine smoothness has been restored to 'like new'. The deterioration of either solenoid or pulley must have been so gradual that I didn't notice any difference when the car was running. Of course the engine management light stays illuminated, but I'm happy to put up with that for the time being, and I have noticed a drop in power, but barely.

Curiously, my fuel consumption has gone from 33.6 mpg to 34.3.

When I replace the cam belt and inspect the pulley, I'll let you know if it needs replacing and photograph the procedure. I hope I've been of some help to anyone else with the same problem.

An update on my problem, which gets worse by the day!!. Finally got the car back on Saturday. No VVT chatter- engine seems to run smoothly and quietly, except....when I get to about 2500 revs and put my foot down in 3rd/4th or 5th gear, the enogine revs go up, but no power! Starting on a hill in first, it struggles. Took it straight back to the garage. He says it looks like the clutch has gone!! Another £400 to replace!

I'm no mechanic, but is there any possibility that the clutch problem could have been caused by their dismantling and rebuilding of the engine after the VVT / compression problems?