Another kv6 cambelt thread

[biffa75]

Been away a little while, taken our 75 off the road for the time being. The rear sill sections have recently been repaired and is now all good once again thanks to my brother.

Having looked through the paperwork.. the timing belts and water pump etc were last done in 2013 at 29k miles. So.. the belts are due.
(Some may say it's okay for a little while longer yet...) However sometimes I have an annoying rattle from cold start that goes away after just a few minutes, couple this with the timing belt being over due by two years now.. I'm wondering if it could be just an idler or tensioner pulley on its way out.
Could be the crankshaft pulley but spraying water on to it, doesn't make any difference.

Anywho.. seeing as its best to just do it anyway, I'm thinking of tackling it between myself and my brother.

Does anyone have any tips or advice?
Pictures would be great (in particular the bolts that I believe go into the coolant passages).

Is it really that hard? We have the kv6 timing tools already.

Rob

[SD1too]

Originally Posted by biffa75

... sometimes I have an annoying rattle from cold start that goes away after just a few minutes ... I'm wondering if it could be just an idler or tensioner pulley on its way out.

Hi Rob,

Quite possibly, although the first time I had your symptoms I found a lateral cut on the ancillary belt. It's very unlikely to be the crankshaft pulley on a KV6, that problem seems only to affect the diesels. So, obviously start by removing the ancillary belt and assess the condition of the associated pulleys. Of course it's the total mileage of the engine which is relevant as far as pulley wear is concerned unless you have an invoice clearly showing that replacements were paid for.

Originally Posted by biffa75

Is it really that hard? We have the kv6 timing tools already.

Regarding the timing belts, the answer to your question depends upon your ability, experience and resourcefulness. There's a lot of dismantling work involved and you'll need a comprehensive tool kit. I'm helping another member with this at the moment. There are lots of tips but I'd recommend that you start by reading as much as you can and ask questions. I'm glad to hear that you have the service tools.

Simon

[biffa75]

Hi Simon,

The rattle noise was present when we bought the car, also suspecting the aux belt to be at fault. The aux belt was removed and the engine was started.. rattle gone (however it's worth noting at this point, the rattle is intermittent) it may present itself sometimes and then go for quite while without any rattle at all.

The aux belt along with the aux belt tensioner and aux belt idler pulley have all been changed. Still the rattle occurs (hence my suspicions of the crank shaft pulley but as I stated in my first post, spraying water on to the crankshaft pulley while the rattle is present, doesn't change anything, the rattle persists (for a few minutes until the engine begin to warm slightly and then the rattle fades away).
(I have checked the upper inlet manifold flap rods and there wasn't any movement (up n down?) Can't remember there was play one way but not in the other direction that is said to be the play that causes the rattle, so I ruled the fanimold out. ��

I have watched the kv6 belt video on YouTube, looks easy in fairness (brand new engine, not in a car so.. will see how that pans out).

I don't have the latest tools and electro gadgets, hand tools mainly accompanied by longer bars for extra leverage on highly torqued bolts etc. (Usually a T bar and impact socket affair with different length tubing which slides over the handle of the T bar. (Broken many of those strong bars over the years, I find the swivel head joints snap).

[Mike Noc]

Originally Posted by biffa75

However sometimes I have an annoying rattle from cold start that goes away after just a few minutes, couple this with the timing belt being over due by two years now.. I'm wondering if it could be just an idler or tensioner pulley on its way out.

Rob

Cliff (Teflon) had a rattle from cold start up that stopped once the engine had warmed up a bit and after some extensive investigation it turned out to be due to piston slap.

[biffa75]

Piston slap, is it a sign of impending doom on the kv6 or nothing to worry about ?

[Mike Noc]

More annoying than catastrophic, but of course Rob if your noise is due to a pulley problem then it is important to get that fixed before it lets go.

[Teflon]

Originally Posted by Mike Noc

Cliff (Teflon) had a rattle from cold start up that stopped once the engine had warmed up a bit and after some extensive investigation it turned out to be due to piston slap.

Indeed. This is what it sounded like (sound starts around 19 seconds into the video):

Originally Posted by biffa75

Piston slap, is it a sign of impending doom on the kv6 or nothing to worry about ?

The mechanic who diagnosed mine said it could safely be left and would possibly outlast me! I wanted it fixed though, so pennies were spent .

Cliff

[biffa75]

Thanks for the video Cliff.
It does sound very similar indeed. Could I ask, did you notice if it was less obvious during the summer months and became a lot more obvious during the colder winter months?. Could be my mind playing tricks on me but I'm fairly sure it sounded like your video, almost every start during the winter. After about a minute or two it slowly begin to dumb down and goes away altogether..

Thanks
Rob

[Teflon]

Can't honestly say if I noticed too much difference between summer/winter.

If it helps, the mechanic diagnosed the issue by using a long screwdriver as a stethoscope on the engine block (engine cover removed). With this approach, he was able to hear a massive difference between the front bank and rear bank, and was even able to tie it down to a particular piston.

Worth getting an expert ear if you're not sure yourself. If it is piston slap, it can probably be left (for a good while at least), but if it's something else, then as Mike says, it may well need more urgent attention.

Cliff

[biffa75]

Unfortunately going to the extent of replacing pistons etc to cure piston slap (if it does prove to be the case) won't be viable for me really.

Fingers crossed it's the crankshaft pulley or something similar. If it is piston slap, I'll just live with it I guess.

Thanks