XSeries-forum

Hi all,

I'm back again in my third X5, my previous 2 both being the 4.4 and my latest one is the 4.6is.

Now it's my understanding that the 4.4 and 4.6 run identical chain and guides but when ever you search for 4.6's for sale there's normally a low number ever for sale which is understandable as I think there were only something like 840 sold between 2002-2003 of which 520 odd are still on the road but you see probably for every 2-3 good ones you'll see 1 ad for a spares or repairs guide failure with the 4.6's, now I don't know if that's simply because failed 4.6's are still worth a premium of sorts where as the value of a failed 4.4 isn't but there just seems to be a high ratio of failed 4.6 to good 4.6's about.

Anyway my question is to all the 4.6 owners out there what's the millage on yours and have your guides failed and been replaced or have you had them done to be sure they don't fail.

Like most faults with cars on forums you see what appears to be high numbers of failures but that's simply how forums work people post problems where as happy motorist don't get a chance to hype up there success stories.

I'm only really wanting to know because I'm considering swapping out my chain and guides in work between Christmas and New year simply because I've done the job a few times (on failed 4.4's in a couple of X5's and a range rover) and can happily turn the job round in under 10hrs and with the dealer parts at trade cost to me through my garage it'll only cost me around £450 in parts as my time is free.

I have no start up rattle at all in mine where as my 2 previous 4.4's which both had higher miles both had start up rattle on cold starts and both remained rattling even after new tensioners were installed and they never gave any issues so I'm wondering if I'm jumping the gun and going over kill in swapping them out with no issue, oh and I dropped the inspection panel when I changed the oil and it was spotless.

I've only had my new 4.6 a couple of weeks this Saturday but I've been busy playing with it changing bits, some may remember me previously with my other X5's and my full throttle approach to cleaning up/modifying my cars in my write up posts I would do of which I'll do my latest one on my 4.6 very soon so watch out for it.

Morning DP and welcome back
I got my 4.6 3 years ago as a replacement for the 4.4, when I took it over it was on 75k with a full BMW history. It's a real Marmite car love when it's going drives me nut's with all the niggles.
Not long after me getting it it suffered a water pump problem which I had changed followed quickly by a thermostat and split rad. All was well for about 6 months in which time I re-bushed the front and rear suspension then it started losing water second replacement rad fitted. Mileage was now around 85k next the rear diff failed that was fun.
Then last Christmas at 91k cruising on the M23 started to head towards the services and oil light on. Engine off and rolled into the services. After the car was recovered to the BMW specialist I use for services the engine was stripped the guides had failed blocking the oil pick causing pump failure.
Having examined the damage myself I believe the that although I had water pump and rad failures the car never over heated but it must have done before my ownership. When it over heats it hardens the plastic guides making them brittle but it also anneals the helper spring in the chain tensioner. Not enough pressure at cold start and chain slap starts to break up the guides the rest is history.
My engine got a full rebuild as I have a warranty when I got the car back I researched pre-oiling systems and fitted an Insta lube system to try and protect it long term. As soon as I turn on the ignition the oil pressure is there before the starter engages hopefully it will last a few years now. As there are fewer 4.6's every year I have considered taking mine off the road who knows it may be worth something one day? Mileage now is 111k

For what it's worth the warranty engineer confirmed my thoughts regarding the cause and told me BMW are not alone Audi also suffer chain guide failures.

Good luck with the 4.6 look forward to seeing what your mods are

Thanks for the welcome and thanks for the reply.

A quick question about you particular failure as that seems a little different to how most report the failure as most report the rattle starts as start up one day but doesn't as normal disappear after a few seconds instead gets louder and louder until it sounds like a bag if spanners.

When you shut it off was it ever re stated?

If it was did you have the death rattle i.e. Was it a total failure of the guides or in your case was it part of the guides had broken away not yet total failure and rattling and you were just very unlucky that the bit was large enough and it got sucked into the oil pick up causing you the lose if oil pressure?

Also the warranty you had what is it and where can I get it?

Mine failed at about 75000 miles and miles had the same problem as greydog with a blocked oil pump strainer and a damaged bottom end. If you can do it yourself at that price then as a precaution there is no doubt I would do it.

Thanks,

I think I'll be doing it anyway for no other reason than piece of mind,

Its not actually a hard job at all, I have all the locking tools it's just a long winded nut and bolt job.

As I said I can knock it out in under 10hrs so if I'm locked away in the garage workshop between Christmas and New year so there won't be any customer's disturbing me I should think I'll drive it there for 7am and be driving it back home that evening.

I removed the engine on mine to do the crank repair so it took a bit longer  >:( >:(. The worst thing was removing the front pulley bolt but I guess you will be used them

Yep I made a tool to bolt to the front of the crank where the 8 small bolts that take pulley off the front come from that has a long bar welded to it that I hook up under the chassis leg that's worked perfect every time.

I have a 4.6 with 127k, no noise but changed the tensioner anyway. There was a difference in the tensioner lengths. BTW owned for 2 years now. Took sump off at last service and everything clean and little black bits free. Have changed the tensioners on my sons 4.4 after death rattle, what a mess. Did the complete crankcase vent system, had to remove inlet manifold to get it off, so went overkill and replaced the water pump and O ring seals on the coolant pipes while I was in the area. I have changed all the bushes to poly bar the rear subframe and these will go poly when they need changed.  Mods are limited to the Simota CAI (it will be getting mapped before xmas) 22x10 and 22x11rear wheels with tyre combo that would not be recommended by anyone. Lowered 70mm, plus sidebars. Runs on LPG. Fitted Dynavin N6, TV module, DAB module and will consider iLink when I've read some reviews of how it performs. Fitted the original Head unit in rear to retain all OBC functions. Do all my own work/servicing, probably not GB if it goes tits up and what I'm not sure of then there is always someone on here with the knowledge who is willing to educate me, great forum this as I'm sure you already know. I'm just coming up to 20k on the tyres, probably another 3/5k left fronts are slightly better than rears.
Don't know the logic of it but my son originally had a 3.0L with less mileage but we changed a mountain of stuff on it, door handles, window motors, seat module, rear hatch solenoid, cat, etc etc. I haven't had those problems. So maybe luck of the draw.
I never mentioned on here but the thing I wasted most of my time on was the passengers electric folding mirror which in the  end didn't actually have anything wrong with it. A previous owner had swapped the drivers mirror for a manual one, they will only stay folded if both work. Didn't know that.
Anyway it seems you have been on here before, obviously before I joined, so welcome back, I'll look forward to your mods   

Thanks

That's great to hear my ones on 110K and as I said on the oil change I carried out last week I dropped the inspection panel and it was spotless I don't know if it's an important factor but the service history on my motor is amazing showing it's had regular oil changes around every 6-7k since new that could be a saving grace given most I'm sure went a hell of a lot longer on old oil between changes.

I'll write up my work/modification post probably tomorrow when I have more time along with a heap of pictures.

Hi DP
To answer your questions I had no early signs no cold start rattles at all, recovery was by the AA and they don't trust their customers diagnosis so the AA guy had to start it before he called a recovery truck. Sounded really bad.
It had a full service history BMW to 75k then 2 services by a BMW specialist and a gearbox service by a ZF specialist plus the stuff I have done myself the car is to say the least "pampered" so the failure was unexpected and sudden. I rebuilt my first car in 1962 so I am no stranger to stripping and rebuilding an engine. As IanP says the plastic strips from the chain guides some in chunks some in fine powdery goo that blocks the strainer causing oil pump failure, mine was treated to a bottom end up rebuild so is a virtually new engine. The tensioner was around 20mm shorter than the new one due to the spring becoming soft that's why I fitted the pre-oiler.

My Warranty is with Warranty Direct had it on the 4.4 (the 4.4 was great until a stuffing great tree fell on it) they transferred it to the 4.6 and I have kept it up (glad I did) they cover all labour and 50% of parts and have been a great support. You will be better off talking to them than doing it on line.

Nice one thanks