Is my N62 engine dead - what's this rattling noise?

[g3org3y]

Did some work on the X5 today, changing the engine partition and put on the summer alloys/tyres. Decided to take it for a drive and wasn't best pleased when I turned it on.

Unusual 'pulsed' rattle I've not heard before (last time I drove the car was months ago and was fine). Seems to be loudest when cold and speeds up with engine speed. No difference if AC off/on.

Car drives fine, not down on power. I couldn't say how long it has been going on as wife drives the car and wouldn't notice anything like this.

Under the bonnet:
https://vimeo.com/556857033

With engine revving:
https://vimeo.com/556857412

Timing chain guides/tensioner/the chain itself? Maybe the AC compressor or some kind of pulley/idler thing? How worried do I need to be?

Advised wife not to use the E70 for the time being and take the E91 or E63 instead.

Edited by g3org3y on Sunday 30th May 16:30

[Mani59]

I am sure you know already but Tim Meek on Bimmerforums is an expert when it comes to the N62 so might be good to share with him.

I hope you get it sorted soon.

[g3org3y]

Will do.

I think (fingers crossed) it could be the water pump bearing.

This guy had the same noise

YouTube Guy said:

That noise, It turned out to be the Water Pump Bearing, it started several months back, and I thought it was the timing chain, because it sounded like a chain rubbing against the guides, so I first heard it then did some research, so in this order this is what I did to fix that noise.
1. Replaced Serpentine Belt & Pully and Tensioner (DID NOT fix noise)
2. Replaced Timing Chain Tensioner (DID NOT fix noise)
3. Replaced Water Pump (FIXED the NOISE)
My car is quite again

[g3org3y]

Any ideas lads? Am probably going to take it to a Specialist rather than chuck parts at it.

[Olivergt]

I don't have any ideas, but agree that it's not a good idea to throw part at it, much better to correctly diagnose and then replace parts.

If you are able, you could remove the serpentine belt and run the engine again, if the noise goes, then it's probably the water pump or one of the pulleys. With the belt off, you should be able to spin the pulleys by hand and hear any bad/rough bearings.

IMPORTANT NOTE: DON'T RUN THE ENGINE FOR VERY LONG WITHOUT THE BELT, YOU WILL HAVE NO WATER CIRCULATING.

[Pastie Bloater]

Sounds like something on the belt drive, likely water pump. Take the belt(s) off and see if it stops, and if the shaft has any play.
I had a very similar sound recently with a bit more of a 'CLACK' to it (could just be the audio though). I'd have absolutely sworn it was left bank valvetrain.
Went away with the belt off, and the water pump had a slight movement to it. Replaced it to no effect, turns out my power steering pump pulley had come loose, the bolts were finger tight. Tightened them up and problem solved.
I'd check everything belt driven including the crank pulley, before even thinking about messing with the internals.

That said when I replaced my timing chains, guides, tensioners etc. an inch of guide slider had broken off top or bottom of 3 of them. They were also loose side to side as the little tabs had broken off, so basically ready to fall off. But there wasn't any noises.

My other thought is valvetronic drivetrain, as mine makes a similar rattle, just once, when it transitions from throttle body to valvetronic idle control after starting. But I wouldn't expect that to just come on suddenly, and can possibly be adjusted out using INPA.

Edited by Pastie Bloater on Tuesday 1st June 08:17

[g3org3y]

Thanks guys, appreciate the input.

I'll give the specialist a bell today. I use the local mechanic in the village for a lot of other stuff, but for this would prefer to use the specialist.

EDIT: Booked in for the 17th June. (they are very busy!).

If it's the waterpump, I'll get the 'stat done, the little rubber tube behind it, the belt, the pulley and tensioner. No point messing around.

Edited by g3org3y on Tuesday 1st June 14:42

[Pastie Bloater]

g3org3y said:

Thanks guys, appreciate the input.

I'll give the specialist a bell today. I use the local mechanic in the village for a lot of other stuff, but for this would prefer to use the specialist.

EDIT: Booked in for the 17th June. (they are very busy!).

If it's the waterpump, I'll get the 'stat done, the little rubber tube behind it, the belt, the pulley and tensioner. No point messing around.

Edited by g3org3y on Tuesday 1st June 14:42

Good luck g3org3y, thinking positive if you want to save a few quid you could get OEM Saleri water pump £90 (BMW £275) and Wahler thermostat £40 (BMW £79).
I also went OEM Continental Contitech belts and INA tensioners/idler.
For thermostat Wahler do a stock 105C version and a lower 101C version (4508.101D).
I have all this to hand due to my recent issue
The water pump pulley is the only plastic one (bar tensioners/idler) so worth replacing.

Edited by Pastie Bloater on Tuesday 1st June 20:22

[g3org3y]

Pastie Bloater said:

Good luck g3org3y, thinking positive if you want to save a few quid you could get OEM Saleri water pump £90 (BMW £275) and Wahler thermostat £40 (BMW £79).
I also went OEM Continental Contitech belts and INA tensioners/idler.
For thermostat Wahler do a stock 105C version and a lower 101C version (4508.101D).
I have all this to hand due to my recent issue
The water pump pulley is the only plastic one (bar tensioners/idler) so worth replacing.

Edited by Pastie Bloater on Tuesday 1st June 20:22

Thanks for the advice Pastie, appreciate it. Where did you source the items?

Is there any advantage to using the lower temp 'stat?

Do you think there's merit in doing the AC belt and other tensioner 'while you're there'?

Fingers crossed it's just something on the 'belt system' so to speak. The car is only on 70k miles and has had quite an easy life and appropriate maintenance so we'll see.

[Pastie Bloater]

g3org3y said:

Thanks for the advice Pastie, appreciate it. Where did you source the items?

Is there any advantage to using the lower temp 'stat?

Do you think there's merit in doing the AC belt and other tensioner 'while you're there'?

Fingers crossed it's just something on the 'belt system' so to speak. The car is only on 70k miles and has had quite an easy life and appropriate maintenance so we'll see.

Autodoc, and using the app is cheaper. Just put in the BMW part numbers, only problem is it can take a good 7 days for them to arrive.

In my experience yes as the actual operating temps will come down from max 115C to about 105C, so lower but not so low as to keep the car on warm-up map (like the £150 'modified' 80C ones will), and it's an OEM unit just lower temp insert. It also gives you a bit more leeway/grace period in the event of say belt failure, lower temp is easier on seals etc.

At 70k I would as preventative, you'll probably find they could do with doing. You can just replace the tensioner/idler pulleys rather than the whole thing but need the Dayco part numbers or they'll come up on Autodoc.
To be fair the AC belt drive isn't critical but the risk is a failed belt or bits of belt being pulled into the front main crank seal.
It's so easy to do them it's a no brainer for me, as failure of any of the bits could be a cooked engine or fubar crank seal (which is no joke).

It looks like ~£120 to do belts, tensioners, idler and WP pulley, so plus the £130 for WP & thermostat is £250, less than the BMW WP.

[g3org3y]

Pastie Bloater said:

Autodoc, and using the app is cheaper. Just put in the BMW part numbers, only problem is it can take a good 7 days for them to arrive.

In my experience yes as the actual operating temps will come down from max 115C to about 105C, so lower but not so low as to keep the car on warm-up map (like the £150 'modified' 80C ones will), and it's an OEM unit just lower temp insert. It also gives you a bit more leeway/grace period in the event of say belt failure, lower temp is easier on seals etc.

At 70k I would as preventative, you'll probably find they could do with doing. You can just replace the tensioner/idler pulleys rather than the whole thing but need the Dayco part numbers or they'll come up on Autodoc.
To be fair the AC belt drive isn't critical but the risk is a failed belt or bits of belt being pulled into the front main crank seal.
It's so easy to do them it's a no brainer for me, as failure of any of the bits could be a cooked engine or fubar crank seal (which is no joke).

It looks like ~£120 to do belts, tensioners, idler and WP pulley, so plus the £130 for WP & thermostat is £250, less than the BMW WP.

Thanks for the info. I'll think I'll just leave the Specialist to supply whatever parts are needed. We haven't got to that stage of our 'relationship' where I can supply parts, plus as you say without knowing what is needed, difficult to plan in advance.

[g3org3y]

Specialist had a look, diagnosis: waterpump bearing. Unfortunately can't get one until early next week.

Have requested to do all the pulleys/tensioner/belt done at the same time. Might be overkill but at least it's all sorted (and I can just worry about coolant leaks, oil leaks, valve stem seals etc...!)

Edited by g3org3y on Friday 18th June 08:26

[g3org3y]

To conclude, was indeed the water pump. All sorted (£££) so the X5/N62 lives another day.

[osirus04]

Oh yes, that dreadful rattle when giving gas. My X5 sport 4.8i was doing the same thing. First it was the AC pulley bearing. Replaced. Then I just removed the belt to diagnose that rattle. Yes, the water pump bearing was rattling when I gave it gas. I replaced everything and pulleys. Sounds so beautiful now.