Event -
Recently as I was accelerating onto a motorway the gearbox kicked down and the engine suddenly sped up from 2000 to 4000 rpm. The surge ripped the water pump (and attached thermostat) apart and sent the fast spinning fan gouging into the radiator core. The timing case cover also took a hit producing a 20mm long crack in its side.

Cause -
What caused it to fail? Lack of stretch in the old drive belt? Belt tensioner allowing too much slack? Thermal clutch adding too much load? Metal fatigue? Vibration over 200,000km? Or a combination of all these factors?

Edit - Definitely the thermal clutch, it was locked solid AND out of balance. Some of the oil had leaked out so that when left standing the 'bottom' side will be full and the 'top' empty - this puts it out of balance when it spins. When it stops it will stop in the same position (heavy side down), constant out of balance vibrations will lock it in place ... and so the cycle continues.

Update - Oct-2018 (nearly 4 years on). All still running fine. No problems at all with the replacement parts. Regularly towing 3T caravan on long trips. Last big one was Newcastle, NSW to Broken Hill, NSW and return - 3000km.

Update 2 - Jan-2024 (9 years after fix) the non genuine water pump shaft seal started leaking and had to be replaced. A bit of google study found that all M57 engine blocks have the same bolt pattern for the coolant pump, but the Technical Upgrade and TU2 have a different, much improved bolt pattern. As there were a great many more TU & TU2 engines produced than the original model it is cheaper to buy a TU water pump AND thermostat than just the older style pump. So that's what I fitted.

Next Post = Strip down for repair

Last edited by bgennette on 16th Mar 2024 1:26am. Edited 4 times in total

Strip Down -
Drive onto ramp, chock rear wheel
Remove the under pan; 30 screws M6 and smaller!
Remove front engine acoustic cover (2 x torx 30 and power steering pump lid)
Remove air bleed screws from cooling pipes
Drain radiator, fit hose to outlet LH bottom of radiator, open tap, collect in bucket
Remove 1 screw (phillips) from bottom centre of shroud
Unclip an air con hose from the bottom of the shroud
Roll off ramp, chock rear wheel
Reposition ramps across front of car, stand on top for easy access to engine
Unclip upper 2 hoses from radiator
Unclip 2 wiring plugs from side of radiator shroud
Remove 2 scrivets from top
Then the fan, thermal clutch and water pump pulley should come out the top along with the shroud Should, but didn't, the shaft of the water pump was so long that it was still inside the engine block,
So I had to find 2 x 32mm thin spanners to separate the fan from the remains of the water pump (left hand thread) before they came out
Next I uncliped the remaining radiator hoses,
Undid the large plastic screws (phillips) holding the top of radiator
Twisted the top corner brackets out
Then tilted and removed the radiator
Replaced radiator with equivalent sized piece of heavy cardboard to protect the air con condenser

Inspection -
I used a work light and mirror to inspect the damage -
Ancillary drive belt and pulleys Ok, including correct action on the tensioner
Alternator, power fluid pump and air con compressor Ok
Exhaust gas recycler plumbing Ok
All hoses and end fittings Ok (except thermostat top outlet)

Water pump housing in 10 pieces
Thermostat housing intact (but snapped off water pump), cover in pieces
Crack in timing cover (a thorough probe with paper clip found no structural damage internally)
Radiator ruined
Thermal clutch locked up – normal for 10 year old clutch to have lost its oil
Fan blade front faces worn down 3mm towards tips, so need to check balance (see below)

Whatever the cause the damage was done, so to the repair. Ordered a new water pump, thermostat, thermal clutch, radiator and drive belts from England. If ordered before end of trade on a Tuesday DHL air freight leaves on Thursdays and parts arrive in Australia by the following Tuesday. $1040 including freight (this is just a little more than the cost of the radiator sourced in Australia, so it is a good deal).

More Strip Down -
I'd left the old ancillary drive belt in place because it was behind the air con compressor belt which I couldn't get off. The tensioner for this is a swing arm through a bushing at the bottom of the air con mounting bracket with a spiral spring attached at the rear and it wouldn't move. Sprayed front and back with WD40 each day for a week and finally got a little movement so the belts could be taken off. This arm is held in the spring unit with a tiny m6 screw (#30 torx head) and should in theory be easy to remove. 10 years of road grime in the bushing however make this almost impossible.





When first designed the M57 engine did not have exhaust gas recycling, this was added later, with its cooling block passing OVER THE TOP OF THE THERMOSTAT. Also on the TD6 version the air tube from the integral air filter down into the turbo prevents movement across the front of this engine so the thermostat can't be manoeuvred into the rigid cooling pipe to its right. These will have to be removed for access.

This partially transparent image below shows the water pump and thermostat behind the fan with the rectangular silver cooling box above them and the curved black air duct at the upper left.

Timing Cover Patch Up -
Clean thoroughly with WD40 (kerosene based) then methylated spirits. Including into the crack.
Roughen surface with coarse sand paper.
Mix 2 part epoxy 'petrol tank' repair and apply 2-3 mm thick, working into crack.

Fit Replacement Parts -
After much trial and error I arrived at this procedure -
Fit thermostat to water pump first. Use thread locker glue
Apply sealant to both sides of new gasket, wait until tacky then press roughly in place
Rotate the water pump/thermostat assembly until the thermostat outlet can be pressed into the rigid outlet pipe at top right, push in and push the clip down. Tug to ensure locking
Rotate the assembly into place
Fit second hose
Fix water pump with 4 bolts. Use thread locker glue
Clip second hose onto thermostat
Thread ancillary drive belt around pulleys
Thread air con drive belt around pulleys
Take out piece of heavy cardboard protecting the air con condenser. Very important!
Drop in the new radiator with the top corner brackets in place
Screw down the large plastic screws (phillips) holding the top of radiator
Clip in the radiator hoses
Bolt new thermal clutch to fan. Use thread locker glue

Reassembly -
Install air duct for turbo
Refit exhaust recycling cooling box and water connections
Refit lower radiator hose
Lower the fan, thermal clutch and the shroud together carefully over the radiator
Wind the coupling onto the water pump pulley (left hand thread). Use anti seize compound
Wiggle the shroud until the clips at bottom and lower sides engage properly
Fit 2 scrivets at top
Clip on 2 wiring plugs at side of radiator shroud
Fix upper 2 hoses to radiator

Test -
Fill radiator with water only
Start engine and add more water as air bleeds out
Screw in air bleeds and fit pressure cap
Check for leaks when engine has warmed up
Turn off and allow to cool

Remove air bleeds and pressure cap
Fit hose to outlet LH bottom of radiator, open tap, collect in bucket
Inspect water for debris, containments, etc
Repeat test if further flushing is necessary

Finishing -
Fill radiator with 50/50 antifreeze instead of water
Start engine and add more antifreeze as air bleeds out
Screw in air bleeds and fit pressure cap
Fit front engine acoustic cover (2 x torx 30 and power steering pump lid)
Drive onto ramp, chock rear wheel
Fit 1 screw (phillips) to bottom centre of shroud
Clip the air con hose to the bottom of the shroud
Fit the under pan; 30 screws M6 and smaller!

Tools/Materials -
ramps and chocks (can get by without, but sooo much easier with)
torx 30
screw driver phillips (short)
screw driver flat, small
pliers, small, needle nosed
open end spanner 32mm x 2
socket m5 (8mm across flats bolt head)
socket m6 (10mm across flats bolt head)
socket m10 (16mm across flats bolt head)
chisel / scraper
WD40 (or equivalent cleaner)
2 part epoxy 'petrol tank' repair
gasket sealant
thread locker glue
anti seize compound
antifreeze type G-48

Notes -
Radiator hoses have female fittings with 'O' rings and stiff wire retainer clips. Pull wire clip out 1/2 diameter of fitting, twist and wriggle fitting to break grime seal then withdraw fitting. Clean fitting and inspect 'O' ring. Replace 'O' ring if necessary. If a fitting won't release pull the clip completely off, but beware, upon removal they normally launch themselves several metres further than you would think possible and will never be found again.

The 'Blue' antifreeze specified is any that carries this �
G-48 Coolant Approved for BMW N 600 69.0

Check Fan Balance -
Hang the fan from a mounting bolt hole via a thin, stiff wire. Hang a weighted piece of string alongside and adjust until the string just touches the edge of the fan.
Take the fan off the wire, turn around and hang back on same hole. If the edge of the fan just touches the string it is balanced in that plain.
Repeat over half of the bolt holes in sequence. All need to balance to the same point.
Not very high tech, but accurate enough.

Last edited by bgennette on 12th Oct 2018 1:22am. Edited 4 times in total

excellent , thankyou ...in the wiki now. ... - .- -.




Y. O. L. O.
.

Wow. I've not heard of this type of failure before. And that despite living in the land of BMW and, literally, being surrounded by these motors. It was one of the more popular motors in BMWs in the past 15 yrs.

BTW, that would be a M57 motor. You have a BM54 radio in your nav system
Stan, if you do put the thread in the wiki you might want to change that. But despite bgenette's excellent repair description, I believe this is a rare failure - even with a locked viscous coupling. Wiki? (Just MO) 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

would it be a m54 in aussie land? or is it defo a m57..... ... - .- -.




Y. O. L. O.
.

Nice write up, my guess would be the seized up fan, they tend to seize off center so you have a large imbalance in them, this is enough to rip the water pump to pieces.

Had a fan seize on an old 2.3 V6 Ford years ago and it snapped the end off the crankshaft with the bottom pulley, which is still lying somewhere up the M1.... Engine out job and new crank....

Glad it's all sorted for you.... Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
-Click here for Thread-
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click here for Project Fatty off roader-

And AFAIK they never fitted the M54 to a Range Rover, it's virtually the same engine as the M57 but I'm pretty sure all Range Rovers just had the M57...

I have been known to talk out my ar5e though....  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
-Click here for Thread-
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click here for Project Fatty off roader-

Forgot to include the all important failure picture -

I'm surprised the belt tensioners and pulleys were in good order, the bottom tensioner is common for failing and I've changed the top one on mine because of a rumbling bearing

Last edited by 47p2 on 3rd Dec 2014 10:53am. Edited 1 time in total

Typical old fella got pensioner on the mind hey John 😜😜 FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.

Fecking Safari spell correction, I need to switch it off

Absolutely! I've nearly thrown my Mac across the room.
Feckin aggressive little spell-check sucker.

stan wrote:

would it be a m54 in aussie land? or is it defo a m57.....

Def a M57. M54 is a 6 cyl DOHC petrol motor.
Not that important, but if it is to be a reference, then people ought to be able to find it with a search.
 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

A tensioner on a pensioner...

Works fine in my safari...

Maybe it just goes off the most used words lol FFRR MY06 facelift With TDV8 Alloys Zeros/ATR's
Mantec Sump Guard, Rigid Load liner, MY10 BT upgrade.

Looks like were doomed, The tick box for spelling is greyed out so I can't change it