XSeries-forum

E53 2004 Facelift diesel 218..

Went to replace the thermostat today....
to discover the most ridiculous bolts ever put on a vehicle... possibly to prevent over tightening I guess...

Like tapered Torx heads... sockets wont remove them...

Any one know what they are called, so I can get some special sockets to remove them ??

Real OEM says M7 x 38 torx screw. Maybe someone has been there before and damaged them?

Nope,
These are the original fitment...
They are best described as a tapered torx bolt... with external points... but the external splines are not parrallel... the taper off...
Ebay has lots for sale as a pump set of bolts....
But these things truly are a ridiculous concept...

What are these bolts called ?  and what will undo them...

they are approx. 6mm thread, & made of Aluminium..

eBay item number:  350613360840

They are 8mm x 32mm Aluminium 'ASA' type E-Torx bolts.  Single use only.

The ones you have listed are not recorded against the E53!  As above the OEM ones are 7x38 Torx

Usually either a Torx spline key, or E-Torx socket/spanner should do the job.  The 'E' stands for 'External'.  It could also be a Torx-Plus but they do use the same tools.

Assuming it's an M8 thread then you need an E10 socket.  M6/M7 is an E8 socket.  For some reason the E tool numbers are not the same as the T tool number!  T tools match the thread size.  T tool is the 'normal' Torx bolt where you put a key in.

They came into being to allow faster assembly times as the tool can be slightly offset to tighten them.

Richard

Excellent Richard... Thankyou...

A trip to Halfords it is later.... Wonder what the chances are of the Halfords Monkeys having these sockets ?

Regards
GB

Should do.  My Halfords pro socket set has them.

So Richard,

What size do you think these Thermostat bolts actually are ?

According to Realoem they should be Torx 7x38mm.  Should therefore be a T40 or T50 key/spline bit.  What have you found them to be?  The OEM part number is:  11517789351.

Those look like the proper 'recessed' type Torx bolts, but your picture shows external Torx which makes me wonder if your pump has been changed and a different type used?  The ones you describe should take an E8 socket.

Can you take a piccie of what is on the car?

Richard.

Hi Richard,

These water pump bolts, are M7 x 28mm... They were a factory fitted E-Torx M7 bolt...

The E-Torx Sockets wizzed them off easily, and for the 1st time in months my Beastie has a proper temp reading now.... Hurrah...

Thanks for the help & suggestions.

At least you solved it.  Just HTH

Richard