12 replies to this topic

[sport2000]

Hi
As we know the expansion cap for Mpi minis and similar are not exactly very reliable,so my question is the obvious same design cap fitted to R52-R53 MINI..
It looks the same fitment,opinions please on whether the spec is the same but maybe better quality being BMW....
The mpi ones tend to not screw down properly and lose pressure,causing boiling over from what I have read..

All the best

[Dan]

 Well the MPi one is BMW too, and to be honest this isn't something I have heard about.

[sport2000]

I believe the Mpi one was Rover branded although Bmw owned Rover..I just thought maybe the Bmw type would be more reliable,different design,upgraded part,as quite a few Rover ones have been poor fitment..
I have replaced mine before and they don't screw done well at all..mine was a genuine unipart one aswell..

All the best....

[Dan]

  I've had a little dig and it seems that BMW didn't use one of their caps for the MPi, they used an old Metro one.  So while that probably goes some way to explain why they might be less than reliable it probably also means they aren't very compatible with the later MINI ones.  Worth a try though I suppose, they aren't expensive parts.

[sport2000]

Interesting,thanks Dan......Yes I think it's worth a try,screw threads,diameter looks spot on,the pressure relief valve looks a better type...suppose in theory would work exactly the same...
Suppose better check that first..

[Dan]

  There are different valving arrangements on different systems, and you should definitely check the pressure rating.  Try asking in a major parts dealer rather than going to BMW as they will have a table of compatible parts in their books.

[zony]

Your right they are rubbish. Just bought a new one from Somerford. Cheaper than ebay.

 

Its about the fifth one I have bought though.  £ 3.50 every couple of years isn't that bad.

[nev_payne]

There's 2 different expansion tank caps that fit, the Metro/100 and the MGF-type:

[sport2000]

Hmm spill the beans Nev...
Differences etc etc..
I'm tempted on the Bmw version as the mpi ones are....well as useful as a handbrake on a canoe

[mab01uk]

The R53 MINI Cooper S was designed and developed by Rover Engineers at Gaydon and Longbridge and funded by BMW....engineers from BMW Munich only got more deeply involved in the later pre-launch stages in 2001, mainly with upgrading the quality control spec as the sudden decision to split with MG Rover and keep the new MINI meant the R50/53 MINI was now to be sold from alongside BMW showrooms rather than through Rover dealers.

ie. BMW were worried about their quality reputation and warranty claims.

Therefore there is a chance the MINI cap is the same Rover sourced part upgraded as BMW MINI Plant Oxford still use many of the ex-Rover component suppliers.....there have been several early R53 pressure cap failures reported on the MINI forums though, usually causing overheating and coolant loss but not an expensive genuine part even from MINI dealers.

MINI R53 Parts listing here (Item 2):

http://www.realoem.c...236&hg=17&fg=05

 

Part No. 17107515499

Edited by mab01uk, 24 June 2013 - 12:15 PM.

[Dan]

  But the power plant and ancillary package had nothing to do with Rover, it was a joint project between Chrysler and BMW and made by Tritec in Brazil.

[mab01uk]

Not fitting the K Series engine remains abit of a mystery......in the book 'New MINI' by Graham Robson it seems the oficial line from both Rover and BMW was that it was too wide with the R65 Rover Midland gearbox across the engine bay (although it was earlier shoehorned into the 2" wider classic Minki project for Rover and BMW to test feasibility). The hidden agenda suggested in the book may have been the reliability concerns as suffered later by Ford with the warranty claims on the early K-Series Land Rover Freelanders. The brand new 1.6 /1.4 Chrysler Tritec engine was already on course to go into production for early 2001 and needed only 300 workers in a new factory in Brazil to produce 250,000 engines a year. Two classic Mini's were exported to Chrysler in the USA so engineers could see what the driving/engine characteristics of the Mini were all about and how a similar modern MINI version was wanted, also all the ancillaries had to be moved to the front face of the cast iron block to gain the necessary crash/crush space behind the engine when fitted in a MINI. BMW also wanted to add variable valve timing but Chrysler declined to add it on development time and cost grounds. The first Tritec prototypes were up and running in UK Rover built test car mules by early 1998. The first MINI test mules used Rover 200 bodys reduced in weight to the target weight of the MINI and with much extra stiffness added by full roll cages to match the MINI's proposed ultra stiff bodyshell needed for ultimate handling in its class.  Although Rover did not get to fit the 'K' Series engine to the R50 MINI the Rover Midland gearbox did make it into the production R50 MINI ONE and Cooper up until the mid-2004 facelift when (like the R53 Cooper S from launch) a stronger Getrag box was fitted to the range due to many gearbox failures under warranty........

When Chrysler later merged with BMW's arch rival Mercedes (for a few years)....a new MINI engine had to be found and was jointly developed with Peugeot for the Mk2 MINI. The soon to come Mk3 MINI range will have all new BMW developed 3 & 4 cylinder engines built at the Hams Hall factory in Birmingham.

Edited by mab01uk, 24 June 2013 - 06:01 PM.

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