Alternative plastic kv6 thermostat longevity

[Arctic]

Today after finishing my weekly checks on the MGZT ie all fluids tyres pressures, all bulbs & lights working as they should.

I checked the V in the engine to see how the thermostat I fitted back in 2014 is fairing photo's below as expected all is good, you can still see the old stains from 2014 when the O-rings failed not the thermostat, that is now fitted to another members car with new O-rings that were suggested by Simon my MGZT were also fitted with the same O-rings which he kindly sent me back in 2014, these were smeared with rubber grease upon fitting of the thermostat with the three lugs in the link above in my other post. Arctic

[Phil-T4]

Originally Posted by DavidBytheway

I think you'll find that it certainly IS in many if not most cases.

David

Not from my experience, it has always been the seals.

[trikey]

I have seen the elbow fail on more than one occasion.

[chris75]

Accounts on here make it pretty clear that failures can occur to either the seals or to the plastic components . In my own case I had a catastrophic failure when the thermostat casing cracked up ; after removal I was able to crumble the lower half of the casing in my hands as it had become so weak and brittle

[SD1too]

Originally Posted by Arctic

HI Simon. They should still be available this is where I purchased mine ...

I bought mine from E Car Parts too earlier this year when he told me that it was the last of this type he had. I'd recommend that potential purchasers check with him on the telephone before ordering.

Originally Posted by DavidBytheway

I think you'll find that it certainly IS in many if not most cases.

It isn't David, I have proved it as I described in my last post. Very few people do what I did which is to refit my original thermostat housing with 'O' rings. They renew everything; the curved pipe, the thermostat housing and the straight pipe all complete with 'O' rings so they have no idea what the real cause of the failure was. I do know because I renewed only one element; the 'O' rings and there were no leaks, until they failed again.

Simon

[SD1too]

Originally Posted by trikey

I have seen the elbow fail on more than one occasion.

Originally Posted by chris75

... I had a catastrophic failure when the thermostat casing cracked up ; after removal I was able to crumble the lower half of the casing in my hands as it had become so weak and brittle ..

Without wishing to cause offence, I suspect that these failures are a result of the force necessary to remove the plastic components; they are a very tight fit. The first time I did the job I damaged the curved pipe through inexperience. The replacement part had been modified by MGR to include a more substantial mounting bracket and a longer fixing bolt. Breakage is made much more likely when the keyhole method is used, particularly if the curved pipe and thermostat housings are levered out using a tool inserted into their hose connections. That's why I always do it the official way.

Simon

[chris75]

Originally Posted by SD1too

..... I suspect that these failures are a result of the force necessary to remove the plastic components;

Simon

Just not so , Simon .
My casing broke whilst in use , not during removal .
Mind you , it did break a bit more during removal.......

[trikey]

Originally Posted by chris75

Just not so , Simon .
My casing broke whilst in use , not during removal .
Mind you , it did break a bit more during removal.......

Same with the ones I have seen, some of the elbows have internal weakness caused by poor moulding.

[marinabrian]

Most if not all of the Chinese manufactured "OEM" thermostat housings will fail after a short period in service due to the inferior materials and injection moulding employed in their manufacture, regardless of installation method.

As pointed out earlier, failure of the CDU3858 O Rings is a common problem, whether this is due to mechanical fatigue or chemical attack is a matter of opinion.

I would always fit a genuine part in this application, preferably a new old stock item, over any aftermarket alternatives, save perhaps the Kaiser 'stat.

Brian

[versus]

Originally Posted by T-Cut

That's interesting. Have you a link or reference to the KIA stat?

TC

The thermostat from KIA KV6 - part number 0K9BV1507XF
The bend pipe from KIA – part number 0K95K15290A
The straight pipe you can’t use from KIA cause it’s a bit longer.
Also you need a shorter bolt to fit them, or cut the original 10mm bolt a bit
Some people from Russia done this before with good results. For example read here and look the pictures https://www.drive2.ru/l/7009933/