HELPkv6 leaking thermostat agin!!!

[P63500S]

Hi all,

last weekend changed the thermostat, u-bend pipe and straight pipe as there was coolant leaking into the valley from a split in the u-bend and crack in the thermostat housing between the wielded seems of the housing.

Topped up coolant following the correct procedure, and then checked for leaks, everything looked ok.:lol:

I have driven about 200 miles in the car during the week, thought I check the thermostat again as the coolant needed a little topping up, took the engine cover off, and to my horror COOLANT IN THE VALLEY AGAIN!!!

The bolt securing the thermostat and u bend was tightened on the refit but i found that there was little gap between the head of the bolt by a couple mm. so the u-bend pipe and thermostat could move slightly, could this play cause a leak? A washer would remove the play on another refit or will the leak settle with time?
Any help would be appreciated.

regards nick

[stocktake]

Hi Nick, From memory when lates did mine last year

On the new housing the lug that the bolt goes through was not as thick/deep so if they had used the original bolt it would have been too long and tightened up in the blind hole before securing the 'stat. sounds just like you describe. If it is hot held tight in place pretty certain it will leak. lates changed the bolt in mine for a shorter one.

HTH

[P63500S]

thanks for the info dave, when I first tightened the securing bolt I thought I may of cross-threaded when tightening so refitted the bolt a number of times with gap under the bolt head unchanged at a couple of mm.
Glad that u have confirmed the bolt being to long, I think a few washers will sort it out.

regards Nick

[Lates]

or you have caught one of the O rings on refit ?

[Jules]

We are seriously thinking of not fitting any more plastic OEM housings, as we cannot guarantee them!!

On a similar subject anyone seen Kaiser ??
His last posts were in Aug

[Simon W]

Originally Posted by Jules

We are seriously thinking of not fitting any more plastic OEM housings, as we cannot guarantee them!!

Jules - Lates & Pete fitted Kaiser's metal housing on my car yesterday.

The two halves of the plastic OEM version seem to be glued together!! - this has to be one of MGR's silliest ideas.

[Jules]

You're right Simon the seams are plastic welded together.
But as I've mentioned before this wasn't a problem on the Rover 600 diesel, as the plastic housing sat in front of the engine block at the front in the airflow.

I think some of the damage is done in the case of KV6's after their engines are switched off during the cooling down period.
All the latent heat of engine block rises to cook the stat, during which time there is no airflow

Just another of Jules's mad theories

[P63500S]

follow up on the leak, seems the leak is comming fom the ubend pipe!
with an aid of a tourch can just see a little wet residue around the ubend pipe housing. Was wondering i might use radwell as the leak is very small? what would u guys reconmmend?

Any ideas would be welcomed.
regards nick

[courier118]

Please do not use radweld.........the stuff of the devil............not good in a KV6

[P63500S]

update, when i squeeze top rad pipe can hear sucking noise/water noise, this pipe goes to u-bend pipe, so me thinks i may have damaged o ring when fitting u bend pipe just like lates said. are the o rings on the u-bend water pipe available separately?

regards nick