thermostat bodge?

[dhla40]

Coming back from brands hatch yesterday my car started to misfire badly and I had to pull over.  On opening the bonnet there was coolant all over the engine which had filled the spark plug wells causing the misfire.  It was not obvious where the leak was from so as I had no water I had to call RAC. When he arrived we topped up the rad and started the engine, all seemed normal at first untill I increased the revs when a jet of water pushed the top hose off the manifold.  On removing the hose a strange looking thermostat fell out of the hose and it became apparent that what was left of the original stat was stuck in the housing and this inline one had been put in the hose.  Unfortunately the body of this stat only left about 10mm of hose to be held by the clip to the housing making a leak just waiting to happen, after reassembling and tightening the clip as much as possible I managed to get home.  Tomorrow I will try to modify the stat to get more hose onto the housing and maybe double clip it, all the joys of discovering the little foibles of a new toy

Sean   

[nistri]

If you can save your thermostat housing (or if you need another one), try to find an old (used) thermostat and test it in a pan of hot water with a thermometer to see if it works OK. Modern thermostats often (always? ) have the same threaded diameter (and shape), but the cross section of the opening is significantly smaller than the original one. That means that, even when the thermostat is fully open at high temp, the coolant flow is somewhat restricted. This is why a fully-tested, old thermostat may be a better choice and keep the engine cooler. Andrea

[dhla40]

I took a hacksaw to the stat today and cut away about 10mm of the body to allow the hose to slide further onto the housing to let the clip get more of a grip on it.  I was surprised the housing does not have much of a lip on it to prevent the hose slipping but with more hose now on it I suppose the friction is adequate.  You are correct the stat does have quite a small opening but as the running temp was ok  before my little mishap I will monitor this and also keep an eye on e bay for a manifold with a proper stat.

Sean