XJ40 ( XJ81 ) 1986 - 1994

Thermostat too big

Old 12-13-2018, 11:59 AM
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Default Thermostat too big

Hard to believe, but the thermostat I fitted a couple of months ago didn't *quite* fit into the recess in the housing ..not too tall or deep, too wide.

Yes, too wide by a hair or two. I know I should have attended to it in a better way back then because when I assembled and refilled the system the housing leaked coolant.
I was doing the service in my brother's driveway in Seattle (no excuse really) so I needed a get-me-home fix. I plumped for cutting and fitting a extra gasket with a smear of gipe just for good measure. Refilled the system again and checked for a leak, all good, so drove back to Vancouver Island.

Pretty much put it out of mind until last week I got the low coolant light on the dash ..wasn't that low, (about a pint and a half) but it was down enough to trigger the light. After filling the header tank up, I had a look around for hose problems, stat housing issues etc and didn't find anything obvious (although the car was already warmed up and I suppose any dribbles had evaporated).

Anyway, I checked again this morning and found traces of coolant under the stat housing ...so obviously my 'extra' gasket idea hadn't worked. Today, I'm going to take the stat out and file the circumference so it DOES fit into the recess in the housing ...damn aftermarket parts!! grrrrr ....

Will report back!

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Don B (12-23-2018)
Old 12-13-2018, 12:13 PM
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Interesting. Do you remember the brand perchance?
Old 12-13-2018, 12:22 PM
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I always use STANT. It has MADE IN ENGLAND stamped on it so they all seem to fit properly.

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Don B (12-23-2018)
Old 12-13-2018, 06:30 PM
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Iím planning on replacing mine too.

I did buy a failsafe Motorad, 192 degrees. I believe the one I have installed could be as low as 176 or 180 degrees.

Iíd imagine that would effect heater performance, wouldnít it?

From my research, the factory EBC3621 stat is an 88 degree C thermostat, or 190 degrees F.

Iíve never had one that didnít fit tho. I have had ones without jiggle pins or bleed holes, however.
Old 12-13-2018, 06:39 PM
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Red face here guys ...when I took out the stat (made in england BTW) I realized I had put the big o-ring on the wrong (block side) of the stat, no wonder it leaked and the stat couldn't seat ...no wonder I had a hard time with it! Nothing wrong with stat, just my brainbox ...

What a goof!

All fixed now.though

carry on

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Don B (12-23-2018), motorcarman (12-14-2018)
Old 12-14-2018, 08:36 AM
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Larry, yup been there done that but the important this is that you figured it out. I have to replace mine too as I just got the car a few months back and I'm not sure when it was last changed. I will got with the STANT that motorcarman recommended. Ren
Old 12-14-2018, 10:48 AM
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I've got a 75įc thermostat in mine and the heater seems to work alright, maybe takes a little longer to roast me out of the car than some, but my previous vehicle (now my wife's) had heated seats so I was used to warming up pretty quickly!
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