Author Topic: Dislocated stat!  (Read 1281 times)

Offline Chevygold

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Dislocated stat!
« on: February 13, 2021, 08:38:33 AM »
Just had a strange experience with my 76 c10, the engine has never seemed to warm up properly so suspecting a jammed or absent stat I removed the housing only to find the stat sitting diagonally in the housing having come up out of it's groove in the inlet manifold.
Seems to me the bore of the elbow is too large to stop it happening again so I made a plate from aluminium sheet sandwiched between 2 gaskets and fitted on top of the stat.
The picture in the parts book just shows a plain gasket which would soon allow the stat to pop up through again, I know some stats have a U section rubber seal fitted but don't see anything similar mentioned?
Graham

Offline bd

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Re: Dislocated stat!
« Reply #1 on: February 13, 2021, 10:03:56 AM »
Post pics.  Either the wrong thermostat or the wrong water outlet (t-stat housing) was installed.  Install the correct parts using a new gasket smeared with Ultra Gray silicone and it should be good to go without further issues.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Chevygold

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Re: Dislocated stat!
« Reply #2 on: February 14, 2021, 08:55:56 AM »
Yes I wondered about the stat housing as I had a spare stat for my Corvette which was the exact same size and I've not had this happen before, I thought at first the PO might have left it out as I've found quite a few short cuts so far!
Stat fits neatly in the recess in the inlet manifold so pretty sure it's correct.
It's all back together now and the stat is going nowhere now. Stat housing has a 1/2" NPT tapping for the temperature sender, there is a plug in the hole in the LH head. Always seemed a bit odd as gauge won't read until the stat opens.
Thanks
Graham

Offline TexasRed

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Re: Dislocated stat!
« Reply #3 on: February 14, 2021, 11:31:46 AM »
the 1/2" NPT in the housing may be for thermally controlled vacuum switches (can't remember what they are called right this second). The allow vacuum through once the engine is hot enough.

Offline Chevygold

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Re: Dislocated stat!
« Reply #4 on: February 15, 2021, 12:02:01 PM »
Ran it up today and it warmed up nicely, trouble is now my gauge goes right up to hot, it isn't though only about 88-90 C so looks like the sender is wrong so I'll need to get the one that screws into the tapping in the head, anyone know what the resistance range is as having a terrible time getting parts from US just now, still waiting for a speedo gear that was posted Jan 16th!! so will need to try to find one over here.

Many Thanks
Graham

Offline Chevygold

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Re: Dislocated stat!
« Reply #5 on: February 15, 2021, 12:43:34 PM »
Just done  search and found the figures, mine was giving around 48ohms when at normal temperature, gauge showing full hot so gauge is good just need a matching sender, looked at the autowire one but with shipping issues at the moment I'll need to try to find an alternative.
Graham

Offline bd

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Re: Dislocated stat!
« Reply #6 on: February 15, 2021, 12:45:52 PM »
For Truck Years:  1974 - 1978

The Temp Gauge Needle Should Point to:
Left Line (Cold) when sender resistance = 350 Ω
Middle Line when sender resistance = 68 Ω
Right Line (Hot) when sender resistance = 46 Ω

See the topic, Correct temperature sender and connector for 1973-1978 C/K trucks [sic].
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline Chevygold

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Re: Dislocated stat!
« Reply #7 on: February 16, 2021, 09:35:24 AM »
All seems to be good now, I refitted the original sender which I replaced because it was reading low but actually it was because the engine wasn't reaching operating temperature. It might be reading a little low but it will do for now and at least I'll be able to see if the temperature goes above the new normal, just below 12 o'clock position.
Took out my heater fan as its bearings were noisy, managed to get some oil into the bearings now so it works good, I wasn't getting much air out of the heater though, had a search around in the engine bay and found a big hole in the air casing, glued a patch of alloy on there and now it's nice and toasty in the cab, direction control works so my vacuum connection must be good enough so happy days.
Many thanks for your assistance and maybe my journey might help others.
Graham