1991 1.6 running cold

[j4ck100]

Hi All,

Just picked up a '91 Eunos 1.6 (what a day to do it, so much snow!!), and so far I love it.

However, on the way down from Sheffield to Reading, i've noticed that the coolant temperature sensor sat at cold for the entire journey and didn't budge, apart from when we hit heavy traffic and it moved up to about the 10 o clock position before moving back to cold again. Now it was very cold outside today, but i'm sure that it should get to 12 o'clock and stay there regardless, like most cars?

Sounds like this could be a thermostat stuck open to me, what do you think? However I asked the seller if he agreed with my thinking it was the thermostat, and he responded:

"Glad you got home safe buddy it has always ran cold. In summer she is always just below half I honestly think it’s the cold weather. Remember it’s got a few holes at the front with scoop and grill .I would wait until you use it in spring until you start to replace things as when it was taxed at that time it ran just below half way.If it was a bust thermostat the top hose would be clock cold."

What do we all think?

Thanks

[Oldandslow]

I think it's a bust thermostat,

... as in stuck open or not even there, possibly the previous, previous owner removed it. Too early I guess but you'll see it in the mpg and it'll always smell of petrol from the exhaust. A new thermostat isn't very expensive or hard to fit. If you remove the old one you'll see straight away if it's open. I suppose the other possibility is the needle on the temp gauge is offset. Does it have after market dials?

[j4ck100]

I'm siding with the thermostat I think!

Would I have to drain the coolant to replace it do you think?

Thanks

[Oldandslow]

You'll lose some coolant in the process and need to top up but it shouldn't require a full drain. Although since it's new to you and you never really know the history it wouldn't hurt to drain it, flush out any sludge and fill up again with coolant of a known spec and quality. How rusty is the current water?

[fatjon]

Or the wrong stat fitted. My 1.8 had a stat with a slightly larger bypass hole in it than it should have and ran clock cold.

[snotrag]

Its the thermostat. The car will be running in 'warm up' mode all the time which does no good for economy or performance.

Dirt cheap and dead easy to fit.

I strongly suggest that you drop the coolant out the bottom of the rad (plug in the middle), unclip the two hoses, and flush the radiator out with clean water, then flush and empty the ful lsystem, before refilling with fresh coolant.

If the cars not lowered, you can probably do it without even jacking it up. There's a wee access hole in the undertray.

You'll need a tiny squirt of RTV to seal the stat housing up too. And be careful not to break off the bypass barb.

[j4ck100]

fatjon said:

Or the wrong stat fitted. My 1.8 had a stat with a slightly larger bypass hole in it than it should have and ran clock cold.

Clock cold! The seller in Sheffield used this term, i'd never heard of it and you've just said it! Is it a yorkshire thing?


Thanks

[j4ck100]

snotrag said:

Its the thermostat. The car will be running in 'warm up' mode all the time which does no good for economy or performance.

Dirt cheap and dead easy to fit.

I strongly suggest that you drop the coolant out the bottom of the rad (plug in the middle), unclip the two hoses, and flush the radiator out with clean water, then flush and empty the ful lsystem, before refilling with fresh coolant.

If the cars not lowered, you can probably do it without even jacking it up. There's a wee access hole in the undertray.

You'll need a tiny squirt of RTV to seal the stat housing up too. And be careful not to break off the bypass barb.

Gotcha, thanks. I suspect so to. Will get stuck in when i've some free time.

[skinny]

classic symptom of thermostat stuck open. Fortunately easy and cheap to change