Sorry to keep creating threads, just want to check that mine is running at the correct temps, once warmed the needle settles about a needles width above the bottom line and in traffic it goes up to the top line and the fans kick in and bring it back to just above the bottom line, fluctuates a little bit but generally rock solid, doesn't seem to be too hot at any point, if anything previous cars always seemed to plonk the needle bang in the middle, so was wondering if potentially it was running a bit cool if anything, which could explain the less than stellar mpg, am changing the Lambda sensor as I think it's been there since 1991 but another thought was perhaps its over fuelling as it may be running to cool, I don't think so but I haven't had one before and am not sure where the gauge should sit.
Engine temps
- Thread starter J4CKO
- Start date
944 man
Active member
Worn thermostats run cooler. If you replace it youll run a good deal warmer, which usually worries people. If you do replace it then be very careful re-filling the coolant, as airlocks and big problems easily follow.
I will find you out an image which gives a value to the positions on the gauge, which can be helpful/reassuring.
Simon
I will find you out an image which gives a value to the positions on the gauge, which can be helpful/reassuring.
Simon
robwright
New member
Don't be sorry about posting mate I was the same when I first got mine nearly three years ago. This forum welcomes questions and input as long as it is valid. You are correct though you engine is running cold. This is because your nearly 25 year old thermostat has probably never been changed. As soon as you change it and you should it will sit about half way up the gauge where it should be. It isn't harming your engine but yes you are losing a couple of mpg because of it. The engine has two coolant temp sensors. One for the dash gauge and one for the DME. The dash gauge one is the one with the spade clips on it and the DME the one with the blue top. The blue top one controls the fueling for the DME particularly on start up when the engine is cold it tells the DME to make the fuel mixture rich until the engine warms up. Hence if the thermostat is not working correctly then the engine is running colder than normal and the fuel mixture is richer and your MPGs will reflect this. Hope this helps mate.
Mine sits where yours does - changing the thermostat is a real PITA .
One of the first jobs I did on the 2.5 and did it again on the replacement engine I put in - before the swap!
But did keep the engine warmer.
Very difficult access, cant see it,20mm inset and even with the correct circlip pliers!
On my 2.5 the circlip had rusted and snapped with lots left in!
So, I'd say be prepared and get a new circlip too.
On the list for the 2.7 but always seem to find other more urgent jobs.......
One of the first jobs I did on the 2.5 and did it again on the replacement engine I put in - before the swap!
But did keep the engine warmer.
Very difficult access, cant see it,20mm inset and even with the correct circlip pliers!
On my 2.5 the circlip had rusted and snapped with lots left in!
So, I'd say be prepared and get a new circlip too.
On the list for the 2.7 but always seem to find other more urgent jobs.......
JamesO
New member
I've said it before, but will mention it again. I have found the in dash gauges to be less than honest. Mine reads a bit high, as confirmed with a spare binnacle and standalone ecu.
Still, best to change the thermostat. Just don't be too shocked if there is no change on the gauge.
Still, best to change the thermostat. Just don't be too shocked if there is no change on the gauge.
scam75
Well-known member
Mine has two recent stats and still sits just a needles width above the first line under normal driving conditions. It wanders to just above half in traffic then the fans come on and knock it back to dead on the first line. It creeps back up a smidgeon when the fans go off.
Stuart
Stuart
If the Lambda improves economy then I probably wont bother, I suspect it will have had one at some point, it sounds like a pain in the bum so will fit the Lambda when my shrink crimps arrive as it is a generic one, wondering if that will be easy, hoping the old one comes out without much of a battle. I read on Clarks Garage that you cant solder them as they use the wire to draw air in so hoping that the shrink crimps are ok as dont want to use normal crimps as I suspect there would be water ingress.
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