Joerg wrote:Have driven my CV8 last week at similar temperature and the water temp needle stood exactly in the middle. The thermostat is definitely not working correctly.
If your heat is working then the thermostat is fine. The cold weather will keep the temp gauge lower than usual.
Joerg is reffering to Felix's car's thermostat comparing it to how his was in the cold weather Slotcaone,
I drove down to town yesterday in my Interceptor, the oil pressure was slightly lower than normal when the car was cold (-1 here yesterday) but as soon as some heat had got into the engine it returned to normal. I have never seen that before. I suspect at that temp the oil was thicker than it usually is but seems odd.
Steve Payne wrote:I drove down to town yesterday in my Interceptor, the oil pressure was slightly lower than normal when the car was cold (-1 here yesterday) but as soon as some heat had got into the engine it returned to normal. I have never seen that before. I suspect at that temp the oil was thicker than it usually is but seems odd.
Steve
Exactly the same happened to me too Steve at the weekend
If the spring in the relief valve is getting a bit tired it will open at a slightly lower pressure when cold than when hot.
Wrt Felix's temp issue I guess the thermostat is not seated properly or not closing completely when cold. The resultant leak-by will leave the engine struggling to keep working temp at the right level. Fyi my FF sits at the normal temp in -15C whatever the the other circumstances. (Although now it just sits till the new oil pump and shaft arrives. )
Per
Not only English cars these days, an Italian is part of the stable again
So the thermostat reading should stay in the middle on the motorway at those temperatures? It did so at lower speeds. I don’t understand why -10C air blowing through the engine bay at 140kmh will not have an influence- conversely on a hot day (30C or above) the temperature gauge at that speed will climb towards the top.
Spoke to an acquaintance who was on the motorway the same day and got into a traffic jam. A Tesla gave up in the cold in the middle of traffic, all lights blinking.
Felix Kistler
C-V8 112/2454, 541DL 2223849
JOC 9465
Secretary/VP JCC Jensen Car Club of Switzerland www.jcc.ch / office@jcc.ch
The heat generated by the engine even at that speed is enough to keep it at the right tem if no energy goes into the rad. Our engines are not overly efficient.
Drive on the motorway until temp has settled at the low level you have seen and the another ten mins. Stop in a layby and immediately lift the bonnet and feel the top hose temp near the rad. If anything but lukewarm or colder the stat is not fully preventing flow as it should. (A wee leakby is there to ensure the stat is exposed to the right temp in the coolant and to prevent too sudden temp changes.)
Per
Not only English cars these days, an Italian is part of the stable again
Ok, thanks Per and all. Unfortunately it has snowed in the meantime and the roads are being salted again, so no more driving in the C-V8. Will watch the gauge in the Subaru though
Felix Kistler
C-V8 112/2454, 541DL 2223849
JOC 9465
Secretary/VP JCC Jensen Car Club of Switzerland www.jcc.ch / office@jcc.ch
The gauge should read more or less the same temperature with the engine at operating temperature, the weather being cold or hot. This is the approximate opening temperature of the thermostat when the temp.gauge sender is in the cylinder head.
If the thermostat is faulty the engine may not reach operating temperature at all if stuck open or get overheated if stuck closed.
Kees Oudesluijs
kees wrote:The gauge should read more or less the same temperature with the engine at operating temperature, the weather being cold or hot. This is the approximate opening temperature of the thermostat when the temp.gauge sender is in the cylinder head.
If the thermostat is faulty the engine may not reach operating temperature at all if stuck open or get overheated if stuck closed.
Kees Oudesluijs
In thoery I agree with you. I know from my own experience when the air temp is extremely low the gauage will read lower and I think the thermostat does its best to compensate. Last year I was driving my Interceptor on a day when the air temp was about 0, on the motorway after about 20 mins the gauge dropped to the point where the thermostat must have been opening and closing as was a lot lower than it is usually. As soon as I returned to A roads and town driving it moved back to its normal position.
Strange, as the thermostat does not open fully instantly, it partially opens and closes as soon as the coolant temperature drops, so the thermostat may not be functioning as it should. Of course there is a range in which this happens but I doubt if that is more than 5-10 degrees.
In my J-H I have very little variation in coolant temperature while driving in cold or heat. A higher temp only happens in slow traffic when the radiator is not cooling sufficiently but between 5-10 degrees higher than normal the electric fan kicks in to bring everything back to normal.
Kees Oudesluijs
After driving my Interceptor for over 30 years I have stopped worrying about the temp gauge. Biggest concern is does the car push out coolant on a hot day after turning it off? The cars that these engines original came in rarely if ever had a temp gauge--just what we call an idiot light here in the States.
kees wrote:The gauge should read more or less the same temperature with the engine at operating temperature, the weather being cold or hot. This is the approximate opening temperature of the thermostat when the temp.gauge sender is in the cylinder head.
If the thermostat is faulty the engine may not reach operating temperature at all if stuck open or get overheated if stuck closed.
Kees Oudesluijs
In thoery I agree with you. I know from my own experience when the air temp is extremely low the gauage will read lower and I think the thermostat does its best to compensate. Last year I was driving my Interceptor on a day when the air temp was about 0, on the motorway after about 20 mins the gauge dropped to the point where the thermostat must have been opening and closing as was a lot lower than it is usually. As soon as I returned to A roads and town driving it moved back to its normal position.
Steve
Exactly what I experienced Steve. Even after a 10 minute stop for lunch the temperature gauge had risen and was back to normal. 6 miles later it had dropped again! Too be honest, it was so cold that I wasn’t sure if it was a good idea to take the car out for a drive. Overheating is never an issue Slotcarone (except for the brakes, and that was Stelvio):
AE13214E-B967-4B17-A0FA-7F05CDAA2268.jpeg (182.03 KiB) Viewed 2191 times
Felix Kistler
C-V8 112/2454, 541DL 2223849
JOC 9465
Secretary/VP JCC Jensen Car Club of Switzerland www.jcc.ch / office@jcc.ch
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