Engine temperature

[HQentity]

Evening all! Hope you are having a good summer with your dolomites!

Just a few queries about temperature really. This year my dolomite has been getting mighty hot according to the gauge, which I don't remember happening last year - up to the 3/4 mark? How do you check the actual temperature? I've got an IR gun, but don't know how much different the coolant temperature is to the outside of the engine. For the 3/4 mark, it came back as 90 degrees for the head, 78 for the thermostat housing, 55 for the bottom radiator pipe - the radiator was hot across the whole radiator so I think its working well.

Temperature gets hotter when I go faster, and cools down dramatically when I put the heater on, to just over halfway.

Tomorrow I'm going to check the thermostat, but just wondered if anyone knows what a 'normal' temperature is, and how to check it? Thanks!

[Carledo]

If the temp rises the faster you go,the culprit is almost certainly the rad. Going faster increases the airflow through the radiator and this should be sufficient to maintain temperature even against the increased heat generated in the engine. If you need to employ the heater rad to control temp, the main rad is not doing its job properly.

Many moons ago I had a customer Sprint that exhibited the exact same symptoms. You could drive forever and a day at 50mph and it would keep its cool, at a steady 60 it would go up to 5/8 and at 70 to 3/4. since the customer used it on European motorways quite a lot, he liked to cruise at 80, which resulted in boiling unless the heater was on. I checked EVERYTHING, flushed out the cooling system several times (water was crystal clean, right from the start) changed the thermostat (twice) even overhauled the water pump. Then I found a small (hand sized) cold patch in one corner of the rad.

A new rad from Serck solved the problem completely.

Steve

[Mahesh]

I have an opposite problem, my car reaches half temp very quickly, and is running over that the last couple of days.

But I have not had a chance (or empty road) to go over 50.

My radiator is not in good condition, and am waiting for a new one from Alicool on Thursday, this is my first item to change, as every other cooling part has been replaced.

[cleverusername]

I have a related enqirey about Sprint engine cooling. I have a Saab 93 rad for my build, mainly because it is alot cheaper than the standard one and will probably work better.

I am building a home made fan control system, I bought a metail pipe section that you can screw a temperature sensor into, because I dont like the kenlow jam a probe in a hose method, seems to be asking for leaks.

The circuit basically compares the sender voltage to a reference voltage to trigger a rely to start the fan.

So here is my question? What temperature should the fan kick in at?

[Carledo]

I have a related enqirey about Sprint engine cooling. I have a Saab 93 rad for my build, mainly because it is alot cheaper than the standard one and will probably work better.

I am building a home made fan control system, I bought a metail pipe section that you can screw a temperature sensor into, because I dont like the kenlow jam a probe in a hose method, seems to be asking for leaks.

The circuit basically compares the sender voltage to a reference voltage to trigger a rely to start the fan.

So here is my question? What temperature should the fan kick in at?

I too have a Saab 9-3 rad and am going to get one of these fan sender pipes myself (the one drawback of the Saab rad is there's nowhere to put this sender, which is why I still have an engine driven fan at present) I will probably be using a Vauxhall sender which, if memory serves, kicks in at 97 degrees C and drops back out at 93. Other makes operate in similar but not necessarily exactly the same ranges. The Vaux one drops out higher than most cos Vauxhall use a 92 degree thermostat. You have to get used to the engine temp fluctuating more and generally appearing to run hotter with a system like this. And it can sometimes take a while to actually trust the system not to boil! A nice accurate capilary type guage, marked in degrees rather than H-N-C is a comfort, but then it is in ANY Sprint!

Steve

[Karlos]

HQentity, I have a used rad for an 1850HL. It is not to far from you, other side of Gatwick, you are welcome to swap it out and see if it makes any difference to your hot running.

[HQentity]

My goodness Karlos, thanks for that! I have my first run tonight since changing the thermostat, I will let you know how I get on!!

[cleverusername]

I have a related enqirey about Sprint engine cooling. I have a Saab 93 rad for my build, mainly because it is alot cheaper than the standard one and will probably work better.

I am building a home made fan control system, I bought a metail pipe section that you can screw a temperature sensor into, because I dont like the kenlow jam a probe in a hose method, seems to be asking for leaks.

The circuit basically compares the sender voltage to a reference voltage to trigger a rely to start the fan.

So here is my question? What temperature should the fan kick in at?

I too have a Saab 9-3 rad and am going to get one of these fan sender pipes myself (the one drawback of the Saab rad is there's nowhere to put this sender, which is why I still have an engine driven fan at present) I will probably be using a Vauxhall sender which, if memory serves, kicks in at 97 degrees C and drops back out at 93. Other makes operate in similar but not necessarily exactly the same ranges. The Vaux one drops out higher than most cos Vauxhall use a 92 degree thermostat. You have to get used to the engine temp fluctuating more and generally appearing to run hotter with a system like this. And it can sometimes take a while to actually trust the system not to boil! A nice accurate capilary type guage, marked in degrees rather than H-N-C is a comfort, but then it is in ANY Sprint!

Steve

I bought the sender and pipe section from China, they cost £8 combined.

I have built a circuit using an opamp and pot potentiometer. In theory is I wire the sender as one half of a potential divider, since it is just a temp dependent resistor. I should have an adjustable temperature control system.

[Carledo]

I have built a circuit using an opamp and pot potentiometer. In theory is I wire the sender as one half of a potential divider, since it is just a temp dependent resistor. I should have an adjustable temperature control system.

Sorry, can you say that in English?

My theory was to to use the thermo switch to switch a common or garden 40 amp 4 pin relay which will run the fan. The Vauxhall switch I would use is the one for a 2.0 8v Cavalier which is what my engine basically is. My car has sufficient space to fit a Saab 9-3 fan (I have 2 in stock) so no problem making it fit the rad and the built in cowling will direct the airflow nicely too. It will obviously be more complicated with the stock Triumph motor cos I don't think you'd get the rather bulky Saab fan motor betwixt rad and engine.

Food for thought is that I don't like the Kenlowe system either but one of my customers has a novel take used on his Rover V8 powered Stag.
Rather than have the sensor bulb in water his car has it cable tied against the radiator core at the inside lower n/s corner of the rad. a little fiddling with the temp control adjustment had it working perfectly! If you really need an adjustable switch this may be a good way.
I don't fit many Kenlowes these days (cheaper and arguably better options abound) but if I do need to do another, I will do it this way now I know it works!

Steve