ideal engine tempreture D24 TDI

[jpliddy]

hi
can anyone recommend the ideal temperature these engines run at
with the very hot weather here even my bottom hose is hot now but not as hot as the top hose which is very hot after a 20 mile run tonight . the reservoir tank is warm too but not really hot . in normal cool weather coolant is much cooler seems much cooler in winter months but heater has always been good then i still don't have a working tempreture gauge but am always lifting bonnet car does not use any coolant am i concerned over nothing . i know its critical to have a working temp gauge by what you guys say !
regards jim

[RedArrow]

TDI as turbodiesel indirect??

It's a good sign that your bottom hose is substantially cooler. If concerned you could always get a new thermostat the wahler 87C or even the 80C wahler works good. IDK what climate you are on bc no location on your profile.

A level sensor would have been nice from factory but never happened.
If feeling slight overheating, temporarily increase the RPMs gently about 20% or to around 3000rpm temporarily since the waterpump is belt driven from the crankshaft so it obviously would process/flow more coolant. Also you could get the 5cyl diesel audi waterpump which has different gearing and spins faster.

Idk what else you could do..
Where do you live? At what temps did you feel-test your hoses?

And, YES, working temp gauge is absolutely critical though somewhat unreliable bc it shows overheat only when it is kind of late already. This temp gauge is your only feedback about the cooling system so it is HIGHLY suggested for you to fix it up asap if not functioning. Cheapest insurance to save a life.

[jpliddy]

hi red arrow
thanks for reply the weather here in our part of England has been very hot over 28 degrees C so been driving 20 miles at the hottest part of the day !
the bottom hose was only cooler than the top hose but top hose very hot wither having 274000 miles now but i don't abuse it after 20 years plus of ownership .i really do need to get someone to fit a temperature gauge with a warning buzzer of some sort with is not hard to adapt to my D24 tic 1995!!

[RedArrow]

As first step it would be great to check and refurb the existing temperature gauge.

You could check the terminal at the front of the engine, right at the very front on cylinder one, on the driver side of the engine (not for you in the UK but in the usa... it is the left side of the car LOL), so check there to see if the wire that runs to the sensor is intact.

There`s leaks and corrosion and also gravitation, so there`s a chance that the connection is bad there (your instr cluster doesnt get the signal from that spot)

The other temp sensor is located in the very rear of the engine near the firewall, behind the IP, which is another temp sensor that is the same, measuring temps for the glowplug relay.
If the temps are warm enough, the glowplug relay doesnt activate the plugs.

Why I`m saying this is that those two sensors are totally the same exact parts and technically you could use the front in the rear and the rear one at the front.

If this helps for testing the system, that could be done too.

I have an engine on the stand and can take picture for you of both sensors. In the rear there is very tight access only.
I`d start by checking and cleaning the surface of the pin of that sensor, then testing the front sensor somehow or maybe measure continuity on the wire.

On certain d24 cars the glowplug wiring also attaches to that area on cyl one so there`s a change that somehow the wire to the sensor was disturbed, chafed, removed, etc. Take pictures and post some

Take a look at this picture. It shows both temp sensors: there`s the one at front to the left of the first glow plug, towards the front... and you can see the one in the back of the head also. It is a d24t but d24 engines have the same configuration.


Your top hose being hot is very normal, do not worry about it too much for now, it really is where the `used hot` coolant exits the motor and is shooting for the radiator to get cooled down in there and then get transferred back into the engine via the lower hose.

The 1995 TIC TD cars are probably very nice! I thought they had already the coolant level sensor for those model years in Europe. Doesn`t your coolant expansion reservoir have a level sensor in it?? If you see electric wires going into it or under the tank, then yes which would be good news. If not, then you can always update your system to have such, by swapping in a sensored reservoir from a younger car and have it wired up to a gauge or an audible alarm or both. A level sensor is as equally great to have as the temperature sensor itself is.
I keep seeing the 850 960 cars in the junkyards and already took home a small-sized reservoir with the level sensor but never made it to have it wired up. It is mainly about the relocation of the existing reservoir and making a new bracket that looks near stock; so that`s why I kept delaying the project.



((A sidenote and general advice to everyone: try keeping all of the coolant hoses free of *all kinds of* cleaners, chemicals such as engine shine, armorall, etc, including dirt, dust, even motor oil, diesel vapor, power steering fluid and literally: everything. Wipe them clean with soapy water, a towel; and try to keep them clean as much as possible at all times.))

[jpliddy]

thats one hell of a engine there like new !
thanks for help .yes i know a bit i know the temperature sensor is at front behind the alternator bracket, its a remove alternator job there to get at it , i managed to partly damage the connector block trying to pull it apart to see if i have power there the outer sleeve broke up .
i have a spare temperature float that pokes into my spare reservoir i have but don't know if it works its got 2 wires from the probe but been in shed for ages got it secondhand ,i didn't know about the glow plug sensor at back of engine though . im not a engineer .im a enthusiastic carpenter . in the next month or so my engine will pass 275000 miles so oil and filter coming up im always living the bonnet to check coolant level !!!

[jpliddy]

hi RED ARROW
have had a look at the tempreture sender at the back of engine it has 1 wire spade connection
i can fee the tempreture sender at front of the engine it has a 2 wire connection
but cant get a good view of it .
thanks for your input . i woud like to post photos here but i don't know how to i can send them via email !

[RedArrow]

When you edit your post, you can see a staple icon and that will help you manage an attachment into your post.

The image can not be supersized but if it happens that the forum system doesnt accept it then screenshot it and attach that instead.

a two-wire temperature gauge at front?

I never personally found one of those on my engines. Are you sure you are looking at the right spot? Or maybe the EU cars are different? esp the newer ones? (did you notice that I called a 1995 new? our volvos here are from the 80s...)

I think it is more possible that what you are seeing is this: that section of the wiring harness has two wires in it and it is running that way, towards that temp sensor, and it does hold two wires, but only one for the temp sensor and the other one for energizing the glowplugs. Im not sure. a picture would be good help.

[ngoma]

RedArrow, his car has a different front temp. sensor than what you are used to. Two-wire, like what the gassers have.

jpliddy, that sensor you see in your coolant overflow tank is not a temp sensor, it is a coolant level sensor (float sensor), a very desirable addition that would be well worthwhile wiring up to a warning lamp/buzzer on the instrument panel. It would tell you immediately when the engine has lost coolant, giving you a chance to pull over and assess the situation before overheat damages can happen.

That way you also wouldn't have to be constantly checking the coolant level.

Since you are a carpenter not an engineer, maybe you can do a trade with one of your clients who has skills to wire the sensor to a warning buzzer/lamp?

[jpliddy]

thank you both for your input there are some spare build indicators at the bottom of my dash .have you seen this sort of set up as the bulbs are very small as you will know .
regards jim

[ngoma]

Yes that is a very good idea, to make one of the unused extra bulbs the indicator for your low coolant level alarm.