Thread: I almost cooked my diesel due to a faulty temp guage. I need an audible alarm.

Thanks Mox. Definately worth some thought.

Hey RoverLord. Got the heater hoses today in Albany WA. Damn fast service. Thanks guys. Great job - Gerry (Wedgetail37)

Originally Posted by mox

What I have is a simpler, cheaper and overall more foolproof way of reducing the risk of overheating a 300Tdi. than the likes of alarms. A temperature sensitive switch on the head. The wire from ignition switch to fuel solenoid on the injector pump goes through this switch which has spade electrical connectors on it. Contacts in the switch opens if head temperature gets to 105 degrees for whatever reason and motor stops. Also have a bypass switch installed so motor can be run for a short period, eg to drive off road if it stops at an inconvenient time. Best push button, so idiots cannot leave protection switch bypassed.


Have noticed when mentioning this setup on aulro in the past, the reaction is most likely someone will claim this is dangerous because the motor could stop in a situation like in the middle of an intersection. Then someone else will thank them for this "useful" post. Maybe this is influence from vendors selling alarms. I would encourage them to instead consider selling my type of protection, which does need alarms of low water sensors.

Dangerous and potentially fatal to the engine, just cause you got it got doesn't mean you shut it down. If you've got it that hot and the coolant hasn't dropped. If you were working at a hard climb in too tall a fear you now can't downshift and cool the engine which will simply continue to stew in its own juices potentially rupturing stuff, whereas p being able to unnloand and keep the engine running at lower or no load will let the cooling system do it's thing.

The better way of doing it if your going to do it this way is to stage it so you get the warning alarm and then after about 20 seconds you get a shutdown. You should also set it up so that when your on the overheat shut down the ad fans kick in giving some air flow through the radiator, there's quite an effective thermocycle available by doing that.

If you've got it set up as a kit and want a hand nutting out how to hook it up drip me a pm.

This principle has been on trucks for quite some time along with an extended idle shutsown

Originally Posted by mox

What I have is a simpler, cheaper and overall more foolproof way of reducing the risk of overheating a 300Tdi. than the likes of alarms. A temperature sensitive switch on the head. The wire from ignition switch to fuel solenoid on the injector pump goes through this switch which has spade electrical connectors on it. Contacts in the switch opens if head temperature gets to 105 degrees for whatever reason and motor stops. Also have a bypass switch installed so motor can be run for a short period, eg to drive off road if it stops at an inconvenient time. Best push button, so idiots cannot leave protection switch bypassed.


Have noticed when mentioning this setup on aulro in the past, the reaction is most likely someone will claim this is dangerous because the motor could stop in a situation like in the middle of an intersection. Then someone else will thank them for this "useful" post. Maybe this is influence from vendors selling alarms. I would encourage them to instead consider selling my type of protection, which does need alarms of low water sensors.

That's particularly dangerous for the driver and occupants to.

I was driving along the highway your honour, the ac kicked in, the engine got a little warmer and then cut out Competely!

I lost power steering, I lost vacuum brakes and all because some clown read a dangerous idea on a forum and decided to copy it!

I have the Engine Watchdog TM4. It has an adjustable warning buzzer and is dead easy to install. It has a gearbox sensor which might be overkill for a manual, but you could put it on the front and the back of the head.

Jeff

A major disadvantage of some types of engine protection systems, is if it relies on alarms or the protection system functioning to stop the motor or warm the operator is that you may unknowingly have no protection if something goes wrong with the system itself. Even just a wire falling off. Far safer with a setup like mine. Most things than go wrong with it cause the motor to stop or not start. Have heard of cases of cooked motors because of malfunction of non failsafe protection devices.


With my setup, if motor unexpectedly cuts out due to head getting hotter than temperature switch allows, effect is same as turning ignition switch off. Can immediately press override button next to it if desirable to drive off road, provide continued oil for turbo etc. With no protection device, often motor stopping with fatal damage is first symptom driver notices. Then power steering and vacuum brake assistance also does not function. Hopefully this does not occur in the occasional situation causing a problem stopping safely. Normally the steering and brakes still function but are much heavier than normal and with may be less responsive if driver cannot apply enough force.


Those who like the idea of warning alarms going off first when there is a problem can still have the cheap and more failsafe setup to stop the motor as backup if does not work. Or, as I have seen mentioned on this forum, if some ignorant driver with no understanding of protection devices just keeps going with alarm blaring. Sometimes offering excuse for cooking motor like "I was just trying to get home".

Originally Posted by mox

A major disadvantage of some types of engine protection systems, is if it relies on alarms or the protection system functioning to stop the motor or warm the operator is that you may unknowingly have no protection if something goes wrong with the system itself. Even just a wire falling off. Far safer with a setup like mine. Most things than go wrong with it cause the motor to stop or not start. Have heard of cases of cooked motors because of malfunction of non failsafe protection devices.


With my setup, if motor unexpectedly cuts out due to head getting hotter than temperature switch allows, effect is same as turning ignition switch off. Can immediately press override button next to it if desirable to drive off road, provide continued oil for turbo etc. With no protection device, often motor stopping with fatal damage is first symptom driver notices. Then power steering and vacuum brake assistance also does not function. Hopefully this does not occur in the occasional situation causing a problem stopping safely. Normally the steering and brakes still function but are much heavier than normal and with may be less responsive if driver cannot apply enough force.


Those who like the idea of warning alarms going off first when there is a problem can still have the cheap and more failsafe setup to stop the motor as backup if does not work. Or, as I have seen mentioned on this forum, if some ignorant driver with no understanding of protection devices just keeps going with alarm blaring. Sometimes offering excuse for cooking motor like "I was just trying to get home".

As well as all the safety issues, immediately shutting down a hot engine is the absolute worst thing you can do to it.

The turbo spinning at up to 100k rpm with a turbine up to 700c suddenly loses oil feed and oil cooling.
The water circulation in the cooling passages stops so that water immediately overheats and boils locally. Creating steam pockets.

Then on restart you get thermal shock as colder water rushes back in and the steam pockets implode.

There is no good point about your system.

Originally Posted by mox

A major disadvantage of some types of engine protection systems, is if it relies on alarms or the protection system functioning to stop the motor or warm the operator is that you may unknowingly have no protection if something goes wrong with the system itself. Even just a wire falling off. Far safer with a setup like mine. Most things than go wrong with it cause the motor to stop or not start. Have heard of cases of cooked motors because of malfunction of non failsafe protection devices.


With my setup, if motor unexpectedly cuts out due to head getting hotter than temperature switch allows, effect is same as turning ignition switch off. Can immediately press override button next to it if desirable to drive off road, provide continued oil for turbo etc. With no protection device, often motor stopping with fatal damage is first symptom driver notices. Then power steering and vacuum brake assistance also does not function. Hopefully this does not occur in the occasional situation causing a problem stopping safely. Normally the steering and brakes still function but are much heavier than normal and with may be less responsive if driver cannot apply enough force.


Those who like the idea of warning alarms going off first when there is a problem can still have the cheap and more failsafe setup to stop the motor as backup if does not work. Or, as I have seen mentioned on this forum, if some ignorant driver with no understanding of protection devices just keeps going with alarm blaring. Sometimes offering excuse for cooking motor like "I was just trying to get home".

But yours could malfunction just as likely as the warning devices.

Jeff