Turbo heat

"If you fit a EGT gauge and you find it overheats, what do you do? "
- back off the accelerator.


"Why do you need this rather than rely on the temp gauge in car?"
- it will give you an early indication than cooling water temperature.

Twinkles

Thought I'd add my thoughts on your questions, although this is only how I perceive the EGT system to work.... not being a mechanic, I may be wrong, but I apply these principles to my own Patrol and so far have been OK...... If I am wrong, I am happy to be corrected!

"If you fit a EGT gauge and you find it overheats, what do you do?"
Basically, it's amatter of finding out what temps are 'normal' for your turbo, and then you can monitor the temp. EGT is measured at the pipe that enters the turbo... which is the exhaust from the engine. The harder the engine is driven, the hotter this pipe gets. So, you need to know what the 'normal' temp is, and what the maximum temp should be..... usually some point well below molten-turbo-degrees-C. Monitoring the EGT then allows the driver to push the engine to a safe limit, then backing off will drop the EGT, rather rapidly. My GQ has an aftermarket turbo, I usually start to drop the power off around 500 degrees C, but some hills require me to "stay-on-it" and it then climbs to the 600 mark, which is the absolute maximum I would push mine to. I also watch my boost gauge and have found that at 11psi boost, which is my max setting, my EGT will climb rapidly. Often backing my boost back to around 7 or 8 psi will drop the EGT, while allowing the Patrol to keep it's power up.

"Why do you need this rather than rely on the temp gauge in car?"
By the time the temp gauge registered an overheated motor, you may have more problems than an overheated radiator to worry about. Possibly you will have mashed turbo bits in the engine somewhere. The EGT is monitoring the temp exactly where it needs to be monitored.

Hope this helps mate...

Cheers

Brian

David, every turbo diesel should have an EGT gauge as standard, is the only way to know what your engine is doing. You would be surprised how hot a standard TD will get when driven "normally", ie, foot hard down into a head wind or what ever, when the fix is to look at EGT and change gears or back off. My two pence worth. John

Hi John,

I have EGT and boost gauges as I have adjusted the fuel pump and boost on my car so now it is operating outside of the parameters set by the manufacturer. However a turbo diesel engine is designed with a specific EGT in mind so it will not go over this no matter how hard it is driven. This is what the engineers intended.

There are a lot of people out there that get an EGT gauge and don't really have an idea of what the are monitoring. There is always the question of "so I have an EGT gauge but what temp should I expect"? One reason for getting te gauge could be "cause old mates got one and it looks cool" (I have see that coment a couple of times on other forums - and I am not that anyone posting in this thread would have this perception either).

An EGT gauge is a reflection of your right foot. More right foot = more fuel = higher temps so knowing what your right foot is doing is an indication of what your engine is doing. For a standard factory spec'ed engine, that should be all thats required however for a modified engine that is operating beyond its intended limits then knowing just how much right foot for a given time is crucial.

Regards
David

David, you are wrong, modern TD yes, older designs no. A standard Nissan TD 4.2 will over heat very readily due to high EGT, lots try and remedy it by changing radiators etc etc, but, in most cases, it is due to over fueling.

You state that EGT is a reflection of your right foot, exactly, older TD's, standard and modified will have very high EGT's if driven incorrectly. With out an EGT gauge, you will have no idea what your engine is doing until the temp gauge starts to rise and then you back off........ An EGT is an early warning device.

Regards John

Thanks to all...............should have been more specific.......70=70series.......single turbo

Tom

"Remember you will need two gauges for the twin turbo."

- or two temperature sensors, a switch and one temperature gauge.

Dave, see reply to Dave above.

bungarra (WA).......

Commonly referred to as EGT...... Exhaust Gas Temperature. I'm guessing that ETG may be Exhaust Temperature Gauge... or possibly a typo.
Also referred to as a Pyrometer.

Cheap (around $3-400 for a good one) Insurance for your turbo. I know people who don't have one and there is a school of thought that factory turbo's don't need one, but personally I wouldn't have a turbo'd engine without an EGT gauge..... like I said it's cheap insurance.

Just my opinion though......


Cheers

Brian

Matt,

Great response, I agree that having an EGT gauge changes driving habits. I will never let an engine lug at low revs under load again!

Cheers,
Dave