Delica Canada | Mitsubishi Van Club

Rattlenbang: thumbs up!

I think theres 3 things.

1. The head isnt good enough, not for longevity, maybe its just a bean counting thing, the extra expense of a better head wouldnt matter for 75% of vehicles, so they dont care, maybe not, but, its likely one day it will have to come off.

2.The probe in the EGT port is not going to be accurate, but it can be indicative, and if it s your vehicle and you know whatthe typical numbers are, you probably know where it should be driver. You could take the time to measure at the EGT point, and measure at the 'correct' point, wherever that is, but it still may only apply to that vehicle with that exhaust etc.

3. Any turbo diesel with a method of managing the wastegate, and the fuelling settings via the pump, can be made to self destruct.

Rattlenbang wrote:...When I think about it, there's also an assumption that internal cylinder temperatures are directly reflected in the exhaust gases, which may not be the case. ...

That's why I mention that the engine around the explosion is not as hot, due to the cooling systems. First thing I wish to clarify is I am not a professional mechanic, I'm a painter, actually, but I have a passion for my Starwagon and I do listen to my mechanic friends.

The campfire metaphor was just to demonstrate how fast heat can dissipate in space as an introduction to the rest of my post.

I was recently on the Queen Of Naniamo and was fortunate enough to get a tour of the engine room, hosted by the chief engineer. He described how the engines work and in the case of his Mirrlees V16s (beautiful machines) at the bottom of the stroke the cylinder is 40°C where at the top of the stroke the cylinder is 900°C (because of compression). Of course these numbers aren't going to be accurate to our little diesels, but you get the idea. The exhaust port doesn't open until the piston has reached the bottom of it's stroke and that's when the used gasses get tossed.

I've been learning a lot about my little Astron since getting my Starwagon (still a lot to learn), currently interested in how the compression system works and it blows my mind how a little adjustment can affect the whole system. The engineering behind these engines is brilliant.

I think one of the main issues behind blown heads is people are "driving them like they stole them".

Anyway, the question still stands: Where is the EGT sensor measuring from?

Falco.

Rattlenbang wrote: The EGT might just be more an indicator of how hard the engine is working rather than an indication of the actual combustion chamber temperature.

I think you're right on there. It's also why I think the gauges are nice, but not essential. There are enough other indicators of how hard the motor is working.

Also, the motor runs at different temperatures....if you drove constantly at 1100 then eventually the turbo and pipe would heat up to some warmer temperature...but the metal is acting like a heat sink so the further you go the less heat...now say the turbo is at 600 and you hit 1100 pre turbo the turbo is going to take some of that heat away....like property location is everything..