EGT gauge reading too low?

[Wilbur]

Hi all,

I have just fitted an EGT gauge to my 300tdi Defender. The kit that was supplied has the thermocouple going in tangentially to the plate, so it doesn't go in very far before it hits the manifold. Also, it will obviously not be right in the gas flow, rather it is in a little pocket.

Driving around town gently it reads around 250 degrees. Crusing the highway at 100 k's it reads about 400 degrees.

Holding it flat to the boards in 3rd at about 80KPH up a 1 kilometre hill it reaches 450 degrees, which seems suspiciously low to me.

I have a camper built on the back of the 130 and total weight is 3.2 tons so the engine does work pretty hard up hills.

Have I got a problem with the EGT gauge, or am I maybe not fuelling enough? The car goes in for a gas fumigation kit next week, and I would like to know that the gauge is accurate.

Grateful for any suggestions.

Cheers everyone,

Paul

[Taz]

Your cruising figures of 250 (gentle) and 400 (100km/hr) sound correct. Full load up hills should be more like 650-700. Looks like you have some room to boost the fuelling :)

[sclarke]

Those figures are SPOT on.....

do a hard Hwy hill then on the down hill clutch it and idle.... should drop to 200 in seconds...

[B92 8NW]

Holding it flat to the boards in 3rd at about 80KPH up a 1 kilometre hill it reaches 450 degrees, which seems suspiciously low to me.


Grateful for any suggestions.

Cheers everyone,

Paul

That figure is not overly suspiciously low. The EGTs would be higher if you tackled that hill in 4th. Next time you run that hill, try it in 4th - if it labours, just keep the foot planted - the EGTs will go well beyond 450.

When I towed with my 200Tdi Discovery, the EGTs dropped markedly if I downshifted to 4th and let it rev rather than strain in 5th.

[Wilbur]

Thanks for the replies - that is just what I wanted to hear!

Reckon I will try boosting the fuelling. It is VERY economical, maybe that's why. The only reason I haven't tried it before is that even with over a ton of camper on the back it is nearly as fast (on the flat) as my TD5 130.

It also gets the same economy......

Cheers all,

Paul

[Wilbur]

Oh also, it does drop some black smoke a bit when under heavy load. Am I right in guessing that means I shouldn't increase the fuelling?

[pawl]

That little pocket is fine, as long as you have 20mm extending into it. The difference between here and No.1 exhaust branch are virtually identical. Ian peterson, http://www.thermoguard.com.au/ who markets his own egt gauge tested these two positions, he is a wealth of knowledge on egts and gauges.( I am not affiliated with him, I just picked his brains).

[Taz]

Oh also, it does drop some black smoke a bit when under heavy load. Am I right in guessing that means I shouldn't increase the fuelling?

Depends where - if it's only smoking on WOT then you can still get more mid range performance by boosting the turbo compensator cct. Perhaps wind the max fuel screw out another 60deg if it is only at WOT.

[Wilbur]

That little pocket is fine, as long as you have 20mm extending into it. The difference between here and No.1 exhaust branch are virtually identical. Ian peterson, ThermoGuard Instruments (http://www.thermoguard.com.au/) who markets his own egt gauge tested these two positions, he is a wealth of knowledge on egts and gauges.( I am not affiliated with him, I just picked his brains).

Thanks Pawl,

That's good to know.

In fact it is one of Ian's thermocouple kits I used, to replace the one that came with the VDO kit that I lost.....

Cheers,

Paul

[Wilbur]

Depends where - if it's only smoking on WOT then you can still get more mid range performance by boosting the turbo compensator cct. Perhaps wind the max fuel screw out another 60deg if it is only at WOT.

Thaks Taz,

Yes, it only smokes on WOT. I am looking forward to having a play. I am taking it to Canberra today for a gas fumigation kit. There will be a lot of fun playing and tweaking over the next few weeks.

Other than excessive EGT, is there any other indication if I go too far on the fuelling?

Cheers,

Paul

[rick130]

<snip>

Other than excessive EGT, is there any other indication if I go too far on the fuelling?

Cheers,

Paul

yep, copious quantities of black smoke and eventually BANG ! (although a bloke posted a pic of a 300Tdi fuelled right up on Outerlimits once. Everything was glowing white )

And just to post a gratuitous pic of one of Ian's pyro's. (taken just this morning on the way back from a morning coffee :D)

https://www.aulro.com/afvb/

This was one of Ian's very first ones years ago, he's supplied over 250 since !

[PAT303]

Only 240k's Rick,she's just run in!!!.I'm going to fit one later in the year when I get it hooked on D/gas.I like the temp gauge,looks good. Pat

[rick130]

and there's the boost gauge beside that reading 10psi, if you could see past the glare.

[Blknight.aus]

Those figures are SPOT on.....

do a hard Hwy hill then on the down hill clutch it and idle.... should drop to 200 in seconds...

I'll back that providing your induction and fueling is stock...

the tdi's/td5 are fairly unique in that they are setup so that when stock you cant burn them out from laboring them to death.


of course that leaves people like me to go... you know that safety margin seems like it could do with a diet.. we then sell our cars to others, forget to tell them to watch the noise pedal and then they go and fry the donk.