Elevated exhaust gas temp

[CraigB]

I have an EGT gauge fitted to my disco II. Recently then temperatures have been a bit higher when idling. It also takes longer to cool down before switching off.

Previously, I would wait for it to go below 200 deg before switching off, but now it won't go below 220 deg.

Could the bypassing of the wastegate that was done recently have anything to do with it.

My air filter is clean.

[Henk Coetzee]

Hi Craig

Nice to see you here too.

I have found 2 things which slow down the rate at which the EGT drops.

The first is engine load just before you stop. If you drive up a steep hill before stopping the EGT will take a lot longer to come down below 200 degrees.

The other is hot weather which has two effects. The first is that the higher combustion temperature means that the combustion chambers are hotter and consequantly the EGT takes longer to come down. The other is that the aircon is on and the added load also heats everything up. I find that if the aircon is running, the EGT will come down to around 220 degrees and no lower until the compressor clutch disengages. On a Disco 2 with the climate control set to auto in Kathu at this time of year, the aircon compressor is likely to be working hard:D.

When will we see you on the Africa forum? There's a nice bunch of people there.

[TEMPL4R]

You need to ask Porny or JONV8, they are much better with TD5s than I am, but if you bypass the wastegate, it will overboost and give problems, won't it?

If it is playing up since you altered something, look at that, it's probably the cause.

chris

[CraigB]

Thanks Henk,

When will we see you on the Africa forum? There's a nice bunch of people there.

Didn't know there was one - whats the address?

[Roger Whittle]

Thanks Henk,



Didn't know there was one - whats the address?


Just use the 'Forum Jump' drop down at the bottom right of the page, scroll down to 'Africa' and join in. :D (I know I'm not from 'round there', but there are reasons why I know Henk and some of the crowd down there.:))

Talking of white smoke Henk, wasn't that what happened to your Disco I in Lesotho?

Roger.

[Henk Coetzee]

Talking of white smoke Henk, wasn't that what happened to your Disco I in Lesotho?

I've tried to work out what went wrong there and haven't been able to reproduce the problem, even going down some pretty steep gradients just south of the Lesotho border.

The conditions that caused the smoke seem to have been (in no particular order)

Slight throttle opening (I know it's wrong to say that with a diesel) on a steep downhill in low range 2nd or 3rd, after a lot of compression braking.
Very low (sometimes <100 degrees) EGT as a result of 1.
Altitude above about 2500m above sea level.
Diesel from Qacha's Nek in the tank.I was the only one to fill up with diesel at Qacha's Nek and it's the only thing I haven't been able to reproduce.