EGR myths and cold starts.

[jpliddy]

hi 5cylinder
this engine is pretty basic regarding EGR a bypass valve that takes a small amount of soot to reburn .
the valve cokes up up very quickly '
so mine is blocked off .with no side effects

[miksu]

I'm still unable to find any information about egr being active or otherwise having any effect whatsoever until coolant temperature reaches about 30 degrees. It does have a significant impact after that though (mostly concerning cabin temperature), but even if it would be on, it would not really speed up the initial warm up according to all the papers I could find.

I need to check this in my car, at least it is not too difficult. Theoretically just logging maf info would reveal use of egr immediately.

[Richardkimber]

Excellent discussion

Thinking about fitting a sump heater and/or getting the EGR valve/cooler cleaned.

Do you suggest one in favour of the other, or both ?

[SwissXC90]

I have the diesel preheater in my D5 and it makes a massive difference in warmup time in winter.

Below around 15°C ambient temperature it is worthwhile running the preheater, it can help the diesel come up to normal 89°C operating temperature in around 1km of driving, from a "cold" (which really means "cool") start.

And as it consumes only around 1 EUR of fuel per hour, it is very cost effective and the benefits are well worthwhile.

Plus it clears my windscreen when I need it:

[skyship007]

Originally Posted by SwissXC90

I have the diesel preheater in my D5 and it makes a massive difference in warmup time in winter.

Below around 15°C ambient temperature it is worthwhile running the preheater, it can help the diesel come up to normal 89°C operating temperature in around 1km of driving, from a "cold" (which really means "cool") start.

And as it consumes only around 1 EUR of fuel per hour, it is very cost effective and the benefits are well worthwhile.

Plus it clears my windscreen when I need it:

Yep they are real good, but an expensive option. A simple plug in heat pad on the oil sump helps and they are fairly cheap.

[SwissXC90]

Originally Posted by skyship007

Yep they are real good, but an expensive option. A simple plug in heat pad on the oil sump helps and they are fairly cheap.

Mine cost nothing as it was on the car when I bought it 2nd hand

[skyship007]

Originally Posted by jpliddy

hi 5cylinder
this engine is pretty basic regarding EGR a bypass valve that takes a small amount of soot to reburn .
the valve cokes up up very quickly '
so mine is blocked off .with no side effects

Tampering with a required exhaust emissions system is classed as a criminal act and it invalidates the insurance policy unless it is declared as an engine modification. They only approve blanked EGR systems for race track use in the UK.

If the EGR does get dirty more often than every cam belt service interval, then something is wrong. Probably the injectors tips are gummed up (Try a direct feed injection system cleaner) or the thermostat is stuck open.

It's a good idea to get an hours worth of Sunday morning WOT on the autobahn once a month to burn it clean. Might need to do an Italian job in the UK (4th rather than 5th gear etc).
Even if the EGR stays clean like mine, the intake will need to be cleaned out every 50K miles or so.