interesting phenomena

[jx2mad]

Having recently replaced the EGR valve with a blocking kit on my '03 L322, I have noticed that it takes a lot longer to warm up. Tonight arriving home (14km drive) with the outside temperature showing 8 degrees, the temp gauge showed a lower temp than normal. I assume that this is because no hot exhaust gasses are getting into the air intake, so the engine runs cooler and takes longer to heat up. Jim

[RangieBit]

Well that could certainly be part of it Jimbo.

So, winter time. Average morning temp about 5-6deg. I used to have a 60km commute and as long as I traveled at a reasonable pace (enough to ensure sufficient airflow thru the radiator/intercooler without fan assistance) it took about 45 of those km before the temp gauge showed a "normal" operating temperature. Up in the alps it once took all morning before the gauge showed a mid range or "normal" temp. I think part of it also is that the gauge isn't showing a real temp, it's being fed the signal prompted by an amalgam from multiple ECU inputs.

That's an unmodified (no EGR blanking) TD6 btw.

This is my recorded experience, your mileage may vary (as they say).

Cheers,
Iain

[Blknight.aus]

errr.....

how about, its colder, you have more cooling effect coming off of the block and you also have the heater on which will be pulling heat out of the engine.

If you have oil coolers they're now also working a hell of a lot more effectively at dumping heat.

[Graeme]

The EGR coolers on the 3.0 TDV6 are closed until the engine warms-up to speed-up engine warming.

[jx2mad]

Thanks all. I assumed it was something like that. I suppose it won't hurt the engine to run cooler? Jim

[RangieBit]

errr.....

how about, its colder, you have more cooling effect coming off of the block and you also have the heater on which will be pulling heat out of the engine.

If you have oil coolers they're now also working a hell of a lot more effectively at dumping heat.

Absotively and posilutely. Hence my comment about sufficient airflow thru things without extra assistance. You know, all that nice cool air flowing by and liberating heat from that great hunk of metal called an engine. The intercooler is now working better at reducing the intake temp because the temp differential is greater. All of this in addition to the things you mention like oil coolers. As has also been pointed out, the EGR would normally be allowing uncooled gases into the intake. Although from my personal experience this may not be as big a part of the equation as some of the obvious things you mention.

Some of this is also about the story after changing something. We tend to get ultra sensitive to things again that maybe we'd just taken for granted when everything was "status quo". Case in point, the temp gauge probably exhibited very similar behaviour last winter but we just didn't really pay as much attention.

Just my $0.02 worth.

Cheers y'all,
Iain