I have the same problem on 80km/h roads
Its not 4th and not 5th gear, but for "heating up" the engine a bit I sometimes stay in 4th for a while.
If I go up in speed to ~85km/h I 'just' avoid fines and 5th gear is smooth enough.

 

its not just my GV then one of the joys of a manual hey

 

If there's speed limits everywhere, no decent long straights without cars and not able to get enough revs on the motorway. How about just driving along in a low gear now and again revving it at about 4,000rpm. Or do we need heat, engine pulling hard to clear out the cobwebs.

 

4,000 rpm might be a bit harsh on my GV lol I do stay in 4th a lot at just over 2,000 rpm and going up the gears I take her up to 2,500 no more than 3,000rpm. Does that place me in the grandma drivers club?

 

or grandad drivers club ..
You too might consider revving the GV up every now and then to avoid turing your GV into a clogged slow hockeymom car

 

Posted last August - all diesels like to be 'ragged' - its the automatic ones that are difficult to rag.

 

Hmm must change my name to an old grandad name like ''Morris''
maybe I could do a few miles at a smidge over 3000rpm that is where the engine is at its best performance wise anyway so no need to make it work too hard and risk something breaking, don't ask why but if it was petrol I have no issues taking them to the red line but with diesel I always been taught to not drive at high revs for too long because they have a must higher compression ratio. As a consequence, more heat is generated putting extra demands on the engine cooling system. diesel engines usually fail 40% more on cooling related problems because it cannot stand prolong overheating. This is why the cooling system is a high maintenance issue.
I have only just fixed my cooling system issue (water pump & connector hose from water pump to oil cooler) and although I am 99% certain is fine, that nagging 1% just tells me to not over do it haha


sorry this reply is longer than I intended

 

The 'cruise catch up' on the auto CRD is set to 3k anyway. Its not the RPM per-se its the heat generated over the time. Caveat emptor doctrine still applies. just watch the gauges like a hawk - as you say - if in doubt - don't do it !

 

If the overheating is what worries you.. I would start revving as soon as the temp gauge is on 1/4th (engine is warm and ready to perform) and stop revving as soon as you get near the red zone.
That way you risks on damaging/overheating are minimized (imho).

 

The most stressed part of diesel engine is the cylinder head and gasket. Compression ratio is between 16:1 and 18:1 depending on the design for NOX emissions, whereas ratio for petrol is almost always under 10.5:1 due to knocking problems. Furthermore, in principle diesels are unthrottled (sometimes light throttling for emission control) therefore the compression pressure is always much higher with a diesel. As most car diesels are turbocharged, the compression pressure is yet higher still at full power.
If you give a diesel an italian tune-up, it's wise not to do it for too long as there could be a blown head gasket. Certainly revs is/are the key to success here. It is universally agreed if you are GOING to do an italian, do it just before you change the engine oil.
While driving normally, every week or so I give it a "full-bore experience", hang the fuel consumption. But as Goggs says, driving around nowadays is like trying to swim through treacle with all the traffic.

Leedsman.