Vauxhall Meriva engine warm up time.

oldagetraveller

I've recently purchased a 7 month old, 2400 mile Meriva with 1.7 Diesel engine. The same engine is I'm sure fitted to other Vauxhall models.
I suspect the warm up from cold is not as it should be. During cold spell last week (0 - 2 degC) it was taking at least 3-4 miles at 40-50 mph before there was any appreciable output from the heater. The engine reaches indicated operating temp only after about 8-10 miles. Stopping and running idle with the heater on causes the temp gauge to fall to about 80 degC and long downhill runs produces a similar result. The temp does maintain about 85degC once reached. The supplying Vauxhall dealer reckons it's o.k. and even states it takes 10 - 15 miles normally which I find hard to believe, I'm waiting to hear from Vauxhall Motors (e-mail). I will pursue further with the dealer but before doing so and avoiding a red face!, does anyone have the same model or one with the same engine as a comparison?

chrisw

I've got a new diesel VW Passat which also takes ages to warm up. It warms up fairly quickly on the motorway, but if I go through town it's usually about 7 miles before it has warmed up fully. As I'm used to petrol cars, I assumed it was something to do with the fact that it's a diesel.

bazza1603

Hi,

Most diesels take a lot longer to warm up than Petrols in my experience. Ask any taxi driver and I am sure they would say the same.

One thing you could do is block some of the cold air supply into the engine bay. However this has risks with it and could result in overheating, or foreign objects being sucked into the engine causing major damage.

I wish I had invested in a heated front screen for my 1.8TDCi Focus. I instead got an instant heater from Woolworths for £6 which helps a little.

Best Regards

Baz

Graham_Devon

All diesels take a lot longer to warm up. Miles quoted are about right.

oldagetraveller

Thanks for replies. My previous cars have all been Peugeot Diesels from older 2.5 litre naturally aspirated to most recent 1.9 litre tubocharged 307. The 307 reached indicated operating temp much quicker than Vauxhall and this is all I can compare with from memory. I'm sure you're all correct and I'm probably just being a bit paranoid?!
However, a friend of my daughter's has the same Meriva model and she's going to ask her for a comparison before I embarass myself at the Main Dealer.

moonrakerz

My 2.0L TDCI Mondeo took ages to warm up - my wife's 1.3 Ka seems to heat up after a couple of hundred yards !
Agree with the comment about heated windscreens, they are brilliant.

chrisw

Graham_Devon wrote:

All diesels take a lot longer to warm up. Miles quoted are about right.

Does anyone know why, as a matter of interest? Do diesels have to retain the heat in the engine block for it to run properly rather than pumping it round the heating system?

northern_munky

chrisw wrote:

Does anyone know why, as a matter of interest? Do diesels have to retain the heat in the engine block for it to run properly rather than pumping it round the heating system?

Are you ready for this? It's because Diesel engines are more efficient than petrol engines.

When petrol and air mixture is burned in the cylinder it produces heat energy at a temperature of approx 2,500° C, only about 25% of this heat energy (thermal efficiency) is converted into useful work. Around a third is lost as heat to the cooling system, so it warms up quicker.

Thermal efficiency of a diesel engine is about 40%, so there is less heat lost and it takes longer to warm the cooling system up.

chrisw

Aha! that makes sense. Cheers.