This winter my diesel Octavia is taking longer than ever to warm up. When it finally does reach temperature on the gauge, running the heater blower on high for just a few minutes soon has the temperature needle moving down. I 've never had this problem in previous winters. The thermostat has been changed but this made no difference, has anyone got any ideas what might be the cause?

Sounds like you may have an air bubble somewhere, had a similar problem last winter

Welcome to winter!

It's perfectly normal, if you are taking more heat out of the engine to warm the interior than it is generating then the temperature gauge will drop.

Both my Octavia's do this.

We see similar threads every winter, the diesel engine is thermally efficient so takes a long time to warm up in cold conditions. My superb for example currently takes 12 miles for the temp to hit 90c, and yes with the heater on high passing cold air across the matrix will cause the temperature to drop. The heater matrix is doing just the same thing as the big radiator at the front of the car, so in effect running the heater cools the engine.

As above - Efficient diesels so no wasted heat. A diesel will never ever warm up idling on a drive. On a really cold day I can do 20 miles at motorway speeds before my needle is at half. Blasting the radiator with cold air...

I do think that an electric heating element in the heater would help, but that would probably require a bigger alternator.

As above - Efficient diesels so no wasted heat. A diesel will never ever warm up idling on a drive. On a really cold day I can do 20 miles at motorway speeds before my needle is at half. Blasting the radiator with cold air...

I do think that an electric heating element in the heater would help, but that would probably require a bigger alternator.

+1

I think that if it gets down to -6 plus again like last year i will be blocking part of the Rad with cardboard in an attempt to get some heat on the go. When it was -12 the one day the needle had just started to get towards the middle after a 20mile motorway run then as soon as i came off the motorway and released the power the needle shot back down....The oil was only up to about 60c by then too.....

also can depend where your driving, urban driving from cold will take forever and a day to see optimum temp but yea this is normal, i warm mine up for apox 4 mins, depending on outside temp and after about 4 miles of urban im onto the national speed limit and it will be a further 10 miles before it is comfortably hot enough.

this is one of reasons i miss my pug 107, warmed up by time id rolled it off the drive!

also can depend where your driving, urban driving from cold will take forever and a day to see optimum temp but yea this is normal, i warm mine up for apox 4 mins, depending on outside temp and after about 4 miles of urban im onto the national speed limit and it will be a further 10 miles before it is comfortably hot enough.

this is one of reasons i miss my pug 107, warmed up by time id rolled it off the drive!

You shouldn't start from cold and leave TDI's idling. You are meant to drive off straight away....

You shouldn't start from cold and leave TDI's idling. You are meant to drive off straight away....

since when? this would cause some damage after time. iv always warmed my cars up.

felt the urge to look this up in my owners manual, only for interests of the environment (which i dont give a dam) should you drive off straight away.

yes maybe 4 minutes is excessive but (the way i have been told) the camshafts and turbo are the last places for your oil to reach, and when the oil is cold it has a thicker viscosity so even more so prelonged, also it take something like 2v to turn the engine over so given chance to let it recharge.

if you set off straight away without letting the oil circulate you will be evidently revving the engine with effectively a turbo starved of oil, not going last long.

Edited 14 December, 201114 yr by Ema_jane

since when? this would cause some damage after time. iv always warmed my cars up.

Since always on these engines.....says in the book! Somthing about hydraulic lifters and needing the oil pressure up to pressure to lubricate stuff correctly. There was another thread on here the other day about it.

Since always on these engines.....says in the book! Somthing about hydraulic lifters and needing the oil pressure up to pressure to lubricate stuff correctly. There was another thread on here the other day about it.

i completely disagree, its logic. the book is not always right, just flicking through my owners manual and come across passive safety, says something along the lines of the driver has sole responsibly of all occupants (seatbelts ect) not correct, anyone who is in the vehicle aged over 14, its their responsibility not the drivers, just a point

1-2 min idle does not harm, any longer you risk damaging catalytic converter too, thought the best way to warm engine/gearbox is by moving easily and not idling.

As a very old motorist (43 years experience) I can confirm that over the decades the instructions have been to drive off straight away. That's assuming you can see out of the windows of course.

Heating and ventilation is one of the big modern improvements. When I had a Morris Marina, one cold winters day it did not fully warm up in 240 miles even with a winter thermostat and the grille blanked off. I peered through the clear area on the otherwise frozen windscreen. Brrr.

Tend to drive straight off (well as best you can when you have to get out and close the garage door), but I do try and make sure I stick below 3000rpm until oil temp is at least 50deg.

(Think the oil temp display is only on Maxidot though). Also I do find that sometimes the oil is not at 50 even when the coolant is up to temp and vice versa.

+1

I think that if it gets down to -6 plus again like last year i will be blocking part of the Rad with cardboard in an attempt to get some heat on the go. When it was -12 the one day the needle had just started to get towards the middle after a 20mile motorway run then as soon as i came off the motorway and released the power the needle shot back down....The oil was only up to about 60c by then too.....

That's what I've done with my Bravo (foam carpet underlay rather than card) for the last couple of years, and it does make a difference.

Fuel efficient engines are great for saving money in summer but in winter it's almost counter productive. It doesn't generate enough heat to get up to temperature and isn't as efficient as it could be as a result.

The advice traditionally was not to leave petrol engines ticking over from cold as the excess petrol in the cylinders was abrasive and would cause additional bore wear. Diesel on the other hand tends to lubricate the cylinders rather than wear them.

I've often left my diesel vehicles idling whilst de-icing and never had any noticeable engine wear on any of them (and I tend to keep them to 150-200k). I've had to scrap a few due to body rust but never once due to a worn engine. Bear in mind that VAG also sell most of these TDis as industrial engines, where they may spend some or all of their lives at not much above idle.

Can you recall anyone who has had to scrap a diesel car engine due to wear? Design, manufacturing or expensive fuel system faults perhaps, but not actual engine wear.

how about this on the rad http://www.superskoda.com/Skoda/OCTAVIA-II/Skoda-Octavia-II-front-grille-winter-cover

how about this on the rad http://www.superskoda.com/Skoda/OCTAVIA-II/Skoda-Octavia-II-front-grille-winter-cover

without sounding dumb iv always wondered what these are actaully for? Is it to keep heat in the engine?

i see them been used on Ice Road Truckers and always pondered why some have them fully done up and some have one side unzipped?

Yes it's to stop the cold air hitting the radiator/engine and cooling it further.

Probably readily available in colder climates for all sorts of cars.

I like Diesel Darrens old (1965) octavia for this... a pull handle inside the car opens/closes the flaps in front of the radiator.

A diesel engine will not produce much heat throughout the engine just stood at idle, the only thing getting significant heat is the top where the combustion at around 500+C takes place and this heat is quickly lost. Even with it's higher viscosity the oil should be around all the parts of the engine in less than 30 seconds and providing lubrication. However not all the parts will have reached their optimum temperature and will be sliding and slapping together in a not too friendly way. The turbo, will have it's oil supply tapped directly from the main oil delivery galleyway drilled into the block so will get a supply quite quickly, the head and valves will be the last to get oil, hence the good reason to allow the engine to idle for up to 30 seconds before driving away.

Yes quite a few VAG TDI engines will be destined for industrial applications but they will operate at significantly higher than idling speed, especially those on generator packs, who will have 2 running speeds, stop and flat out. At work we have a generator which is powered by a turboed straight 8 Rolls Royce Eagle engine, that has 2 running speeds like I said earlier and one of the pre-start instructions is to pre charge the turbo lubrication circuit, nothing about the rest of the engine, 0 to 1800 RPM straight away! Impressive noise though!!

Back to the original question, yes wooly, it sounds about right for the engine to lose coolant temperature if you are only running at very light load with the interior fan on full, putting a cover over the radiator will help retain temperature though you should always leave some of the matrix exposed to allow some cooling, keeping an eye on the temp guage as getting too hot is worse than too cool. Here endeth my tuppence worth.

Ian.

+1

I think that if it gets down to -6 plus again like last year i will be blocking part of the Rad with cardboard in an attempt to get some heat on the go. When it was -12 the one day the needle had just started to get towards the middle after a 20mile motorway run then as soon as i came off the motorway and released the power the needle shot back down....The oil was only up to about 60c by then too.....

can see me doing this as well seeing we hit -18 at the beginning of the year. i did think something was up after a 10mile journey and it still wasnt @ 90

My old 2004 Mondeo TDCI was the same. Cold for 10 miles.The real difference was the superb heated front window and excellent standard handling.

Now we have established this is a fact not a fault, Whats the best method to block the front grill a bit and would it help or do any damage?

There was a huge thread on blocking the grill last winter.

Opinions were divided but a good portion of posts seemed to think that blocking the grill was pointless as the thermostat regulates the engine temperature and simply compensates for the differences in airflow offered by blocking off part or all of the airflow...

There was a huge thread on blocking the grill last winter.

Opinions were divided but a good portion of posts seemed to think that blocking the grill was pointless as the thermostat regulates the engine temperature and simply compensates for the differences in airflow offered by blocking off part or all of the airflow...

Hmmm, not sure that it does, if it did the temp gauge wouldn't plummet with the heaters up or 'coasting' along with no load (ie pulling off a motorway and going down the slip road....last year mine literally went from 90 to about 50). I think an experiment is in order with working out the average time to get to 90 say over a week with no heater on and then block off the grill and do the same. This will only be accurate though if the average temp is the same....but i think this time of year it should be pretty steady...