heater warm up time

[RW1]

So why does a 10 year old Honda (and every other car Ive driven- most of them much more 'basic' than the Roc) warm after 5 minutes if idling??

I think the reason lies with the lower thermostat it uses. ie. the 80'C as I've described in the posts on this topic. Plus as Andy states, the engine isn't under load and so doesn't generate enough waste heat to warm-up and counter the use of the heating system and an early opening thermostat.

The 80'C thermostat opens earlier than a lot of engine thermostats do. So the whole cooling system is being used early-on while the engine block 95'C cooling circuit hasn't opened up. This cool coolant coupled with the Climatronic/Climatic system working is sufficent to keep the engine temperature down at idle. The 1.4TSi-160PS twin charger will never fully warm up left standing. I've had mine standing 30 mins and it reached only 60'C and then remained static.

To draw a parrallel, I had my old Mk2 Scirocco's head skimmed a while back. Initially with a "standard" 87'C the engine would warm up as usual but the problem I had was that it had no reserve on hotter days to cool the engine. So it had the radiator fans on very frequently.

To overcome this I fitted a 80'C thermostat. All went back to normal until ...... in winter, the heater was cooler and the warm-up was much longer due to coolant circulating in the whole system earlier than the original 87'C thermostat would have allowed.

The answer could be to "up" the lower temp thermostat to the 1.4TSi-122PS's 87'C. Just may look at changing the waxstat from 80'C to 87'C. My doubts of doing this are around the cylinder inspection results in the summer. The inspection showed some signs that running hotter may not be desirable, ie. the red colour on the valves. Link to 1.4TSi boroscope inspection of cylinders.
(Ignore the misfire counts. The misfire counting strings in VCDS have since been determined to be attributable to the algorithm inside the ECU coding and light throttle closure. They were not true misfires. Phew!)

C.

[albertz33]

I cannot comment on the scirocco as yet but having had a Mkv Golf for the last 3 years id say its the only major complaint i have
The heater in our Golf is diabolical
It takes an age to warm up and dont try the old tried and tested approach of starting your car for a few minutes whilst scraping the Windscreen hoping the interior will heat up as it wont

We have found you have to actually drive the Golf for at least 5 Minutes for the heater to kick in
Ive ran the engine on idle for upto 20 minutes with no heat you have to actually move the car to get it to kick in

I went from a Mk 5 GTI to a Scirocco, and swapped them over during the cold snap in January '09, i immediatley noticed the Roc was much faster to warm up than the Golf ever was.

[RW1]

Seems the 1.4TSI 122ps engine is getting a mod for the lack of heating during cold weather. The engine ECU software is to be updated soon. Then once the revised software is loaded, it is possible through an "Adaption" channel (No.24) to set a bit which changes the engine temperature to "high".

Details are scant at the moment. As the engine doesn't have an electronic thermostat, my guess is that during the early warm-up period, the valve timing change to give internal exhaust gas re-circulation and fast initial warm-up can be extended in duration by setting the Adaption channel. At present valve/camshaft adjustment is initally upto 30 seconds duration on a cold start. That's the diesel type sound effect that can be heard with the 1.4TSi just after starting.

Nothing yet for the 1.4TSi 160ps.

C.

[RW1]

Nothing yet for the 1.4TSi 160ps.

It appears at last that VW have done something to rectify the lack of heating on cold days for the 1.4TSi 160PS. Initially introduced in July 2011 as the manual switching in the diagnostics of the 122PS (it is now automated as built into the latest 122PS engine ECU maps as of end of August).

1.4TSi 160PS Engine maps introduced at the end of August contain some coding to rectify the problem of insufficient engine heat to heat the cabin, dropping back of the coolant temperature gauge and the engine is not warm enough. These are 160PS Engine ECU map numbers are:
1676 (Man.) and 9256 (DSG).

(ECU map 9256 (DSG) has been updated again to 9660 (DSG) mid September 2011 for the misfire at coolant temperature 35'C [typically 1 - 2 minutes into cold start warm-up. It occurs for about 10 second period as the coolant temperature rises through 35'C]. No change to 1676 has been made.)

C.

[skyblues11]

this is great news! especially with winter is around the corner.

Is it something the VW dealers will update for free, or we have to find our own ways?

[RW1]

You need to state that the following is happening as stated above.
"Insufficient engine heat to heat the cabin, dropping back of the coolant temperature gauge and the engine is not warm enough."

They will have to confirm it is the case for it to be a warranty claim.

My previous experience of the problem, is that the conditions won't occur until the outside air temperature drops below +5'C.

Quote bulletin 2027544-02, dated: 05.10.11..

If they accept/confirm your experiences, then you will get the newer ECU map for the DSG/engine ECU combo of G9660.

There is a sting though. People are reporting maps 1676 and 9256/9660 are using more fuel.
I haven't found anything yet to support why this may be happening.

What I suspect the map change has done is continue the inlet camshaft warm-up adjustment much longer after the the initial catalytic converter warm up in the the first minute when you hear that "diesel" like noise out of the rear half of the exhaust. Only, it is a milder inlet camshaft adjustment, just to induce more heat into the cylinders during the remaining warm up phase to operating temperature. And not as noisey.

As I am sure you have read this. I have already gone a different way with plugs and re-gapped them to 0.74mm (29 thou) after trialling 0.79mm (31 thou). This has brought about a slightly improved coolant warm up time to full operating temperature. Just under a minute less of the 10 mins it took during my drive to work at 20 - 30mph :groan:. Plus the MFD is showing a marked higher dynamic mpg indication than previous (yet to prove with brim to brim filling). The Scirocco is a lot better to drive and the DSG holds gears markedly better (presumably because the torque sensor reading is not jumping around due to mumuring misfires).

(NB: You have to be very careful re-gapping fine wire spark plugs that have very small diameter platinum or iridium alloy electrodes. Feeler gauges or wire gauges should be used with gentle care when testing the gap by comparing with the feeler gauage NOT passing the feeler gauge through the gap. Otherwise the central electrode tip will be damaged.)

You may like to try the spark plug gap change now and see how it goes, given what it has done to mine.

I'm also sceptical of the new spark plug that has been introduced 3 weeks ago as running hot (part number 03C 905 601A has superceded 101 905 626 in the 160PS Surperchraged engine). I've never seen evidence of the plugs running hot in the traditional sense of a white clean insulator tip. Hence why I went for the spark plug gap change.

C.

[Heha]

I, on the contrary wish the opposite. I m now living in a hot humid country. A good 15-20min spirit driving on mountains could launch the water temp to somewhere between 115-120 degreeC. (i have water temp gauge installed).

I have been trying to find a solution, possibly a 80c thermostat for my 2.0 scirocco, but to no avail.