Warm Time of a 1.4TSi?

[RW1]

Had the 1.4 Scirocco for 5 weeks now. Done 1,100 miles.

With these colder days recently, its brought home how long my 1.4TSi takes to get warmed up from a cold standing start overnight. Compared with the older VW's I've had, the 1.4 seems quite slow to reach working temperature and settle down. Also after a hot motorway run it never appears over hot, ie, metal tinkling cooling down noises.

Irrespective of outside temparaure between 0'C and 10'C, these are the reading I get with a little bit of variance.

My water temperature comes off the stop at 50'C after 6 minutes approximately. Acheives 90'C after 12 minutes.

The oil reaches 50'C after 11 minutes and gets to full temperaure of about 85' - 87'C after 27 to 30 minutes.

Nothing really changed during the running period.

Is this normal with the 1.4TSi????

C.

[trix]

hmmm i may have to go check my manual to recall what dial is what (I'm a girl ) but that seems a long time compared to mine..

S

[RW1]

Thanks Trix

I used the trip time and the left hand water temp gauge, very bottom = 50'C and the vertical = marked 90.

I have the highline MFD and Multi-Function Steering Wheel for the oil temp. Can't remember that on your photos.

"what dial is what (I'm a girl )"
not like you, you mustn't go down in my estimation!

C.

[trix]

bad day/evening, give me a break
no haven't got the highline comp (the one thing i think i should have gone for in hindsight) my water comes off 50 at about 4-5mins & hits 90 at about 8 latest (will try & pay attention tomorrow)

maybe its telling me i should drive it abit easier when i set off (i don't push it though, guides honour)

S

[RW1]

Those figures if they check out OK tomorrow are more like i'd expect.

Anybody else got actual figures?

C.

[ZephyR]

Ok I shall be paying close attention to attention to my dials tomorrow morning. But if I run in to the back of someone it will be your fault RW
Am I right in thinking that the oil temp gauge remains as --- until 50'C.
However I'm sure the time it takes will related to the type of driving you are doing. 10 minutes at 50mph has got to heat up quicker than 10 mins in stop start traffic jams.

I seem to recall reading somewhere a good few months ago that the Roc was pretty quick to warm up but my experience over the last week or so is that its slower than other cars I've had. Maybe its linked to fuel efficiency or something but it takes ages before I get any decent amount of heat from the heater system.

[RW1]

Ok I shall be paying close attention to attention to my dials tomorrow morning. But if I run in to the back of someone it will be your fault RW Really!! You pay attention to the road, this is not a science test with a stopwatch!

Am I right in thinking that the oil temp gauge remains as --- until 50'C. Yes it is.

However I'm sure the time it takes will related to the type of driving you are doing. 10 minutes at 50mph has got to heat up quicker than 10 mins in stop start traffic jams.
The times I have given are +/- 1 minute on most occassions. I've also seen that slow traffic effect too, today in Christmas shopping traffic was a shocker - water, at 90'C by 17 minutes!

I seem to recall reading somewhere a good few months ago that the Roc was pretty quick to warm up but my experience over the last week or so is that its slower than other cars I've had. Maybe its linked to fuel efficiency or something but it takes ages before I get any decent amount of heat from the heater system.
Thats my problem at the bottom of all this, VW's heaters usually roast you fairly quickly.

Thanks Zeph.

[trix]

right water temps in mine.. off 50 by 4 minutes, to 90 by 6 minutes
(drive to work; brief crawl, 3 minutes ish at 40mph, 65-70mph for the next 10 mins ish [with a traffic light controlled roundabout in the middle), then 5 mins ish at 30-40mph)

[RW1]

Thanks Trix

I can replicate that drive and compare.

Hmmmm....... a tad shorter than my 17 mins to 90'C yesterday.

C.

[trix]

I will double check on my way home.

S

[Nobby]

I've noticed mine is pretty slow to warm up now that it is getting cold, we're down to arround -6°c at the moment but that's just the start of it

I'm only about 7 or 8 minutes from work, so now the needle is just getting off the stop when I arrive

Even my X-Trail Diesel heats up quicker than this

In the summer when I got the car I thought it ran pretty hot as it was up to 90°c very quickly and the fan always kept running after I stopped, now I wish it would heat up a lot quicker !!!

[ZephyR]

Forgot to watch mine this morning
You get a better run than me trix. 4 and half miles to work and I'm lucky if I get in to 4th gear for more than 100 yards.

I'll try and remember tomorrow. Certainly get very little heat out of my Roc until I've almost arrived. Even then its not exacty hot.

[trix]

its only just over 15 minutes in traffic though ZephyR & only get the speed because I live on the outskirts of Norwich & work slightly further round so get the benefit of the a47, if I worked in the centre I would be lucky to get any speed up.
would certainly think twice before working in the city again!

S

[RW1]

Tried another route out of home today and got going at between 30 - 40mph. Very little change, 50'C went from 6 mins down to 5 mins and 90'C remained at 12 minutes. Besides the lack of heat available, it can't be fuel efficient.

[ZephyR]

Definately not fuel efficient. First mile from cold in stop start congestion, rarely more than 2nd gear - usuallly shows as 10mpg or less.

[rhcp128]

I was thinking the same thing this morning and actually looked how long it took to get the water to 90 degree - about 12-13 minutes. Outside temp was around 0.

Seems a bit slow to warm up. My last car took about 4-5 min. to get to 90 degree in the winter...

[RW1]

Outside Temp 5'C, 7 mins to 50'C and 17 mins to get to 90'C today, longer than the usual 6 & 12 mins. Terminated the 23 minute trip in the dealers with the recordings. No real warm air from the car's heating for most of the trip. They agree it's not right and want the Scirocco next week to investigate.

I think Thermostat No.1 (80'C) is suspect and not fully closed when cold. This is the one that the Water temp gauge reads and takes the engine block cooling upto temperature and provides the passenger cabin's heating source. This problem has all the hallmarks of a stuck thermostat.

C.

[RW1]

Well after a prolonged investigation with two dealer visits, my engine warm-up has been fixed. I must say the dealers have gone out of their way - SKF Stockport, I have praise for their patience and efforts.

The VW Tech Dept at Milton Keynes blocked a warranty claim by stating the prolonged engine warm-up was normal. :roll: It got to Christmas and I was freezing in the car after a 1 hour motorway trip!!! Normal, my ****. My diagnosis has prove correct.

The dealer has paid for the labour and coolant while I have bought the thermostat. Long story but having found the fault, will go back and seek it all to be a warranty claim.

So here a write up for the 1.4TSi 160BP owners. (May also apply to the 1.4TSi 122BP engine as it shares the same dual thermostat arrangment for engine cooling.)

Scirocco 1.4TSi – Slow Warm-up Problem

Problem

Just after delivery in November 2009, the Scirocco's heating started to be less effective. Coupled with this was a slower than normal warm-up of the engine. Max oil temperatures observed had dropped from 90'-91'C to 86'-87'C no matter how hard the engine was worked.

On inspection, the engine top and bottom radiator hoses were very warm but could still be hand held. Both were of a similar temperature. Also the input cooling system feed input pipe to the air-conditioning system was also the same very warm temperature.

The exhaust tailpipes were observed to wet and sooty all the time unlike the initial couple of weeks after taking delivery. They had been a dark slate grey and dry.

The conclusion reached, coupled with the whole engine never getting really hot, top and bottom radiator hoses the same temperature was that a thermostat was stuck open or too far open for the engine coolant temperatures or wasn't fitted!

Technical Explanation of 1.4TSi Cooling System

The 1.4TSI 118Kw (160PS) engine uses a dual cooling system design. Both cooling circuits are joined and use a common water pump to circulate coolant. One circuit cools the cylinder head, the other the engine block.

The cylinder head cooling is controlled by 80'C No.1 thermostat wax-stat with a dual acting valve plate (See Photo). The design permits the thermostat to open progressively even under extreme pump flow pressures due to higher engine rpm. The small internal valve plate opens approximately 2mm to relieve pump pressures and initiate the flow of cool coolant. As the engine heats up, this small plate pushed by the thermostat wax stat unit, forces the larger overall valve plate to open until optimum engine operating temperature of the coolant is achieved. Running the cylinder head cooler helps prevent pre-detonation engine knocking.

The engine Cylinder Block 95'C No.2 thermostat is a simple cupped plate valve operated by a wax-stat. It operates like a normal single plate action thermostat.

Together these thermostats give optimum engine operating temperatures to achieve fuel-efficient and low emissions output.

Analysis

Engine warm up taking longer on the water temp gauge from cold.

Urban 30mph traffic, travelling at 25 – 30 mph.

Old thermostat fitted
50'C in 7 to 10 minutes, 90'C in 15 to 20 minutes

After new thermostat fitted
50'C in 5 to 6 minutes, 90'C in 12 minutes consistently

------------------

Fast Drive at 70mph after 2 minutes driving at 30mph

Old thermostat fitted
50'C in 6 minutes, 90'C in 12 minutes

After new thermostat fitted
50'C in 3 minutes, 90'C in 5 to 6 minutes

Fault Found

Examination of the thermostat waxstat (80'C unit) removed showed a 2.75mm longer length dimension than the replacement unit (Thermostat part no. 03C 121 110L). This dimension is sufficient to hold the smaller plate of the No.1 thermostat open, creating an effective 11 mm diameter hole for coolant flow through.

This would explain the top and bottom radiator hoses being of similar temperature and the coolness to the engine even after motorway driving heat soak.

Secondly, the waxstat when tested in a pan of boiling water did not expand until the water temperature passed 95'C.

Conclusion

The Waxstat (80'C) had failed in the No1 Thermostat (Cylinder Head Cooling circuit.) This was allowing the water pump to always circulate the full cooling system, even when the engine did not require extra cooling coolant such as during the warm-up phase.

The1.4TSi engine needs to be driven hard to raise the water temperature to normal operating very quickly like older VW engines. The cooling system is quite efficient. Hence why when lightly driven in Urban traffic, the warm-up to 90'C is around 12 minutes. If the engine is left to idle in traffic, this has a cooling effect on the engine and prolongs the warm-up to 90'C even more.

Improvements following the No.1 Thermostat replacement
VW Part No. 03C 121 110L

Radiator top hose now hot rather than fairly warm
Radiator top is hot and bottom hose is cold or cool (before both very warm)
Engine warming up faster.
Heater warm air is available within 6 minutes rather than 15 minutes in Urban traffic.
Aircon temperature now able to get to demanded Climatronic set temperature.
Exhaust tailpipes no longer wet and sooty, now dark slate grey and dry.
Engine no longer "gargles" when accelerating. Engine runs very smoothly
Engine has more response and acceleration.
Throttle control not difficult/hesitant when setting off from a junction.
Axle Tramp/skidding has gone.
Peak oil temperatures with engine under load has raisen from 86'/87'C to 94'C.

RESULT!!!!




How to Conduct a Thermostat Test

If you are experiencing extended warm-up periods of

- Longer than about 13 minutes or longer in Urban traffic at 30 mph to reach 90'C water temp.
- Longer than about 7 minutes or longer on a short 1 minute drive at 30mph followed by 70 mph to reach 90'C

(If during the warm-up period the car is stopped and engine idling say 3 minutes, this will prolong the warm period by roughly idling time.)

Prolonged timings against the above may suggest that the No 1 thermostat - 80'C for the Cylinder Head may not be working correctly.

If a Waxstat fails, its failure condition is usually to fail extended, thereby permanently opening the thermostat and allowing all the cooling system to circulate irrespective of engine temperature.

Checks to determine the No.1 Thermostat is stuck part open or not working:

Run the engine for 40mins by driving the Scirocco to heat soak the cooling system and oil. Pop the bonnet open and feel the engines hoses within 2 minutes as follows with the engine still running. Do not do this with the engine stopped.

Be warned there are parts on the engine that will be VERY HOT such as the Turbo Shield plate and pipes next to the engine block above No.1 Thermostat housing.

Top radiator hose.
Under normal conditions on the 1.4TSi it should be almost impossible to wrap a hand round the top radiator hose. The maximum I could hold the top hose was for 2 seconds before it began to sting.

If the thermostat is staying open then the top hose will be very warm to hold but not so stinging that it has to be let go of.

Top and Bottom Radiator Hoses.
Under normal conditions, the top hose will be stinging hot, the bottom radiator hose will be cool or cold.

If the top and bottom hoses are of a similar temperature, the thermostat is open more than it should be which is leading to over cooling, hence the slow warm-ups.


C.