Heating issue

[swalker]

Hi Folks,
I have an issue where my 2.0D is not getting up to temp.
When i bought the car it wouldn't go over 70, the dealer took it back, spent 2 days on changing 2 thermostats, and then kept it a third day to test and make sure it was right...

Now it will get to 90, but twice as long as it should if you ask me, and if you are sitting in traffic or at lights it will slowly drop back to 70 again.

Does this still point to a thermostat issue?

When i got the Q5 the expansion tank was full, as in i had to remove 300 odd ml to get the level below max, it was the same after the repair. With the level corrected the fault remains.

So i am thinking maybe that second thermostat is an awkward job and they didn't/couldn't do it?


I should add it is a second hand dealer attached to a nissan main dealer -so not an audi garage.

I have sent them a short email, which also details the live data for the DPF, differential pressure at 6.9 mbar at tick over, soot mass at 7.9, which is just short of alight coming on if i am not mistaken?

What are they doing wrong do you think?
Thanks for reading.

[Crasher]

If the thermostats are new and genuine the symptoms don't make sense.

[swalker]

Yep i am with you there, hence my suspicion that they didn't do something or did something wrong.
I was told the 2 day repair was due to waiting on a seal from audi - hopefully they also used genuine thermostats.

I will ring them later and confirm,

Thanks

[mickeybo]

Whats the engine code on your vehicle

[swalker]

its a CJCA.
I didn't ring them but on the way home last night i tried a couple of things.
with the hvac turned to lo (not ideal these days) the gauge looks like it acts as expected, sitting ticking over for 5 minutes it wil stay at 90.
turn it to high and it will drop while sitting ticking over to close to 70 within 5 minutes.
Back to lo again and the gauge will return to 90.

so I am thinking its a faulty (main) thermostat just not fully closing?

[Crasher]

Don't place any faith in the gauge accuracy, it reads 90 at 77 and still reads 90 at 116, use VCDS to view it in live data.

[swalker]

good call - i did check it against live data before the work. I shall get live data up for the journey home.
thanks for the input.
If i get out tonight i will start it from cold and see if the top hose heats slowly or suddenly, along with the one going to the EGR cooler.

[swalker]

heat.jpg

poor quality that
blue is coolant
orange is oil temp
grey is radiator output temp

looks like too much flow through the rad to me. It is going back again for them to sort it out.
Only trouble is it has got MOT on Monday and a day in the body shop Wednesday to sort out scruffy bumper.

edit count 100 bloody picture lol

[swalker]

Its going back this week again. The service history shows a new waterpump due to overheating about 60k miles ago. I know old school thermostats had a bit that melted away if that happened. Is there a separate yoke in these newer engines that could have went and not been replaced?

[swalker]

it looks to be fixed.
I picked it up and the dealer said he got a VW mechanic to look at it and it got up to 90 quickly and stayed there, ie don't come back again...
He also said that "it was a genuine part fitted, whatever difference that makes" lol
I am also confident that a competent mechanic was on it - my dash was changed to show MPG front and center and when i turned the HVAC back on it was set to HI.

yeah it came up to 90 quickly, the stop start now works as it should - it was intermittent before, and i also got the best MPG out of it on the way home 39, compared to the 32 on the same journey before.
That was just the journey home - the good wife has it today as I need to take her yoke for rear pads.