"52" Mk1 Octavia Vrs

After driving for long enough for the engine to be upto normal operating temperature I have noticed the temp gauge slowly oscillating between 70-90 degrees, and a notible drop in temperature from the heater vents. Everything else appears normal.

Due to the drop in temp from the climate control my hunch is the thermostat is not closing fully, although I haven't completely ruled out the cts.

My plan of attack is to change the thermostat and housing? (I've heard the housings are easily damaged), Is this the most logical way to fix the problem or am I barking up the wrong tree?

Its tricky to change the thermostat. You need a good socket set with a few extensions (I used 1/4" drive) with elbow/wobble joint. And Allen bit.

Buy a genuine thermostat - mine went bad after 6 months from GSF. Sucked. Get a new O ring too and the correct g12++ coolant as you may lose a bit.

Edited 16 April, 201214 yr by Liverpool-Lad

Its a much easier job to change the CTS but the thermostat is a cheaper part.

If you have VCDS you can log the CTS readings to be sure if the CTS is at fault. The readings will be ludicrously high or low if that's the case.

From your symptoms though it does sound more like the stat is stuck open so I would replace that first even though it's a ballache to do.

Thanks,not to bothered about job complexities so I'll go for the stat first, is worth changing the housing aswell or do they only break if overtorqued?

You could but I had no issues.

Had no issues with the housing on mine, it looked fine when I took it off. I also tested the thermostat in a pan of water before I replaced it just to be sure it definately was knackered.

I would put some copper grease on the two bolts that hold the stat housing to the block as it'll make it a bit easier to get them out again in future.

The housing is plastic so be careful.

Should be fine if tightened right.

Not sure of torque required though sorry.

Thanks for the help/advice, much appereciated. I'll post my findings once I've changed the stat. Now to dig out the service book as I think I made need to change the cambelt aswell. Has it really been 4 years!!!!????

Changed the thermostat yesterday and all is good again in fact I think the stat had been on it way out for a while as the water temp reaches 90 sooo much quicker now and stays rock solid once there.

To aid access I un-shipped the p-clip from the alternator mounting stud and also removed the stud, this eliminates the need for any uj's. Lost between 500ml-1ltr of coolant.

thermostat - 050 121 113 C

o-ring - 038 121 119 B

cost - £26ish

Whilst the engine cover was removed I also noticed the rocker cover breather "y" pipe split 06A 103 221 AH I believe this is fairly common? Currently have a mate searching his garage for one which we hopefully have left over from a corrado 1.8T conversion.

Looks like after 5 years of owning the old girl is starting to show her age, still only 75k covered though.

Next jobs, replace breather and then cambelt.

My thermostat was stuck open, it was okay till weather dropped cold last year then it wouldn't get warm and threw a right wobbly, dash lit up like a christmas tree and cooling fan running all time. new stat been fine since

The breather pipes are fairly easy altho i would replace them all including the plastic 90 degree bend that comes out the block as they go brittle and snap, ebay creation motorsport do silicone versions and they do black ones if you want to keep the oem look

Get a genuine cambelt kits aswell as it comes with all bits you need to replace plus get a water pump at same time as they have a tendency to fail and easy job while the belts off altho changing the cambelts abit of a pig as its abit tight between wing and engine especially working round the engine mount

Sorry to hijack the thread but I was wondering if my cts or thermostat is on the blink as my temp gauge seems to take a long time to get to 90c it will get there and stay solid but just to get to 70 seems to take a while even just the needle to move takes maybe at best 10mins or longer

Thanks all

Does the gauge go down on the motorway and goes back upto 90 in traffic after a while? If so usually the thermostat has gone.

When my Thermostat went I first thought it was the temp sender as it would stay under 90, but when the warmer temp started it would go to 90 in traffic. When it first started to go it used to slowly drop temp at 80mph. Doubled checked using vcds lite and comparing the ecu temp and the gauge temp

Does the gauge go down on the motorway and goes back upto 90 in traffic after a while? If so usually the thermostat has gone.

i have never really noticed it tbh just that all i know is from cold the car seems abit lumpy or at least feels it not too sure on that tbh and it takes a while to get upto temp even sitting in traffic for 5mins might raise it up abit but only to 60-70 just when it hits 90 the car feels verily normal and it never goes above or below that till the engine goes cold and then its the hole routine again where it takes ages to get upto temp but i am going on the dual carrigeway tommz to a friends house so will check and see if the temp is dropping then rising again in traffic but i dont think i have ever seen it go that before

thanks all

Edited 22 April, 201214 yr by vrs 180t

Mine seems to take a while for the temp gauge to go up and it never really seems to go to 90 on the gauge.  I used torque app and the ECU was reporting the engine reaching operating temp well before the needle actually gave the same reading...I changed the thermostat over 8 months ago, it wasn`t an official VW though I don`t think.  When I replaced CTS over a year ago that wasn`t an official one either.

Edited 11 October, 201312 yr by sammyhale30

Id replace both mate with kosher ones.

well while this thread has appeared it seems to me the temp is getting worse.i know the weather is getting colder so i can understand that it takes longer to warm up but it does seem to take an age to get to 90c and before it does it seems to run quite rough even at 60-70 i cant seem to give it the full beans i have to wait till it gets to 90 then its pretty much ok. it's hard to explain how it feels but best way i can is that it feels like its hitting a brick wall. when i get chance on the weekend i will check everything over but from last check up only thing i have noticed is there is a fair amount of oil around the pancake pipe area. but also like to mention it has had the coilpack recall altho that was quite a while back. oil and filter change a few weeks back or so and of course correct oil and has had a sports cat fitted but it was being silly before that,

 

thanks all

How much is the official VAG CTS from a dealer?

About £30