low temp thermostat

**h100vw** · 25-03-2016, 02:57 PM

Originally Posted by sambb

jeez I just sat down to a coffee after waking up after my nightshifts (which is why I've been a posting fiend of late) and that whole other variable of inter dependent oil temp is too much for my dusty brain to comprehend right away.
So it sounds as though the exchanger system once everything is up to temp will work to hold the oil and water in equilibrium around 90 degrees.

It will try it's hardest to do that, yes. What you see on the temp gauge is damped, so could be higher or lower in reality. VCDS is the true gauge showing actual numbers. I only every saw my polo indicate anything but 90 or a happy laps at QR towards the end of the session.

So if you were running an oil cooler (and especially if you didn't have the heat exchanger in place) you'd need the oil system to be thermostated or at least have a manual bypass of the oil cooler in place for when you're not on the track or its winter or your oil may not get up to temp?

I'd never fit an oil cooler without a thermostat in it. Overcooled oil is as bad as under cooled.

So if the spec oil temp is 90 degrees, how far outside of that will our oil temps climb just in street driven settings, and how out of hand do they get when the car is pushed hard (assuming the exchanger is still in place in a stock setup)???

Back in the U of K, I had an oil cooler on my G6O GTI. Circa 200hp. Oil would rip past 120-130 degrees during a track day. With the oil cooler on and the heat exchanger deleted, each session, 20 minutes per hour for a full day. The oil temps climbed by 5 degrees, due to starting the session with the oil just a little hotter.

You could see on the dash that within half a lap off the gas, the oil temp count back down.

inline answers

If there was a downside to the G60 set up, I over spec'd the oil rad and didn't appreciate the total effect the oil heat had on coolant temps, once removed. VW clearly balanced the size of the radiator against the heat generated by the oil.

So the water temps were well down all year round. To such and extent that it would barely lift the needle off the stop in winter. I doubt that this would be a big issue here, driving in traffic, plus the higher year round average temps.

**sambb** · 25-03-2016, 03:29 PM

Thanks. There's been a lot to digest in this thread. One last question gav - is there an oil temp sensor that can be monitored in vcds? I went through it quickly last night but couldn't find anything.

**Martin** · 25-03-2016, 09:45 PM

Originally Posted by h100vw

The current oil cooling is assisted by the heat exchanger, that is part of the oil filter mount. The purpose being that the heat in the water warms the oil as the engine heats up from a cold start. Perfect logic for colder climates than Australia.

Good point

I deleted that item in my Nissan 350Z

**sambb** · 26-03-2016, 07:56 AM

"I just got off the phone to VW parts. The part they carry for our car is an 83/102 degree. My best guess is that this is what's referred to as the stock 90 degree thermostat by ECS. The ECS/neuspeed one is listed as 82 degree which probably means open 92/closed 72. If anyone can confirm that that's how they name the thermostats relative to their open/closed specs that'd be great."

Well at any rate, given that the consensus seems to be to leave the thermostat at the stock 89 degrees, the way thermostats are designated may be a bit of a trap for people not even trying to make a change. I'd always assumed that a 90 degree thermostat opened and closed at values above and below that to maintain a 90 degree average. Like in the post above where the part number for our car is on VW's books as a 83/102 and known elsewhere as an 89 degree or something. But I've since spoken to a lots of other people including mechanics who said they always thought a thermostat was rated at its cracking temp. eg the tridon catalogue does this too - a '180' is a 180 farenheit (82 Celsius) thermostat that the catalogue says cracks/opens at 82 degrees! etc

So whats the truth. Is the local VW one listed as 83/102 actually an '83 degree' thermostat, maybe taken one step cooler by the local factory for aussie climes, and the 89 degree ones I've seen for our car were euro/north american spec. Or is the one that VW hold in fact a 90'ish degree because the open/closed temps fall either side of that temp? I'm starting to think it could be the former.

**Martin** · 26-03-2016, 11:23 AM

Yeah, I thought the rating was when they opened

You can test them in a saucepan of water to find the opening temperature

**sambb** · 26-03-2016, 11:56 AM

Alright I have a plan. I'll call a couple of different VW parts places and see if they carry the same part I mentioned above and then i'll just go ahead and get the much cheaper tridon version that matches those specs. When I go to do the swap i'll saucepan check the one that I pull out and we'll know if the thermostat spec has changed. I know the 06' models were pretty much first cars off the boat - I think they went on sale even before Europe got them so it'll be interesting to see what the factory put into my car.

Somethings going on though because the tridon site lists the 90 degree as the standard for my car. They just happen to also carry an 82 degree that matches what VW now carry??

**h100vw** · 26-03-2016, 02:47 PM

Originally Posted by sambb

Alright I have a plan. I'll call a couple of different VW parts places and see if they carry the same part I mentioned above and then i'll just go ahead and get the much cheaper tridon version that matches those specs. When I go to do the swap i'll saucepan check the one that I pull out and we'll know if the thermostat spec has changed. I know the 06' models were pretty much first cars off the boat - I think they went on sale even before Europe got them so it'll be interesting to see what the factory put into my car.

Somethings going on though because the tridon site lists the 90 degree as the standard for my car. They just happen to also carry an 82 degree that matches what VW now carry??

The level sensor also does oil temp. Lots of Audi's have a gauge for it. Our A4 does. No idea on the block, so just start at 001 and go up.

**sambb** · 26-03-2016, 09:38 PM

Went out to get some last minute Easter eggs and looked at vcds. Block 004 for coolant temp and I found block 104 which had a temp that I picked up on at 81 degrees, climbed to 87 and had dropped to 85 after the car was parked for a while. I can't confirm that it's oil temp but it looked like it and unfortunately the excel log didn't give a better description of it than "temperature".
I doubt I have a 90 degree cracking thermostat. Doing 70kph in 5th for a couple of Kay's saw coolant temp ( that's head exit temp) get down to 81 degrees without too much problem. Idling it for a few minutes parked before I turned it off though saw it hit 94 and it went to 96 after I'd switched the engine off, so I do think it would climb pretty sharply after shut off at an event and get pretty hot. And this is on a 25 degree ambient night. Makes you wonder why they even have a temp gauge. More than 15 degrees of variance just in pedestrian use and the gauge said 90 the whole time.
That temp that I suspected was oil temp was basically bolted to 87 degrees the whole time I was driving - idling, a few squirts and cruising along.

**h100vw** · 27-03-2016, 03:13 PM

Originally Posted by sambb

Went out to get some last minute Easter eggs and looked at vcds. Block 004 for coolant temp and I found block 104 which had a temp that I picked up on at 81 degrees, climbed to 87 and had dropped to 85 after the car was parked for a while. I can't confirm that it's oil temp but it looked like it and unfortunately the excel log didn't give a better description of it than "temperature".
I doubt I have a 90 degree cracking thermostat. Doing 70kph in 5th for a couple of Kay's saw coolant temp ( that's head exit temp) get down to 81 degrees without too much problem. Idling it for a few minutes parked before I turned it off though saw it hit 94 and it went to 96 after I'd switched the engine off, so I do think it would climb pretty sharply after shut off at an event and get pretty hot. And this is on a 25 degree ambient night. Makes you wonder why they even have a temp gauge. More than 15 degrees of variance just in pedestrian use and the gauge said 90 the whole time.
That temp that I suspected was oil temp was basically bolted to 87 degrees the whole time I was driving - idling, a few squirts and cruising along.

disconnect the level sensor and see if it disappears.

Or start the car from cold and look at water and the random temp.

If the water temp gauge swung all place the common driver would be bricking it.

New Beetles just have a warning light that is cold and off. Then a rd one for over heat. Ideal for girls