VR6 Mocal cooler boys - show us your temps!

[buttles 0]

Hour and a half lunch break? Slacker!! The intercooler position is possibly blocking some forced airflow. Only the temps when stationary are odd as well. The fans at 95 only come on for 5 or 6 seconds so there is good flow through the water rad. Will have to wait till next summer to sort it as now all is within normal limits. :? Cheers

[Kevin Bacon 5]

OK mate, let us know how you get on.

 

I'm only paid to do 9 to 5, but I'm here until 6 usually, so I thought I'd take a long lunch today :D

[fla 9]

my engine bay is cramped with the aircon rad in place so its a bid more fiddly to get to the mocal. Kev, have you got the original water/oil cooler in place? I've removed mine, plus i dont have the bolt extension that allows for both the sandwich plate and old cooler to be fitted.

I'm thinking of plumbiing in a diverter that will mean during winter less oil will go to the mocal rad and will come straight back into the engine. In theory the stat in the sandwich plate should control this to an extent, but like you mention, its 80C, so maybe too low for winter driving. Also, the water stat is terrible, as it takes ages to close and even then, motorway water temps are 72ish MAX! I've recently (last year) flushed and refilled my cooling system, with a nearly new rad and all new components, but the coolant is already murky brown again, which i cant understand and thats using the orange vw flushing fluid :shrug:

[Kevin Bacon 5]

Yeah I'm just using the standard water/oil heat exchanger.

 

72 water temp. Is that on the dash guage or read with VAG-COM?

If the former, I wouldn't believe it. Get it verified with VAG-COM.

 

You must have a load of silt in the block / radiator / matrix somewhere. You'll have to keep doing flushes / refills until it's all gone!

[buttles 0]

fla, it took me a good five or six flushes even with a new rad to get clear coolant. Now a happy pink :camp: Do not restrict the flow to the Mocal heat exchanger 'cos it needs to be free when the bypass valve closes in the plate. If you do you will restrict the oil system :gag:

[boost monkey 0]

VAG make their own coolant system flush stuff. I might still have the Part # if you're interested.

[Kevin Bacon 5]

Yeah it's the Orange schitt Fla mentioned.

 

I had a tub of that at home and it turned yellow within a couple of weeks, so you do need to use it soon after buying it!

 

I can't see that it does anything useful tbh. If you've got rust, silt and limescale build ups in your cooling system, no amount of chemically goodness is going to shift it. Just good old fashioned repeat flushing unfortunately.

[big ben 10]

i have a 15 minute drive each way, and my temps get to about 90-94, i basically dont give it any stick at all at the moment :(

[jamiehamy 0]

Excuse my ignorance, but does anyone know the optimum operating temperature for the oil? Okay from the factory we all know VR's run pretty hot, and that must have been deemed acceptable, but what is the best?

 

The 8v's in the Golf's and the Ibiza's we've had always ran oil about 70 most of the time without them ever being modified and they never seemed to suffer - indeed the Ibiza is going strong at 130k without ever being touched!

 

Mines sits around 80 now most of the time and until now it's never bothered me (although i've experienced the mayo occasionally if it's not been driven hard same as Kev, not HG). Before I start playing with blanking panels, it would be good to know what oil temperature i should be aiming for,

 

Reminds me of my old Land Rover in winter, blanked most of the radiator off to try keep it warm!

[big ben 10]

i thought 100 is what you want, but suppose it depends on the oil?

[Kevin Bacon 5]

Yeah aim for 98-100 once fully up to temp.

 

100 deg C is one of the key viscosity measurement temperatures for all motor oils and manufacturers will choose an oil based around it's viscosity data. For example, VW recommend a 10W/40 for the VR6 because they know at 0 and 100 deg C, the oil is a certain thickness that won't strain the oil pump or cause any other pressure related issues.

 

VR6s should hot idle at 2 bar and cold idle at 4 bar. Hot motorway cruise (80-90) = 5 bar. Cold motorway cruise = 7 bar, depending on oil viscosity.

 

With the Mocal, I was getting 6 bar cold idle and 9 bar cold motorway cruise!!!. 3 bar hot idle. I thought my pressure gauge was borked and ignored it, but removing the Mocal and doing nothing else has put the pressures back to factory. I'm not entirely sure why that should be unless my thermoplate was stuck open??

 

I use a 10W/50 full synthetic because turbo bearings need a top quality oil and it's good for 130-140 deg C, but I wouldn't hang around that temp for too long!!

 

For standard and lightly modded VRs, stick to the 10W/40, or if it's burning on the over-run, the 10W/50 will reduce consumption.

[buttles 0]

Thinking of fitting a pressure gauge to mine. What gauge have you used Kev? And sender? Ta.

[Kevin Bacon 5]

3 hours on the motorway yesterday, sat at 98 degrees, perfect :D

 

Thinking of fitting a pressure gauge to mine. What gauge have you used Kev? And sender? Ta.

 

I use a 10 bar VDO and 10 bar sender from here mate :-

 

http://www.etbinstruments.com/VDO_Range ... l_Pressure

[coullstar 0]

Few hundred motorway driving miles yesterday and it was 75-80deg. 2 laps on track and it was 100deg!!

[corrado9a 0]

i am running a 16 row thermostatic oil cooler along with the factory cooler, both at the same time.

 

oil temps run pretty similar both in winter and summer, about 102 to 106ºC. yesterday i sepent some time giving the car some love in the mountains and with the cold mountain temps (about 8-6ºC) the oil stayed at 106 while the watter stayed around true 90º (validated with vagcom). i am running the cooler in front of the radiator so is cooling quite all right, specially now.

 

for me there is only one thing to decide about when runing an oil cooler:

keep the original oil/water cooler along with the air to water, or not;

to run a thermostatic sandwitch is a must not an option.

[C488ADO 0]

hmmm mine standard trim runs on motorway 112

[Abdul 0]

hmmm mine standard trim runs on motorway 112

 

Mine does the same when i go 90ish and above. At 70 it sits just under 100. In this weather just above 90. Depends on how i drive it tbh lol.

 

I do want a Mocal for the summer traffic jams.

[jamiehamy 0]

Hmm, something was bothering me all weekend about the evaporation of water from the oil.

 

Anyway, a quick check on google reminded me of what I remembered from school, namely that water can evaporate at any temperature. It will boil at different temperatures depending on the pressure. I asked my other half about burning off contaminants (he is studying Chemistry) but he reckons it's very hard to quantify which contaminants will exist and what temperatures would 'burn them off' - too many variables apparantly in terms of age of oil, brand, grade etc...

 

Soooooo I feel none the wiser as to running hotter than my MOCAL gives me just now. I'm presuming running about 80 most of the time, up to 94 on a hard run isn't actually going to do any harm? Unfortunately I don't have an oil pressure gauge to check what she runs ( as per kev's post).

 

The car has had a MOCAL on and off for years, so doubting cool(ish) oil can't really do much harm? Thoughts?

[Kevin Bacon 5]

I don't think it will do any harm. So long as you give it a nice long run every now and then, it'll be fine.

 

My current engine, until the other day, also had the Mocal on it for 4 years and over 50K miles and I'm not seeing any signs of permanent damage, so I wouldn't worry about it.

 

Sorry, the aim of this thread wasn't to worry people about their oil ! :D

 

I wasn't expecting my oil to run so cool after taking the Mocal off because previously it was like C488ADO's and running 112-114 cruising at 80.

 

I'm just wondering if the oil does actually get that hot. Might be worth sticking a turkey temperature probe down the dip stick :D

[jamiehamy 0]

Yeah, I've always wondered actually how hot it is, and how much I should trust the sensor. I wish i knew more about oilways within the engine and could find out what temperature was in different areas ie sump, mocal inlet, outlet etc...I suppose it's possible, just a pain to do!

 

One thing I have noticed which i find it strange is that if i cycle the MAF round in say 5 times, the oil temperatures can change greatly in a number of seconds. It will be at 84, then 'suddenly' on the next cycle round show 56, then 72, then 84 again. Sometimes the display for the oil actually jsut shows dashes! Somehow I'm doubting that the oil changes that much, so would this indicate a faulty sensor? If left the temperatures displayed are always steady tho, it's just when I press the MAF button and cycle it round.

 

Hmmm... the joys! :)

[Kevin Bacon 5]

One thing I have noticed which i find it strange is that if i cycle the MAF round in say 5 times, the oil temperatures can change greatly in a number of seconds. It will be at 84, then 'suddenly' on the next cycle round show 56, then 72, then 84 again. Sometimes the display for the oil actually jsut shows dashes! Somehow I'm doubting that the oil changes that much, so would this indicate a faulty sensor? If left the temperatures displayed are always steady tho, it's just when I press the MAF button and cycle it round.

 

Yeah that is odd! The MFA only starts showing the temp from 50 deg upwards (hence dashes below this temp) but it should definitely not change like that when cycling through. The only time mine does that is when it's stuck on an odd degree, like 99, so it will change from 98 to 100 when cyling through, otherwise it always reads the same thing.

 

The oil temp sender is a cheap part and easy to replace once you can get to the darn thing, so that might be worth a go? Or you can also try cleaning up the electrical contacts because the sensor is exposed to rain water coming through the radiator.

[big ben 10]

went for a longer drive last night in the cold, my temps got to a nice 100 and she was runnning MINT 8)

[jamminvr6storm 0]

Now mine is back after my gearbox misshap....

 

I took it for a nice long run today, at 6am on the motorway it stayed at 76/78 then after the outside temp warmed up a bit, around 1pm it sat at 84/86.

[big ben 10]

that seems very low to me

[jamiehamy 0]

Virtually the same as mine. :)

 

Now mine is back after my gearbox misshap....

 

I took it for a nice long run today, at 6am on the motorway it stayed at 76/78 then after the outside temp warmed up a bit, around 1pm it sat at 84/86.