Oil radiator installation. Possible troubleshooting solutions?

[Richard T6.1]

It would be helpful to know what the specified / designed working temperature range is, we can then match the stat to suit, even the 92 will off gas & evaporate any fuel or coolant that finds itself in the engine oil.

The stat has no influence on the oil temp as such (that's depending on engine, load, power etc.) The stat only controls the temp when the oil cooler starts to work and thus, how long it takes for the oil to reach its operating temp (whatever that is). The size of the cooler, its position (airflow) and the ambient temp determines how much temperature drop the cooler achieves. That said, if the oil temp drops in or below the opening range of the stat, it does control the oil temp in a sense that it would (start to) close the flow to the cooler.

The opening range of the 102 stat between 100-114 C seems absolutely spot on to me.

 

[Richard T6.1]

Reading my post above again > an attempt to add some more clarity (not a native English speaker, sorry! )

Ideally you need to know two things to choose the right stat. The average oil temp of your engine under normal conditions and second, how much temp drop your cooler setup achieves on average. You only want the cooler to step in when the oil temp is heading towards too hot. Not before because then it would delay - or even prevent - the oil getting up to its normal working temp range. Both are not good (the medicine being worse than...).

To illustrate with some real numbers taking my own 150 HP camper van as an example:
- Normal average oil temp year round(!) hovers between 96 and 105 C
- Fully loaded under super hot 40 C summer conditions at high speeds and/or during long hill climbs etc. it creeps up to 110 - 114 C

If I were to fit an oil cooler that provides an average temp drop of 10 deg. C (example) I'd want the stat to be fully open at 115 -ish C - not before 'cos everything is perfectly fine up to that point. Fully operational at 115 C, the cooler would gradually bring the oil back down to 105 - ish C. Still in the 'perfect' range.
In this same example, if I would us a 92 C stat, the cooler would open up too soon and would at least delay my engine to reach its normal operating temp range. Or, under cold/winter/low load conditions, it'll likely prevent the oil to reach its normal operating temp range at all (say 98 minus 10 C from the cooler). Not good!

It's all about a matching/calibrated 'triangle' between your particular engine, the temp drop from the cooler and the stat that controls the operational window.

I hope this clarifies a bit more!

 

[catfood12]

Sorted it!

Red if flow, from the centre of the oil filter.
Blue is return, to the outside of the oil filter.

View attachment 286228

I thought it was the other way fella? Oil from the pump into the outside of the filter, clean oil out of the middle.

For cartridge type filters you can see what's been stopped, i.e. metal shavings between the pleats of the filter on the outside, and for spin on cartridge types, OEM/proper ones have a rubber flap over the holes on the outside side of the element to act as a one way valve and stop oil draining back through the pump into the sump.

 

[Cog Head]

I think it depends on perspective, I’m looking for flow from the engine to the oil thermostat/ cooler (centre of oil filter), and the return is from the thermostat/ cooler, back to the outside of the filter

 

[FerrisBFW]

@Richard T6.1 you could have fooled me, you written english is dam good.

Right I fitted a HEL 102 thermostat to my Mocal oil SWP. I thought it was worth a try for £12. I fitted it tonight, I was in a rush as I needed to be somewhere so just pulled the plate and swapped it over fast. I just tried it and its not working at all. Temp is struggling to get above 60d on a short run that would normally see 90+

I will explain, the 80d thermostat looks identical dimensions as the 102, as it did on the picture, but the little plungy thing on the top was much shorter. I gave it a go and it didnt work. I also hate the way I have routed the pipework. These are make your own pipes and I have a lot of connections and pipe spare so I am going to try another route. Once I get this right I will order the right length made up ones.

I can get a Mopar 92d thermostat for my plate so I could try that for another £14. If I want 102 I will need to buy a HEL one for £120. I will decide over the weekend I guess. I guess I bite the bullet and get a 102d HEL plate for another £120 :-(

 

[Richard T6.1]

Thank you @FerrisBFW. I refuse to use ChatGPT or something - gotta learn and get better myself!

So your current try-out setup seems to drop the temp from 90 to 60 C? That's a lot for an oil cooler.
Thinking out loud; is it possible to test-run without a stat for a few trips to see what just the radiator and pipework does? I'm not an expert but a -30 C drop seems too much to me. That would require a stat that opens at 120-125 C to keep the oil temp somewhat within the right range (125 - 30 = 95-ish). And 120-125 C sump temp(!) is quite/too high already for prolonged time.

Maybe the radiator is too big? During testing you can put tape over 1/3 or half of the radiator to see what happens.

 

[Cog Head]

Thanks for your update.
I’m still sulking about missing my HEL delivery on Friday… it would be bumper on, running and remap on Monday…life gets rite in the way sometimes!

I think the stat is the wrong item, it sounds like my old Evo 9, it took FOREVER to get to 60+ degrees as it had no stat fitted, but that was a different beast altogether.
You could have the biggest cooler in the world, a properly designed and fitted stat will keep the cooling fluid within its working window.

Give me a shout I you want a price for the HEL SWP.

Can you post a photo with your oil pipe routes marked in “markup” (as per apple iPhone)
I’m going to use the underside of the upper crash bar, that holds the bonnet catch, to fix my cooler pipes to, there’s quite a bit of space under there.

 

[FerrisBFW]

I think this route will be obvious from the photos. This was a doddle tonight. No messing about pulled it all apart. Put the 80d therm back in and then to test the 90 degree fittings for new vertical route (pic1)



Around the fan and down behind the washer res pipe (pic2) down the far right of the rad (tuns of room)



(Pic3) two more 90 degree fittings into my cooler under the IC. Changing pipes was a mare and messy as hell.


On a run out to Surrey Hills mtbing tomorrow so a good test.

So decision is 92d thermostat for £15 or 102d HEL one from you @Cog Head fir something less that £120 rrp

 

[FerrisBFW]

PS What is it with modern cars!!? You think you have every tool but the random sizes of spanners and sockets i keep needing to buy is tiring. 20mm for the therm bolt now. I guess this is actually AF?

 

[Marc R]

My DD kit is going in next week... excited.

 

[FerrisBFW]

yep 80d is way too early. I am ordering a 102d HEP unit ASAP.

 

[Cog Head]

So I finally got my hand on my missed HEL order this morning... im still no closer to completing it

The oil take off plate I've used has AN-8 fittings, no problem I thought, ill use AN-8 to AN-10 adapters and banjo swivel's ... NOPE

I've now ordered some AN-8 male to AN-10 female adapters so the banjo fittings will hopefully fit, if this doesn't work ill have to replace everything with AN-8, and that really will p!ss me off!
I'm hoping the top of the AN-8 to AN-10 adapter will finish where the top of the hexagonal part finishes on the adapters below, this will allow me to sneak the low profile banjo bolts in there, then I can finally get the front back on the van and start making some actual progress.

 

[FerrisBFW]

Everything is so tight in there isnt it? I now have a P029900 error and in limp mode yesterday, I bet I have knocked something. Vacuum pump coming tonight to try and narrow down

 

[Cog Head]

It’s crazy tight down there, the latest batch of HEL parts should hopefully sort it though.
Thankfully they accept returns, so if I have to change to AN-8, I’ll only suffer the cost of return postage.

That’s a strange one, most, if not all turbo vac lines are up high, then again I bet they all use the same source of vac, one leak, they all drop.
Hopefully you get it squared away easily, my favourite for vac faults is the smoke test, can’t miss it!
I’m half expecting to have some faults to chase around when I eventually got it back together, as I've stripped a lot back to get to the intake manifold & EGR, I think I’ll run it upto full working temp before I put the bumper back on.

I turned the ignition on the other day to roll it back a little, the dash lit up like a Christmas tree! It’s gonna be codes galore!

 

[Marc R]

The Darkside Development oil cooler kit came with a 80 degree thermostat and i really think that's too cold so i have ordered a 92 degree thermostat insert for 30 euro....i hope that solves the problem.

 

[Marc R]

I think this route will be obvious from the photos. This was a doddle tonight. No messing about pulled it all apart. Put the 80d therm back in and then to test the 90 degree fittings for new vertical route (pic1)

View attachment 287259

Around the fan and down behind the washer res pipe (pic2) down the far right of the rad (tuns of room)

View attachment 287260

(Pic3) two more 90 degree fittings into my cooler under the IC. Changing pipes was a mare and messy as hell.


On a run out to Surrey Hills mtbing tomorrow so a good test.

So decision is 92d thermostat for £15 or 102d HEL one from you @Cog Head fir something less that £120 rrp

View attachment 287261

How did your test drive go? i am interested in your experience....

 

[FerrisBFW]

Too cold . I am buying a Hel 102 asap.

 

[Marc R]

Thanks for the feedback, i'll try the 92 degree and revert here.

 

[Cog Head]

The oil take off plate I have is putting up a good fight, it has AN-8 threaded bosses, I’m using AN-10 pipe and fittings to keep the flow rate and cooling capacity up, because the area it’s fitted in is so incredibly tight, I’m having to use AN-10 low profile banjo fittings with an AN-8 to AN-10 adapter, which then puts the banjo too high and it touches one of the engines hard coolant inlets, I’ve entertained the idea of switching to AN-8 but you can’t get the low profile banjo fittings in that size…. Fun… rite!?

I’ve spoken to a local engine builder, who I’m going to see tonight, and hopefully get it done there and then…
We’re going to mill the two bosses off completely, so it’s a flat plate with the coolant passage running diagonally, the two bosses will then be bored out and re-threaded to take the AN-10 banjo’s, and then… just maybe… I’ll be able to get the thing fitted and finally get the van back together and running again, towing our caravan with our EV (BMW iX) is OK, but it’s only OK and has highlighted just how great our T6 is at towing.

Here’s some photos…

 

[Marc R]

So this week I had some maintenance work done on the van, DSG oil service, Engine oiil service, 340mm brakes and oil cooler fitted.

I had a nice hour long drive home and where the oil normally is between 100 and 105 c without towing..... the temp just reached 95 c with some spirited driving (as far as that's possible with a van) with an outside temperature of 22c

I am a happy with the result regarding the 92c thermostat i used..
also the cooler itself is placed on the drivers-side next to the VW logo, nicely in sight behind the grill


BTW how do I post pics on this forum?