Oil cooling a 1.6TD?

[tylernt]

So, I decided to go ahead and keep the turbo on the junkyard 1.6 I obtained. But I can't leave well enough alone, and want to ditch the oil "cooler" for several reasons:

1. Some people are of the opinion that it doesn't really cool the oil much, due to the routing of the coolant hoses.

2. The special tee'd coolant hoses are apparently rare and expensive.

3. I will be thermal-coating the piston tops.

4. I will not be running insane amounts of boost; this car will be a grocery-getter.

5. I like things simple.

Does anyone think my oil will get too hot without an oil cooler?

[jtanguay]

run an oil temperature gauge if you are running without any type of oil cooling.

the oil heat exchanger cooler mainly equalizes the temperature of both coolant and oil to some degree.  the efficiency is pretty low, in that when you drive hard, it takes the coolant a minute or so to catch up to the oil temps...

imo it's better than nothing... and works wonders in the winter time! BUT mine broke on me and did some weird stuff... so I replaced it!  i'm not sure if it was the dufus' at the oil change places reefing on the oil filter... i mean come on how tight does an oil filter have to be? morons...

if you can get your hands on a nice thermostatically controlled oil cooler that isn't too big, then i would recommend that you install it.  andy2 told me that the one he has still flows a little bit of oil through (bypassing the thermostat) which is not good in the winter time...  you would ideally want to find one that has a 100% seal and good working thermostat.

[tylernt]

Funny you should mention that -- before I posted, I did find an oil thermostat for about $50 that does just that, flows 10% through the cooler below 180*F and opens up above that. I think it's designed for aircooled aircraft but ought to work for us.

My suspicion is that with the pistons kept cool with the thermal coating, the turbo will be the main source for heated oil. The question is, will the turbo overheat the oil by itself or not and if so, how much of an oil cooler do I need. I've seen transmission and P/S coolers that are just a loop of tubing in front of the radiator, and I wonder if that by itself would do the trick. If so, maybe I wouldn't even need the thermostat since perhaps such an inefficient cooler would not cool the oil too much.

Too much speculation though... need more data!  

[jannemann]

That you need:

http://www.busschmiede.de/bilder/oelkuehler_kit.jpg

[BlackTieTD]

its as much a 'heat exchanger' as an oil cooler. if it doesn't leak and you have the hoses to make it work, i'd just leave it on there, especially on a grocery getter. no sense spending money/complication on a true oil cooler...and the part was put on specific engines for a purpose. if the heat exchanger is on a little loose, then complications from over tightening the oil filter can sometimes loosen the threaded pipe that runs through the center of the cooler housing -- just make sure its on there tight. i have some pictures of the different hose configurations on this page, might help

you have options for hoses.

[tylernt]

When you say heat exchanger, do you mean that the purpose is to heat cold oil as much as cool hot oil?

My hoses are old so I will be replacing all of them. The special hoses are $30 and $20 but the normal hoses are $5 and $3, plus the heat exchangers are known to fail and mix coolant and oil, so that's kind of why I'd like to delete it. I agree that it has a purpose on a stock car, but my hypothesis is that thermal-coating the pistons will negate that need...?

[burn_your_money]

but my hypothesis is that thermal-coating the pistons will negate that need...?

Perhaps.. the heat will be transfered to the valves and the head, which are cooled by the oil as well. You are also putting more heat into the piston rings which will shorten thier life.

[BlackTieTD]

When you say heat exchanger, do you mean that the purpose is to heat cold oil as much as cool hot oil?

yep

My hoses are old so I will be replacing all of them. The special hoses are $30 and $20 but the normal hoses are $5 and $3

some of the 'normal hoses' can be used if you get a different metal water pipe. there are pictures of two different setups in that link in the first post i made here.

the heat exchangers are known to fail and mix coolant and oil, so that's kind of why I'd like to delete it.

its basically a metal box (holding coolant) with a metal pipe running through it (holding oil). the metal pipe is threaded at both ends. as long as that metal pipe is tight, the thing can't leak. the pipe itself wont rot out or leak. the metal housing around the coolant could fail and leak the coolant externally, but personally i've never come across that. the only time i've had issues with it is when that metal pipe comes loose (happened on my G60 corrado...same part). resulted in a very noticable oil leak.

[tylernt]

Perhaps.. the heat will be transfered to the valves and the head, which are cooled by the oil as well.

The head also has a lot of coolant in it though, so I think the oil and coolant temperatures in the head will quickly equalize. If you look at the bottom end of the engine though, with hot oil coming from the turbo and getting squirted on the piston bottoms, there is not a lot of coolant-oil thermal interaction and things would heat up. With thermal-coated piston tops, though, the remaining contributor to heat is mainly the turbo.

You are also putting more heat into the piston rings which will shorten thier life.

Hmm. I'm not coating the piston skirts, just the tops, so the rings will be sitting in grooves that are cooled by the oil squirters. How much do you think I will be shortening their life?

[jimfoo]

Just get an external cooler. The engines seem somewhat thermally challenged as it is. Most setups you can get have a built in thermostat.

[burn_your_money]

Hmm. I'm not coating the piston skirts, just the tops, so the rings will be sitting in grooves that are cooled by the oil squirters. How much do you think I will be shortening their life?

No idea, probably not by a whole lot.

[745 turbogreasel]

If you do want to use the VW oil cooler(VW recomend a $360 replacement unit every time you work on the motor, but I can find them as low as $85..they DO fail in a number of evil ways)
My way is to eliminate the POS VW oil-coolant heat exchanger Along with 3 hoses and 6 clamps, and one rusty metal tube. I can then use the hose fittings on the engine for my SVO heater.
I did this by using an air-oil cooler&hoses from a Saab turbo, and thermostatic oil filter/cooler adapter form a Gas turbo Volvo740. saab oil cooler lines worked fine, but they are often old and leaky, so you might want new ones. Get the threaded tube from the gas car too, I didnt, and had to buy an expensive tap to thread my VW/Audi tube deeper after I cut 1/2" off it. A new Oring is also a good investment, $8 at the dealer.

Pictures are here:

http://groups.msn.com/Avatargif/volvoturbodieseloilcoolermod.msnw