Oil coolers

[ghost123uk]

I am very likely swapping from DG power to DJ power in the near future, but retaining my carb and manifold with BLOS LPG. I know most (all?) DJ motors have a "sandwich" oil cooler between the filter and the filter mount. My new DJ will likely have a cooler, but the reason for posting this is for other folks who have DG motors, as, even with my DG I have often mooted fitting an oil cooler. It would be a very easy mod and fitting would not take long at all (I know because I had to replace the one on our Scirocco some years ago)

So, two points :-
1:- Is the general consensus that fitting an oil cooler to a DG is worthwhile?
2:- I wonder if the "sandwich" oil coolers fitted to most of the Golf/Passat/Scirocco/Skoda/Audi in line 4 motors is the same fitment? It would be good if it was as they are common in the breakers. Anyone got Etka or summat and could check?

[bigherb]

So, two points :-
1:- Is the general consensus that fitting an oil cooler to a DG is worthwhile?
2:- I wonder if the "sandwich" oil coolers fitted to most of the Golf/Passat/Scirocco/Skoda/Audi in line 4 motors is the same fitment? It would be good if it was as they are common in the breakers. Anyone got Etka or summat and could check?

1 Not really the DG is a smaller bang and at lower compression so doesn't run so hot.
2 Yes it is a pretty common oil cooler fitted to T4's Golfs etc.

[CovKid]

Agree. The only time I've ever fitted an oil cooler is on a vdub lump that has been rebuilt for performance. Waste of time on stock ones unless you're partial to redlining all the time.

[123-jn]

I was happy without a cooler until I fitted an oil temp gauge. You then find that your oil temp runs at around 90 degrees on a pleasant amble about but as soon as you throttle up on a motorway it flies up to 110 and on hot days up inclines up to 135 degrees. Although engine oil especially newer synthetic oils are happy past this I am told that it is right on the limit for mineral oils. I decided that rather than add all that heat to my cooling system with a stock cooler I would fit and air/oil changer with a sandwich plate. I have a 13 row cooler mounted next to my transmission in the airflow with an 80 degree stat. Now my oil runs at between 90 and 102 degrees depending on what I do which I reckon will cause less thermal stress on the engine and the oil its-self. I have also fitted a cooler to my auto trans and removed the coolant based one. This immediately helped my cooling system and has stopped my trans smelling of hot oil after a run. (The reason I went for a small 13 row cooler was that I didnt have the stat to start with and I didnt want over cooling It did lengthen warm up time considerably thus the stat.)

[ghost123uk]

it flies up to 110 and on hot days up inclines up to 135 degrees.... I am told that it is right on the limit for mineral oils.

I was wondering what the max recommended temperature for a classic 20/50 mineral oil was (my Google research got "clouded" by all the references to temperature re viscosity stuff )

Does anyone know if all 2.1 WBX motors have an oil cooler as original equipment? (just out of curiosity)

E D I T = I just looked up on VagCat and it doesn't seem to mention oil coolers for WBX engines at all
(I was checking to see if they are the same as the common Golf/Passat/Scirocco/Audi?Skoda ones, I suspect they are).

[ghost123uk]

Found these old thread entries whilst "Googling around" for part numbers :-

Looks like this has been covered before (surprise surprise )

I rely on TenCent for the reasons why the WBX's can go bang after a 100 or more thousand miles. He believes it is an oil temperature problem. When ragged very hard the oil in the wbx can reach over 130 deg C. This thins the oil and lowers the pressure. But, if you observe oil pressure, and maintain a healthy oil temperature then these engines should go on as long as the degrading rubber of the head gasket will allow. That is why I think the single most important gauge on a wbx is oil pressure. If it starts to drop, slow down, if pressure comes back (as the oil cools) that's fine. Tencent will only guarantee them if an oil cooler is fitted. In the states lots of standard engines get well over 200,000 miles.

Yes, Simon's correct, oil in most T3s can get very hot, a VW oversight (cost) in not fitting oil coolers to these heavy and somewhat under-engined & rear-engined vehicles.

The OWHX (notice I don't call it an oil cooler; it is not) is for fast engine warmup to lower overall emissions (oil takes three times as long as water to reach temp otherwise).

Once warmed up, the OWHX can keep the oil temp close to water temp but doesn't have enough exchange area and too low a temp differential to prevent high temp excursions, you need external oil cooling to put a lid on those.

Note who wrote that last quote above
So what "we" call an oil cooler, the sandwich type under the oil filter, does little to actually cool the oil (apparently) interesting (well I think so )

[MGP]

VagCat lists the WBX oil cooler under the pump and filter heading, part no 068117021BX same as big block i4 engines.
Im personaly not convinced that they are of much use as there in not much of a temperature difference between the water and the oil.

[CovKid]

Be hard to 'rag' an engine when you're loaded with beans, bacon, beer and assorted family members. They can certainly get warm when you're in hilly terrain or stuck in traffic but then any cooling effect would be through convection rather than any semblance of a passing breeze. The cooling system takes charge then. I kind of understood the need on a tuned Aircooled engine (built many) but not convinced its worth the effort when regular maintenance and oil changes probably matter far more.

[toomanytoys]

Found these old thread entries whilst "Googling around" for part numbers :-

Looks like this has been covered before (surprise surprise )

I rely on TenCent for the reasons why the WBX's can go bang after a 100 or more thousand miles. He believes it is an oil temperature problem. When ragged very hard the oil in the wbx can reach over 130 deg C. This thins the oil and lowers the pressure. But, if you observe oil pressure, and maintain a healthy oil temperature then these engines should go on as long as the degrading rubber of the head gasket will allow. That is why I think the single most important gauge on a wbx is oil pressure. If it starts to drop, slow down, if pressure comes back (as the oil cools) that's fine. Tencent will only guarantee them if an oil cooler is fitted. In the states lots of standard engines get well over 200,000 miles.

Yes, Simon's correct, oil in most T3s can get very hot, a VW oversight (cost) in not fitting oil coolers to these heavy and somewhat under-engined & rear-engined vehicles.

The OWHX (notice I don't call it an oil cooler; it is not) is for fast engine warmup to lower overall emissions (oil takes three times as long as water to reach temp otherwise).

Once warmed up, the OWHX can keep the oil temp close to water temp but doesn't have enough exchange area and too low a temp differential to prevent high temp excursions, you need external oil cooling to put a lid on those.

Note who wrote that last quote above
So what "we" call an oil cooler, the sandwich type under the oil filter, does little to actually cool the oil (apparently) interesting (well I think so )

Yep.. Oil temperature control is pretty poor.. the oil "warmer" doesn't goo a very good job to be fair..

and "ragging" doesn't mean driving like a twonk.. it means, loaded with beans/bacon/camping gear/people. up a hill.. a heavily laden vehicle will ask more of the engine than an empty one.. so will generate more heat..

I have seen over 120 deg even in a lowly DG with the "2.1 oil cooler/warmer....

[toomanytoys]

Found these old thread entries whilst "Googling around" for part numbers :-

Looks like this has been covered before (surprise surprise )

I rely on TenCent for the reasons why the WBX's can go bang after a 100 or more thousand miles. He believes it is an oil temperature problem. When ragged very hard the oil in the wbx can reach over 130 deg C. This thins the oil and lowers the pressure. But, if you observe oil pressure, and maintain a healthy oil temperature then these engines should go on as long as the degrading rubber of the head gasket will allow. That is why I think the single most important gauge on a wbx is oil pressure. If it starts to drop, slow down, if pressure comes back (as the oil cools) that's fine. Tencent will only guarantee them if an oil cooler is fitted. In the states lots of standard engines get well over 200,000 miles.

Yes, Simon's correct, oil in most T3s can get very hot, a VW oversight (cost) in not fitting oil coolers to these heavy and somewhat under-engined & rear-engined vehicles.

The OWHX (notice I don't call it an oil cooler; it is not) is for fast engine warmup to lower overall emissions (oil takes three times as long as water to reach temp otherwise).

Once warmed up, the OWHX can keep the oil temp close to water temp but doesn't have enough exchange area and too low a temp differential to prevent high temp excursions, you need external oil cooling to put a lid on those.

Note who wrote that last quote above
So what "we" call an oil cooler, the sandwich type under the oil filter, does little to actually cool the oil (apparently) interesting (well I think so )

Yep.. Oil temperature control is pretty poor.. the oil "warmer" doesn't goo a very good job to be fair..

and "ragging" doesn't mean driving like a twonk.. it means, loaded with beans/bacon/camping gear/people. up a hill.. a heavily laden vehicle will ask more of the engine than an empty one.. so will generate more heat..

I have seen over 120 deg even in a lowly DG with the "2.1 oil cooler/warmer....

[The Bishop]

So in conclusion can we just get one out of a breakers yard?

[ghost123uk]

Yes, off any of the 1.8 or 2Ltr VW inline 4 engines (Golf/Passat/Scirocco/Audi/Skoda) that have them fitted (many of the earlier carb engines of that range don't have them).

Seems that there is room for discussion on whether they do much to actually cool the oil though. Tencent says he reckons they do no good cooling, but are there for faster warming = emissions. iirc, it was KevTheRev who somewhere on here said he noticed an improvement in average oil pressures under load after fitting one (he may be along to confirm or deny my memory of that post). There was another thread where, when this was discussed, I suggested the poster who had fitted one, and also had an oil temp gauge, tested it on a known run, under same ambient conditions, with, and then without his cooler (bypassing it temporarily with a joining piece of tubing) and report his findings.


I will at some time in the next few weeks be going DJ power and as far as I know they are O.E. on those engines. Whether that is summat to do with them normally being injection, or to do with U.S. emissions laws, or because they do cool the oil and DJ's, as we know, need good pressure to the shell bearings, I simply don't know. Ian / Si ?

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Aside = I understand from reading the Pro's opinions on here (you know who you are ) that a higher capacity oil pump is definitely a worthwhile purchase and one I will likely go for on my "new to me" DJ.

[toomanytoys]

Nope... "stock type oil cooler" ... they don't do all that much.. A new one is about 45 quid...
Better to fit an external oil cooler with tstat... if you want good control over the oil temp...

Oil pump.. nothing wrong with the std oil pump IF the oil temperature is well controlled.. all that happens is the extra pressure is dumped out of the pressure relief...

[The Bishop]

They say that air cooled engines are really oil cooled engines.

Surely, air flowing though an oil radiator is going to cool the oil and in turn the metal. I can't see that there is any debate about that.

I am sure it will cool my engine. I suppose the question is, do I need to cool my engine, after all , they say you need to warm it up in the morning.

[CovKid]

The cooling effect is largely dependent on air flowing past/through the cooler. If you're sat in traffic this is severely reduced even if some heat is radiated away.

Bearing in mind that a 2.1 is a fairly maxed-out WBX engine, VW did take time to introduce features designed to reduce elevated temperatures.

External oil coolers are fantastic on the track since you can fairly accurately predict the volume of air moving past the cooler and tune accordingly. This is rather difficult if not impossible to predict given the stop/start nature of driving in everyday traffic (more 'stop' on Fridays) and I'd suggest that the regular cooling system does far more work in that regard. I suppose the ideal might be an independent water-cooled oil cooler but it all starts to get silly then. It needs (at the very least) to be an intelligent cooler to be of any real use.

As I said earlier, it made a lot of sense on performance-built Aircooled engines but thats a world away from a camper which has a very different purpose. Personally I'd be looking at fine-tuning when the main fan kicks in and making sure the main cooling system is in tip-top condition. This alone would do much to keep temperatures within an acceptable range.