High temperatures cause oil to break down more quickly. There are plenty of commercials on TV to remind you that heat is the number-one enemy of your engine. It's a basic fact of life: any high performance Volkswagen engine driven hard will get the oil hot enough to make an auxiliary oil cooler a good idea, if not essential. New Dimensions has taken a fresh look at the problem of adding increased oil cooling capability to the water-cooled VW.

Don't get us wrong: Water-cooled VWs are designed to run with relatively high oil temperatures for reasons of both economy and emissions reduction. But a mildly modified engine, driven hard, will cause oil temperatures to soar to the point where damage to the oil can occur. That's true with any normally-aspirated engine. If your car is supercharged, or equipped with one of the ND Stage III Turbo setups, an oil cooler becomes essential. There is nothing like a turbocharger to help warm your engine oil in a big hurry.

So we need to cool the oil. An aluminum oil pan can help to dissipate some of the heat, but a racing-style cooler is the best bet for serious cooling. And a thermostatic adapter is essential. An oil thermostat is designed to allow the oil to warm up more quickly. It shuts off flow to the cooler altogether when cooling is not needed, like during warmup. You'll want to make sure that high-quality oil lines and fittings are used. VW oil pressure run quite a bit higher than the typical British sports car, or even a Detroit V8. Once you have everything, you need to assemble the lines, which is never as simple as you might think.

Getting the right parts is relatively easy, if you know what you're looking for. The trick is getting them to fit. New Dimensions has taken a long, hard look at the problem and offers an interesting set of solutions that cover most of the A1 and A2 VW applications, including some of the more tricky air conditioned setups. They even offer a kit for the Rallye Golf grill on cars with and without A/C-a rare application that came in handy on Project A2 GTI.

The super-sano ND oil cooler installation works like a charm. Everything fits with no rubbing or interference. Oil temps stay right at a 175 F in normal cruising, rising to a manageable 200 F under hard usage.

The Factory Way
In the pedal-to-the-metal world of the autobahnen, the GTI has always had an auxiliary oil cooler. While we seldom drive flat out, almost all U.S. cars are fitted with air conditioning. AC steals the usual location for an oil cooler.

Volkswagen addressed the high oil temperature question stateside starting with the A1 GTIs. A water-to-oil heat exchanger was installed on that and later performance engines. It helps alleviate the temperature problem somewhat, but when driven hard, or in highly modified form, it's still easy to get these engines' oil temperature up higher than is desirable. The factory oil cooler also preheats the engine oil, getting it up to operating temperature more quickly. We recommend keeping it for quicker warmups and reduced emissions, not to mention reduced engine wear.

If you have a turbo, the warmup feature of the factory heat exchanger means the oil temp will come up sooner, and you can get it into boost that much quicker on a cold winter morning. If you are adamant and do insist on removing the factory oil-to-water heat exchanger, New Dimensions carries a conversion kit, part number ND-17-570 through 580, with all the parts you'll need to remove the factory unit. All of the ND Oil Cooler kits will work with or without the factory oil cooler in place.

The ND Oil Cooler kits use quality hardware all the way. The cooler is a racing quality 19-row unit, but the hose is different-it's a bright blue industrial hose. Braided stainless steel-covered hose looks racy, for sure. After all, it's the stuff the real racers use. But it's expensive, as are the fittings. Those aluminum fittings can be damaged if you don't pay close attention. A braided hose that can rub against something makes an excellent saw. The outer stainless covering is abrasion resistant, but the covering itself is also an excellent abrasive, cutting and scratching any part of the car it rubs against. Assembling the fittings and braided stainless hose can be a hassle, too. Is there a way out?

The ND solution is to use steel-braided rubber hose with a blue rubber cover industrial hose with steel fittings. And the best part is the hoses come cut to length and pre-assembled for each application. ND has done their homework on this one-no cutting and assembling on your part. The industrial hose is heavy duty, with excellent wear and pressure characteristics. The steel fittings feature tubing bends that allow full oil flow with minimum restriction. Brackets, all mounting hardware and complete instructions are included for each application, making installation a snap.

Prices range from $249 to $299 for the complete kit, with detailed instructions and free tech support form the competent staff at New Dimensions. If you want to use the traditional aluminum fittings and the braided stainless steel covered hose, any kit can be upgraded for a cost of about $60.

Installing the A2 Oil Cooler
We took a look at ND's A2-120 kit, designed for all 1985-up A2 cars with the factory aerodynamic headlights. The kit works on cars with and without air conditioning. It's different than the kit installed on our Rallye Golf, but we thought it more interesting to the readers as it is a more common installation.

New Dimensions assigns each product a "do-it-yourself" skill rating on a scale of 1 to 10: from first-time-do-it-yourselfer to semiprofessional technician (whatever that is…). This kit is rated 6, putting it within range of most serious hobbyists and budding mechanics. ND notes that if you feel less than comfortable performing the more serious steps, you can mount the cooler and have the pros hook up the vital oil lines to your engine. You spend a few bucks but gain some peace of mind. Since you have to remove the filter to do the installation, an oil change interval is a good time to perform the install.

Tools
Normal hand tools and a few drills are all that's needed for the most part. An oil filter wrench of your choice makes it easy to pull the filter. The Allen mounting screws require a 4mm hex drive socket or wrench. A 1-in. socket and 1-in. wrench is a bit out of the ordinary for us metric folks. An adjustable wrench, like a crescent wrench, will do an acceptable job if used with care, but a socket will do a much better job on the adapter. We'd also recommend a ruler and center punch to accurately measure and mark the holes for drilling. You'll also need Loctite®. Always a good idea is a bit of touch-up paint to keep the edges of the newly drilled holes from rusting.

The Step by Step
Step one: jack up the car and put it on jackstands, drain the oil and remove the filter. In order to install the oil cooler, both the upper and lower grilles must be snapped out. Take care not to break the tabs holding the grille in place.

With everything cleared away, the work begins. Some models have a horn mounted in the grille area. Since the ND oil cooler goes where the horn is right now, the horn must be relocated. The ND kit supplies directions and the Nylock nut and washer to remount the horn below the stock location. Unclip the horn wire from the core support so that it will reach the new location, and don't forget to wire it up.

Next, assemble the custom ND brackets to the oil cooler. The shorter two brackets mount on the driver's side of the car, next to the headlamp. Each of the four brackets mounts to the cooler using a single 6mm bolt, Nylock self-locking nut and a pair of 6mm flat washers. We mounted the fasteners snug, but not tight, for the trial fitment.

With the brackets in place, trial-fit the oil cooler. ND mounts the oil cooler as flush to possible against the radiator or AC condenser. Measure twice, drill once! Center punch the mark and drill the four holes. As always, drill a smaller pilot hole then the finished hole so as not to distort the metal. The holes by the headlight use the smaller 3/16-in. hole, while the holes at the core support are ¼-in.

Trial assemble the hoses to the oil cooler at this time, leaving them a bit loose. The hoses have AN flare fittings. You don't need to use any sealant, Teflon tape or pipe dope to get them to seal. A bit of engine oil on the threads will make things go on smoother. The hose on the small bracket/headlamp side goes behind the other hose (see drawing). Trial fit the cooler-if everything lines up, tighten down the hose fittings to the oil cooler. Do not overtighten: the oil cooler is light alloy and can easily be abused.

Time to bolt the cooler in. The brackets should still be loose enough to allow for adjustment. Use the two 5mm Allen screw on the headlamp side and two 6mm bolts with Nylock nuts and the large fender washers at the core support. Make sure everything is lined up before the final tightening.

ND provides two large tie wraps to keep the hoses in place. At this time, they need to go around the hoses loosely-they are not tightened yet. With the hoses together, route them into place: inside the front bumper, through the radiator support and into the engine compartment, around to the oil filter flange.

Next get the thermostat/sandwich adapter ready for installation. Install the two threaded AN adapters into the plate, allowing the O-rings to seat into the groove.

The sandwich plate mounts to the oil filter housing or factory oil cooler using the large hollow adapter bolt. Fit the rubber gasket (like an oil filter gasket) to the top of the adapter using a little oil, and clean the threads coming out of the factory oil filter mount. Using a thread-locking compound like Loctite on the inside threads of the adapter bolt, install the sandwich plate. Don't tighten the bolt all the way at this time, you need to be able to rotate the plate to install the hoses.

Now it all comes together. Attach the oil lines to the adapter. The illustration shows you how to arrange the hoses, with one below the other. With everything in place, tighten down the adapter nut, sealing the sandwich adapter to the oil filter boss. Check each fitting and the cooler mounting brackets to make sire they are tight. Install a new oil filter and, if you drained the engine oil, fill the engine with 4.7 quarts of oil.

Doublecheck the installation, and tighten the tie wraps to keep the hoses together. Cut off the excess. Start the car and let it idle. Check carefully for any leaks. You'll want to allow the car to idle long enough for the thermostat to open and flow oil to the cooler. You can check that with your hand-the oil cooler will get quite hot when the thermostat opens. Make sure you have adequate ventilation when idling the car for long periods of time.

When you're sure that the thermostat has opened and there are no leaks, button things up. Shut off the engine. Doublecheck that your horn works, then reinstall the upper and lower grille. Check the engine oil level, topping off if necessary.

New Dimensions recommends checking the fittings during the first 1000 miles or so to be sure there are no leaks. If you have any questions during your install, ND products offer tech support and help along the way.