DIY: After market oil cooler install 2006 335i N54

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Joined: 29 Oct 2012, 15:20

DIY: After market oil cooler install 2006 335i N54

Post by DubVersion » 17 Nov 2017, 18:00

Hi all,

i've just completed installing an aftermarket oil cooler from ebay.
The car does have an OEM oil cooler, but temps are still hitting the 120 Celsius regularly, and i want them down or at least come down quicker.

there are several brands selling an after market oil cooler, but they quickly cost up to USD 1000. For other cars (other brands) the prices are often not as high. As there's nothing special about building an oil cooler in a BMW, i went the ebay route.

I purchased a 16 row oil cooler with fitment for the BMW N54 engine from the company "G-plus" Performance Parts and chose the "Racing oil cooler" for BMW N54. I paid GBP 85, so about USD 120.

I has the oil lines, the cooler and a block that fits the extra cooler in between the oem setup.

I decided to put the oil cooler in front of the passenger's side BMW kidney; it's not too difficult to access, you'll have to take off the bumper. Mounting is done on the hard plastic (it does require trimming the hard plastic on a few places). But because the oil cooler is fitted, it actually makes the whole thing stronger again.

You could argue that blocking the radiator may spike coolant temps, but a few people i spoke to said this is not an issue; the cooler oil makes up for it and of course the air does flow thru both the oil cooler AND the (stacked) radiator.

I'm still to test the system properly and will update this thread when i have done so.

It took us 2 nights with 2 people to figure out how to fit the oil cooler and route the oil lines (first night) and actually fit it, making the custom brackets. (second night).

It also requires a custom made aluminium bracket on which one side of the oil cooler is bolted. The other side is bolted in the hard plastic with a long M6 screw.

To get the oil lines to this part of the car required only a "sleeved" cut into the same hard plastic; the engine bay can be reached.

It's a tight fight to get the oil lines onto the cooler once it's installed. We first had one line on it (on the driver's side) then pushed the cooler+line in place and then struggled a bit to get the passenger's side line on the fitting.

Also to bolt the additional router onto the OEM fitting is not so easy, there's minimum space, particularly due to the cooland line going to the oil filter/thermostat housing. But we managed.

some pointers:

- you'll need to cut into the hard plastic. A one blade handsaw helps, a (wood or metal) file helps. Using a dremel is not so handy; it melts the plastic. A drill with a wide drill bit (22 mm or so) may also help, especially to cut the sleeve/hole for the oil lines.

- Make sure no oil leaks on your V-belt. I had a plastic bag covering the whole belt, all the way up to the bolt that you need to remove from the housing.

- Remove your engine floor board under your car. No need to get it full of oil.
- Remove the fan. It's easy and gives you much more space.

Here are some pics of the process:

i'm happy, soon we'll do some road test to find out if it was worth the trouble. But so far we have proven that installing a second oil cooler can be done with 10 hours of work and USD 120 for the oil cooler.







final result:

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