Sunday, April 17, 2011
Replaced Secondary Air Pump and Check Valve
Earlier this week I ordered the pump, check valve, gasket and two copper lock nuts from my local dealer so I could replace the secondary air injection pump this weekend.
Late this afternoon as the sun raced for the horizon I started work. I disconnected the hoses, replaced the check valve and then the pump, and wrapped it up by reinstalling the hoses. Shortly after tightening the last hose clamp I glanced at a clock and was pleasantly surprised to learn that less than 45 minutes had elapsed.
As I was disconnecting the check valve the vacuum hose cracked in half near the nipple of the valve, but I anticipated as much and had the required hose "in stock" (actually, it was left over from the last time I replaced this hose circa 2007). Although the job only requires about 8 inches of hose, BMW supplies a three foot length so I have enough hose to do the job one or two more times.
I found the inside of the hose that delivers air from the pump to the valve covered in a bright yellow dust. This is consistent with the pictures I've seen of old pumps disassembled to reveal the horror that is a bright yellow watery goop (condensate, really) that pools in the motor and causes the pump to fail. The hose itself was in good shape so I shot some brake cleaner through it to clean it up and reinstalled it.
The parts cost $450. Book labor on this job is 1.5 hours or $192, hence the value in the labor-saved column. The 20 percent discount brings the DIY dividend to around $300.
 The air pump is larger than would appear from its installed position because the motor extends below the mount. |
 At $18 each I wasn't about to replace perfectly good isolation mounts, so I transfered them from the old motor. |
 The root cause of the motor failure -- the check valve -- was replaced and installed with two new copper lock nuts. |
Miscellaneous Factoids
A brake job for a modern 3 series vehicle is now $1800. This I overheard quite unexpectedly while waiting in line at the cashier at my dealer to pay for the air pump parts. I wasn't the guy paying and I nearly considered checking my underwear for a skidmark. The last time I quoted the job it was around $1200 and I thought that was insane but $1800 is ludicrous. The parts cost around $400 (at 20% off -- dealer cost is lower, obviously) and the job takes a pro no more than about an hour per axle. They're making a cool grand (or more) doing what has to be one of the easiest jobs on the car. And people pay it without blinking. I'm in the wrong business, obviously.
I also confirmed that a brake fluid flush is $200, a microfilter is $250 and a coolant flush is another $250. I couldn't help but wonder why the microfilter job is more than the brake fluid flush in spite of the price of the filter, as it takes considerably less labor to replace the microfilter in the currently-shipping vehicles (pop hood, take out two thumb screws, replace filter...in other words, a couple of minutes of work). The E36 is the biggest pain in the ass of any BMW made and it only takes me 10 minutes. As I've said here before, many of the newer BMWs come with wheels that permit the tech to bleed the brakes without removing the wheels, so that's a 10 minute job as well. And don't think for a second they drain your coolant from the block as they technically should during a coolant flush. The dirty little secret is that they drain the radiator, replace about a third of the fluid in the process, and refill it with little need to bleed the system. In other words, they can do it in around 10 minutes. Let your calculator reveal the injustice in all three cases.
As of today the E36 is mechanically "squawk free" for the first time in five months so I'm not planning any additional work until the front suspension overhaul. The plan is to collect the needed parts over the next several months and do the job in late June or July. My brother just broke ground this week on his toybox and the hope is to be in the building by that time so this job may serve as its christening.
Mileage: 206916, Parts: $450, Labor saved: $192, Parts Saved: $110.