Sunnyvale Auto Repair

Last week we had a customer with a 2011 BMW X5 come in with an overheating problem. Since the 2011 BMW 530i does not come with a temperature gauge it can be very disconcerting when the instrument display is telling you your car is overheating. The customer stated that he saw the warning and also heard the engine auxiliary fan roaring at full speed.  Now when the customer told me this I already had a good idea of what may have happened.    BMWs with N54 or N55 motors (between 2008 and 2014) come equipped with a electric water water pump. The electric water pumps were installed to make the engine more efficient in terms of power, fuel consumption and emissions. It does this by letting the computer control the flow of coolant rather then the engine itself. By removing the old mechanical water pump there is less load on the engine. The old mechanical style water pump could rob as much as 3 to 5 horse power from the engine.     The first thing we did was to ... read more

It is the end of December and as we are winding down 2017 I’m doing my best to manage the shop, my family and my life.  I have been thinking about all of the complex problems that we had to solve this year and was trying to pick one to talk about.  In the last month I encountered one of the most difficult BMW problems I have ever seen, but to tell you the truth I do not have the energy to explain it this year, so I’ll have to save that for next year!  I then thought about writing a puff piece on winter driving, yet I have written similar articles and did not feel like doing it again for now.  Then, as I sat contemplating what I was going to write about,  a long time customer walked through the door and asked me if I could take a look at his clutch pedal.  A week earlier the customer had brought in his 1990 Nissan pickup because the clutch pedal was going all the way to the floor and would not come up.  We checked to see if there was a lea ... read more

Lately I have been writing articles on things that I have never seen before in my 28 years of working on cars and this article will be no exception. About a month ago we had a relatively new customer tow in his 2008 Subaru Forester XT 2.5 Turbo.   The customer stated that he was driving and the car shut off.  We asked the customer what he felt and he stated that the car had a slight hesitation and then just lost power.  After we pushed the car into the shop we started to check all the basics (fuel and spark). The ignition system had spark but the fuel system had no pressure. We then sprayed a small amount of starting fluid into the intake and the engine ran. We then checked power and ground to the fuel pump. The fuel pump had power and ground. I called the customer and explained to him we had to replace the fuel pump and fuel filter.  The reason we always replace the fuel filter with the pump is that if there was a restriction in the fuel filter or dirt in the fue ... read more

There are certain common trends that we all can see or predict in everything we do.  The interesting thing about automotive repair is that there are so many moving parts and because of that we can’t always assume these common trends or problems always manifest themselves in the same way. We had a 2002 Subaru Forester L with 103027 miles come in with a Check engine light.  After pulling the codes we saw a P0130 bank one oxygen sensor incorrect information and a P0171 system too lean. When I took a step back and look at those two codes I could say the the bank 1 oxygen sensor (P0130) might be going lean and is causing the lean code (P0171).  Yet I have been doing this for way to long and realize we have to look at the data first.  When a code is set it is accompanied by Freeze Frame Data. This Freeze Frame Data will tell the technician the environment conditions of the code. For example; speed (MPH), temperature, revolutions per minute (RPM), position of the t ... read more

In September, I wrote about electric emergency brakes. At the end of the column, I told everyone to read their owner’s manual to have a better understanding of their brakes if they encounter a problem. The subject recently hit close to home. My wife drives a 2011 BMW X5 diesel that just so happens to have an electric emergency brake. I noticed that her electric emergency brake switch was getting loose, but I kept telling myself that I would order the part and install it when I got a chance. While driving to church, I looked down and saw that the e-brake switch had broken off. I asked my wife what happened, but knowing the switch was already loose, I didn’t press the subject. I also realized that I could still line up the broken tab and possibly position it well enough to make it useful. As we arrived at church, I found myself in a predicament: Should I engage the e-brake or not? In the back of my mind, I somehow thought it would be kind of a cool experiment. So I did it. At that exact ... read more

In November 2015, one of my newer customers brought in his 2011 BMW Z4 35i because the service-engine-soon light went on. He explained that the car did not idle well and was low on power. We connected the car to the Integrated Service Technical Application, because it was a post-2008 BMW, and were able to pull several codes related to the primary operation of the engine. We pulled Digital Motor Electronics (DME) codes: DME 002CF6 Throttle valve potentiometer 1 – plausibility to air mass; DME 002CF7 Throttle valve potentiometer 2 – plausibility to air mass; and 002D2E DME Throttle valve angle – intake vacuum correction. READ CODES WITH CARE But one must be careful when reading codes. It would be easy to think that there may be a problem with the throttle body, but the third code is extremely important (DME 002D2E Throttle valve angle – intake vacuum correction). The correction code indicates that the volume of air entering the throttle is not the same amount being processed by the engin ... read more

A new customer recently brought his 1999 Subaru Outback to the shop. The man said the car was overheating and making noise whenever he drove it. Because most of the time I write about complex diagnostic scenarios, I’m sure that many of you think this is going to be a column about a really tough cooling-system problem. But that’s not the case; the cooling-system problem was the typical Subaru 2.5-liter head-gasket failure. I am bringing up this problem to discuss the anatomy of the failure. MORE ON MOTORS I first must explain the different types of motor configurations. There are four configurations of internal combustion engines: inline, V, boxster (flat) and rotary. Inline engines are those with cylinders that are literally “in line” – lined up back-to-back. The most common inline motors are 4, 5 and 6 cylinders. The “V” used to describe a V6, V8, V10, V12 and V16 does not actually stand for a word, but instead the shape of the pi ... read more

I recently had two customers bring me two common problems on the same day, so I thought that it would be interesting to bring these issues to light. We had a 2004 Acura TL with a power-steering pump whine and a 1999 Toyota Camry XLE V6 with no idle when cold. I find these problems interesting because there is no built-in warning light or technical code to identify them. The Acura owner told me that when he starts the car in the morning, he hears a whining noise in the background that increases when he turns the steering wheel. Acura hydraulic-power-steering systems use a power-steering pump, power-steering reservoir, power-steering rack (rack and pinion) and power-steering hoses that tie it all together. The power-steering fluid starts in the reservoir and is pulled into the pump through the suction hose. The pump pressurizes the fluid and then delivers it to the power-steering rack. Once there is pressurized fluid at the power-steering rack, the steering wheel turns easily – even if t ... read more

Last month a new customer brought in his 2012 Subaru Forester X. He said every time he fills his wiper fluid, it leaks out almost immediately. He added that it leaks even faster when he engages the washer sprayers. We lifted the car and removed the lower-left front-fender liner to gain access to the washer reservoir. That’s when we discovered that three of the hoses were damaged – but not by normal wear and tear. Rodents had chewed them. Two years ago I wrote an article on how rodents will eat just about anything on cars. Since then we have found engine valleys completely filled with acorns, ignition wires eaten, wire harnesses eaten, under-hood insulation eaten, cooling hoses eaten and even a small mouse city – with nests – inside of a dash (perhaps using the blower motor fan as a treadmill). This epidemic seems to be getting worse. HOOD RATS Besides the fact that rodents seek a warm, dark place to sleep and nest, it was unclear to me why more and more of them use car parts lik ... read more

Last week a customer brought in her 2002 Mazda Protege5. The car came in for basic maintenance (85,000-mile service), but the customer noted that the vehicle suffered a rough idle at stoplights when warm. I told my technician to perform the regular maintenance and test-drive the car to check the idle. After driving it for approximately 15 minutes, we could not confirm the customer complaint. A common problem on this Mazda engine is that the main air intake boot from the mass airflow sensor to the throttle bodies may crack. When the car comes to a stop, the extra air from the boot may cause the idle to drop. But in this case, the boot was in great shape. We also checked the throttle plate while the air boot was off. There was a little bit of carbon buildup, but nothing that would affect the idle. We cleaned the throttle and put the boot back on. We connected the car to the scanner to check for engine codes – there weren’t any. We checked engine data, but everything was in specification ... read more