Here is an underappreciated tech tip when trying to troubleshoot an AC Compressor. Any good mechanic (and even alot of bad ones) will have gauge meters for the ac system. You really should have one if you are working on AC. Getting the high and low pressure readings can tell us alot about what is going on in the system.

High Side: The high side tells us what the compressor is pumping out. Anything over 150-200 tells us the compressor is pumping. Larger compressors for bigger vehicles could go as high as 300-350, but generally over 200 will give you some cold.

Low Side: The low side tells us what is happening at the low side of the system. Ideally we are looking for about 30. That tells us that the auto air conditioning compressor is sucking properly and the big key; that there are no restrictions on the low side. Many techs end up with 200/85 or something like that and assume its the compressor. The 85 tells us that most likely we have a restriction in the low side. Either at the AC Condenser, Evaporator, A/C Expansion Device or something else on the low side. Sucking is actually easier for the compressor, so it can be, but is rarely is the compressor.

Some other common numbers are 150/30. This often indicates the system is under pressured and need to be filled and charged to spec. Another common one is 300+/50. This is typically an overcharge on the high side and some pressure should be released although you have propably blown the compressor at this point.

Hope this helps clears up some basic AC system troubleshooting.

Getting some questions on flushing a power steering rack, so here goes.


The basic idea is to get any contamination out of the system and replace with clean fluid. The main problem is metal flakes from a defective steering pump. Start by removing the return hose and putting it into the bucket. You can drain some fluid there and run it through a coffee filter. This will allow you to check the fluid.


To flush the system. Have someone pouring steering fluid into the system with the engine running. It will go through the steering pump down into the steering gear and into the bucket via the return line.


Do this until the fluid is clean or about 2 bottles of steering fluid. Once you are satisfied, seal up the system and fill to capacity at the fluid indicator. You should be good to go. If you are not clean after 2 bottles you will need to replace the steering pump and probably the hoses as well.


Turn the wheel left to right with the cap open to remove air pockets.

Whether you are looking for BMW Parts body parts or Mercedes Parts or any other parts for that matter, understanding your warranty is important.

There are two things to understand about auto parts warranties. First, all parts warranties are just that, parts only. Any labor, time, rental car, etc, etc are not covered. This is the biggest reason to buy new or other high end automotive parts. You are always responsible for these extra costs. Don’t buy cheap stuff, it will cost you later.

Second factor of auto parts warranty is how they handle the problems. Any reasonable warranty should last at least 1 year and offer a replacement option. Many warranties make you take the part off, ship it back, and wait for them to fix or replace it. This is not a good warranty. What are you going to drive while you wait? This could be weeks. They should allow you to pay a deposit to get another part right away and send that back for credit. That is a reasonable and fair warranty.

Do more homework than just buying the cheapest option. There is a reason why some places are very cheap.

Be sure to check out review pages too. Good way to check up on how companies behave.

With the current heat wave we’re getting lots of questions about how to get better performance out of your ac system. Besides having a good working ac compressor you can also look at the ac condenser to make sure it is working properly.


It should be free from dents and dings to ensure good flow. The more surface area you have to cool the refrigerant, the better your system will perform. You can also look at the fin design. The two popular current styles are serpentine and parellel flow. Both provide good cooling flow, but are more likely to get clogged in a system failure and thus have to be replaced more often.

Helping someone change out their ac compressor and they asked about what else needs to change. This is very important on an ac system. The ac receiver drier is the filter on the system and must always be changed. It pulls moisture out of the high side of the system. There are other parts like the ac expansion valve and the condenesor, but they can be changed if they are contaimated of damaged.

The drier must always be changed. It pulls mositure and debris from the system. Not changing this can put all the old contaminats back into the system. You should evacuate and flush the system before putting on new parts.

Had a friend installing a power steering rack and ran into an interesting problem. After he had installed the rack the car steering too far to the right and not far enough the left. He thought maybe the rack had been misbuild but I told him it’s near impossible to misbuild a steering gear.

The trick to it is that the rack is not centered. What we had to do was to remove the steering coupler off the top of the rack. Center the rack, the wheels and the steering wheel. Once everything had been centered we re-attached the rack and we were good to go.

People often ask me about engine oiland the bottom line is that there is no way to know without a whole lot of data and research. I personally don’t have a problem with the synthetic.

I Changed my oiil this weekend and went with a penzoil synthetic blend . I have a 4runner SUV and it calls for Synethic.

Seems to run great on the synthetic. It is quiet and the temp never gets up, so it must be doing the job. I’m looking for some thoughts that anyone else has on the subject. Especially anyone running a turbocharger and their thoughts.

So I was filling up my car today, an 2005 4runner with a 4.0L engine, and it was not a good experience. Spending $82 to fill up is not fun. While not all of us can go get a hybrid or bike to work, there are a few things you can do to ensure your car is getting the best gas mileage.

1. Fill up the tires. Usually about 35psi each. (check yours). Going 35 on the front and 36 on the rear will give you the best combination of gas mileage to ride ratio.
2. Check the air filter in your car. Dirty air filters can cause the car to work harder than it should.
3. Run the air conditioning at lower speeds and roll up the windows. That is the best combination for low speeds.
4. If you are running a turbo or superchager make sure they are clean and well lubricated. They can really improve the performance, but have to be working properly.
5. Check the spark plugs and oxygen sensors. They usually need to be changed at 75K – 100K miles, but really vary depending on vehicle.

Let us know other tips and we’ll add them to the list.