Getting your car ready for winter

Times have changed and so have the cars here are a few tips.

Rotating your tires is still a routine exercise but today your car may require the TPMS (Tire Pressure Monitoring System) to be retrained after you rotate the tires so that the dash reports the correct pressures and tire locations. Putting the system into training mode can be as easy as one GM system where having the key on and holding the lock and unlock buttons on your key fob until the horn sounds two times. Then you can first go to the left front tire and let out some air from the tire and the horn will beep one time. The horn beeps when the system receives the tire pressure sensors signal which goes into a fast update when the tire pressure changes rapidly. Continue the retraining by going around the car to the right front and repeat the step of letting some air out, then onto the right rear tire and finally the left rear tire. When the last tire is trained the horn will beep twice again instead of just once.  If you only get one beep at each wheel you may have to access the spare tire as well. The last step is to then reset all of your tires to the proper specification which will be on a label on the driver’s door or its frame. This was just one example, there are a lot of different systems out there so consult service information or your local shop for your model.

Time to change your oil?

There was a time that the only thing you needed to know was the SAE grade and to look for the API and ILSAC ratings. Today even the simple oil change is much more complicated. Specifications like GM’s dexos1, Chrysler’s MS6395R, Ford’s WSS-M2C930-A all greatly exceed the current API SN and ILSAC GF5 ratings. The engine oil life monitor systems on today’s cars countdown start-ups, mileage driven, temperature conditions and will alert the driver once it’s time to have the oil and filter changed. While conventional oils may last the 6000 miles that Honda and other Asian manufacturers require, they often do not last long enough for Ford and GM vehicles which can call for serices to be done in the 7000 to 10,000 mile range while a manufacturer like BMW may reach 15000 miles.

Is it time to replace your battery?

For many people replacing a battery when it gets to be five years old is simply about buying the peace of mind that they know the car will start once the bad weather really hits. For others they will make that battery to go until they know that it needs to be replaced. Either way there is more to it than just dropping in a new one. One step is to attach a memory minder so that the car doesn’t get completely depowered while the battery is replaced. That’s pretty convenient for not needing to reset your clock and the radio stations but it also keeps the other memories on important computer systems from being cleared which can have some unpleasant surprises. Another important issue is today the charging systems are computer controlled and it has been adjusting to that older battery and that will cause it to charge the new one incorrectly if that isn’t reset. Many techs associate that with manufacturers like BMW, when in fact just about every manufacturer has this function. Once again consult service information for specific details about your car.

Engine Coolant, Antifreeze

Beware of claims of universal antifreeze, there is no one size fits all specification. Some manufacturers require silicates, while others ban them. The same goes for phosphates, and borates which are all good for some things that may be used in a car’s cooling system and can be bad for others. When you go to the parts store to buy new antifreeze consider buying it pre-mixed where you don’t add water. That saves you an important step that most don’t realize. Antifreeze isn’t designed to be used with tap water, if you buy concentrate you are supposed to mix it with distilled water.

Did your doors freeze and get stuck closed last year?

A little silicone spray on the rubber door seals will displace the moisture that can freeze and make it difficult to open the door in the morning.

Do you need to use dry gas or injector cleaner?

Gasoline today is up to 10% ethanol which is an alcohol. “Dry gas” is normally isopropyl alcohol, and a common property of each is they like to be in solution with water more than they do gasoline. Dry gas never took water out of fuel, it simply helps prevent any water in the system from freezing, so no,  you really shouldn’t need to use a dry gas additive anymore  but injector cleaner is different. Using an extra injector cleaner additive can help keep your car running better and a good rule of thumb is use it once a year or every 25,000 miles. Manufactures like GM recommend Chevron Techron especially if you normally don’t purchase a Top Tier fuel. That’s a subject you should Google, Top Tier Fuel, there is a difference in gasolines that you can run in your car.  

 

Not Ready For Testing

Not Ready For Testing.

This is a common problem that we deal with a couple times each week ,  usually the story goes something like this.

The car was due for inspection and the check engine light was on so it failed the emissions test. During the course of the repairs the codes get cleared and then the owner is told that they have to drive the vehicle for a while to try and get the car ready for its emissions test but it keeps coming up not ready. 

The OBDII emissions test is really carried out by the car every time that it is driven, all the states emission test does is collect the cars data as it reports if it passes or fails. When someone clears the codes they also clear all of the test results that make up the monitors that the state needs to see completed in order to know if the car is operating correctly or not. If all of the tests that make up a given monitor didn’t get to complete, then that monitor won’t be set to ready. When we have to deal with one of these situations, understanding what it takes to get given tests to run is very important because tests can be stopped from running because of the car’s operating environment failing to meet certain minimum criteria. One example of that could be if the ambient temperature was too low or too high or if the engine coolant temperature did not stay within the programming limits. Both of those would be considered blocking conditions where the tests are prevented from running because the results would be too unpredictable. There are other times where the vehicle might not have been driven long enough to ensure full system operating temperatures. Some of those aren’t even directly measured but are inferred by operating conditions such as the catalytic convertor temperature. The engineers use modeling to try and predict how hot the catalyst would be based on the way the vehicle was driven, then with a catalyst at that temperature, they measure the oxygen storage capability of the catalyst and write the testing tables for the vehicle’s computer to run.

Once we have confirmed that no blocking conditions are occurring, we then have to make sure that each test enable criteria is met. This is easy to do in some cases with a scripted drive cycle that most manufacturers publish, or it can be done with a scan tool as in Chrysler’s case where the scan tool displays the parameter limits and the vehicle just has to be driven within them for a period of time.

If a test fails and it’s a two trip test, you will find a trouble code but it is set in global mode seven and those are known as pending codes.  They have to fail twice in a row to turn into a confirmed code and cause the check engine light to come on.

2002 Rendevous won't shift

This vehicle just had a used transmission installed and it wont shift correctly. When in drive it starts out in third gear, and once up to about 30mph it shifts into second. Then at forty it shifts to third for a few seconds and then goes into limp in mode, which is back to second gear. Reverse operates normally. Typically the limp in or failsafe modes for an electronically controlled transmission will give you one forward gear, which is what ever gear both shift solenoids turned on creates, and you will have reverse, neutral and park. All of these are commanded by the manual valve which is directly linked to the shifter cable. The computer in the car was setting a P1875 for the pressure control solenoid circuit open.

To test for the cause of that code, the technician needs to access the PCM which is inside the air cleaner housing. On connector #2 pins 44 light blue / white, and 45 red / black provide the feed power to the solenoid and the ground return to the PCM. By unplugging the connector at the PCM the resistance of the circuit can be measured and the circuit was open. The next step is to find out where and why the circuit is open and then plan to do the repair. One of the easiest things to do is to remove the connector at the transmission and jumper the two pins together and then ground one at the PCM connector and provide power through a small lamp. In this case something that draws 1.5 to 2 amps such as a brake lamp bulb. The lamp lit up confirming that the wiring was OK, and that means that the problem is inside the transmission or with the connector itself.


The following two pictures are screen shots captured with my bore scope.

The red arrows point out the damaged pins, note the second one on the top, right hand row and the fourth one are pushed out of place, while the third is bent up out of line.

Most of the time when a connector is damaged like this it isn't a big deal to disassemble and repair it. Unfortunately with the way this connector for the transmission harness is assembled, that's going to mean that the transmission will have to come apart to access the other side of the connector.

Caring for the customers

Typical call, the owner has a van that he does all his own work on and it failed the emissions test. Being a 95 it gets the TSI which is a two speed idle test in Western Pa. My first thought was it's a van, yuck. I've never liked working on them and the older I get and the harder it is to move around it just gets more unpleasant. The guy was fun to talk to however and he wasn't really too interested in repairing it right now as much as he wants to do just enough that it qualifies for a waiver sticker. To get a waiver in Pa the owner only has to spend up to $150 attempting to repair the car. Only certified repair technicians can authorize a waiver so he was told to call us. When diagnostics and repairs are done by a shop the whole bill can be applied towards the waiver fee. If the owner does the work himself only the parts that were used qualify and he has to provide the receipts for the parts, have two failed emissions tests and then the technician has to confirm that the work was done and follow the rest of the routine to authorize the waiver. The customer had only put on about $70 in parts so he didn't qualify for the waiver yet, but they could be applied towards it and if we do the diagnostics that would get him to where he needs to be. He joked about just getting a bill to put him over the limit but I have my policy on that and if he has to spend a dime we make sure that he gets some value out of the expense and we really work towards making an improvement in the vehicles performance. (I won't throw parts for the sake of throwing parts). The last thing we agreed on was since this is a (conversion) van and the engine cover needs to be removed, he would pull the passengers front seat and have the engine cover fully exposed so that I would not have to spend any time doing that. He set his appointment for this morning (Friday).

This morning he called to let us know that he couldn't keep his appointment today. His son went into sudden cardiac arrest last night and he has been in the hospital with him all night and he had to head back there. The worst part was when he said that it doesn't look good for his son. Meanwhile he was apologizing for not being able to make it in and was worried that it would be an issue for us. All I could do was offer our sympathies and let him know that we would add his son to our prayers and re-assured him that his family was more important and taking care of his van can wait. We will be there for him when he is ready, and for him to not worry about us because I have plenty of work to keep me busy. Just thinking about what he was going through put a dark cloud on the whole day.

Silver Bullets don't make for a real diagnostic routine

In one of the classes I present I have a point where I paint a little picture for the techs and the shop owners and it goes like this.

Picture you have a 2005 Chevrolet Malibu come into the shop and its setting a P0101 Mass Airflow sensor performance. You test the system and confirm the sensor has dropped out of calibration, replace it and road test the car confirming that it is indeed repaired.

Now imagine nineteen more Chevrolet Malibu's and every one of them set that same P0101, and every one of them is repaired by replacing the mass airflow sensor. "How do you approach the twenty-first Malibu that shows up at the shop setting a P0101?"

In your perspective Steve, (Steve is a moderator on another forum) and in the ideas of anyone who works like you are thinking, you would replace the mass airflow sensor and ship the car. But what if that doesn't fix this car and the light comes back on setting the same code? In that customers eye's they got ripped off, you don't know what you are doing, and they would be correct. (Never mind the fact that you got it right twenty times) The correct answer for that twenty first Malibu should have been to test it exactly the same as you did the first one, and the nineteen in-between and the details would have led you to find the restricted exhaust, or whatever caused the volumetric efficiency of the engine to fall below design expectations. That by the way is what the code really means which is that the airflow being reported by the mass air sensor at a given engine speed and throttle opening is below the threshold value. Sure a sensor under-reporting the airflow will generate that code but its not the only reason that could happen.

The trap here is someone who pulls the code, and throws the part if they get it right can be really fast and can in fact make themselves more money while they are risking getting caught doing sloppy work. The tech who stays disciplined in his/her approach gets it right every time, but since that takes longer, they actually in many cases make less money by the end of the week. What's worse is when that twenty-first car comes back, shops often direct that not to the tech who did the first repair, but to the one who will make sure to figure out what is wrong and solve the problem. Oh, and since its a comeback that means the customer likely isn't getting charged so there is no diagnostic time to be paid and that means the tech isn't getting paid either, well at least not directly. When I worked at the dealership they would promise to "make up the time" by giving me pre-delivery inspections, or other gravy tickets. (The same kinds of work that have grown to be known as wallet flushing)

As far as finding sites dedicated to mechanics that you mention, there are other sites that you likely have never been to that don't advise techs to rely on silver bullets. In fact we prove why trying to do that hurts them as well as the customer and the trade in general. As part of a group (Edmunds) that tries to advise consumers correctly it makes no sense to continue to promote poor habits as if they are really valid. More than 50% of what I do each day is something I've never seen before and likely won't see twice in my career. That's why problems like the fuel pump wiring harness issue mentioned wouldn't even be a note-able event. Nine months the guy fought with that problem that should have been addressed in under an hour. I do blame the perspective that having to rely on someone seeing that failure before in order to solve it is what it took. That's totally false and misleading for the consumers.

Imagine diagnosing a loss of communication between the computers on a Mazda where the chip in the transmission controller that drives the communication signal is failing and causing it to send out a pulsed wave that steps on other modules communication bits. Now also understand that the body computer also acts as the connection hub for the high speed CAN "STAR" network that this is crashing and multiple modules connect to it in ganged plugs. On that car it just so happens that the PCM shares the same plug as the transmission controller, and since the PCM has one of the termination resistors in it so disconnecting that plug shuts down the entire bus the moment that it is disconnected. On top of that, once the network shuts down the problem disappears and it then will take up to half an hour of operation for it to re-occur. That's the kinds of problems that guys like me often deal with today, and tonight I'll be demonstrating how to figure that car out to the techs that are in the class I'm teaching. Just taking the idea that the network is crashing and saying that the transmission controller needs to be replaced isn't good enough because that's what fixed that one car. As a shop you'll make yourself and your tech look foolish when that doesn't work the next time because there is a different cause for the loss of the network. That's the way a techs job really is and the silver bullet stuff needs to be put away with the points and condensers.

#Silver Bullet, #silver, #bullet, #CAN, #wallet flushing,

I'm going to try and upload a little video. This is my Escape with just over 30% oil life left on the monitor and the engine has a little over 65,000 miles.

Steve on Edmunds posted that he was irritated by a picture of an engine that was nearly spotless inside at some 100,000 miles. Well maybe he should be irritated if his engine doesn't look like this inside. BTW the average mileage for each service is 7400 miles, with a high of 9100 one time when there was still 9% oil life left. At our shop we only use oils that meet the O.E specs, that doesn't mean it has to come from the manufacturer but it takes a little more effort to choose the correct product for your car than to just look for the viscosity on a store shelf.


http://www.youtube.com/watch?v=k770HSmZU1c&feature=youtu.be

 

 

 

2010 Ford Escape AC. What I found

 

 

I finally got to attend to my Escape’s AC, and I wasn’t surprised by what I found.

If you recall the static pressures were taken after the car had been sitting for more than an hour, and with it not working right I had not turned the system on for more than a week. The last thing that was expected was for the high and low pressure sides to not be equalized. Upon seeing that they were not equal, and excessively high on top of that, this wasn’t just a broken car, someone had done something that made it even worse.

The normal routine for a car that a shop isn’t familiar with is to use a refrigerant identifier for the first step, and then a sealant test for the second one. The following photos are from my refrigerant identifier. It gets connected to the low side and a small sample is bled off of the system. In the past some people would substitute propane for R-12, hence the need to detect hydrocarbons, and other blends would use R22 to boost pressures in the systems under the assumption that would force more refrigerant liquid through the expansion valve or orifice tube. In an expansion valve system with a receiver drier, there may be some validity to that assumption but not so much with an orifice tube type system. One other contaminant is air. Just like R22 in an automotive system air, nitrogen and oxygen isn’t condensable into a liquid at the pressures and temperatures that the system runs at.  By not being able to make it change state between a liquid and a gas being in the system forces the pressures higher but doesn’t help the system produce any cooling at all.

 

So here is the first picture from my identifier, and it shows that there is no R-12, or R-22 in the system.

 

This second picture shows that the refrigerant is R134 but also that 15% of the sample taken was air. So how did air get into the system?

 

 

That we may never know but the identifier just confirmed the suspicion of why the pressures in the system were so high. There easily could have been a service performed where someone’s AC equipment hasn’t been maintained correctly and they may have drawn air into their recycle tank. Maybe the system was discharged and sat open for a period of time and then was charged without being evacuated. That one seems the most likely and could also explain the system having sealant added to it. As you will see in the next photos the sealant was responsible for the system stopping working.

 

 
 

 

   This is the receiver drier, some of the AC oil can be seen in the connection port and that is the outlet that the hose to the expansion valve connects to. The schreader connection at the top of the photo is for the high side pressure sensor. The next photos are the desiccant cup and filters from inside the drier assembly.






       

Here is what is inside the drier assembly. The orange plastic circle is the top lock for the filter and the desiccant beads that are inside the black cup, these all fit into the bottom of the drier assembly. The tube passes through the center of the cup so that liquid refrigerant that collects underneath the filter and desiccant cup is fed to the outlet of the drier and onto the expansion valve.

These are the felt filters that are at the top and bottom of the cup, their job is to hold the desiccant beads in the cup as well as be a filter for the system.

In order to make the sealant more visible I took the top filter screen and cut it in half and flipped part of it over. As you compare the picture above and this one, note the swirl pattern visible from the spaces in the orange lock disc, that's the top side. Then on the bottom side you will notice two colors, both a grey and spots of green. The green is the sealant that has crystalized in the felt.









The last two photos are of the expansion valve. There was no way to know if it was OK or not prior to disassembly other than to replace the drier, and then run and test the system. With the system already open it made more sense to simply plan and replace it which also allowed me to flush oil and sealant from the evaporator core as well.