22

You've come to the right place. There's a lot that you can do on your own. Even if all you end up doing is gathering more information for the mechanic who ends up working on the car, they never mind a hint as to where the problems might be! What are some of the possible causes for the "check engine" light that can be diagnosed at home? All of them. ...


20

It could possibly work, but the better question is why would you want to test it this way? You'd be "grinding the gears" for no reason (even though it's the synchros you'd actually be grinding). This also would not provide a definitive "yes, my clutch is slipping" response. The reason for this is, even with a slipping clutch, in most cases the clutch would ...


16

There are several methods to detect vacuum leaks of unmetered air into the fuel delivery system One method is to use soapy water in a spray gun. The real issue here is how are you going to detect a vacuum leak and how do you know you've found it. What is a vacuum leak in this context related to a fuel delivery system? Unmetered air in a fuel system is ...


15

Cats can stop functioning in a couple of ways: physical deformation due to high temperatures According to this article, the catalyst melts at temperatures above 2100 °F (1200 °C). In the event of a meltdown, the catalyst gets permanently damaged, at which point it doesn't scrub the nastiness out of the exhaust gases and serves as a major exhaust ...


15

Motivation Fuel trims are a neat mechanism employed by auto manufacturers to reduce the sensitivity of fuel management to operational deviations. Modern-day fuel-injection systems rely on inputs from many sensors that expect several engine sub-systems to be in tip-top condition. With use and age, many of these sub-systems will experience some degree of ...


14

One tool overlooked here is an ultrasonic leak detector. They work by listening to the noise of a leak. Obviously they would be better used in a totally quiet environment, but it's a possibility. I've used them to determine automotive refrigerant leaks, and for water leaks from outside to inside the passenger compartment of a car. For vacuum, dunno ...


13

Even before a cat plugs, you can test your cat using a laser thermometer. You are looking to compare the inlet and outlet temps on your cat. Do the following: Run the engine up to operating temperature (at least ten minutes so the cat should be fully warm) Check and record the inlet temperature. You're looking to measure the temperature right where the pipe ...


11

The propane test is used to find vacuum/air leaks in the intake of an ICE I used to use this test until I lost my eyebrows. You use propane to find vacuum leaks by applying the propane to suspected air leak areas of the intake of a combustion engine. You are looking for air leaks between the carburetor or throttle body and the cylinder head. An air leak ...


11

To directly answer this question, no it won't work and you run the risk of damaging your alternator if it is good while doing so. The test you are asking about was used quite successfully with generators, but should not be used with alternators. Alternators are internally regulated. When you pull the battery lead, you run the risk of killing the regulator. ...


10

Failure Modes Mechanical thermostats fail in one of two ways: Stuck-closed The pintle/spring doesn't retract to permit flow at the set-point temperature that is usually stamped on the thermostat itself. which can lead to the engine running at hotter than expected. If hot enough, this can lead to serious issues such as a compromised head gasket or warped ...


10

First, think of the possible failure modes: Spark plug is clogged with carbon or has an isolation error - it conducts current, but doesn't generate sparks, because the current flows through the carbon from electrode to electrode. Break inside the plug, e.g. broken / worn electrodes - plug doesn't conduct (and of course doesn't generate sparks) Cable has a ...


10

In "measure resistance" mode, the DMM (Digital Multi Meter) uses an op-amp (Operational Amplifier) to put a constant current across the probes. It then measures the voltage drop that results, and by Ohms law (V = IR, voltage equals current x resistance) you then know the resistance. This assumes that the voltage present is only that from the DMM. I don't ...


10

Some people have stated listening for a vacuum leak noise and if located within a vicinity disconnect and add a new line of the same diameter and get a cigar and blow smoke from the cigar in the line. After blowing smoke in the new line cork the end and look around to see if any smoke is coming through. If you don't smoke you could always look into getting ...


9

What you see could very well be burned coolant as well as oil. As the glycerin burns in the combustion process it can take on corrosive properties that degrade the electrodes. Typically with oil in the combustion chamber you don't see as sever of a an electrode degradation as illustrated in your photos. I think your head gasket change is looming and ...


9

I would not recommend it: Most likely something will experience excessive wear or damage. There are some other advices on various "tests" around, mostly they test if the engine stalls while pushing in some gear and breaking at the same time. I would advise the following test: Drive the vehicle on some long stretched inclining slope. Drive some high gear, ...


8

The dollar bill test is quite simply using a dollar bill (any denomination ... doesn't have to be American currency, even) and placing it against the exhaust tip while the vehicle is idling. You are looking/listening to what the bill does while against the exhaust tip. If it just flutters there without making much noise, you have healthy exhaust valves. If ...


8

It can be very difficult to isolate if it is from the tires or the drive line.. but most of the time, it is the tires. Looking at the tires with the naked eye when there is no load on the tire is not very telling though. The best thing is to find a shop with a Hunter DSP 9000 or similar machine that measures so called road force. This will measure the tire ...


8

The ELM327 is (almost?) as powerful as any other diagnostics solution. That's simply because it only translates the low level OBD protocols to some other format. Bluetooth connections on mobile phones seem to be flaky on many devices. Usually, this shows as established connections suddenly failing during transfer. Restarting the app, and/or turning the phone'...


8

A smoke test is used to find leaks in any hollow body like the exhaust system, evaporative emission system or intake manifold. The smoke test works like finding a leak in a bucket. Fill the bucket with water and see where it drips out. Similar with the smoke test you fill the hollow body with smoke and see where the smoke comes out. A bright lamp can assist ...


8

You would follow these simple steps. Remove plug from engine Place plug into coil wire Make sure threads of the sparkplug are grounded to a metal surface. Validate metal surface goes to ground by using a multimeter Here is some multimeter basics for you. Multimeter - Basic Functionality and Howto Once the sparkplug is grounded to the chassis of the car ...


8

One other way to look at this, sort of from a different direction. As I get older I really like being able to do more with less and do so safely. I think its sometimes awesome that an old guy with barely any tools can out perform the young guys with an expensive tool box. (And yeah, I used to have many of those tools... now I'm trying to downsize a bit.) I ...


8

@DucatiKiller gives a very good assessment of how to look for leaks. Using these same efforts, you can also use gas from a propane torch around the same areas described. When the gas finds a vacuum leak, you'll find a definite change in engine RPM due to the fuel which is found. Mind you, you are opening the valve and using the gas itself, unlit. You don't ...


7

I think you may have mistaken a service interval indicator for a check engine light. Modern cars will ask to be serviced at regular intervals, even if no fault exists. There indicators can usually be reset the but procedure is usually manufacturer specific. A check engine light is something else and generally indicates that a fault has been logged by the ECU....


7

This is how I diagnosed a vacuum leak in my car. I removed the air filter from the intake pipe (mine was a turbocharged lancer evolution with an after market intake pipe) started the car. (Make sure your surroundings is not dirty and is very quiet). After starting the vehicle, I placed a book to block the air being sucked into the intake pipe (do not place a ...


7

Another way that has not yet been mentioned is artificially creating a vacuum or pressure in the intake. Vacuum is naturally there when the engine is working, but often the iconic hissing sound a leak makes is overwhelmed by the natural sounds of a working engine in the case of tiny leaks. If you reproduce the vacuum or create pressure with the engine off - ...


7

You should have 2 coil packs on the back side of the engine near the throttle body. Wires run to individual cylinders. I don't know how easy it would be to find locally but you can use an inductance spark tester. http://www.amazon.com/Lisle-19380-Spark-Tester/dp/B0002STS3U Another way to see if the coil pack is firing would be to pull a wire out and use ...


6

Testing Your Stator There are three yellow wires that come from your stator. They come out of the left side crankshaft cover and route into your sprocket cover and out along the cast bottom portion of your frame on their way to your rectifier. They connect directly to the rectifier. You can disconnect them from the rectifier and test them with a ...


6

Your question need answered with another question. What diagnostic capability do you want? While the generic side of OBD-II leaves something to be desired and has been stagnant since it's inception, the manufacturer specific side of OBD has made tremendous leaps and bounds from where it started in 1996. My old 1996 Nissan Sentra had about 2 dozen pids. ...


6

There are three tests that can be preformed using a multi meter. A DIS type coil that services two cylinders works like a transformer. The primary windings are controller by the ECU. The secondary windings are the output to the two cylinders. The primary and secondary windings should never touch. Using the ohm function check the primary and secondary ...


6

If it's a vacuum leak, it will be sucking in air, and you'll probably be able to hear it. With the rest of the engine making noise, using something to pinpoint the sound would help: Take a piece of rubber hose and hold one end up against your ear, moving the other end around the engine listening for the hissing/sucking sound. It's kind of like using a ...


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