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9
votes
4answers
2k views

Finding a possible vacuum leak

One of our cars has a bit of a rough idle which disappears at about 1,000 RPM. After eliminating everything else I concluded that this is due to a minor vacuum leak. This was confirmed by the use of a ...
8
votes
2answers
9k views

Test Gasoline for Water Content

I live in a small town, and the Gas station there has a bad reputation for gas quality. With rumors like peoples gas tanks freezing solid and such. Is there a quick, safe, cheap way to test for ...
8
votes
1answer
115 views

Is there a way to test ignition coils with built-in ICM?

My car's service manual shows this for the ignition coils: What is the ICM? Related to http://mechanics.stackexchange.com/a/2850/31, is there a way to check the coils to see if they are working ...
7
votes
4answers
126 views

Do no-name tires go through thorough testing?

Tire (tyre) brands come in three categories: Major brands that advertise extensively Relatively unknown brands that are actually made by the major brands Relatively unknown brands that are ...
6
votes
2answers
57 views

The top speed in the my owner's manual seems to be too low. Is this normal?

How the quoted figures for top speed determined for a car (from 2003)? To be specific, my 2003 Opel Agila 1.2i has a quoted top speed of 96mph, but I have exceeded this on several occasions on flat ...
6
votes
1answer
679 views

Does driving at top speed damage a car or stress the engine?

Lots of manufactures like Vauxhall/Opel and Ford seem to test their new models of cars by driving it at top speed for hours on end. What is the point of this? Does it stress an engine?
6
votes
2answers
94 views

Hand-testing Shock Absorbers

Does manually hand-testing shock absorbers have any validity for checking if a shock is good or bad? Does hand-priming shock absorbers help? I usually hand-prime shock absorbers that I feel are ...
6
votes
1answer
64 views

How to test the function of a water pump?

Is it possible to test a water pump for proper function (ability to move a certain volume of coolant) without disconnecting it from the engine? If so, how would one do that?
5
votes
2answers
142 views

How is barometric pressure related to emissions testing?

In the VW emissions cheating scandal, news reports say the following: According to the EPA, "the position of the steering wheel, vehicle speed, the duration of the engine's operation, and barometric ...
5
votes
1answer
1k views

Is cylinder leak down test needed if compression test results are fine?

If I compression test my engine and the results are fine, could there ever be any need to leak-down test it as well? IOW, can a leak down test ever fail if the compression test is fine. RELATED: ...
5
votes
0answers
36 views

What Is The Output Voltage For The Mazda 626 GF 2L 98-2002 Coil Pack?

I've seen after market "high voltage" coils that output 40kv, but what is the output voltage for the standard OEM coil pack? I want to use a spark tester with an adjustable gap to check the strength ...
4
votes
2answers
3k views

How do I know when to replace shock absorbers?

In my last trip to the shop, the mechanics told me that I should replace my shock absorbers. When I inquired as to why, I don't feel that they were very clear with their answer, like they normally ...
4
votes
1answer
47 views

The Testing Procedure for the Mazda 626 Alternator in the WSM is Unclear

I have some questions regarding the alternator testing procedure outlined in the 98 US work shop manual ( this is related to my battery warning light question ), my car has the FS engine: When it ...
4
votes
1answer
212 views

How Many Times to Crank During a Compression Test

I've read a number of different recommendations on how many times to cranks the engine during a compression test. I've read those that say to crank until you reach a stable reading. In the book, ...
4
votes
1answer
246 views

Block Test: Can't suck any more air, is this normal? (1999 Suburban)

I performed a block test recently to diagnose a problem I'm having. The liquid stayed blue, but I want to clarify I have done this right. The purpose of the test was to see if I could prove a head ...
3
votes
1answer
304 views

Cylinder Leak-down vs Compression Test

I understand that both cylinder leak down and compression tests are used to test for cylinder head, cracks, warps, and gasket leaks. I understand the difference between how each works: compression ...
3
votes
1answer
21 views

How does cylinder leakage tester kit work?

I was browsing Amazon in search for a combustion leak detector (AKA "block tester") and I stumbled upon a cylinder leakage tester kit, which is supposed to do similar things? But I am not quite sure ...
3
votes
1answer
80 views

How do I test fuses with a circuit tester?

Lights all flicker. When I an in the cabin the head lights flicker. I want to test my fuses with a circuit tester. Should the engine be running or will I be blown away? Please help, I'm a newbie ...
2
votes
1answer
61 views

Strokes during compression test?

Just wondering what the general consensus out there for the amount of times the vehicle turns over during a compression test? I have heard anywhere from 5-8, and personally crank 7. What is the ...
2
votes
1answer
126 views

Checking a fuel pressure regulator that is out of the car

I happen to have a fuel pressure regulator of a petrol car lying around left by the previous owner and suspect that it might be still good, since the previous owner was just changing parts randomly ...
0
votes
0answers
21 views

Car Radiator Fan may have a Fault, I'm an electrical noob [duplicate]

I took the fan out from my engine compartment and am now ready to test it. It consists of two fans, one larger than the other connected I believe in series with two large wires, one red, one brown ...