Motor Vehicle Maintenance & Repair Stack Exchange
Motor Vehicle Maintenance & Repair Stack Exchange

Questions tagged [compression-testing]

Compression testing is the act of testing the air pressure generated by a cylinder in an internal combustion engine.

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Diesel runaway - stopped miraculously by itself

A little background (Little longer, please excuse): Few days before while we were driving Maruti Suzuki Dzire vdi (Engine: Fiat Multijet 1.3 DDIS, CRDI engine) around 40kmph. All of sudden there was a noise from engine and while we attempted to…
Narayanan
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In Cylinder Pressure Testing With a Pressure Transducer and a Oscilliscope

Recently I've been looking into buying a higher PSI pressure transducer to do in cylinder pressure testing. I've encountered vehicles which would of benefited from this approach and wish I had thought to try this in the past. I've been watching…
Ben
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More In Cylinder Pressure Testing Questions

So I was looking at a 06 Pontiac G6 2.4l with a complaint of low power on hills. Had been at another shop to have the transmission checked and they referred the customer to us. Road test confirms car doesn't go anywhere fast. I didn't really think…
Ben
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Is it ok to plug in battery backward to do compression test?

On engines with compression release valves, the recommended method for testing compression is turning the engine in reverse direction. I'm working on a lawn tractor (with a Kholer K241AQS), so there aren't a lot of fancy electric systems. What…
anonymous2
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How to leak down test a cold engine?

I'm thinking of doing a leakdown test on an engine before I install it in my car. Of course the problem is that the engine will be cold and things won't seal the way they do when they are hot. So how does the leak down testing procedure change when…
Robert S. Barnes
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What are these two rubber-ended attachments used for in a compression tester kit?

I'm looking to buy a compression tester kit and am a little puzzled by the purpose of the two rubber-ended attachments shown below. Am I right in assuming that these two attachments can be jammed into the spark plug hole without threading to perform…
Zaid
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Used Car Condition - Is a Compression Test a good proxy of engine health? (and what's a leak down test?)

I'm looking to buy a used car and aside from the advice here (which is mostly functional) I want to know if the oil has been changed "enough" to prevent gunk build up that could starve parts from being lubricated premature engine wear I've heard…
eAndy
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Engine consuming oil and white smoke comes out when starting the engine while cold

my car has been consuming oil for a while now but only recently has started to smoke when it is started while the engine is cold. I thought that maybe because I am using a synthetic oil in a high mileage car but after switching to non-synthetic one…
method
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If an engine starts does that mean compression is fine?

I am looking at buying a second hand 2-stroke engine. I have seen a lot online about checking compression before buying used engines. I don't have a compression tester, but will buy one if necessary. My question is, if the engine starts and runs…
Swag_B
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Low compression on all cylinders - Flooded Engine - Maybe Washed Cylinders?

I just did a head gasket replacement on my 1995 Acura Legend. Before the replacement, compression was good on all cylinders except #3, which had blown. While the engine was open: I cleaned off the pistons and cylinder walls with WD-40 until they…
superjax
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Toyota corolla verso 1.794 petrol vvt-1-t2

Recently Purchased Vehicle @milage 81.075 in the past vehicle has consumed 5.25 Litres of oil a full oil composition test was carried by my Garage. They also advise it is an uneconomical repair it has no oil leaks the oil is going out via the…
Alan Haines
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Are compression tests neccessary?

A friend told me when buying a car compression tests are not necessary since if there were problems you would hear the engine misfire so just listening to engine is enough. I'm currently investigating why my car is feeling a bit sluggish and I asked…
James Wilson
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Does substantially increased compression test numbers after adding oil to the cylinder necessarily imply that piston rings and/or cylinder bore is bad

SOLUTION: The tubes on the top of the motor for the PCV system were backwards. See https://invidious.fdn.fr/watch?v=07ssRI8k81E for correct configuration. Oil would pool in the air intake until you drove it up hill, and then it would start to enter…
user73135
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Replaced Head on Propane Engine; Now I have too high compression. Why?

I hade a misfire in my propane burnisher (buffer). The Exhaust valve is stuck and wont move, as a result the push rods bent. Manufacturer recommended I get a new head. I replaced the head according to the instructions. New gaskets, new push rods,…
Bondark
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How to interpret slightly varying compression between cylinders?

I have a 99 Toyota Corolla with 255k miles. According to the service manual, cylinder compression should be 145-218 psi, with no more than 15 psi variation between cylinders. I tested mine and read 30 psi variation before adding oil for a wet…
zwiebelspaetzle
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