If Your Engine Isn’t Running Right, Do This

If Your Engine Isn’t Running Right, Do This

rev up your engines, today I’m going to
show you, how you can check if your engine is worn out or not, over the years
I’ve had quite a few customers that came to me from another mechanic, and spent a
bunch of money on a vehicle that still didn’t run right and so I said hey, first thing
we’re gonna do is check your engine because if that’s worn out, forget it you
don’t go any further or you gotta put another engine in your car that’s where
good compression tester comes in basically car engines are giant air
pumps, they suck air in through the air filter mix it with fuel and put it
inside the engine where the Pistons are then the spark plugs in the ignition
system fire that creates the power that moves the Pistons down using gas, then
once that power of the crank is moving the car the exhaust valves open, then
that burned air fuel mixture comes out the exhaust and then exit out the
tailpipe it’s all just pumping gas, now the more efficiently your engine runs
the more power it has the better gas mileage it gets, but of course over
time friction wears parts out inside the engine and with a good compression
tester you can test to see how worn the inside of the engine is, the more worn it
is the less efficient it’s going to be and of course eventually it can get worn
enough that the car won’t even start anymore it won’t even run, now technically
it’s a relative compression test you want to test the compression relative to
each cylinder because the absolute accuracy of the gauges and how you’re
doing it changes a lot, you have to do it consistently though, you can’t check one
cylinder one way and one another way now today I’m gonna do it the easy way
and it’s pretty accurate, because a cold engine will often show its problems
better than a hot engine, so you make sure the engine is cold then remove all
the spark plugs, out they all come and here’s the last one, so now when you
crank the engine it’s gonna crank the same all the time, there won’t be any
spark plugs in so the engine won’t start and like I say I’m doing on a cold
engine cuz you’ll often find a problem on a cold engine easier, like I said you
can test it lots of ways you can test it like I am just with the cranking, you can
test it cranking with the throttle open to get more air inside, but it’s easy
just to be cranking it with your foot not on the throttle with it just sitting
there so each one will be tested exactly the same, now there’s also various ways
to test but this has adapters for each spark plug in this case here’s the one
that matches our spark plug, as you can see the spark plug is the same as this
so we can put this in just like the old spark plug, using our spark plug socket
cuz it’s the same size then screwing it into the engine, you want it snug so
it’s not leaking, then you just screw the hose in, it goes to the gauge, sometimes
you have to wiggle a little to get them in cuz it’s kind of a weird angle but
after a while you get it on tight, then you just get the gauge and it snaps
right on the other end, then you crank it over and in this case it’s 190 psi
which is pretty good for an engine that has over 240,000 miles on it and then
of course you do the other three, and in this old Toyota engine hey it went
between a hundred and eighty five hundred ninety psi, that’s pretty good
for an engine with two hundred and forty thousand miles on it, now I generally work
by myself, so screwing in it is the best way to do it, but if you’ve got a helper
you don’t have to do the screwing in you can just use this it pushes in by hand,
just push it in the hole and crank it up here we go by 189 psi that’s even faster
now of course things never wear evenly so you’re always going to have some type of
difference between the cylinders but if you have more than let’s say 12 to 15
percent differential, that means that the lower ones are much more worn than the
higher ones and in that case either the piston rings that seal the pistons going
up and down are worn, or the valves that are inside the head are worn and don’t
seal right, either way it’s gonna be a super expensive repair, you got to take
the engine apart either do a valve job or put new piston
rings in, but if you want to find out which one it is that’s a pretty easy
test too, all you have to do is put about a teaspoon full of oil in the cylinder,
then do a compression test and if you find that the pressure goes up quite a
bit that means that the piston rings are worn and the oil sealed them a little
bit to give you a higher read, but if the pressure remains low that’s often a sign
of the valves are bad and they’re not sealing and if a valve doesn’t seal a
little bit of oil isn’t going to help because that’s metal on metal and if the
valve is cracked or the heads got a crack in it, the air is still going to go through
and make the compression pressure low so now you know how to check if your
engine is actually physically worn out and since this is mechanic Monday, I’m giving
away one of these blue driver compression tester kits to have a chance
to win just place a clean non offensive comment on the YouTube comments below, and
the winner will be chosen randomly by computer to be able to figure out if
their engine is worn up or not, so if you never want to miss another one of my new
car repair videos, remember to ring that Bell!


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  2. Hello everyone, i hade a probleme with my octavia 1.9 tdi 2011, i changed piston rings and valve guide, after that i got big powerloss, the turbo is running fine(kick in) we cheked all sensors, i got scanned from 2 scanners, no probleme, the mecanique told me to change the piqton rings, i got changed the piston rings second time, and the some probleme, i didnt understand nothing, plz help Scotty kilmer

  3. Thankks for info. Have done comp. tests on some of my cars over the years but did not know about the little bit of oil to see if it was valves or rings.

  4. Scotty u have made my life become more clear and understanding to proper diagnosing and trouble shooting vehicles and for all the tips on saveing me some cash I salut u Scotty Kilmer u have been my Guiding MC ANGLE lol 🛠

  5. Got ripped $$ by mechanic he put a new engine on a Honda Element and it vibrates when ac on. I know nothing about cars. Please help.

  6. you do a great job letting pepole know about cars i work on everybodys car so much i cannever find time to work on mine can you work on mine well i fix every one eles

  7. I noticed you only show removing the spark plugs from the forward bank. You failed to mention the difficulty of remove the plugs in the back bank because they are up against the firewall and obstructed by stiff cables, making working on the back bank a very slow and painful experience! It's one of the things the designers done to make working on your car as difficult as they could, and they can a lot!!

  8. Always Toyotas… Yes, they are ultrareliable but a friend of mine had a Peugeot 206 HDI from 2001 that lasted over 500000km without any trouble. Sadly it was involved in an accident and the damage was beyond repair…

  9. Scotty, can you help me out on this one? My 2011 Malibu with a 2.4 has a smell that I cannot get rid of. Let me tell you some facts about it. When I start it, it starts up just fine, but within a few seconds, I start to get a sulfur smell through the HVAC if I have the HVAC on or if you stand outside the car, you can smell it too. Part of me feels that the car is running a bit rich but I have the chrome tipped tailpipe and the whole thing on the inside is quite black, but I never see any sort of black smoke come out the tail pipe. It's always steam and every so often I'd see a little bit of clean water drip out the back of the tailpipe which from what I see is normal. I try cleaning the tailpipe every so often but it's like a dry almost a slight sooty film. I also have a slight sulfur smell when I accelerate hard or moderately going up a hill. I had the catalytic converter replaced last year by the dealer and that didn't seem to solve anything. I don't have any check engine lights on. Is this normal or is something going on?

  10. Can I get a free one. My car down and I want to be my own mechanic. It was cranking but never started. I got a battery it cranked right up only with a boost .. Idk. Not to mention it was already jerking when put in park or drive.

  11. Hi. Scotty I'm from ,Toronto, ontario Canada. I do folow your youtube chanel. I'm from the old school like you, but I never got my liscense, the the opurtunity was not there for me. you are doing a great Job keep it up my freind. God bless

  12. Scotty in one of your earlier video on compressoion test you advised to do it in a warmed up engine and now you say to do in a cold engine which one is correct?
    Ps: confused plz help

  13. My truck runs good till about 30 minutes then loses power. So then I stop, shut off engine and start back up. It runs good again but only for bout 10 to 15 minutes and loses power again. What's my problem? Thank you.

  14. My question is answered after all these years. Used to have a five O Mustang and always wondered how to separate a piston ring problem from a bad valve seat.

  15. Changing the oil to a thicker kind, like 40 weight will help a lot on old engines. Many dummies put too thin new car oil on old worn out engines. That will wear out the engine a lot.. I saved a lot of engines with Engine Restore cans added and then thicker oils..

  16. The World Wide Web has made it easy for us to tell our mechanics go" screw your muffler. Scotty I appreciate you on Earth

  17. Mate you're the best mate you're the best I'm telling you now I've watched my Seal videos and you've helped me alot now I got to go buy one of these gauges oh wait a little bit because you're giving it away 1 hopefully fingers crossed it's me hahaha I suppose I better go buy one save a lot of time haha keep up the good work mate you're a crazy guy that's why I love yaa

  18. Great videos Scotty. Practical down to earth help and suggestions for all motorists. Thank you and keep up the good work. Cheers!

  19. Hello sir I watch a lot of your videos and I having. An issue check engine light is on and I had an issue with cylinder 3 misfire and and I changed all spark plugs and coil packs and fuel injector all cylinder 3 and about to by a computer cause a mechanic told me it’s the problem I need help I have shaking and major hesitation. When I put foot to the pedal need advice

  20. Scotty can you marry my 24 years old Asian sister ? We live in Seattle. In that way I can get a free repair from you.

  21. Hi from france ! i like a lot your videos , Japanese car, very good car

    I will end up buying a Japanese car .. cuts to the top! incredible for 240 000 km!

  22. I wish I had a good mechanic like you near me. But I guess the next best thing is subscribing to your videos. Thank you for your extensive knowledge and information Scotty!

  23. Scotty, thank you for your videos. I have learned a lot from you, and I must say I agree with you on most of the analysis you do of all the different car and truck brands.

  24. Scotty so far your one of thee best mechanics on YouTube i think!!!😎
    Because you put so much detail into what your explaining I've learn so much from you on how to fix a car and how to build a routine thank you..

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