4:32 High compression readings could mean carbon on top of rings which results in pinging. 4:45 Low compression means valve and piston rings. Do “wet test” in each cylinder again after putting 1 tablespoon of motor oil in the cylinder. If compression rises, that means piston rings and valves.
nice to see this video this morning :), the last time i did a compression test was in 1974, on my 1968 Camaro it had a 327 10.5 compression ratio, I was working for an emissions checking Lab contracted by the federal govt...and i got to use all the sophisticated test equiptment we had there,,,dynamometers, scopes, etc....fun days.
@@dannysdiygarage Just did the compression test on my '97 Del Sol. 138 - 150 psi with four cranks, 8% variation. One thing i noticed is that the 18-21 ft-lbs torque recommendation on the back of the NGK spark plug box (gasket type plug in aluminum heads) is 38 to 61% higher than Honda's recommended 156 in-lbs. I have watched your valve adjustment video and will be using it as a reference also. Thanks again.
Thanks,first time I did compression test.06 Honda accord 3.4L #’s 120,140,150,150 also oil turns black in a few hours after oil change.tried driving n I could not leave my street.I determined the engine has lost of life.
Here is my readings 1.6L civic FD 175 , 185 , 180 and 198 psi Is that normal ?? And engine losses oil clearly about one litre every 5000km running and no seal leaking Please advise danny
You did not specify the year and mileage, however most likely you have carbon build up on your valves causing higher compression, if you’re not experiencing any drivability issues I would of not worry about it, loosing a small amount of oil is normal with higher mileage also, also a good check is to look at your plugs to determine engine condition, a oil soaked plug would be a problem with rings, a pitted or carbon build up also would be a problem, a de carbon is an option, although I usually don’t recommend it unless you have to do it
what compression should i expect on my 76 F150 with possibly only 118,000 miles on it, judging from the seat and pedals which are still 95%intact. never having done one before i got a low of 82 on #4 cylinder with all the other ones about 95-110. it does seem to have been running rich quite a while judging from soot in muffler and ex manifold leaks and entire passenger bank also an intermitant miss and i cleaned up the plug as best i could before reinstall but plan on changing all four on the side with low compression to see if that helps
hey danny can you please send me the gauge you using here for the compression test? i found bunch of compression tester and i dont know which one of them will fit
Mine is not available anymore, it's 20 years old, Amazon has many to choose from, they will all work, they adapt to many of the cylinder holes, if you need me to pick one out for you I will, but remember the more you pay the better product you will get
no, the cylinder stroke needs to spin freely, meaning if a plug was in it would be compressing air and fuel, this would cause resistance and cause bad compression reading, hopefully I explained this so you can understand, short answer is all plugs need to be out and if possible the throttle wide open so the engine can get as much air as it can.
Hi Dannys, on dry test, compression of my Honda CR-V 2.0 - 2013 ,60k mile (R20A6 Engine) is: 149, 157,157,156 Psi. Is that normal ??? And i see a lot of air coming out of the oil filler cap when engine is running . Is that worrisome?
From my experience most motors will blow air from the oil filler cap due to the pressure generated in the crankcase from all of the moving components. If the air blowing out seems excessive, smells like fuel, or is accompanied by loud hisses or sounds, then it may be possible that the vehicle has worn piston rings, and is experiencing what is called combustion blow by. Engine blow by is when the engine’s piston rings have worn out enough to allow combustion gases and pressure to escape past the rings, into the engine crankcase. This is more likely for high mileage engines. I would also check to make sure that the vehicle’s PCV valve and system are not clogged, possibly causing a vent restriction, and an increase in pressure. You could do a wet compression test to check the condition of the rings
@@dannysdiygarage thank's alot for your answer, very helpful and make feel no more think my engine was in a bad shape because the number are below from the standard 🙏🏽🙏🏽
I have an no start condition on my 2007 Hyundai Accent 1.6 l.. I have spark, I have fuel. Compression test, dry, ( and cold), is 90, 75. 80, 80, (1-4 cylinders). I'm wondering if I have a blown head gasket or not, here. Thanks much.
That's really low compression, I would do a wet compression test 1st , then a leak down test, this will help pinpoint valves or piston rings as the problems hope this helps, I'm guessing there is a lot of miles on the car?
@@dannysdiygarage Yes, car has about 170K on it, I think .It ran fine / drove fine, the night before - the next morning, though, it cranks but won't start. Also, when I tried starting it, earlier, with all the plugs in it, I noticed air / bubbles going into the radiator resevoir. Took the radiator cap off and looked while cranking it and noticed much upward movement of coolant rising to the rad. fill cap surface and overflowing it. So does this mean I have a blown head gasket across the board and that it's pressurizing my coolant system? If so, I shouldn't have to do a separate leak down test to determine where the compression it leaking to, correct? There is no sign of water in the oil on the dip stick. Thanks much, Danny.
@@steveandrews8301 that's correct, you could do a leak down test and see the air going into the cooling system, however, I think it would just verify what you already know, you might want to price out another engine, this might be a better option, just a thought.
@@dannysdiygarage Thanks, Danny. About a year or two ago my son drove it, had the timing belt break, it bent 4 valves. Had a machine shop fix the head / replace with new valves / head job. I replaced head gasket (a metal multi layer type) and installed head, and now it's seemingly blown, again. Is there a special way to install these type metal head gaskets where they'll not leak? I don't trust them. I'm old school, used to the fiber type head gaskets, but this multi-layer metal head gasket is what it called for. Thanks much.
Excellent video friend continues this way I wanted you to give me the data of the compressions that an engine of a honda crv from 1997 to 2001 would have to have the B20B engine since in google I find the data of 8.8 but I do not know how much it is in Psi then I would like to know if you could give me the information in advance, thank you very much
Everything I read says 135 to 145 for that engine. , Healthy engines should have compression over 100 psi per cylinder, with no more than 10 percent variation between the highest and lowest readings. ... TIP For a cylinder below 100 psi, pour 1 teaspoon of engine oil into the plug hole and retest. If the reading jumps, the piston rings are worn. If not, think valve problems.
@@dannysdiygarage I'm curious. What is the downside to not removing it. You mentioned that you did not do it, but it is a good idea to do so. Can you explain what the pros and cons are? I enjoyed how your video is quick and simple, right to the point, while explaining what the results mean. I have 190,000 miles on my 8th gen civic and want to do this test to ensure the engine is healthy so the car is worth putting money into.
Removing the fuel pump relay disables the fuel pump from running, if you have spark and fuel a fire can happen, it’s a safety thing, but if the coils are removed there is no spark, always a good practice to be safe
