Compression Test Results
Hey guys, I got a rotary compression tester off a member on here to borrow for a few days and hooked it up today.
I got some wide readings, and plugged them into this java program I found on here, and they didn't look real good. Anyone else care to calculate these readings and tell me what they think? Car was not cold, but not hot. I think it probably sat for 30 minutes after being driving by the time I got around to checking the compression. Car wasn't cranking fast enough so I hooked another battery up which explains the wide rpm difference. Rear rotor 78 80 80 psi 215 rpm 72 75 74 psi 193 rpm Front rotor 82 81 80 psi 208 rpm 73 75 74 psi 184 rpm Thanks guys, - Logan. |
Yup... those are all under the minimum allowed tolerance.
Look into a new engine from the dealer before the warranty expires (if it hasn't already). You have 8yr/100K mile warranty on the motor (provided you kept a good maintenance record). |
Compression results verification
Can I ask where you looked to verify the results? I just had a compression
test done at my local Mazda dealer with the following results. Dealer said rotor 1 was just below spec but I shouldn't worry. He suggested I replace the plugs, coils, and wires due to the harder start when warm (takes about 2-3 sec of cranking). They would be happy to do it for ~$650 but I plan to do it myself. P.S. The compression check was $156. Rotor 1 Rotor 2 ---------- ----------- 1) 6.8 96.72 7.4 105.25 2) 6.8 96.72 7.7 109.52 3) 7.2 102.41 7.6 108.10 RPM 294 303 DIFF 5.69 PSI 4.27 PSI Rotor to Rotor Diff 12.8 PSI |
mljhn yours appears to be within tolerance.
|
I have problems identifyin the graph.
It may be pretty low at 300rpms though. |
Originally Posted by Sheehan
(Post 3828390)
Hey guys, I got a rotary compression tester off a member on here to borrow for a few days and hooked it up today.
I got some wide readings, and plugged them into this java program I found on here, and they didn't look real good. Anyone else care to calculate these readings and tell me what they think? Car was not cold, but not hot. I think it probably sat for 30 minutes after being driving by the time I got around to checking the compression. Car wasn't cranking fast enough so I hooked another battery up which explains the wide rpm difference. Rear rotor 78 80 80 psi 215 rpm 72 75 74 psi 193 rpm Front rotor 82 81 80 psi 208 rpm 73 75 74 psi 184 rpm |
Originally Posted by mljhn
(Post 3836839)
He suggested I replace the
plugs, coils, and wires due to the harder start when warm (takes about 2-3 sec of cranking). |
Originally Posted by mljhn
(Post 3836839)
Can I ask where you looked to verify the results? I just had a compression
test done at my local Mazda dealer with the following results. Dealer said rotor 1 was just below spec but I shouldn't worry. He suggested I replace the plugs, coils, and wires due to the harder start when warm (takes about 2-3 sec of cranking). They would be happy to do it for ~$650 but I plan to do it myself. P.S. The compression check was $156. Rotor 1 Rotor 2 ---------- ----------- 1) 6.8 96.72 7.4 105.25 2) 6.8 96.72 7.7 109.52 3) 7.2 102.41 7.6 108.10 RPM 294 303 DIFF 5.69 PSI 4.27 PSI Rotor to Rotor Diff 12.8 PSI Soon you will see it in the 5.x zone. |
Well I have been searching and reading so I am a little concerned by the 6.8
readings, especially at 294 rpm. I'll give the plugs, coils, and wires a try and even try cleaning the engine with the DIY/TSR. It's an '04 with 53k miles. Bought it used a couple weeks ago, my first one, so I'm not even sure if there was a problem Mazda would replace the engine since I don't have any of the previous owners oil change records apart from a few listed in the carfax. |
Originally Posted by nycgps
(Post 3836892)
Dying.
Soon you will see it in the 5.x zone. Hey nycgps, u know any good spots in NY to get a compression test done ? |
Man, you guys are depressing me...
|
Originally Posted by CVale127
(Post 3866873)
Hey nycgps, u know any good spots in NY to get a compression test done ?
seriously, I ordered the official tester but its a long wait, I probably get it next month tho. Other than that, you can go Wayne Mazda to do the test, but its gonna be 100 bux (I charge 20) |
1 Attachment(s)
I called up my local mazda dealer and requested an engine compression test today. He asked me what was wrong with the car, I said poor gas economy, and that theres some white residue on the dipstick. lol didn't really know what to say, I just wanted to know what kind of condition my engine was in before warranty ended. but anyways, so began the engine compression test($100). about 30mins later the dealer calls me to tell me that my starter is very slow and won't get an accurate reading for the test, (starter was moving at 130rpm). He tells me he can replace it for 380, but unconvinced I told him to do a diagnostics first (additional 100). The cause was a with my remote start and the clutch bypass, for some reason it made cranking slower. He ended up not charging me for diags, and proceeded with the compression tests. and heres the result:
300RPM chamber1: 900kpa 910kpa 900kpa chamber2: 890kpa 900kpa 910kpa I'm the 2nd owner with almost 60k miles with original engine. I'm not sure what the specs are but i think these numbers are decent. Eh at least i know my old engine is still good. As long as the mazda techs says its good i'm fine with the engine. What you guys think? most of the compression threads /posts i see are in psi or running at 200rpm, these numbers ok? |
Originally Posted by Junirol
(Post 3868312)
I called up my local mazda dealer and requested an engine compression test today. He asked me what was wrong with the car, I said poor gas economy, and that theres some white residue on the dipstick. lol didn't really know what to say, I just wanted to know what kind of condition my engine was in before warranty ended. but anyways, so began the engine compression test($100). about 30mins later the dealer calls me to tell me that my starter is very slow and won't get an accurate reading for the test, (starter was moving at 130rpm). He tells me he can replace it for 380, but unconvinced I told him to do a diagnostics first (additional 100). The cause was a with my remote start and the clutch bypass, for some reason it made cranking slower. He ended up not charging me for diags, and proceeded with the compression tests. and heres the result:
300RPM chamber1: 900kpa 910kpa 900kpa chamber2: 890kpa 900kpa 910kpa I'm the 2nd owner with almost 60k miles with original engine. I'm not sure what the specs are but i think these numbers are decent. Eh at least i know my old engine is still good. As long as the mazda techs says its good i'm fine with the engine. What you guys think? most of the compression threads /posts i see are in psi or running at 200rpm, these numbers ok? |
Originally Posted by nycgps
(Post 3868318)
wow, fuck outa here, those "numbers" are so made up and 300 rpm is just rare.
Should I go back and verify these numbers? You thing this is bogus? like i said I haven't seen others with similar test results.. Not sure if this is a good or bad thing, but my engine running strong. |
Originally Posted by Junirol
(Post 3868396)
Should I go back and verify these numbers? You thing this is bogus? like i said I haven't seen others with similar test results.. Not sure if this is a good or bad thing, but my engine running strong.
but thats just rare. no point going back there. I mean if they were lying, u think they will tell u the truth now ? if the test was real, then u will just get the same results. just let ur car be at this time. |
Originally Posted by nycgps
(Post 3868414)
well I mean you could be "lucky" to have a proper clearance engine.
but thats just rare. no point going back there. I mean if they were lying, u think they will tell u the truth now ? if the test was real, then u will just get the same results. just let ur car be at this time. |
Originally Posted by nycgps
(Post 3868318)
wow, fuck outa here, those "numbers" are so made up and 300 rpm is just rare.
http://pic0.picsorlinks.com/ph_or_77028_f08b778.jpg |
Originally Posted by Charles R. Hill
(Post 3836880)
Did you have the throttle at WOT during this test? The cranking RPMs are still too low and you'll need to have the battery load-tested and will want to make sure you have the "updated" starter before drawing any further conclusions.
|
Hi Guys,
What do you think of these compression values? The 322 RPMs are real or that what the computer printed, I was present at the test (new starter, new & powerful battery, I guess), it was not done on Mazda but by a guy of my local forum that the rotary compression tester that goes to a computer. The car is a 2007 with 25.000 miles that never had a decarb (not my car). The test was done at 2165 feets (Madrid). RPMS: 322 Front: 791/811/818kpa Rear: 783/798/794kpa |
Originally Posted by rotaryPilot
(Post 3868474)
Those numbers are pretty standard. No such a big deal.
http://pic0.picsorlinks.com/ph_or_77028_f08b778.jpg its just rare the stock starter even updated one can spin this fast. Unless his battery & starter are new and both rotor's numbers are too close to each other, which is just "another" rare. especially when the engine has gone thru lots of miles. but like I said he could be "lucky". Thats all I can say. |
Originally Posted by nycgps
(Post 3867180)
in NYC? There is a place but its not open for business yet ... its called NYCGPS :lol:
seriously, I ordered the official tester but its a long wait, I probably get it next month tho. Other than that, you can go Wayne Mazda to do the test, but its gonna be 100 bux (I charge 20) |
Originally Posted by nycgps
(Post 3868757)
I was talking about 300 rpm.
its just rare the stock starter even updated one can spin this fast. Unless his battery & starter are new and both rotor's numbers are too close to each other, which is just "another" rare. especially when the engine has gone thru lots of miles. but like I said he could be "lucky". Thats all I can say. |
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