Compression test Woes :(
#1
Compression test Woes :(
Hey all. After blindly buying an 8 in September and learning a tonne since I've found myself in a tight spot.
So i will give you a run down.
Bought my Japanese '05 manual GT 8 September (can only assume GT w/ leather seats. Bose sounds. And other features.....)
2 owners. First owner - Japanese off the shop floor owner. Body kit. 19" rims, Race ecu tune (I am unsure of the tune itself) was in 7 races. Again don't know how long they were. We're they drift, endurance.etc What kind of stress did the engine suffer.etc
Second owner bought it at 88,000kms 2013 had in shipped over here to New Zealand - treated it like a baby.
Had it serviced twice a year and thrashed it every weekend.
Compression test August '14 showed the following results Rotor #1 - 104psi Even Rotor #2 - 108psi Even
After getting the car home early Oct (400km drive!) I suffered a cracked radiator head. Replaced.
Drives like a dream. Puts smiles on my face daily.
The question - at 104-108psi respectively and now up to 104,000km (67k miles) - do I start considering a Rebuild??
On the verge of calling my local rotor expert.
I would hate for the compression to drop sub 100psi and loose the engine.
The only bad symptoms I can state are. On a dead cold start (~14hrs rest) it fires after 1.5sec - 2sec crank. As it fires there's a rattley sound for almost 1sec then it goes. Engine idles at 1500 for maybe 10sec then drops to 900 and eventually 850/900 once it's warm (10min)
No issues driving. From what I can tell no backfire. Unless - if I'm stationary. Neutral. Rev her **** off bounce 9.7k twice. It'll pop and stuff as it drops from 9.7~6k rpm then she's quiet.
So - should I consider another compression test after 10k kms? (where I'm at now) Should I be concerned for the health of the irons and engine at 104,000kms considering the results last last August compression wise?
Any key signs I should look to for wear and tear / symptoms of apex death.etc?
Any and all help would be greatly appreciated
So i will give you a run down.
Bought my Japanese '05 manual GT 8 September (can only assume GT w/ leather seats. Bose sounds. And other features.....)
2 owners. First owner - Japanese off the shop floor owner. Body kit. 19" rims, Race ecu tune (I am unsure of the tune itself) was in 7 races. Again don't know how long they were. We're they drift, endurance.etc What kind of stress did the engine suffer.etc
Second owner bought it at 88,000kms 2013 had in shipped over here to New Zealand - treated it like a baby.
Had it serviced twice a year and thrashed it every weekend.
Compression test August '14 showed the following results Rotor #1 - 104psi Even Rotor #2 - 108psi Even
After getting the car home early Oct (400km drive!) I suffered a cracked radiator head. Replaced.
Drives like a dream. Puts smiles on my face daily.
The question - at 104-108psi respectively and now up to 104,000km (67k miles) - do I start considering a Rebuild??
On the verge of calling my local rotor expert.
I would hate for the compression to drop sub 100psi and loose the engine.
The only bad symptoms I can state are. On a dead cold start (~14hrs rest) it fires after 1.5sec - 2sec crank. As it fires there's a rattley sound for almost 1sec then it goes. Engine idles at 1500 for maybe 10sec then drops to 900 and eventually 850/900 once it's warm (10min)
No issues driving. From what I can tell no backfire. Unless - if I'm stationary. Neutral. Rev her **** off bounce 9.7k twice. It'll pop and stuff as it drops from 9.7~6k rpm then she's quiet.
So - should I consider another compression test after 10k kms? (where I'm at now) Should I be concerned for the health of the irons and engine at 104,000kms considering the results last last August compression wise?
Any key signs I should look to for wear and tear / symptoms of apex death.etc?
Any and all help would be greatly appreciated
#2
Registered
I'd recommend another compression test at a different dealer. Your previous numbers sound bogus. The chances of all three rotor faces showing the same compression are miniscule. I suspect your prior test was done with a standard piston engine compression tester which doesn't really convey much usable information about the health of your engine.
Take your car to your local Mazda dealer and have the engine checked with a rotary specific compression tester. The dealer will give you a printout with 2 sets of three numbers and some pass/fail info.
Take your car to your local Mazda dealer and have the engine checked with a rotary specific compression tester. The dealer will give you a printout with 2 sets of three numbers and some pass/fail info.
#3
What am I doing here?
Join Date: Mar 2006
Location: 2017 Miata RF Launch Edition
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For the price of 3 compression checks you can get the compression testing tool and do it yourself. Model ReCT
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