Excessive catchcan oil
Thread Starter
Senior Member
iTrader: (14)
Joined: Oct 2006
Posts: 677
Total Cats: 6
From: South East Florida
With the leakdown tester hooked up, take the oil cap off and listen for air in the oil cap, through the intake, and out the tailpipe. At 30+% one/all of them will sound like a very, very leaky air compressor fitting.
Oil cap = rings
Exhaust = Exh. valves
Intake = Int. valves
If you hit the wrong TDC, the leakdown will be ~45%. If you get 45%, spin it over again and try again. Then go 1-3-4-2 from there.
Your numbers (assuming its rings) would probably produce blowby, yeah. It's time for a shortblock.
Oil cap = rings
Exhaust = Exh. valves
Intake = Int. valves
If you hit the wrong TDC, the leakdown will be ~45%. If you get 45%, spin it over again and try again. Then go 1-3-4-2 from there.
Your numbers (assuming its rings) would probably produce blowby, yeah. It's time for a shortblock.
Anything else I should be testing before I start removing the engine?
I have never pulled an engine on a miata, and only once before in my life. Is the general consensus that I take the transmission out with it?
To complicate matters, this car is going to be returned to stock. I am trying to decide whether to pull the MS now or after I get the new engine started. Preferably, I would like to pull the MS and swap in stock injectors now. Opinions?
I guess me and boost were never meant to be
with the leakdown tester hooked up, take the oil cap off and listen for air in the oil cap, through the intake, and out the tailpipe. At 30+% one/all of them will sound like a very, very leaky air compressor fitting.
Oil cap = rings
exhaust = exh. Valves
intake = int. Valves
if you hit the wrong tdc, the leakdown will be ~45%. If you get 45%, spin it over again and try again. Then go 1-3-4-2 from there.
Your numbers (assuming its rings) would probably produce blowby, yeah. It's time for a shortblock.
Oil cap = rings
exhaust = exh. Valves
intake = int. Valves
if you hit the wrong tdc, the leakdown will be ~45%. If you get 45%, spin it over again and try again. Then go 1-3-4-2 from there.
Your numbers (assuming its rings) would probably produce blowby, yeah. It's time for a shortblock.
First I did compression test:
1# = 190 psi
2# = 190 psi
3# = 185 psi
4# = 190 psi
and then leakdown test:
1# = 4% leak
2# = 50% leak
3# = 11% leak
4# = 6% leak
cyl 2# didn't seem normal so I did it again and it was over 80% leak. I remove the exhaust manifold and could feel how air was escaping through
Ex.valve(s) stuck or..?
I found a leakdown tester and just tested all the cylinders
First I did compression test:
1# = 190 psi
2# = 190 psi
3# = 185 psi
4# = 190 psi
and then leakdown test:
1# = 4% leak
2# = 50% leak
3# = 11% leak
4# = 6% leak
cyl 2# didn't seem normal so I did it again and it was over 80% leak. I remove the exhaust manifold and could feel how air was escaping through
Ex.valve(s) stuck or..?
First I did compression test:
1# = 190 psi
2# = 190 psi
3# = 185 psi
4# = 190 psi
and then leakdown test:
1# = 4% leak
2# = 50% leak
3# = 11% leak
4# = 6% leak
cyl 2# didn't seem normal so I did it again and it was over 80% leak. I remove the exhaust manifold and could feel how air was escaping through
Ex.valve(s) stuck or..?
Bottom line:
Compression Test = Waste of Time
BTW, Fae discoverd that even if you don't disconnect everything, the car has an "auto-disconnect" feature as you rip the engine/tranny out. So, no worries.
Compression Test = Waste of Time
BTW, Fae discoverd that even if you don't disconnect everything, the car has an "auto-disconnect" feature as you rip the engine/tranny out. So, no worries.
Personally i think you should drill a hole in your oil cap and route your catch can back into you oil cap. Problem solved. Now bow dow. To your new master and get out there and run the biitch!!!
Thread Starter
Senior Member
iTrader: (14)
Joined: Oct 2006
Posts: 677
Total Cats: 6
From: South East Florida
One piece exhaust ftw 
I grew tired or the 3", and ended up with the stock exhaust from the 99. Spool suffered at least 1000rpm. Pretty sure I datalogged if there is interest. Having it quiet was nice.
The exhaust shop took a couple liberties I was not comfortable with, but I did not complain, as I did not think I would be in the situation I am in. Will likely cut the downpipe to mate with the 2.5" on the 99, rather than getting a new one.

I grew tired or the 3", and ended up with the stock exhaust from the 99. Spool suffered at least 1000rpm. Pretty sure I datalogged if there is interest. Having it quiet was nice.
The exhaust shop took a couple liberties I was not comfortable with, but I did not complain, as I did not think I would be in the situation I am in. Will likely cut the downpipe to mate with the 2.5" on the 99, rather than getting a new one.
Thread Starter
Senior Member
iTrader: (14)
Joined: Oct 2006
Posts: 677
Total Cats: 6
From: South East Florida
This is what my ebay f1 stage 3 clutch looks after 4 years and around 35k miles looks like. Practically down to the rivets.
I drove this daily and slipped first hard on a regular basis.
I drove this daily and slipped first hard on a regular basis.
In general about this HF tester - it is huge pile of junk as is and shows bad numbers.
For future use - first change the second gauge with a 100 psi one (i.e. from McMaster.com). Also cut the aluminum block and change the orifice size cause the one inside is nowhere in spec. Do a 0.040 in (1.0 mm ) orifice.
Then measure the leakdown with 100 psi at the inlet.
For future use - first change the second gauge with a 100 psi one (i.e. from McMaster.com). Also cut the aluminum block and change the orifice size cause the one inside is nowhere in spec. Do a 0.040 in (1.0 mm ) orifice.
Then measure the leakdown with 100 psi at the inlet.
I kept out of boost and speed down to 75mph, and it still puked oil.
Harbor Freight was the only place I could find a leakdown tester unless I wanted to order online. This is the exact one that I got. Feels cheap.

I tried it last night, and quit when the mosquitoes got bad. This was my first attempt ever, and I think I screwed up. I did not put the car in gear after finding TDC.
Here is the method I used:
- disconnect battery
- pull plugs and wires
- find TDC for #1
- test
- went to TDC from cylinders in order 1 - 3- 4 - 2
- did not put car in gear
First round:
1: 63
3: 29 ; 30
4: 59 ; 70 ; 65
2: 20 ; 21
Second round:
1: 22 ; 34 ; 53 ; 100
3: 27 ; 34 ; 37
4: 26 ; 22
2: 39 ; 33 ; 24
Third round:
1: 40 ; 100 ; 37 ; 37
eaten alive
I am guessing that these may be mostly useless since I did not lock the engine from spinning.
I will try again on Saturday.
Harbor Freight was the only place I could find a leakdown tester unless I wanted to order online. This is the exact one that I got. Feels cheap.

I tried it last night, and quit when the mosquitoes got bad. This was my first attempt ever, and I think I screwed up. I did not put the car in gear after finding TDC.
Here is the method I used:
- disconnect battery
- pull plugs and wires
- find TDC for #1
- test
- went to TDC from cylinders in order 1 - 3- 4 - 2
- did not put car in gear
First round:
1: 63
3: 29 ; 30
4: 59 ; 70 ; 65
2: 20 ; 21
Second round:
1: 22 ; 34 ; 53 ; 100
3: 27 ; 34 ; 37
4: 26 ; 22
2: 39 ; 33 ; 24
Third round:
1: 40 ; 100 ; 37 ; 37
eaten alive
I am guessing that these may be mostly useless since I did not lock the engine from spinning.
I will try again on Saturday.
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