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91 XFI COMPRESSION TEST
Topic Started: May 5 2011, 03:59 PM (1,541 Views)
BornN2Grave
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I just tested the compression on a 91 xfi that I obtained a few months ago with 170,000 miles on it.
cyl 1 185/dry 215/wet
cyl 2 185/dry 215/wet
cyl 3 185/dry 205/wet

The motor is dirty with oil and crud all over it and it doesn't appear to have been dissasemble anytime recently.
How are these results possible? It had to of had atleast new rings and exhaust valves right? :hmm

Next I plan to check to make sure the proper transmission is in the car and look at the camshaft to verify they are both original to an xfi.
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Coche Blanco
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Possible because it's an XFi. :P
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dayle1960
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Fastest Hampster EVER

BornN2Grave
May 5 2011, 03:59 PM
I just tested the compression on a 91 xfi that I obtained a few months ago with 170,000 miles on it.
cyl 1 185/dry 215/wet
cyl 2 185/dry 215/wet
cyl 3 185/dry 205/wet

The motor is dirty with oil and crud all over it and it doesn't appear to have been dissasemble anytime recently.
How are these results possible? It had to of had atleast new rings and exhaust valves right? :hmm

Next I plan to check to make sure the proper transmission is in the car and look at the camshaft to verify they are both original to an xfi.
You got those numbers and want to crack the head open? Leave it alone unless it is doing something it shouldn't be. Run it until it has 150 across the board and then open it up. Otherwise you might just be asking for trouble. :thumb
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BornN2Grave
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Coche Blanco
May 5 2011, 04:11 PM
Possible because it's an XFi. :P
The xfi rings don't wear as fast or the valves don't burn? Or is the compression with the gapless rings higher to begin with?
Or are you being sarcastic?
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dayle1960
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Fastest Hampster EVER

BornN2Grave
May 5 2011, 04:28 PM
Coche Blanco
May 5 2011, 04:11 PM
Possible because it's an XFi. :P
The xfi rings don't wear as fast or the valves don't burn? Or is the compression with the gapless rings higher to begin with?
Or are you being sarcastic?
I don't think CB is being sarcastic. You need to feel blessed that you have a car that is in great mechinical shape. Rarely does a metro go over 150K without the need for internal fixes. You have that magic car that will go for 300K probably. It's your lucky day. Be happy. :thumb
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BornN2Grave
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I don't want to crack the head open. I would like to take the valve cover off and look at the cam. There is a photo floating arround here somewhere that shows the difference between an xfi and standard cam just by appearance. If I remember correctly, the xfi has pointy lobes.
I'm not looking for trouble sir, lets all just get along. :cheers
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Coche Blanco
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The XFi turns at lower RPMs for it's entire life. The engine spins less to cover the same distance. That, with the "special" rings may make them last longer...idk I wasn't being sarcastic though. :)
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BornN2Grave
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dayle1960
May 5 2011, 04:31 PM
BornN2Grave
May 5 2011, 04:28 PM
Coche Blanco
May 5 2011, 04:11 PM
Possible because it's an XFi. :P
The xfi rings don't wear as fast or the valves don't burn? Or is the compression with the gapless rings higher to begin with?
Or are you being sarcastic?
I don't think CB is being sarcastic. You need to feel blessed that you have a car that is in great mechinical shape. Rarely does a metro go over 150K without the need for internal fixes. You have that magic car that will go for 300K probably. It's your lucky day. Be happy. :thumb
Thanks for the encouragement.
There is no way I could have screwed up a simple compression test to get these #'s is there?
What scares me is that I am never this lucky or fortunate, lol my guage must be broken :D
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BornN2Grave
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Coche Blanco
May 5 2011, 04:39 PM
The XFi turns at lower RPMs for it's entire life. The engine spins less to cover the same distance. That, with the "special" rings may make them last longer...idk I wasn't being sarcastic though. :)
Now that makes sense. Thank you for elaborating.
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Coche Blanco
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As long as the numbers are contestant and over 150, you are good.

190,190,150 means you have problems.

185,185,185 means your have a healthy engine.

130,130,130 means you have a worn engine that needs rebuilt.

Edit: Also, the lower RPMs make valves not as likely to burn. :)
Edited by Coche Blanco, May 5 2011, 04:44 PM.
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BornN2Grave
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Mecanically I am good to go then. Engine seems to run good with no flutter. She is a leaky pig though. Appears to be the front cam or crank seal. From reading these great forums I know to do the whole shibang while the timing cover is off.
Thank you both for your responses.
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mcmancuso
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Do both cam and crank at the same time, buy 2 cam seals(cheaper and identical) also probably do the distributor o-ring 15/16" inside diameter 1/8" thick washer.
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Rang-a-Stang
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Schmuck

mcmancuso
May 5 2011, 05:02 PM
Do both cam and crank at the same time, buy 2 cam seals(cheaper and identical) also probably do the distributor o-ring 15/16" inside diameter 1/8" thick washer.
:gp
When i bought my 92 XFI, the entire engine was a giant black glob of oiley goo. After a good steam clean, a distributor O-ring and Cam/crank seal, its as sealed as it ever was and hasnt dropped a drop of oil in the 9000 miles since. The good news is those oil leaks did a great job of rust proofing the rest of my car (and probably yours too)! The frame horns are as solid as they were when they were delivered. Took about 4 hours to do all 3 oil leak fixes...

Also, plan on cleaning your EGR passage. that seams to be a common issue with our cars. its free to clean, takes less than an hour, and made a significant difference on my turd. :)
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Car Nut
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Rang-a-Stang
May 5 2011, 05:18 PM
made a significant difference on my turd.
Poor Metro, he didn't really mean to call you a turd. Ugly duckling maybe, but not a turd.
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Johnny Mullet
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Fear the Mullet

I would go ahead and do a 60K service. This would be a new timing belt, go ahead and replace cam and crank seals, plugs, wires, cap, rotor, oil change, PCV valve, trans fluid change, air filter, and all that good stuff you car been needing.
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