A while back a prospective buyer had my 92 SE engine checked by a mechanic. I was told that it suffered from low compression on cylinder one, and that the engine should be replaced. Not the spark plugs, not the injectors, but the WHOLE engine.

Does this sound right to anyone? Do I have any hope that it will be easier than that? The engine only has 92k miles and still runs pretty well. Acceleration may be a bit lagged, but not terrible. (It’s likely been in this condition since I bought it at 83k miles) I had the emissions tested today... came back with high something-carbons (unburned fuel I was told). It passed the Oregon state tests about six months ago, but I did have to try a couple times.

Any ideas are most appreciated.

Chris
'92 MaxSE 5spd

 

You have to figure out WHY it has low compression. If it is really bad rings/burnt valves etc... it's probably cheaper to replace the engine with a good used one vs rebuilding it.

 

yes there is hope...sent u PM

 

I thought Oregon didn't have emissions?

just do the compression test yourself, record your results, if it is infact really low on #1, then you can do a leak down test to see what is causing problems (rings, intake valves, or exhaust valves)

 

Some counties do if they are highly populated. I lived in Portland.

PLEASE Please please tell me how to do this.
Thanks. Chris

 

Unburned fuel would make sense if you really did have low compression on a cylinder. You wouldn't be burning the fuel in that cylinder effectively. You can also take the compression on that cylinder, then squirt a bit of oil in there, then take the compression again. If the reading increases, chances are it's bad rings. If not, it points more to the valves. Either way, I'd do the test myself to see.

 

go to an auto parts store and buy or rent a compression tester

remove ALL spark plugs at the same time

screw the compresion tester in the cylinder of choice

go in the car hold the throttle wide open and turn the motor over 5 to 10 times then get out and see what the gauge reads

like stated above. if it reads low (i think low would be below 140psi but someone else can conform) pore alittle oil proboly like 1 or 2 teespoons down the into that cylinder and repeat the other steps

 

First I'd like to thank everyone for their responses.

I've been doing some research on compression testing (I'm a newbie mechanic), but just don't know if I'll be able to do the test myself. Here is the main obstacle I foresee:

I own a Chilton manual, but I can't find any clear, simple diagrams of the engine with step-by-step instructions for various procedures. For instance, three of the spark plugs are easily accessible (right?), the others are beneath the head (or block or something?), but nowhere in the book are they clearly labeled. Same with the injectors... every now and again I see an arrow pointing to an injector, but not like "here are the locations of all six injectors, and this is how to get to them." Even just straightforward locations would be helpful.

Okay, say I do try this compression test myself. When I remove the head or block or whatever the plate is that gives access to the other three plugs, WILL I NEED TO BUY AND INSTALL A NEW GASKET? Do I even need to do this? AM I WAY OFF HERE?

Another question - Anyone know the numbers of the cylinders and where they are located? IE if I suspect cylinder 1 or 5, where is 1 or 5 or whatever?

Thanks so much for reading this. It is a good learning experience for me. I have to start somewhere.

Best Regards,

Chris

 

your way off there are no heads or blocks (laughing histaricly no offence) to remove in order to remove the spark plugs. all you do is remove the coils packs (black round things, 3 in front 3 in rear 10mm bolts hold them down) take the bolts out (the front 3 coils only have 1 bolt each the rear 3 have 2 bolts each) pull the coils out then stick your spark plug socket down the hole (youll need some extentions especialy for the back 3)

cylinder number 1 is (looking at the engine from infront of the car) the back left

 

heres a pic of my engine the 3 black round things above the "nissan 3000" are the front coil packs the rears look the same and are in the pic about 15 inches behind the front coils on the top near the back of the engine

 

I feel smarter already. Thanks for the info.