help me understand engine well being

[bagodoosh]

i'm trying to understand exactly how a person can determine that an engine is in a healthy condition. my understanding so far..

an engine makes power & loses power (let's eliminate some factors such as fuel quality/delivery, air temp/humidity/delivery & modifications). to verify that an engine is running tip top, the following can be examined:

compression: proves condition of valves, rings & gasket, (timing?)
oil pressure: relates to oil viscosity & shape of bearings
losses: transmission, clutch (slipping)
cams: wear measured manualy
timing: chain & cam gears

is that all?

i mean if i measure compression, oil pressure & inspect cam wear & timing, and they fall within spec, i can conclude that my car is running as good as it could?

[InEEdBooST]

9 hour pity reply.

[NoRulzAt140 Mph]

Originally posted by InEEdBooST
9 hour pity reply.

bagodoosh = 4:26 PM

Ineedboost = 3:19 AM

:thumbup:

UNLESS your time is NOT eastern but central

Then I retract my statements :)

[InEEdBooST]

thanks

[bagodoosh]

yea it was closer to 11 hours, thanx.

god forbid someone asks a technical question. people are so full of egocentric opinions & so little facts. look at the most viewed threads. :wiggle:

[WutARyd]

okay, homey. lemme see if I can maybe afford some insight...

in addition to all of the aforementioned, some other tell-tale signs include -- spark plugs, amount of carbon built up on the exhaust tip (inside or both in/outside if you don't polish it). high water temp and egts could indicate head gasket failure or worse.

now, the answer you're really looking for. DO A LEAKDOWN TEST. Air is pumped into the cylinder at say 100 psi. This then reads back to the output side of the leakdown gauge. So, if your engine reads 95 psi, then you have 5% leakdown. A leakdown test allows you to pinpoint EXACTLY where the cylinder is losing power. Anywhere from 0 all the way up to 7 or so should be an acceptable leakdown percentage for a street driven engine. Since the Celica revs to 8300 (assuming you have a GT-S), your most common problems are most likely going to occur in the head at the valve seats. I'm not sure exactly what the numbers should be for a Celi, but if you think your car is running strong/well, then a sure sign of a leak will be a variance from cylinder to cylinder.

Got it?

[bagodoosh]

Originally posted by WutARyd
Got it? maybe.