Hyundai: for HyundaiTech

You have no compression in one of the cylinders and the car has normal
power at highway speeds? This is difficult to believe.

If true, the 2nd repair facility hasn't yet performed enough testing to
determine the source of the lack of compression. A technician can perform
a cylinder leakage test by introducing compressed air into the cylinder
through the spark plug hole while the valves are closed for that cylinder.
If there's no compression, the air should leak out of the cylinder
somewhere. Through the intake or exhaust indicates a cylinder head/valve
problem. Through the crankcase indicates a piston/ring problem. Through
the radiator usually indicates a severely warped cylinder head. All of
these repairs will be quite substantial in cost. I would expect no less
than $1500. To find out for certain where the problem is and what will be
required to fix it, the cylinder head must be removed and the head, block,
and pistons inspected. I also wouldn't be racing to purchase a used
engine unless I knew there was some catastrophic failure or a serious
issue with the block. You have no idea the condition of a used engine.
With your car inspected, you'll know what condition the engine is in.

Well, actually, you'll only know that if the facility checking your car is
competent and honest. So far, the dealer's diagnosis is much more in line
with your symptoms than the second facility's. You report stable idle in
gear, normal acceleration, and normal highway driving. No compression
should cause a misfire, resulting in a vibration at idle, very poor
acceleration from a stop, and reduced power and horrible fuel mileage all
the time.

Sorry. Forgot to mention in last post. Driving with no compression in a
cylinder isn't good for the engine because large amounts of unburned
gasoline will get into the oil. There are possibly other hazards of
damage depending on the specific reason for no compression.

If your dealer's diagnosis is correct or partially correct, which I
suspect it is, the idle servo could short out and fry your computer,
making the car undriveable.

"hyundaitech" <hotmail.com> wrote in message
news:talkaboutautos.com... 

well, I dunno... the guy said he needs to do more tests to find out the
problem, but that there's no compression in the third cylinder (doesn't know
why. maybe he just tested it with the error-code scanner?)

I will take it to a second hyundai delaer but I'm afraid they'll give me a
third reason for my problem...
 

while in gear and stopped, the idle is stable but high. while in gear but
the car slowing down under it's own power (no brakes), under 60 km/hr RPM
fluctuates between 1000 and 2000
acceleration is as "normal" as it could be for a 9 y/o 4 cylinder 140hp
engine... I can't say it's normal, just that it's not striking me as
horribly slow.
at highway speeds, I get no problems.
sometimes the car does vibrate at a stop.

while stopped and in gear I have to press the brakes hard to keep the car in
place because the idle is at 1500, so I guess I can't say I have very poor
acceleration from a stop.

also, depending on the temerature outside, the idle oscillations could be
between 1000 and 2000 (very wild) or just between 1800 and 2200

To determine a cylinder has no compression, one must do a compression test.
This is done with a compression tester/gauge and cannot be accomplished
with a scanner. It is possible with a scanner to isolate a misfiring
cylinder, but it's not possible to determine the cause of the misfire to
be no compression without an actual compression test.

Everything you've posted leads me to believe you have no misfire (or if
you do, it's only at idle), putting tremendous doubt on the no compression
diagnosis.

Hello.

My wife's 1996 Hyundai Sonata will not pass emissions inspection here in
Pennsylvania beacause of DTC P0110. I am told that it is a malfunction of
the Intake Air Temperature sensor. I did not buy the car new, I have had it
only for 1 year.

I have two questions:

1# Is this a repair that I can do myself?
2# If I cannot do it myself, could it be done at a dealer under a recall
notice?

Any information you can give me would be very much appreciated.

Thanks!

Jim K.
Allentown, PA