sam-80 wrote:
> I have a Honda Prelude 88 and in last couple of days steam came out of
> the exhaust so i put some seal up stuff into the radiator,i faced to
> another problem, black smoke(unburnt fuel)comes out of exhaust even at
> low rpm�s and the car is very sluggish?anybody has an idea?
>

1. blown head gasket.
2. tw sensor not bathed in coolant. see #1 above.

look in the coolant expansion bottle when the engine is [warm] running.
you'll see bubbles.

from there, you have a couple of options: changing the whole motor or
repairing the current one. if you're doing the work yourself, it
affects the math, but check out jdm import engines and balance that
against the considerable labor charges of paying someone else to do this
work [and not necessarily doing a very good job].

if repairing, it's essential that whoever changes the gasket does not
use abrasives, and that includes scotchbrite, when cleaning the head and
block surfaces. if they are used, tiny particles will remain in the
cylinder and cause rapid wear and thus high oil consumption and low
compression. use a knife blade [carefully so you don't gouge], or
better yet, spray-on gasket remover. i prefer the latter. use lots of
it repeatedly until the surfaces are clean. be prepared to spend some
time doing it properly.

i would also advise you to avoid having the head skimmed if you can
avoid it. unless completely cooked, honda heads rarely warp so it's
unlikely to be necessary for that reason, and skimming affects the
compression and valve timing. it's also the lazy mechanics way of
cleaning the head. google this group for more info. go to home depot
and get a large builder's straight edge then use your feeler gauges to
inspect.

last thing, i strongly recommend getting the honda workshop manual from
helminc.com. it is by far the best way to keep a great car like this on
the road.