1991 porsche carrera 2

Could someone please post the three most common signs that you would need a top end rebuild. such as, buning excessive oil, loss of power and so on. Thanks Mike

Henry964

I would like to know too

Indycam

#1 , Bad leak down results .

boxsey911

#4 You have the money to spare so decide you're going to get it done anwyay

MisterRisky

specifically, leak down results showing that your valves are leaking.

also, oil leaks that require pulling the heads... 'cause "while you are in there..."

Bearclaw

#1(a): You're trying to sell your car, and buyers keep telling you, "With those miles, it's gonna need the top end done pretty soon." ???

joey bagadonuts

#2 , See reason #1

You could probably confirm via a dyno but that's just more money. Leak down would be fairly definitive.

elbeee964

(...everyone's a Letterman w/ that question)

gfunk

If the valve guides are worn you can have decent leak down results but still need a rebuild.

darth

Without getting into compression/leakdown tests:

Even after a valve adjust you still hear the tickity tick and/or while driving on deceleration then reapplying throttle you see a puff of blue smoke ( also on start up) - indicating worn valve guides. An easy check is to look at the spark plugs they should be dry and tan in color not wet oily black.

Hard starting - which may indicate leaky or burnt valves not creating a perfect seal and in turn creating an imperfect combustion charge.

Hope this helps
Bill
90C2

Crystal Cranks

#7(c) Your wife finds that stash of cash you are keeping for upgrades and mods but you explain its actually for a very necesssary rebuild.

Ritter v4.0

Your mechanic's kids need their teeth straightened.

elbeee964

It's summer, and your neighborhood is mosquito-free for the first time in years...

MisterRisky

Lonnie is right on. Below is the 1950's era visualization:



Thanks to the Hawaiian Department of Heath and Google Image Search

ilko

You read Rennlist too much and think every sound out of the ordinary is your valves walking away from you.