top end rebuild

[terryb]

What are the different symptoms you use to determine if it's time for a top end rebuild? Mileage? Oil consumption? Strange noises? Leak down test? Is a visual inspection possible?

I've noticed that when my car gets good and hot I can hear a pretty noticeable clicking or ticking sound at idle. It seems to correlate with the idle's roughness, meaning the clicks vary in loudness, or clarity I guess, when the idle varies.

It's a daily driver (although only about 15 - 20 minutes each way) with a little under 130k and uses about a quart of oil every 700 - 800 miles.

Is this sound be due to valve guide wear? Is there a rule-of-thumb mileage when people do a top end?

Thanks for any advice.

[ZOA NOM]

Read This Tech Article

[bigchillcar]

can't speak for a carrera, but ticking indicates time for a valve adjustment in a mid-year car anyway..
ryan

Related thread: What are the classic symptoms before a top end overhaul?

[bigchillcar]

btw, mikkel,
compared to clouseau, attila the hun was a boy scout leader..

at least i think that's right..
ryan

[terryb]

Thanks for the links Zoanas (and also for the avatar) and Mikkel. To paraphrase Wayne, a leakdown test and visual inspection of the plugs are really good investigative diagnostics.

The valves were adjusted less than 5k miles ago. Twice actually because I took it back thinking that they misadjusted the valves due to the clicking. They said the valves were correct and didn't mention anything about lateral play, although I didn't know to ask back then. Periodic puffs of blue smoke on startup, but I've never noticed any on acceleration or downshifts.

Whats starting to keep me up at night is the thought that the exhaust valves aren't seating properly and on their way to valve hell, especially if I'm winding it up at the time.

Any recommendations for diagnostic shops in North County San Diego? Supertec?

[dweymer]

worn valve guides will usually allow blow by on rapid decel from high rpms; it will puff blue smoke from exhaust. So take it out, run it up to 6k in 2nd and let off the gas sharply, look out your drivers side mirror to see the show . How is oil pressure?

[Sumotang]

Question.

Can you have worn valve guides and very little oil consumption?

[Magnus Rostadmo]

Sumotang !
Yes indeed you can.
My -86 only used about one litre 5w-50 Mobil 1 during 15 000 km. Contrary to most engines valve guide trouble it`s most common that on 3,2`s the inlet valve stems and guides are most worn. Did the top-end on mine at only 136 000 km and could re-use the exhaust valves but had to buy new inlet valves because of stem wear. Other symtoms are that it becomes difficult to adjust valves as the adjustment won`t stay long. If you are familiar it can also be heard as the valves overall will generate slightly more noises. When he engine is warm even a distinct, light "knocking-sound" on the ones most worn ie excess of a millimeter gap between stem and guide.

[Sumotang]

Thanks Mangus!

Thats what i feared. My mechanic says that the valve guides are worn and thats why the engine is so noisey. Well the wrong kind of noise. However, i dont use much oil at all and most of the threads indicate that with worn valve guides you get excessive oil consumption.

Guess I will have to have the top end rebuilt. Might regrind the cams to 964 when i have it done.