kanek4

Hey all. '88 Cutlass Supreme 307 VIN Y... I've been hearing a noise that I can only describe as ticking/tapping. The noise is only present while I'm driving, and only under very light load. It increases in speed when I accelerate but only up to a certain point/(rpm?). No noise when idling, and no noise under heavier loads, so its been very hard to pinpoint. It comes and goes, its not constant. I've been watching videos on youtube of all different types of clicks & ticks & taps & pings & I think I'm going nuts I've checked the pulleys because it reminds me of a bad bearing, but they all seem fine. It sounds like a valve tap but as I said its quiet as a mouse when idling. I'm also burning a ton of oil (its my daily driver, burning about a quart a week, but I am CONSTANTLY checking & keeping the level up). Any ideas?

Smitty275

Its detonation. Most likely due to your major oil consumption issue. Is there oil in the hose going to the PCV valve and air cleaner housing? If so replace the PCV valve. Otherwise its time for some investigation to see if the oil is sucking past the intake gasket or if it is coming in past the rings.

kanek4

I actually checked the other day and did notice some oil coming thru the pcv valve & filter so I ordered both of them. I also noticed the valve covers were covered in a thick coat of gunk so I ordered those gaskets as well. I figured when I take the covers off to clean them I can unclog the oil drainback holes too since that might be part of the reason I'm losing/burning oil. I've read that I'm not supposed to let that gunk fall further into the engine; is their a fail-proof way to unclog them? Thanks again for the help guys.

Greg Rogers

If your drain holes are clogged then the oil won't drain back and may get sucked it thru the valve seals. If you find this problem you can clean them out with a piece of course wire or the like to unclog them. You could use a shop vac you don't care about (cause it will mess it up good) and suck out the crud as you are jamming the wire down the holes. If you are doing this and you think this was the problem you may want to install umbrella type valve seals though this will require removing the valve springs. But you will be half way there after you remove the valve covers.

kanek4

I definitely need to open the covers up and take a look before I get too far ahead of myself. Probably won't get a chance until later this week though. I'll update when I get there. Thank you guys.