1999 s-10, 4.3L auto, 80K miles, coollant flushed at dealer 3 months ago, using dexcool. About two weeks ago I could hear a quick rattle at strat-up that lasted about 1 second. Then twice in a row it rattled for 20 seconds then cleared up. The last time I strted it up it rattled for about 6 or 7 minutes before it eased up and went away. Sounds like a lifter/valve rattle. It started using coolant recently, it empties the overflow tasnk in about 1 month. I don't see any leaks. The oil on the dipstick looks great, clean. The level is not high. My main concern is the valve/lifter noise, anyone have any ideas as what to look at? Thanks

Classic lower intake leak that sprays Dex Cool into the valley on the lifters and evaporates - 3 of my 4 have done this and no water shows in the oil - that slow coolant drop is the sign unless the heater core, water pump, or a hose leaks. If the oil and filter are new and it still happens thats where I'd place my money.

Get the intake gasket fixed ASAP. The coolant in your oil is causing major bearing wear in your engine. If you wait it will cost you a total rebuild of your engine. Trust me, I speak from experience. If you doubt you the coolant is in your oil get an oil analysis done. The small cost of 20.00 is nothing compaired to a new engine.

http://www.blackstone-labs.com/

ouch, big time damage occuring.

wow!! my friends blazer is doing exactly the same thing. It happens to b a 99 too. At start up it rattles like crazy specially when left sitting overnight. Then it gopes away after 1 or 2 sec. So you guys say that it is the intake gasket? We just replaced the oil today b-cause to me it sounded like it was a lifter and he said that it was missing about a quart of oil and the coolant kept dissapearing and no leaks at all. The sound does come from the intake mani!

Yip, disappering coolant would be an intake gasket or a head gasket.

get that sucker done fast

I have the same problem. No noise at start up, though.


What type of replacement gasket should be used so this won't happen again?


Are there better after market ones than OEM?



What's worse, head or intake for the engine?

Another cause can be using a Fram oil filter.