john_

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

muddog321

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.

Jeremy Fitch

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/

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1996 Blazer LT 4 Door, 4x4, 4.3L Vin W.

BlazerLT

ouch, big time damage occuring.

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1995 Factory Blazer Service Manual for sale, PM if interested.

juanito115

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!

BlazerLT

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

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1995 Factory Blazer Service Manual for sale, PM if interested.

redwheeler

get that sucker done fast

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and yes i am a ASE Master Auto Technician

1996 chevrolet silverado 5.7L 4x4
nothin but a k&n for now i just got it

laxman21

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?

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'92 s-10 4x4 EC p/u

'99 Blazer LT

'99 Suburban LT

BlazerLT

Another cause can be using a Fram oil filter.

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1995 Factory Blazer Service Manual for sale, PM if interested.