OT late model question s-10

[Land Yacht]

My truck, 1999 chevy s-10, 4.3L 80K miles. Has developed a lifter/valve rattle at start-up. Oil pressure shows normal, 45psi cold. Began a couple weeks ago, lasted about 2 seconds at startup. The rattle started lasting about 20 seconds a couple times, now lasts about 6/7 minutes until it warms up. Its also started using coolant, it empties the overflow tank in about 1 month, I belive it is losing it in the motor and when it cools draws from the overflow to replace what was lost. But I see no drips, and the oil looks good on the dipstick, level normal. It's going somewhere, not sure where though. Any ideas of what to look at for either of these problems are appreciated-  John

[Dave]

My truck, 1999 chevy s-10, 4.3L 80K miles. Has developed a lifter/valve rattle at start-up. Oil pressure shows normal, 45psi cold. Began a couple weeks ago, lasted about 2 seconds at startup. The rattle started lasting about 20 seconds a couple times, now lasts about 6/7 minutes until it warms up. Its also started using coolant, it empties the overflow tank in about 1 month, I belive it is losing it in the motor and when it cools draws from the overflow to replace what was lost. But I see no drips, and the oil looks good on the dipstick, level normal. It's going somewhere, not sure where though. Any ideas of what to look at for either of these problems are appreciated-  John

Never heard of a 4.3 doing that but i suppose it can. Any milkyness when you pull the oil cap or the pve? That would show coolant in the oil. Is the oil over full? That could indicate coolant too. If its getting coolant in the oil the oil would thin causing a lifter rattle.
Dave

[tomslik]

My truck, 1999 chevy s-10, 4.3L 80K miles. Has developed a lifter/valve rattle at start-up. Oil pressure shows normal, 45psi cold. Began a couple weeks ago, lasted about 2 seconds at startup. The rattle started lasting about 20 seconds a couple times, now lasts about 6/7 minutes until it warms up. Its also started using coolant, it empties the overflow tank in about 1 month, I belive it is losing it in the motor and when it cools draws from the overflow to replace what was lost. But I see no drips, and the oil looks good on the dipstick, level normal. It's going somewhere, not sure where though. Any ideas of what to look at for either of these problems are appreciated-  John

look pretty close at the intake gaskets and then of course dex-cool.......

[Dave]

My truck, 1999 chevy s-10, 4.3L 80K miles. Has developed a lifter/valve rattle at start-up. Oil pressure shows normal, 45psi cold. Began a couple weeks ago, lasted about 2 seconds at startup. The rattle started lasting about 20 seconds a couple times, now lasts about 6/7 minutes until it warms up. Its also started using coolant, it empties the overflow tank in about 1 month, I belive it is losing it in the motor and when it cools draws from the overflow to replace what was lost. But I see no drips, and the oil looks good on the dipstick, level normal. It's going somewhere, not sure where though. Any ideas of what to look at for either of these problems are appreciated-  John

Never heard of a 4.3 doing that but i suppose it can. Any milkyness when you pull the oil cap or the pve? That would show coolant in the oil. Is the oil over full? That could indicate coolant too. If its getting coolant in the oil the oil would thin causing a lifter rattle.
Dave

humm meant PVC
Dave

[Land Yacht]

Haven't checked the pcv, oil looks really clean. The intake gaskets are a known issue for coolant leaks on these, but with the oil being clean I dunno. I may drain the first cup or so from the pan, coolant should be there since it is heavier than the oil. If it is a slow leak it could be burning off of the oil when it gets hot, again I dunno...

[parklane]

If you're losing coolant, and the oil is clean, I would say it's either going into the combustion chamber or out of the engine,into the atmosphere. Never seen a coolant leak into the oil without turning milky.

John

[Arnold]

My truck, 1999 chevy s-10, 4.3L 80K miles. Has developed a lifter/valve rattle at start-up. Oil pressure shows normal, 45psi cold. Began a couple weeks ago, lasted about 2 seconds at startup. The rattle started lasting about 20 seconds a couple times, now lasts about 6/7 minutes until it warms up. Its also started using coolant, it empties the overflow tank in about 1 month, I belive it is losing it in the motor and when it cools draws from the overflow to replace what was lost. But I see no drips, and the oil looks good on the dipstick, level normal. It's going somewhere, not sure where though. Any ideas of what to look at for either of these problems are appreciated-  John

look pretty close at the intake gaskets and then of course dex-cool.......

 Those items..then I would pressure test it...do it when you have a bunch of stuff to do around the house/SHOP.Keep the pressure on it..if it drops a bit..pump it back up.The longer you can keep it pressurized the greater chance you will see where it's goin'.If it's losin.pressure and you can't see the leak..maybe it is goin' into the oil in small amts..or fire it up..maybe there will be enough to see it there..or maybe some nothing leak (hopefully) that you can now see..or a drip.Could be some evil little gremlin where it is a tiny leak onto an exhaust man/pipe or something.
  Doubt if the lifter and the leak are related.

[Land Yacht]

Thanks for all the replies.  I  had an independent mechanic check it out, replaced the intake gaskets, and all lifters, $600....  I didn't have the guts to pull it apart with all the junk in there.

[tomslik]

Thanks for all the replies.  I  had an independent mechanic check it out, replaced the intake gaskets, and all lifters, $600....  I didn't have the guts to pull it apart with all the junk in there.

might i ask what oil you are using?

[moose]

My 96 S-10 4.3 did the same thing. The oil never showed signs of contamination but the intake gaskets were leaking into the engine. Replace gaskets flush oil pan back in business.....

[Arnold]

If you're losing coolant, and the oil is clean, I would say it's either going into the combustion chamber or out of the engine,into the atmosphere. Never seen a coolant leak into the oil without turning milky.

John

  I think that small amounts of anti-freeze getting into the oil..and not being easily detected by the typical milky look..days are over.I think that dex-cool.long life,lo tox and a few other types of a/f as well as the different blends of oil.Plus the lack of lead in the gas..different blends of gas..much,much leaner engines..lower carbon/cleaner.Old acidic a/f.These..some of them..all of them..in combination with other factors must weigh in.

  Proof positive that especially in these engines..a/f leaking into the engine oil..even in small amounts..is very hard to detect..by looking at the oil..and it toasts engine bearings.Over enough time.

  I don't know as much about American engines..but here..Canada..Toronto..very recently I have noticed this same topic many times.These same symptoms.Same results.I happened to catch a radio talk show yesterday while driving.There were 3 guys who seemed to be authorities on this particular problem.1 of them said that if a regular customer calls and says his o/flow went low.They ask when did this start.If they say just now..or very recent..they say to TOW the car in.In these cases not enough a/f has gotten into the oil to damage anything yet.Those intake gasket repairs they do.If it has gone on for several months.Those repairs they simply refuse to do.Too often in the past they did them.Only for the customer to lose the lower end of the engine not long after.Customers have had the repairs done elsewhere..only to lose the lower end soon after.With a perfect engine..just the a/f leak..that has gone on for a while..they re-gasket and bearing the motor for $2500.The callers to the show echoed the above.Interesting when they talked of pulling some of these seemingly good lower ends of motors down..and ones that have been toast..They may have sounded good..but no question..a/f was eating at the bearings.

 These guys sort of laughed a bit about the old days of adding a/f..and the new days of adding a/f.Just 100% sure where is the a/f going?

 I worked around literally million dollar engines for a decade.These engines NEVER EVER ran a/f.Just for this very reason.They also never "changed" the oil per se.They added some chemical to the cooling system water that could be detected in the engine oil if it was leaking internally.Spectographic engine oil analysis.The analysis came back..change the oil..strip the thing..there is a coolant leak.Do it.

[Land Yacht]

Thanks for all the replies.  I  had an independent mechanic check it out, replaced the intake gaskets, and all lifters, $600....  I didn't have the guts to pull it apart with all the junk in there.

might i ask what oil you are using?

I was using Penzoil synthetic blend aka semi-synthetic, 5W-30.


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