Engine clatter

Hi all. 2000 Blazer, 4dr, 2wd, about 180,000 miles. Intake manifold gasket blew recently. I did not let it overheat, but caught the problem and got off the road. Topped off the water and limped it a short distance home.

I finally changed the gasket. I noticed spark plug #1 had a lot of build up (the other 5 spark plugs were just worn, but not bad with no build up). I changed plugs and wires, reset the time using TDC method (distributor cap and rotor got knocked loose during repairs). I lined up the rotor indent and paint mark, put it in and it settled flush to the arrow with the "6" on it which is the indicator mark.

It fires right up and runs normally, except for a clattering noise somewhere in the engine. I changed the oil (which was milky). I tried pulling the spark wires 1 by 1 to see if it changed anything. No change. The clatter is instant when it fires up and is constant with the engine. Pulling the spark wires did not change the sound at all, nor the tempo, so I don't think it's pre-ignition related. Buddy of mine thinks it is timing related somehow.

The noise did not happen when I limped it home (at normal temp). It ran fine then. Soon as I started it, I get this noise. It has to be something related to the repairs I did or the timing possibly (though I can't see how). Any advice where to go from here?

Youtube video of the sound: http://www.youtube.com/watch?v=6fSn-FKfnuk&feature=youtu.be

Sure sounds like a collapsed lifter to me. Milky oil means coolant got in it... coolant in a lifter will collapse it. Figure out which side, (tough to do) and pull the rocker arm cover off. Wiggle each rocker arm up and down, you'll find it, (the push rod will be loose).

Thanks! I'll try that. Hopefully it's not hard to get to. Thing that gets me is that it was running normal when I last shut it down, then repaired it, then this sound was instant when I next started it up. Can that happen like that?

Thanks! I'll try that. Hopefully it's not hard to get to. Thing that gets me is that it was running normal when I last shut it down, then repaired it, then this sound was instant when I next started it up. Can that happen like that?


with the oil contaminated I would change the oil again [HOT], and add 8OZ of marvel mystery oil to hopefully clean up the sludge which I guess is causing the lifters to not hold oil.

this is what happens when carbon/sludge get into the lifters.

give the oil time to drain out hot. I would also replace and clean up the crankcase vent/PCV system.

When coolant contaminates the oil, it eventually works its way into the lifters. Coolant is thinner than oil, so when it gets in the lifters, as soon as the cam lobe pushes the lifter up, it forces the coolant out and the lifter collapses. If in fact this is the problem, when the oil is no longer comtaminated, the lifter will pump up and function properly.

The other end of the spectrum is lifters contaminated with sludge. In this case the lifter will pump up and not bleed the pressurized oil out, the valve will not close completely, and you've got a misfire. Marvel Mystery oil usually fixes the problem. Valve lifters are a "shock absorber" for the valve train. Too sloppy or too stiff will cause problems.

When coolant contaminates the oil, it eventually works its way into the lifters. Coolant is thinner than oil, so when it gets in the lifters, as soon as the cam lobe pushes the lifter up, it forces the coolant out and the lifter collapses. If in fact this is the problem, when the oil is no longer comtaminated, the lifter will pump up and function properly.

The other end of the spectrum is lifters contaminated with sludge. In this case the lifter will pump up and not bleed the pressurized oil out, the valve will not close completely, and you've got a misfire. Marvel Mystery oil usually fixes the problem. Valve lifters are a "shock absorber" for the valve train. Too sloppy or too stiff will cause problems.


with water in the oil . when first starting the water/coolant will be at the bottom of the pan. this gets sucked into the oil pump/engine at first cranking.

oil floats on top of water after it has time to settle out on engine shutdown.

operating with a coolant leak into the engine also wil damage the O2 sensors.

with water in the oil . when first starting the water/coolant will be at the bottom of the pan. this gets sucked into the oil pump/engine at first cranking.

oil floats on top of water after it has time to settle out on engine shutdown.

Perfect!


operating with a coolant leak into the engine also wil damage the O2 sensors.

Not sure I'm following you on this one, please explain.

Update: still have a similar noise. Here's the youtube link: http://youtu.be/0Jw5I-ErK5s It runs, drives fine. Whenever I let off the throttle, it drops to a rough idle, then stabilizes eventually. I tried running 2 pints ATF along with fresh oil for about 30 minutes, letting it warm up and rev'ing it. Clatter changed to a quieter sound, but still is there. I changed the oil again and put 100% oil this time. Last oil change came out clean (except for the red tint from ATF). I've got a little Marvel Mystery left, but need some more tomorrow. I've also heard Liquid Wrench (or is it Liquid Mechanic? Something like that). I THOUGHT it sounded like the ride side, so I pulled the rocker covers off, and the rockers were all solid and had clean oil in their little pans. I'm trying to figure out if something if physically damaged or if it's just a clog or sludge.

I fixed a really noisy lifter on my 2000 GMC Jimmy 4.3L by flushing the crankcase with Gunk brand crankcase flush. Here is my suggestion. Go buy 4 quarts of cheap oil and a cheap filter along with the Gunk stuff. Drain your oil and install the new oil, cheap filter, and the Gunk. Start up and idle and I mean freeking idle for 30 minutes. Do not under any circumstances rev the engine or drive the truck. After 30 minutes, drain and re-fill with new oil and a new filter.

I fixed a really noisy lifter on my 2000 GMC Jimmy 4.3L by flushing the crankcase with Gunk brand crankcase flush. Here is my suggestion. Go buy 4 quarts of cheap oil and a cheap filter along with the Gunk stuff. Drain your oil and install the new oil, cheap filter, and the Gunk. Start up and idle and I mean freeking idle for 30 minutes. Do not under any circumstances rev the engine or drive the truck. After 30 minutes, drain and re-fill with new oil and a new filter.


[NOT MY VEHICLE]

I had an engine that had oil sludge issues. lots of goop in the engine oil .

I used the gunk [solvent] with draining the old oil out. adding new oil [CHEAP] . replaced the filter and idle only for like you say 30 min.

this did loosen the goop up and it did cause the engine to be cleaned. you cannot get it all out however. I had to add new oil to flush out the gunk solvent. it is a long process but in the end the engine was cleaned better than I expected.

after that marvel mystery oil was added 5oz. to the engine oil and the remaining sludge was slowly removed. @ 1000mi changed oil /filter again because it was dirty . this then got it back to being very good quiet running. no lifter noises.

the burning of engine coolant it is reported kills the O2 sensors. this is what is stated with much information concerning these sensors.

With your NASA comment, I have to agree with you that this should be still in operation . unfortunately our president felt that starting a war in IRAQ was more important. 1 trillion plus all the guys killed and hurt was not a wise move.

you just can't trust any of these elected people .

the burning of engine coolant it is reported kills the O2 sensors.

Ahh ok, I understand... I agree, burning coolant will eventually destroy an oxygen sensor, but the OP, (and I) were referring to coolant in the oil, which will not affect the oxygen sensors. When the intake gasket sprouts an internal leak, the coolant drains down into the oil and contaminates it. It is possible, but not likely, for an intake gasket to leak coolant into an intake port. Physically it's a long way for the coolant to travel horizontally. Neglected coolant is what deteriorates the intake gasket around the coolant ports, the coolant will run down, (gravity) before it will deteriorate an intake port gasket.

Ahh ok, I understand... I agree, burning coolant will eventually destroy an oxygen sensor, but the OP, (and I) were referring to coolant in the oil, which will not affect the oxygen sensors. When the intake gasket sprouts an internal leak, the coolant drains down into the oil and contaminates it. It is possible, but not likely, for an intake gasket to leak coolant into an intake port. Physically it's a long way for the coolant to travel horizontally. Neglected coolant is what deteriorates the intake gasket around the coolant ports, the coolant will run down, (gravity) before it will deteriorate an intake port gasket.

don't forget the crankcase venting system. this sucks crankcase vapors into the combustion chamber. this is used to reduce emissions with oil/engine gases created. now you have a leak of coolant into this engine oil and quickly the coolant vaporizes under the high oil temps. this all gets thrown/sucked into the combustion chamber.

my guess is that the silicates or other compounds that are / were used are the cause for the damage. I believe some coolants have removed these silicates last I have checked.

Good point about the PCV system, and yes, it's the silicate in the coolant that destroys the oxygen sensor. Dexcool coolant, used in 1996 and newer, is silicate free.