My daughter has a 2002 Blazer with 4.3 V6 engine. The oil keeps disappearing. It has a 4.5 quart capacity. It has about 1300 miles/3 months on the current OCI. No oil showing on the dipstick. This is about the 3rd time this has happened. No apparent leaks, no oil in coolant, no smoking from tailpipe. A friend suggested stuck rings. Only 109k on engine. I plan on running a bottle of Auto-Rx through it, along with a thicker oil. Maybe 10W/40 for one oil change. Other suggestions as to what might be happening here?
2002 Blazer 4.3, Where's the oil???
- Thread starter otis24
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When you drain it, does a lot of oil come out? Try an Italian Tuneup 
What's an Italian tune-up???
Last time I changed it, I was lucky if I got a quart out.
If it's burning oil that bad you need to check it at least weekly
It must be burning the oil, and it is smoking, you just aren't seeing it. I once had a car that burned a quart of oil in 100 miles, and it didn't look like it smoked much. Also, wow, you have been running it with virtually no oil in it, so it is probably getting it just that much more worn out. I think that you are a candidate for a thicker oil, or maybe STP. Trouble is winter is coming, and very thick oil in cold weather isn't good either. Is this a new to her vehicle?
Check the crankcase ventilation system.
Get some AC Delco top engine cleaner and new spark plugs and do an oil change very quick after doing it.
I have used the top engine cleaner in the link below with very good results:
https://www.amazon.com/s?k=top+engine+cleaner&ref=nb_sb_noss_2
But lets face it, the engine might be worn out.
Get some AC Delco top engine cleaner and new spark plugs and do an oil change very quick after doing it.
I have used the top engine cleaner in the link below with very good results:
https://www.amazon.com/s?k=top+engine+cleaner&ref=nb_sb_noss_2
But lets face it, the engine might be worn out.
This vehicle does not have a PVC valve. Just a tube going from valve cover to air filter cover.
Make sure the tube going from the valve cover and PCV valve attached is clear and open. Ed
In order to see smoke from the tailpipe, you need to be burning more than a quart every hundred miles.
It's burning it for sure, and that oil needs to be checked every fill-up. NO exceptions, no excuses, or it will run dry.
Which, of course, will solve your problem permanently...
It's burning it for sure, and that oil needs to be checked every fill-up. NO exceptions, no excuses, or it will run dry.
Which, of course, will solve your problem permanently...
I checked the oil and it was low. Topped it off. Not too long afterwards, I checked it again. No oil on dipstick. Changed the oil. In 1300 miles, no oil showing on dipstick. Guessing it was about 2 quarts low. This is my daughter's vehicle. Trying to get her to do anything besides get in and drive vis nearly impossible!
Don't worry, if this keeps up, it won't be long before it stops moving.
AutoMechanic
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It’s definitely going somewhere. Hopefully the head gasket isn’t leaking I’ve seen those consume massive amounts of oil and other fluids before.
+1
And with something burning it that fast I'd definitely switch to at least a 15w40 if not a 20w50.
I have a neighbor that was talking about he used that a little too much of that STP stuff in a car back in I assume sometime in the 70s maybe early 80s when he owned a Monza and he went to turn the car over on a cold winter day and the oil filter blew apart.
It does have a PCV valve on the driver side valve cover. Pull one of the valve covers & see if the engine is Sludged Down....I've seen them so bad that the oil can't properly drain back to the pan & the PCV will suck straight oil.
The 4.3 is not noted as an oil burner. I've got a 99 with 160,000 miles with minimal consumption. Rear main seal leaks, of course but you'd see that on the driveway. Hopefully your PCV change helps out. But the "check oil with each fuel fillup" commandment should be in place for every vehicle IMHO.
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