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What's wrong with my trailblazer?

404 Views 7 Replies 4 Participants Last post by  Schurkey, 
Ryan602
Hello everyone. I'm Ryan, 25, living in Phoenix Arizona. Self taught and always willing to learn more to help me succeed.

I have a 2003 Chevy trailblazer LS With the inline6 4.2 engine. I have been doing all my own work except for an occasional oil change or recently an alignment.

(I stopped driving my truck after this happened.) I was driving on the road this weekend heading to the lake when my truck started to shudder and chug as if it was running out of gas. When I would sit there and tap tap tap the gas pedal. It eventually stop doing that I pulled over and got some more gas even though I was half a tank.
I continued to go on but something seemed wrong. I didn't make it there because I eventually turned around and went home. The trip did not take any longer than an hour and a 1/2.
Right before I got home it started to make a clunky knocking noise. It sounded like somebody was knocking on metal and then when I would accelerate it sounded like a woodpecker.
The woodpecker noise was pretty much every time I would accelerate.The knocking on metal noise would come and go.
Today I pulled the belt off and started it up and immediately heard a knock knock knock very loud and really fast on start up and then it stopped knocking. After about fifteen seconds then it started to slightly knock at a low volume.(no belt on)
I let it run for about a minute and then checked the oil. It looks thicker. I can't tell if there is coolant in there as I have never seen coolant the oil. It does not look like chocolate milk but it is a thicker consistency. It also has a weird smell. Kinda burnt. I do work on cars and I do know a good amount but this is something. I don't really have experience in but I'm also considering that my engine is no longer any good. I'm just hopeful. When the vehicle was acting like it was running out of gas I looked up what could be causing all these issues. Some of the Research said that it could either be a fuel line or maybe it's the combustion at wrong times so I'm hopeful that maybe just maybe... It's fixable. like everybody else I would still like to know what's wrong with it at least without putting too much money into it- That will eventually be wasted if it is no good.
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flyboy2610
The thick oil does sound like coolant is getting in there. That would definitely affect how the engine is being lubed. Sounds like overhaul or replacement time.
It could also be a stuck injector, but excess gas would thin the oil, not thicken it.
You could try changing the oil and see if it helps, but it sounds the damage has done been done.
I hate to be the bear of bad news.
Table Plant Nature Grass Carnivore
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2002 TB LS
Best of luck to you. Only Clunk/knocking noise I remember getting was due to the VVT sensor. It gave a violent shake for sure!
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Schurkey
What is the fuel pressure?

Connect a scan tool, verify EVERY sensor and computer output including but not limited to the cam phaser. O2 sensor and MAF sensor are the only sensors that are known for wearing-out with age. All the other sensors can last "indefinitely"; sure they go bad now and then, but O2 and MAF have a known problem with age/miles.

How old are the spark plugs? Fuel filter? Air filter?

"Thick" oil is likely oil that's not up to proper operating temperature. Potentially, no big deal. If you're concerned about coolant in the oil...is the coolant level low? If the coolant in the overflow bottle and radiator isn't low...not likely you have coolant in the oil.

When my '03 w/ 4.2L six-popper chugged, first time it was a plugged catalytic converter. Second and third times it was a failed ignition coil--first the coil for #1, then the coil for #3. Those times, I got the P0301, and then the P0303 codes.
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Ryan602
Brand New spark plugs but a cheaper Brand. Catalytic converter was removed and straight piped due to damage. I need to get it to the O'Reilly's down the road for a scan tool. How do I check the sensors? I was thinking the fuel filters need to be replaced. Air filter is clean and inspected.
Schurkey said:
What is the fuel pressure?

Connect a scan tool, verify EVERY sensor and computer output including but not limited to the cam phaser. O2 sensor and MAF sensor are the only sensors that are known for wearing-out with age. All the other sensors can last "indefinitely"; sure they go bad now and then, but O2 and MAF have a known problem with age/miles.

How old are the spark plugs? Fuel filter? Air filter?

"Thick" oil is likely oil that's not up to proper operating temperature. Potentially, no big deal. If you're concerned about coolant in the oil...is the coolant level low? If the coolant in the overflow bottle and radiator isn't low...not likely you have coolant in the oil.

When my '03 w/ 4.2L six-popper chugged, first time it was a plugged catalytic converter. Second and third times it was a failed ignition coil--first the coil for #1, then the coil for #3. Those times, I got the P0301, and then the P0303 codes.
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Brand New spark plugs but a cheaper Brand. Catalytic converter was removed and straight piped due to damage. I need to get it to the O'Reilly's down the road for a scan tool. How do I check the sensors? I was thinking the fuel filters need to be replaced. Air filter is clean and inspected.
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Schurkey
"Good Luck" getting O'Reillys to scan your vehicle. I've used them a few times when I've been "on the road" hundreds or thousand of miles from my own scan tool. O'Reillys will code-read, but not scan. The last time, the tool they had wouldn't even read manufacturer codes, just generic codes--so their tool claimed I had "random" misfires instead of misfires localized to #3, which I would have fixed by buying an ignition coil. Since they couldn't tell me which cylinder was misfiring, I had to drive home and connect my own scan tool to find out anything useful.
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Ryan602
Do you have a scan tool that you recommend? I get paid this tuesday and can purchase one.
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Schurkey
Ryan602 said:
Do you have a scan tool that you recommend? I get paid this tuesday and can purchase one.
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