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Discussion Starter · #1 ·
Well, on the way back from school today we were in a 55mph zone and a car was doing 30. My friend stomps it and goes out and passes it and I passed right after. As I'm slowly creeping past the car I hear what sounds like gun shots. They were high pitched and EXTREMELY loud. Well, he pulled over right after.

Some more background info. His truck is a 1998 Chevy 2500 with a 350 and true dual flowmasters ( which could explain the intensity of how loud the backfiring was ). It backfired about 4 or 5 times with a little time in between, which at this time he was cruising at about 2000 rpm. He said he didnt even hear the backfires, just felt the truck shuddering. He figured it was a tranny issue at first, figuring the truck has 199xxx miles on it, and has been a plow truck for a while. The oil pressure dropped to 0 and check gauge light came on. He shut it off while he was still in motion and pulled off the road.

He had someone tow it and it hasnt been looked into more yet. Any ideas of what it could be?

Also, about a week or 2 ago, leaving school he started it and it died right after. Kept doing it and it wouldnt idle. If he kept revving it, it would stay running. Then eventually it cleared out. I figured it was just something stuck in the fuel filter and it let go.

As of now, I'm thinking either an oil pump problem, or maybe a valve through a piston.

Please, lets keep this topic sane. If you dont know about the problem, DONT REPLY. I am looking for people who actually know what they're talking about and arent trying to get this off topic. Any help is appreciated.[/color=red]
 

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Open the hood, remove the dipstick, check oil level, replace the chevy with a dodge, reinsert dipstick. Jking

What happens if you try and start it now, anything? more backfiring? personally it doesnt sound to me like it blew up but possible, since you said that the oil pressure dropped it maybe wasnt getting oil in the right spots. I dont think you could get the valve through a piston since the flat side of the valve is closet to the piston, you could pull the valve covers off just to see that all the valve are in there spots, if you turn it over you can maybe listen for something grinding or clicking, hard for me to be much help i need to be there looking at to do alot of good
 

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Discussion Starter · #3 ·
Turns over a bunch now and fires occasionally then dies right after.
 

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sledcrusher said:
Turns over a bunch now and fires occasionally then dies right after.
here any clicking or chattering?
 

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Discussion Starter · #5 ·
Nope. Only thing I can think of is a timing chain.
 

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Pull the dipstick, and see if the oil looks like milkshake.

Do a compression test, he might have dropped a valve, or it could be a simple as a broken rocker.

You said the oil pressure dropped to 0, was that with the engine still running or had it quit. With 0 oil pressure, he probably just scored up the motor pretty good.
 

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If the oil pressure went to 0 before the engine died a rocker arm is the least of your problems. You need to find the cause of no/low oil pressure. Make sure it has oil, if so then smell it and see if it smells burnt. If it has oil something stoped oil flow, possible the engine coming apart and clogging the oil inlet or something going through the oil pump. Im leaning towards a catastrophic failue on this one.
 

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Yeah, same here...

Drain the oil, if there's shavings or chunks, start looking for a new motor.
 

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i am thinking timeing chain is stretched and skipped (or broke) advanced it self and might have hurt it. start tearing it down. or go to autowrecker and get another 350 and drop it in.
 

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A pop and a loss of power with no oil pressure could be a broken timing chain or camshaft. When you crank it over it should build some oil psi 5-10 psi if everything is still together.
 

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loss of oil pressure is mainly from the cam bearings and the main and rod bearings going bad......the oil pumps in them barely ever go bad but it can happen.....if it made a loud noise you could have broke a timing chain but if so you would not have had to shut the truck off it would have done that itself.....and if it jumped time your oil pressure would not nececarily drop to 0 due to the fact that the cam would still be spinning which in turn spins the distributor then the oil pump.... to me it sounds like you may have more than one problem i would say a spun bearing for the loss of oil pressure (you may have jumped timing and spun a bearing at the same time)
 

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either no oil in the engine, or broken timing chain. Take a valve cover off and see if the rockers are moving. If not, broken timing chain. If timing chain is intact and there is oil in the engine, you are looking at more serious engine damage.

But lets face it, you don't really want help, you already have decided to ask for help and then not take anyone's advice.
 

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Discussion Starter · #13 ·
TriumphoverU said:
either no oil in the engine, or broken timing chain. Take a valve cover off and see if the rockers are moving. If not, broken timing chain. If timing chain is intact and there is oil in the engine, you are looking at more serious engine damage.

But lets face it, you don't really want help, you already have decided to ask for help and then not take anyone's advice.
Actually so far I have listened. This kids pretty lazy and his Mom just got a new boyfriend that said if anything major is wrong with the motor, he will be ordering a crate 350 from Summit.

He said he checked the dipstick and the oil level is fine and looks fine. Has spark as well.
 

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Sounds to me like it could just be a loose wobbulator shaft. Easy fix. They have them at home depot next to the shingle stretchers.

Good Luck!
 

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Have it towed to a good engine mechanic and have them take a look at it. If the engine is shot then you'll need to consider if it is really worth spending the money on a vehicle that has 200,000 miles on it or it it's better off to junk it and spend the money on a newer used vehicle with less mileage. Sometimes when things break down it's a blessing in disguise to get something newer.
 

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^A 98' 3/4 ton is worth fixing all day IMO. That's a good truck. Good opportunity to buy a 350 crate motor if you ask me
 

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I think the 350 crate motor is the best thing to do at this point. if the motor was running with no oil pressure there is a good chance he did some damage to the cylinders, pistons, and or the valve train. Crate motor = easiest and cheapest solution.
 

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I have basically the same exact truck and it did the same exact thing. I actually found that when I had changed the oil I had actually put in a little too much oil and it didn't take it very well, It would run great for about 5 minutes then oil pressure would drop off the map and it would studder and die. I drain about a quart out and changed the filter again and it ran much better. Might not be his problem, just something to think about.
 

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Discussion Starter · #19 ·
sledneck1978 said:
Sounds to me like it could just be a loose wobbulator shaft. Easy fix. They have them at home depot next to the shingle stretchers.

Good Luck!
My dad was going to fix one of my friends cars when he said that something was wrong with it. Well, when he went to the kids house to check it out ( he wasnt home at the time ), he discovered a GIANT hole in the oil pan. Well, the motor started acting funny a few miles from home. We had him convinced it was the gonculator valve. When he realized we were kidding, he asked what the problem actually was. Wasnt to pleased to here "No, your motors just toast"

brian126 said:
Have it towed to a good engine mechanic and have them take a look at it. If the engine is shot then you'll need to consider if it is really worth spending the money on a vehicle that has 200,000 miles on it or it it's better off to junk it and spend the money on a newer used vehicle with less mileage. Sometimes when things break down it's a blessing in disguise to get something newer.
Lots of money into the body and interior of this truck. Frame is like new as well. Would be cheaper to buy a crate 350.
 
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