The Stupid Engine Questions Thread

[Mschaffer92]

This could have been answered already but I tried to look but couldn't find anything. My motor finally went on a 1997 gmc sierra 350 with the vortec. I have been looking for a replacement or to rebuild it. Now the question that I have is can I also put in a throttle body style motor in replace of the expensive to rebuild vortec. But unsure what I all have to switch over on the truck as far as the motor to work in my truck.

 

[SAATR]

A vortec short block isn't really any more expensive to rebuild than any other SBC. The biggest difference between the TBI engines and the Vortec motors is the heads, induction setup, and roller cam. If all those parts are still good, then the cost difference is practically non existent. Heck, new Vortec heads are cheap these days. What exactly failed on your engine?

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[Mschaffer92]

Not exactly sure just let. Drove it home and heard almost like sockets inside of the valve covers at idle and soda cans rattling inside the oil pan during driving. Dont know much about motors besides regular maintance and changing of normal parts. I noticed at the top light before my home which is a few blocks away the oil pressure guage dropped to 0 then went back up to 18. And it even stayed at 18 when doing 65 on the freeway on my way home.

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[SAATR]

Low oil pressure without a doubt. Sounds like it was low enough to make the lifters rattle quite a bit, but you don't seem to be describing rod knock. Easiest thing to do is to cut open the oil filter and see if there is any metal debris to be found. A severe failure will look like glitter or aluminum flake paint. If you find that, the bottom end is toast. If it's free of metal, you may be lucky enough to only have a worn out oil pump or clogged/ruptured pickup tube. One way to test is to overfill the oil by a quart. If the pressure issue and clattering is gone, your pickup tube has a hole in it. If not, you could still have a bad oil pump, clogged tube, or bad bearings. I would definitely troubleshoot further before tossing the engine, or blowing it up for lack of diagnosis.

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[SAATR]

Double post.

 

[senja]

This sounds like a problem I had. In my situation, there was water in the oil. Where it comes from is a mystery. Check your dipstick for more fluid in the oil pan that what's suppose to be. At idle, if there is oil in the water, the water will sink to the bottom of the oil pan and be picked up by the oil pump. Oil pressure will be next to zero. When you rev up the engine, the pressure will increase. Also, when you first start the engine, there will be plenty of oil pressure, then after a minute the water (if there is water in the oil) will get into the oil system and the pressure will drop. I know this is kind of a long shot, but it's easy to check out before spending and big bucks on a rebuild.

 

[sewlow]

This sounds like a problem I had. In my situation, there was water in the oil. Where it comes from is a mystery. Check your dipstick for more fluid in the oil pan that what's suppose to be. At idle, if there is oil in the water, the water will sink to the bottom of the oil pan and be picked up by the oil pump. Oil pressure will be next to zero. When you rev up the engine, the pressure will increase. Also, when you first start the engine, there will be plenty of oil pressure, then after a minute the water (if there is water in the oil) will get into the oil system and the pressure will drop. I know this is kind of a long shot, but it's easy to check out before spending and big bucks on a rebuild.

Water in the oil? Vortec? Intake manifold gaskets!!!

 

[kkirwan71]

Alright guys I'm having an issue. My truck will not stay running at an idle and idles really rough all the time


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[SAATR]

Alright guys I'm having an issue. My truck will not stay running at an idle and idles really rough all the time


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How can it not idle and idle rough at the same time?
How does it run otherwise?
Have you tried anything to fix the issue?
Have you performed any other tests to find the cause of the issue?

 

[kkirwan71]

No it idles rough then cuts out


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