Noobie in Need of help

[Nickasdf]

Hi, my names Nick, and I'm kinda new to non-fuel injected, big engine trucks (my previous cars were a '71 superbeetle and an '88 crx ).

I recently purchased an '81 Jimmy, and I am starting to have some problems with it. It came with an inline 6 and 3 speed on the floor. Recently, a kind of clicking noise has started coming from my engine bay. It sounds like it could be a lifter, but when adjusting the valves I noticed nothing out of the ordinary. I next moved on to the rod bearings, which, while in need of replacement, apparently weren't the cause of the noise, and while cleaning the oil pan out before reinstalling it, I found several small chunks of metal at the bottom of the pan, not enough to get sucked through the filter, and definitely not recognizable.

So here I am, stuck, not sure whether its worth getting a new set of cam and lifters and seeing if thats the problem, or just saying forget it and swapping in a new motor, rather than pour money into a bad one. Opinions on what the noise is or if I should fix this engine?

Also, if I should put a new engine in, should I stick with the inline 6 or go with a basic chevy 350? Thanks for any help given up front
-Nick

 

[4X4HIGH]

If you're wanting to swap engines then i would go with a SBC. A 350 is a direct swap into you mounts. Obviously you'll need some items such as carb, exhaust, and all the accessories with matching pullies. Post up a pic of this piece of metal you found, i'm an automotive machinist by trade and might be able to recognise what it is and where it came from.

 

[jonrpick]

Hi, my names Nick, and I'm kinda new to non-fuel injected, big engine trucks (my previous cars were a '71 superbeetle and an '88 crx ).

I recently purchased an '81 Jimmy, and I am starting to have some problems with it. It came with an inline 6 and 3 speed on the floor. Recently, a kind of clicking noise has started coming from my engine bay. It sounds like it could be a lifter, but when adjusting the valves I noticed nothing out of the ordinary. I next moved on to the rod bearings, which, while in need of replacement, apparently weren't the cause of the noise, and while cleaning the oil pan out before reinstalling it, I found several small chunks of metal at the bottom of the pan, not enough to get sucked through the filter, and definitely not recognizable.

So here I am, stuck, not sure whether its worth getting a new set of cam and lifters and seeing if thats the problem, or just saying forget it and swapping in a new motor, rather than pour money into a bad one. Opinions on what the noise is or if I should fix this engine?

Also, if I should put a new engine in, should I stick with the inline 6 or go with a basic chevy 350? Thanks for any help given up front
-Nick

I'd stick with the "six" unless you have a really good reason to go with something else. I assume it's a 250 since a 292 wasn't offered in '81 Blazers and Jimmys.

Those are usually really reliable motors that last for a long time. To me, the cost of converting to a V8 would be much more than fixing the 250.

The first thing I'd be doing is trying to figure out where those metal chunks came from. I wouldn't drive it until I got that sorted out. Luckily those engines are pretty easy to work on in terms of being able to access everything.

Good luck with the truck... You rarely see one that came with a six, and even less often do you see one that still has it installed. I'd love to see pics of the truck (and engine) someday.

 

[USSkoval]

I also would try to stay with the six, if possible. But if it ends up being toasted, I think it would be cheaper to stick a 350 in there. I had a '78 Blazer with a 250, and I miss it dearly.

 

[Nickasdf]

Well sadly I no longer have the pieces of metal that were in my oil pan (my pops threw them away). But I have decided to try and fix the 250

Next week I have a new cam and set of lifters going in, which hopefully will fix the problem.

Thanks for all your help and quick replies!
-Nick

 

[rufusbooth]

while you have the pan off take a look at the bottom of the piston skirts. you might have a skirt that broke off. It will cause a tapping noise. The metal pieces came from someplace, try to find where they came from. Just about everything inside an engine is fairly important.

Cheers,
Rufus

 

[Desert Yeti]

Are you reasonably certain the metal bit and the clicking noise are related? Tiny exhaust leaks where the manifold bolts to the head will make a "ticking" sound that can sound an awful lot like an internal click. I've had a shorting out spark plug wire arcing to metal make what I thought was a clicking sound too.

Apologies in advance if this is all too obvious and you've already checked it out. I'm just trying to make sure you don't spend a bunch of time and money when the internals may all be fine!

My engine opinion: Kinda depends on what you use the truck for, but unless you're towing a significant amount of weight or wanting to do hardcore wheeling involving huge tires or high horsepower (like mud) that 6 cyl will serve you just fine!

 

[Thunder]

Check the timing gears. When they go bad they will make a clicking or slight knocking sound. The chunks of metal could have been one of the teeth.

 

[buefchris]

My engine opinion: Kinda depends on what you use the truck for, but unless you're towing a significant amount of weight or wanting to do hardcore wheeling involving huge tires or high horsepower (like mud) that 6 cyl will serve you just fine![/quote] Plus, that inline 6 weighs more than the 350 I've been told.

 

[jonrpick]

Plus, that inline 6 weighs more than the 350 I've been told.

No, it weighs less... Not sure by how much. A 292ci L6 weighs less than a SBC, and the 250 is a shorter block, so it weighs even less. (The 292 is taller because of the really long, 4.12" stroke )

IIRC, it's not a significant weight savings, but it is less.