Tranny problems?

I own a 1990 "box" Caprice with a 305 and auto transmission. The original engine broke a rod, but has since been replaced. The piston shattered, and the rod broke completely free before wedging itself between the crank and block. When that happened, the engine instantly locked up and I had to coast off the road. The car didn't stop, it coasted 3 1/2 blocks, and even then I had to use the brakes to stop it. The engine has been replaced with a recently rebuilt '78 2-bolt main 305 w/350 crank and flywheel. The engine runs rough and gets poor acceleration. I drove it up and down the road, but it's not road worthy yet. I still have to work out the exhaust and dipstick problems. If I have the accelerator pedal all the way down, it will accelerate way too slow. I know the rockers need to be adjusted some. The exhaust valves aren't closing all the way. Does this sound like a transmission problem, or is it because of the valves? Any other ideas and help is appreciated.

I own a 1990 "box" Caprice with a 305 and auto transmission. The original engine broke a rod, but has since been replaced. The piston shattered, and the rod broke completely free before wedging itself between the crank and block. When that happened, the engine instantly locked up and I had to coast off the road. The car didn't stop, it coasted 3 1/2 blocks, and even then I had to use the brakes to stop it. The engine has been replaced with a recently rebuilt '78 2-bolt main 305 w/350 crank and flywheel. The engine runs rough and gets poor acceleration. I drove it up and down the road, but it's not road worthy yet. I still have to work out the exhaust and dipstick problems. If I have the accelerator pedal all the way down, it will accelerate way too slow. I know the rockers need to be adjusted some. The exhaust valves aren't closing all the way. Does this sound like a transmission problem, or is it because of the valves? Any other ideas and help is appreciated.

Check your engine over well. None of it sounds related to the tranny. Now, I'm going to point something out - you'll probably get some vibration in that engine that over time could prove fatal for it - the crank you said was from a 350. Now, the 305 and 350 (as well the 267) use the same stroke and the same casting crank, but they are balanced different and if you throw a 350 crank into a 305, it's going to throw the rotating assembly balance to the wind. This will lead to bearing failure.

As for the rest of it, make sure your valves are properly adjusted, and check out the rest of it. Are you using the '90 heads and intake setup with the TBI?

I've never seen a car just run like crap when the tranny is bad. I have seen the following....

Usually a tranny problem is announced with a "flare". The engine will act like its freerunning very briefly. You'll most often notice this when the temperatures are very cold, usually under 40 fahrenheit. You'll also notice it more often in first gear and reverse.

After the flare you'll then feel the transmission engadge, often like it's been neutral dropped "bang". Flare can last from a fraction of a second to several seconds. It reminds you a bit of slipping in snow or ice, except that the speedo won't pace with the flare.

You can also get "shudder", but that can be due to wear or a problem with your heat riser. I've been told that a slipping tranny can get very hot, but I've never seen this in person.

Eventually the tranny will began to act like it's slipping constantly. You can lose gears too, like you suddenly have a two speed transmission. Either first can drop out, or third can drop out.

The fluid will start to change color. First it can turn almost "transparent" but will start to have a "burned" odor. As the game progresses the fluid gets darker and darker, until it looks like ink. It will smell awful. You'll notice "grit", which is parts of the tranny going into suspension in the fluid.

If you bother to change the fluid you might notice a "shiny" pateen to the fluid, like glitter paint. One time I had a bad slip caused by vacuum leaks which dumped an eight of an inch of clutch and band material into the bottom of the pan.

Eventually it'll just sit there and do nothing. You can also hear grinding and clattering. I once drove a 200R4 that way for five miles. The rebuilder said, "Nothing worth salvaging" when he got it apart.


1978 engine? Are you using the 1991 ECM with this setup? Could be head compatibility issues.

Yeah, if the valves are not adjusted properly the car will run poorly. If the exhaust system is obstructed the car will not run properly.

I am not knowledgable about crank balance issues. I know that they matter a lot. Please reconsider a long term use of this engine.

Gene

I am running '90 Caprice heads and stock TBI on the '78 engine. The inner 2 head/intake bolt holes on each side are different. I found that out the hard way. The engine was bought used with very few miles. The previous owner said that he had his machine shop friend build it. I'll adjust the valves and see how it runs afterward. I was thinking that maybe the reason why it was getting poor acceleration was because of the valve adjustment. If nothing else I'll buy a used stock 305 for it. I'll be selling it as soon as I get it running again, because I really need a truck. I still have 2 other vehicles that need engine and frame work, so I need to get this taken care of. Thanks for your help. I'll let you know how everything goes.
It's not a '91 Caprice. But, it may very well have the '91 ECM. I know several parts on it are from the later '91 Caprices. That is because it's one of the "mix-n-match" cars. I don't see why they would build any of these "frankenstein" cars. It gets irritating when it's time for a repair.

If you're using '90 heads and a stock TBI intake, there should be no problems with the center two bolt holes on the heads. They were all 72° holes since 1987 (except some Corvettes). If you have a mismatch of heads, that could be part of your problem.

If you're using '90 heads and a stock TBI intake, there should be no problems with the center two bolt holes on the heads. They were all 72° holes since 1987 (except some Corvettes). If you have a mismatch of heads, that could be part of your problem.
I was just explaining that I am in fact using the later 84+ style heads(not the '78 heads, to be used on another engine). The heads were off the same '90 Caprice. I'm going to adjust the timing today(Wednesday) after I wake up. Next time I'm going to adjust the valves BEFORE installing an engine. I just finished a project yesterday, so now I can get working on the Caprice again. I only have one project left that can possibly stop me now. :licka:

I found some repair car manuals at http://www.real-tuning.tk because
i have problems with the engine.. the manuals are free if you are interested ..
Good luck , I hope i Helped you

Update. I have adjusted the valves and changed my water pump. I found several valves were tightenged too much, or not enough. I also found out one spark plug wire came off. The water pump I had on there was the '90 Caprice pump. For some reason the pump was over pressurizing the radiator. The water was spewing out of the radiator cap and overflow bottle. The belts were put on exactly as shown on the radiator shroud. It seems that the older engine won't work well with the newer reversed pump. I have the older pump on there now. The only problem I found was that the pump had an extra peice on it for accesories that was hitting on the power steering pump. That problem was fixed with a die grinder and a cut-off-disk. Everything is back together and I tried to start it. Now all I have to do is get a new battery. There aren't any Caprice manuals on that site. I have yet to find a good manual. All I can find is the "full size car" manuals.