# Chevy 350 problems



## 350 small block

My chevy 350 small block does the same it has the floats adjusted its the 1980-1989 engine came swapped from a 305 into a 350 in my new truck my friend has a 94'maybe? and it has a knocking just like mine and my grandpa said its the lifters? Is it common in these 350s?


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## octaneman

Hi 350smallblock



Can you be more specific on the knocking noise ? Do you hear it from the top or bottom of the engine ?


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## wolfen1086

the most common knock out of a 350 is a lifter, a rod, fuel pump rod if you have a mechanical fuel pump, or loose bolts holding the torque converter on, How loud is the noise and what part of the engine is it coming from.


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## kjms1

do you hear it all the time or just when giving it gas or under a load

My hearing isnt to good and cant hear it over the internet LOL


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## wolfen1086

Your ears over the Internet 
my eyes in reality , I am starting to have a hard time seeing in daylight. so I actually had to have my 17 year old replace a fuel pump on a 75 Chevy Pickup today I lost $20 he made $20


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## 350 small block

its gotta knocking noise when it idles and it sounds like its around the air intake and valve covers when I put a load on it its fine when you give it gas but when you floor it the engine stops but still revs up and than takes a few seconds to get the power to the rear wheels and sometimes when you floor it, it sputters and dies. (gas tank gauge reads 1/2 a tank) any suggestions? Im fixing to give it back to the owner (getting sorta tired of it).


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## octaneman

The carb needs a rebuild the accelerator pump has to be replaced.


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## Amd_Man

The sputtering could also be a clogged fuel filter and is it more like a tick, tick, tick sound your hearing?


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## SABL

How many miles on the engine?? What carb is on it?? 

A knocking high up on the engine could be a wrist pin.....a ticking could be lifter adjustment......or a wiped camshaft. The stock 350 only has a lift of .258 if I remember correctly....I've seen wiped cams many times on high mileage 350's. Please clarify if you hear a knock or a tick.....big difference when it comes to diagnostics. 


The hesitation on acceleration could well be the accelerator pump....seen that many times. If it backfires through the carb when you floor it at highway speeds it is more than likely floats or needle and seat leakage. The engine will be running too rich and the fuel is still burning when the intake valve opens.....100% of the hot gasses are not exhausted due to piston clearance at the top of the stroke and the combustion chamber, itself. 

Hesitation can also be due to timing......how's the vacuum advance on the distributor?? What do you have the timing set at??


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## 350 small block

Its gotta fresh rebuilt motor and 4 barrel carb (according to the guy i got it from) and its got 68XXX miles on it and the ticking is a fast ticking noise but when you rev it up it stops and sometimes starts louder, and i cant do anything over 45 cause tranny wont shift (replacing tranny soon) not sure about the distributor but the headers get awfully hot after a few mintues of running it can that be a sign of bad timing? And Im replacing the whole fuel lines cause its been sitting for 3 years never started till a few months ago.


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## octaneman

The headers are getting hot because raw fuel is being dumped in the exhaust system and your engine timing is too far retarded.


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## kjms1

get a timing light and set timing

The timing is making it run lean and HOT ... need to fix that lean is bad on a engine and that is the noise you are hearing when you gives it gas, timing ping ... if timing is OK check for a massive vacuum leak
.

The tranny not shifting check the vacuum line going to it


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## wolfen1086

The timing will need to be set a certain amount before or after TDC. Make sure you fully read the emissions label. To set Fuel air mixture of the Carb. I was always told to use a vacuum Gage and turn each screw,reward out 1/4 turn until the Gage read the highest possible vacation for that side then repeat on the other screw. However on my old truck I found that turning the both at the same time works just as good if not better


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## 350 small block

Tranny were gonna replace and it runs fine just down on power...


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## SABL

You're getting to the messy part.....time to check the valve adjustment and compression. Check the compression on all cylinders.....the 350ci should have 150psi with a minimum of 130psi. 

*The following is for Hydraulic Lifters Only!!* Ask the former owner/rebuilder and find out what type of lifters were installed.....also find out what was replaced with the rebuild. 

Remove the valve covers......start the engine and observe all rocker arms for movement. Each one should be moving as much as the one next to it.....the lift is almost identical for intake and exhaust. Observe each rocker arm where it seats on the push-rod....all should have oil squirting from the end. 

There are two ways to adjust the valve lifters.....I do it the messy way with the engine running. (Splash shields are handy for this method) Loosen each rocker arm nut until the rocker arm starts ticking......carefully tighten the nut until the ticking stops. Tighten the nut another 3/4 turn in 1/4 turn increments. Move to the next rocker arm and repeat til all valves have been adjusted. 

Less messy way is to bring #1 cyl to TDC on the firing stroke.....rocker arms will be even with each other. Make sure the timing mark is close on the harmonic balancer and the timing indicator......if the timing mark isn't close you have other problems!! Loosen the rocker-arm nut enough to get some play between it and the push-rod......tighten the nut while turning the push-rod until you can't turn it (push-rod) any more. Tighten the nut another 3/4 turn.....in 1/4 turn increments. With breaker bar (or long ratchet) and correct sized socket on the harmonic balancer bolt, rotate the engine *exactly* 90 degrees in the direction of rotation. *Carefully* look for two more rocker arms that are even with each other and repeat the process used to adjust #1 cyl valves. Do this until all 8 cyls have been adjusted.....

Unless you rebuilt this engine yourself, you have no clue on the history of the assembly process and any adjustments that were, or were not, made. Make sure the basic mechanics are correct...then move on to the finer points of carb adjustment and timing. Pay special attention to the timing mark and #1 cyl at TDC......sounds like it may be 1 tooth off.


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## 350 small block

well its not like 100% putting power down cause if you do it sputters.


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## 350 small block

And I didnt rebuild it and the people who rebuilt it i think moved the person i got it off never messed with it and the only thing we did is set the carb adjustments thinking that it would be the engine was getting more fuel than it needed. (like our 67 ford f100 does with the 390)


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## SABL

If the engine is making a "ticking" noise, that has to be corrected first.....and the timing needs to be verified as being correct. You can adjust the carb to your heart's content but if the engine is not assembled correctly or the valves are not adjusted you are not going to get a strong running engine. 

What cam was installed...is it stock??



> and 4 barrel carb (according to the guy i got it from)


Are you relying on the word of someone else or do you know for sure what you have?? Who is the manufacturer of the carb?? 

Can you find out why the engine was rebuilt?? Was it a replacement or was it rebuilt to increase the performance?? 

The first thing that needs to be determined is if the engine is "right".....


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## 350 small block

As from what he said he bought it rebuilt the truck originally had a 305 (5.0) and he put a 350 in it (5.7l) For reasons why he did that I have no Idea as for everything else im also not sure and the carb might be a remanufactured 4 barrel.....


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