3.8 intake gasket engine trouble ect.

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ram_man

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So my friends mom has a 97 lss the engine overheated and a friend who is a mechanic took the engine apart sort of. He removed the upper intake and then said it needs a new engine. The oil is clean as is the antifreeze. The engine will turn via a wrench?
Is there a way to do a compression test without re assembling the whole intake?
And it says it could have two gasket options. One with locating pins or one without. How do I know which one it needs? Is there an easy way to tell by vin or something? Thanks everyone
 
As long as the valve train is there, you should be able to do compression, just be careful not to suck rags and things in...be really careful of what electrics are where too...
 
Originally Posted By: Shannow
As long as the valve train is there, you should be able to do compression, just be careful not to suck rags and things in...be really careful of what electrics are where too...


Yes, and be sure the injection and ignition are disabled if the injectors are mounted on the heads or lower intake- wouldn't want the thing firing off and running without any throttle at all... though I guess it would solve the question of whether the engine is bad or not...
wink.gif
 
There is an upper and lower intake unless its supercharged the lower intakes seldom go bad you can get an aftermarket intake complete for 75 the gaskets themselves are half that but the intakes crack or burn thru at the egr.
 
Originally Posted By: 440Magnum
Originally Posted By: Shannow
As long as the valve train is there, you should be able to do compression, just be careful not to suck rags and things in...be really careful of what electrics are where too...


Yes, and be sure the injection and ignition are disabled if the injectors are mounted on the heads or lower intake- wouldn't want the thing firing off and running without any throttle at all... though I guess it would solve the question of whether the engine is bad or not...
wink.gif



It can't start and run away like a Dodge with the intake opened up. It uses a MAF and wouldn't spray enough fuel to idle let alone run away. It's best to disable the fuel just the same as it will spray enough fuel that unwanted eyebrow removal is possible.

If you're going to do a compression test with the intake off, go ahead and crank it over for a few seconds with the spark plugs out to clear most of any coolant from the cylinders first in case that's why the intake is off.
 
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We have seen a few of these engines with damaged plastic upper intakes and the motors were fine as they are very tough engines. After blowing out the engine and installing another plenum they ran ok. If the lower intake gaskets are leaking buy the FelPro "R" improved repair gaskets and have at it. Dorman also makes metal fittings for the bypass fitting on the right side of the intake.
 
Everything but the tensioner and lower intake is off. Should I go ahead and replace the lower and upper?
 
I really doubt the engine is bad.

Compression test can be done, just make sure to disable the fuel pump and/or injectors, as already stated.

Replace lower intake gaskets with the Fel-Pro T series gaskets (steel framed). Do not gamble by not replacing them, as they suffer from the same issues as the other plastic framed GM LIM gaskets.

Replace the whole upper intake with a Dorman or equivalent.

Now is also a great time to replace the thermostat with a new OE unit.
 
Replace with Fel-Pro problem solver gasket as mentioned.

What made the guy say it needed an engine?

It overheated so I have to ask has the radiator been checked?
 
Originally Posted By: ls1mike
Replace with Fel-Pro problem solver gasket as mentioned.

What made the guy say it needed an engine?

It overheated so I have to ask has the radiator been checked?


radiator looked fine however when the engine overheated the top radiator hose was sucked closed collapsed. So probably a thermostat.
Not sure why the guy said the engine was bad.....he took 375 bucks to buy an engine and never did it or returned there calls. He removed the upper intake and stopped.
 
Originally Posted By: ram_man

Not sure why the guy said the engine was bad.....he took 375 bucks to buy an engine and never did it or returned there calls. He removed the upper intake and stopped.


So basically she found the same sort of mechanic that Technologs likes to hire. To me this means that you should remove the lower intake without cranking the engine and remove whatever he dropped in there before it makes it past a valve then reassemble and start fresh.
 
Originally Posted By: yonyon
Originally Posted By: ram_man

Not sure why the guy said the engine was bad.....he took 375 bucks to buy an engine and never did it or returned there calls. He removed the upper intake and stopped.


So basically she found the same sort of mechanic that Technologs likes to hire. To me this means that you should remove the lower intake without cranking the engine and remove whatever he dropped in there before it makes it past a valve then reassemble and start fresh.


yes the guy is pretty backwoods stuff thrown everywher reassembling it should be fun.
 
Because it is 30 bucks for a new one. and you are in there doing everything else and since the car is not running you can't be sure the pump isn't bad.
 
Originally Posted By: ls1mike
Because it is 30 bucks for a new one. and you are in there doing everything else and since the car is not running you can't be sure the pump isn't bad.


thats a good point. However with the guy owing them money they may or may not be able to afford it. But I will recommend it.
 
Originally Posted By: ram_man
So my friends mom has a 97 lss the engine overheated and a friend who is a mechanic took the engine apart sort of. He removed the upper intake and then said it needs a new engine. The oil is clean as is the antifreeze. The engine will turn via a wrench?
Is there a way to do a compression test without re assembling the whole intake?
And it says it could have two gasket options. One with locating pins or one without. How do I know which one it needs? Is there an easy way to tell by vin or something? Thanks everyone


Iron block and heads. It can take a bit of heat without getting to bent out of shape.
Lots of good advice in the thread i don't have much to add except as yonyon said check down those intake ports before cranking the engine, he may have tossed something down there to blow the engine if it wasn't already.
 
5 out of 6 cylinders had zero compression. She drove it About 12 miles in rush hour traffic before it lost power and died. This engine was brutally murdered to the point it made me sick!!
 
"5 out of 6 cylinders had zero compression"

Is that your test, or the guy that needed $375 for rent?
 
Originally Posted By: 951Indy
"5 out of 6 cylinders had zero compression"

Is that your test, or the guy that needed $375 for rent?


Mine . It very much shot!!
 
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