carolinafan4life63
1/2 ton status
this isnt about my blazer ..just wondering how hard it is to cange the intake gasket on a 1998 monte carlo with the 3.1 motor...any info would help a lot .......thanks
CK5
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gm techs
- Thread starter carolinafan4life63
- Start date
Just like anything the right tools and some time. One bolt on the rear valve cover can be tricky. I don't disconnect the fuel lines from the rail. I just move the whole thing out of the way. Be sure to replace all the o-rings on the misc heater hoses. Plan to do the thermostat while you wre there.
Lots of gm guys here if you need help.
Lots of gm guys here if you need help.
K5dreamer
1/2 ton status
super easy, just gotta take your time. removing the fuel rails and injectors, its been a long time but i seem to remember removing the coil packs when i did em.
but to give you an idea, one of the techs i worked with loved doing intakes, they were his bread and butter, he was very very good at them and could knock out anywhere from 5-8 in a day if he had no other work to do. all those old sixers had leaky intakes.
but to give you an idea, one of the techs i worked with loved doing intakes, they were his bread and butter, he was very very good at them and could knock out anywhere from 5-8 in a day if he had no other work to do. all those old sixers had leaky intakes.
carolinafan4life63
1/2 ton status
thanks guys....i heard that he intake gaskets on those motors were problematic because they were plastic , and over the years the plastic would deteriorate , causing leaks .....hopefully this is my problem and not the head gaskets
carolinafan4life63
1/2 ton status
ok , guys , just pulled the intake and the plastic gasket was cacked around all four of the water jackets!!! i do have another question though........when i took the air filter assy. out the air filter was soaking wet and the tube where the mass air flow sensor is just poured water out of it........is this a symptom of a leaking intake gasket on these motors?????????? this is the first time i have ever messed with the 3.1 in a 1998 monte carlo , thanks
Slapperbar
Retired Navy NDT Examiner
All I know is what you found. The gasket shrinks around the water jacket and, BLAMMO! Ingested water.
K5dreamer
1/2 ton status
was the water the same color as the coolant???
carolinafan4life63
1/2 ton status
no the water in the air filter was just water.........the oil was oil and water mixed(milky) and when i pulle the intake upper and lower there was a milky mixture running out of them!! i replaced the plastic intake gaskets and cleaned the maf sensor , upper plenum , and intake .........then flushed the coolant system and changed the oil twice after running it for 30 mins to an hour each time!! seems that the intake gaskets were the culprit...........any one else who attempts this intake gasket change who are not familiar with these motors , be aware that the intake and exhaust pushrods are diferrent lengths..the exhaust is 6.00 inches and the intake is 5.375 IIRC , other than that not a very hard job at all.......i know my mother will be happy........lol!!! thanks for all the input guys!!! oh and by the way when you clean the maf sensor , make sure you use maf sensor cleaner speciffically made for that!!!
K5dreamer
1/2 ton status
oh wow yeah, forgot about the pushrod issue, good catch. like i said, its been a few years since i did one of these 
congrats on getting it put back together.
the fluid in the intake mainfold was most likely from the PCV valve. you always get an oil residue, if you had coolant in your oil, (as you stated the oil was milky) that would transfer through the PCV and into the intake ducting. Should be solved with the intake repair.
congrats on getting it put back together.
the fluid in the intake mainfold was most likely from the PCV valve. you always get an oil residue, if you had coolant in your oil, (as you stated the oil was milky) that would transfer through the PCV and into the intake ducting. Should be solved with the intake repair.
oldtoyboyd
1/2 ton status
They make a metal type replacement intake gaskets that solve the problem.
carolinafan4life63
1/2 ton status
ok guys...fixed the intake gaskets..ran great for a week or so...
now the low coolant ligt flickers on and off , and after about thirty mins of driving the temp gauge will peg out and then go right back to normal temp!!
i replaced the thermostat and installed a new upper radiator hose .and this problem still persists
i bled the coolant system as required , made sure i wasnt losing coolant , but just cant figure this out
could the temp sensor have bit the dust from getting to hot when the initial problem ( intake gaskets) occurred and be causing eratic temp gauge behavior? any and all ideas and suggestions are welcome , thanks
now the low coolant ligt flickers on and off , and after about thirty mins of driving the temp gauge will peg out and then go right back to normal temp!!
i replaced the thermostat and installed a new upper radiator hose .and this problem still persists
i bled the coolant system as required , made sure i wasnt losing coolant , but just cant figure this out
could the temp sensor have bit the dust from getting to hot when the initial problem ( intake gaskets) occurred and be causing eratic temp gauge behavior? any and all ideas and suggestions are welcome , thanks
carolinafan4life63
1/2 ton status
someone told me earlier to take the serpentine belt off while the car is cold , take the radiator cap off , top of the coolant and then crank the motor up and if there are any air bubbles present in the radiator fill neck , if there are any air bubbles , then i have a head gasket problem.......anyone else hear of this detection method??? could someone please advise ..........i really dont want to tear the heads off if it's not necessary , thanks
