Question about 1978 Chevrolet Caprice

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Excessive intake manifold suction

I installed a aluminum manifold on a 1979 small block 350 engine, there is a severe sucking sound coming from the carb , causing the motor to run very rough what is causin this problem?

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Posted on Sep 25, 2009


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My x5 BMW engine was overhaul recently. Now we found that it sucks the oil from the oil sump into the intake manifold

That will occur via the crank case ventilation system. If there is excessive vacuum in the system, oil will be drawn out of the sump, through the tubing system and into the intake manifold.
The cause of the excessive vacuum needs to be addressed and without running checks I cannot tell you what the cause of the excessive vacuum is on your complex BMW engine.

Nov 11, 2015 | BMW Cars & Trucks

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How to fix oil leaks in chevy ss impala 1996


1. Removal

Unscrew the bolt that holds the negative connection to the Impala's battery. Set this bolt aside for later use.

Remove the engine cover to access the intake manifold and manifold gasket. Disconnect the throttle body inlet duct from the engine.

Twist off the radiator cap to allow draining of the coolant to flow more smoothly. Place an empty container beneath the radiator's drain plug, and remove this plug. Allow all of the engine coolant to drain into the empty container. Replace the drain plug once you are finished.

Tag all of the electrical wiring and hoses before removing so that reconnection is precise to factory settings. Remove these parts, individually, from the intake manifold.

Loosen the bolts that hold the intake manifold to the Impala's engine block. Lift the intake manifold from the block once all bolts have been completely removed.

Use the flat-head screwdriver to pry the old intake manifold gasket from the engine block. Discard this part once you have removed it.

Clean the engine block thoroughly with the engine degreaser and linen cloth. If necessary, use a gasket scraper to remove excess buildup and grime.

2. Installation

  • Coat the top and bottom of the new intake manifold gasket with a chemical sealer so that it bonds to the engine block securely. Position this new manifold gasket so that it lines up perfectly with the cylinder ports of the Impala's engine block.

Place the old intake manifold on top of the newly-installed manifold gasket until it aligns with all of the holes of the cylinder flanges and manifold gasket.

Attach all of the bolts with your hand to the manifold. Once all bolts have been positioned, use a torque wrench and apply 15 foot-pounds of pressure to the bolts to secure the manifold into place.

Reconnect all of the necessary hoses and electrical wiring to the intake. Pour the engine coolant back into the radiator.

Reattach the engine cover on top of the intake manifold and engine block. Start the Impala's engine and check for any leaks around the new intake manifold gasket.

Jul 08, 2012 | 1996 Chevrolet Impala SS

1 Answer

I have a 1998 dodge 1500 ram 4wd it sucks high vacum from the valve covers..pull pvc line and also breather line from valve covers, ,either way when you hold a finger over either valve cover hole there...

It sounds like you may have a small (for now) leak into the intake manifold by way of the valley cover (bolted to the bottom of the intake manifold). I have read of this being a common problem with these engines. Getting at the valley cover underneath the intake is a tedious job too. I was told that if you can look down the throttle body with flashlight and see oil inside, the cover is leaking. Apparently it comes with lots of mile although my 2001 with 162K isn't showing it yet. I was advised to get an aluminum cover if mine failed since the original is steel and thin---you can stick a magnet down the throttle body to check if the switch was done by a previous owner.

Nov 06, 2017 | 1998 Dodge Ram 1500 4WD

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My 2003 jeep liberty is showing a P0300 code. In the past we have replaced the computer and multiple vacuum hoses. I think it is prolly another vacuum problem but I dont know where to start. My...

it is multiple misfires on cylinders(random). this can be due to your vacuum leak over somehere on intake manifold. you can diagnose leaks by spraying brake pad cleaner on engine block when it is running. one location at a time. if idle speed or sound changes you will understand that there is a vacuum leak and it is sucking excess air from there. if it is only a misfire, this can be a micro crack on intake manifold.

Aug 20, 2011 | 2003 Jeep Liberty

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In what pattern do you use when taking heads off on a 350 small block?

i have always drained the antifreze completly down first, then, remove the exhaust manifolds from the sides of the motor, then disconnect the throttle linkage, and the fuel ilne, then remove the spark plug wires, and number them for proper installation, then remove the intake manifold, and remove valve covers, then remove the bolts that hold the heads on, and remove heads from block, you might have to tap the heads with a rubber mallet to free them up, installation is reverse, but you will have to tightened all of the bolts back down in sequence and according to the specifications of the 350 engine that you are working on, hope that this information has helped you.

Apr 05, 2011 | Chevrolet Monte Carlo Cars & Trucks

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Veh is leaking water at front of intake manifold.

it is never a good idea to guess take it to a mechanic or 4 get several different quotes if 3 are same the it is the likely problem and you know where you stand

Jan 13, 2010 | 1997 GMC Jimmy

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I have a 1979 Cadillac Eldorado Biaritz with a 350 V8 gas engine, having a problem with my car starting when cold, I have changed the cold start sesnor, all plugs and wires and distributor cap and rotor,...

Sounds like the temperature sensors. I believe there are 2 on the intake manifold. This tells the computer when the engine is cold so that the computer can adjust for a cold start. I have had to change these several times.

If the starter was an issue, the engine would not crank.

Oct 18, 2009 | 1980 Cadillac Eldorado

1 Answer

Oil running out my tail pipe

Excess engine oil can only enter combustion chamber from four areas, (1) the intake manifold [pcv system failure], (2) Valve stem seals worn out [pluged oil return holes in heads causing oil to get sucked past worn seals] (3) Worn/varnished up/broken piston rings,(4) Highly unlikely but a hole in piston. Since you only show excess oil on left rear, suspect #2 or #3 although usually more than one set of rings will wear out or (gumm up).Check compression with all plugs out, ignition & fuel disabled, i believe 120 to 150 psi is good, if ok , check #2. If this has the older efi intake, its rare, but also could have a failed intake gasket for that cylinder and be sucking oil from underneath.Hope this helps!

Feb 15, 2009 | 1998 GMC Yukon

1 Answer

Air sucking noise from below the intake manifold.

Look for a vacuum hose that isn't hooked up

Feb 13, 2009 | 2003 BMW 325

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