I've been having problems with my 96 Monte LS latley and was told by a friend to have the motor replaced. This car is in great shape and I do not really want to get rid of it. I've had it to my mechanics and he had the codes read which were mass airflow sensor (changed) and EGR valve which I did not change yet. And i got a multi cylinder misfire code. I changed the spark plugs and wires, coil packs, ignition module, fuel pump, filter, and fuel pressure regulator to hopefully rule out fuel problems. But nothing is working. It is idldeing very rough and missing terribly. There is a weird sucking type noise coming from the back of the motor. Some one mentioned to me that it could be a failed lifter. Anyone here ever experiance this or have an idea what could be wrong?

 

Sucking noise would sounds like a vacuum leak, which could be the cause to your trouble.

 

I wish i could describe it better, It doesn't really sound like that kind of sucking, it's weird. More like someone smacking there lips together. I don't know much about engines, someone said it sounds like its coming from my head and asked if I was using anti-freeze, which I don't believe I am. My overflow tank is slightly low, but I've had the car for 2 years now and have never had to add any.

 

I would hope you're using anti freeze...

 

Obviously I'm using antifreeze, that's just the question I get a lot. I assumed they were referring to the car using it unusually.

 

There is a vaccum line that hooks to the EGR valve....
Siince you havent replaced it...yet....That would be the next thing I would do! Change it immediately!

The EGR stands for exhaust gas recirculation valve....

If its not recirculateing the exhaust...will more than likely make the multi misfire code?

 

Ok thank you! I'll have to see if I can pick up a used one somewhere for cheap. I'd imagine I can change it myself. Thanks for all the feedback guys!

 

It might be wise to get a new one...instead of a used one IMO....

 

I'm not familiar with the 5th gen Montes and what engine went with what package. If this is a 3100, here are some IMPORTANT piece of info:
1 - There is a breather tube on the back valve cover (should go up to the front air intake hose). Make sure that is properly connected.
2 - I've seen where the metal flex tube from the rear exhaust manifold to the EGR is damaged. With the engine cold, inspect it.
Neither 1 or 2 should cause the idling issues.

Also, the 3100 (especially '94-'95 models) had issues of the passage between the EGR pedestal and the upper intake "gumming" up. If that is clogged, the EGR will not work right and will through an EGR code. I've used a stiff rod/wire (best tool, old chunk of speedometer cable) and a can of carb clean. Take the EGR off, spray in the carb clean, take the speedo cable and worth it down that passage until you know enough has gone through that it should be behind the throttle body.

FYI - If your plugs are BOSCH spark plugs, I and many others have had issues with them in the 3100/3400/3800. Problems include issues out of box or issues developing in 6 months from install. I recommend AC Delco or NGK plugs. NO BOSCH.

Check for vacuum leaks (a sucking noise is typically a good sign of a vac leak and that can cause the entire issue). Get a can of starting fluid and mist it around any vac line or seal while the car is idling. If the idle changes, use the can and mist more in that specific area, try to pin point what is the issue.

Hope this helps.