96 GrandAm engine problem

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- Dennis M
  
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posted
20 years ago

Sat, Apr 10, 2004 5:44 PM

Hey guys,

I am trying to help my gf's family. They have 96 GrandAm and the car don't start. Her father says 2 cylinders sound right, but the other

2, don't want to grip and at some point during cranking car backfires (I am not sure if that's the correct term, but exhaust comes out through the intake).

Can anyone guess what can cause this? The father says, crankshafts (its DOHC) maybe misaligned, but the car has a timing chain (so he's been told by a mechanic). Those things don't start slipping, do they? And if the camshafts are misaligned, would that at some point damage the valves? Or is the engine non-interference? Could it be the distributor?

Anyone see similar problems?

Thanks, for any info you could give me.

-- Dennis

- T
- Tom Alverson
  
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posted
20 years ago

Sun, Apr 11, 2004 7:20 PM

Is this the Quad-4 engine?? If so, check the plastic thing that serves the purpose of wires on a normal engine. Remove the coil/wire assembly and disconnect the coils from the assembly. Check all the "wires" for shorts between them. I had about a 20k ohm shot develop on mine that cause the engine to run on 2 cylinders (very poorly). The catalytic converter would get red hot probably due to all the unburnt gas coming from those 2 cylinders. While you are at it, check the primary and secondary of the coils to make sure they both have the same readings as each other, as a bad coil (or coil driver) could also take out 2 cylinders.

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- HLS
  
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posted
20 years ago

Sun, Apr 11, 2004 10:09 PM

This has to be a variant of the old Quad Four, a VIN T.

Has no distributor, Dennis. It has a DIS ignition, also called a waste spark system, which uses two coils to fire four plugs. As Tom posted, you need to check these out and their connectors, drivers, crankshaft sensor, etc.

These things have had their plagues. They are prone to crack heads, blow or leak at head gaskets, etc. They have four valves per cylinder driver by the DOHC arrangement.

Run a compression test and find out if all cylinders are holding pressure as they should.

Be systematic and you should be able to find the faults.