91 2.2 Cavalier Mystery problem

[the_bandit87]

Ok, the car just up and died. Tried for three hours to start it, it fired a few times, but it didn't start. It gets fuel, has spark, has compression. Here are the only 2 symptoms, There air/fuel mixture is coming out of the dipstick, and for some reason the intake manifold is blowing back. Could it be a sensor or could it have slipped out of timing. Mechanically the car should start, does any one know what the problem could be??

 

[RichP]

Ok, the car just up and died. Tried for three hours to start it, it fired a few times, but it didn't start. It gets fuel, has spark, has compression. Here are the only 2 symptoms, There air/fuel mixture is coming out of the dipstick, and for some reason the intake manifold is blowing back. Could it be a sensor or could it have slipped out of timing. Mechanically the car should start, does any one know what the problem could be??

If you have gas in the oil then sounds like a stuck open injector flat out flooding the engine. I think I would do a compression test first though, could also be a blown head gasket or cracked head.

 

[old_man]

How bad is it blowing out the dip stick? You have several symptoms. I gather that it cranks, but are you getting any fire? A common problem happens when you get a no start condition. The plugs get wet from raw gas and won't fire. If there is liquid gas in the cylinders, it can get forced by the rings and end up in the oil. The worst case is that you get so much gas in the cylinder that you hydrolock and pop a hole in the top of the piston. A popping back through the intake is either a sign of a valve that isn't closing all the way or is burned.

Not familiar with that particular engine but if you have quite a few miles, on many of the small engines the cam is driven by a cog belt and the belt will slip a tooth or two. That puts the cam out of phase with the crank. On some engines that can make the valves hit the pistons, ending in a hole in the piston. In others it just runs crappy or not at all depending on how far off the timing is.

Find a manual and determine if it has a cam belt. Figure out how to see if it is still in sync. From your symptoms, this seems to be the problem. The task now becomes to determine if any damage was done. No matter what you do, before you start it up, drain the oil and replace it and put a fresh set of plugs in. If you have enough gas in the oil and you start it up, blowby can ignite the gas and cause one heck of a nice boom, leaving your oil pan on the ground and the possibility of a nice fire.

 

[yellowxj]

famous for head gaskets...any signs of coolant seeping out of the head bolt or head at the front drivers side of the motor? thats usually where that problem starts...

 

[Matthew Currie]

You say it has compression, but how much? Do all cylinders check out? If it's blowing air&fuel out the dipstick when it cranks, you need to find where it's coming from.

Last vehicle I had with symptoms like that was a junkyard XJ. Someone must have cooked it thorougly. It had about 60 pounds compression on all 6. Spark and gas, but no go. Just couldn't run. I tired a compressed-air blowdown test and when it blew the dipstick out I knew the battle was lost.