94 Chevy Lumina APV Minivan won't run

Sound like to me is timing chain as well. Check for engine compression or pop the valve cover off which ever the easiest. Perhaps someone else here may have experienced this before but that is what I would do.

If there is no rocker movement, there is nothing driving the cam (and rockers), hence, your timing chain is gone (or a component thereof). Take the timing cover off and fix it. Chains (and sprockets) are not much money. If you are having it done, phone around to price the labour. It sounds high.

Les, I have had the same experience you just described with my 3.1L V6, the timing chain let go when I was climbing a hill also. No warning. Not good news because the 3.1L is an interference engine,which means internal engine damage. A couple of bent valve at the least.. Good luck.

I've hard of seized or broken camshafts on the similar 3.4 engine after coolant leaking into the engine from the intake.

Thanks everyone for your posts.

JoJo could you give more details on your experience. Could you hear the t.c. go? Loud? Did you repair it yourself? If so any advice will be greatly appreciated. How did you determine which valves were damaged?

But my biggest question is what does "interference engine" mean. Not at all familar with that term.

I guess it's off with the t.c. cover as soon as this rain stops.

"Les" wrote

Probably the easiest way (if the timing chain broke) is to install a new chain and gears, and then do a compression test. This will let you know which holes have the bent valves.

In simple terms, it means that the valves and the pistons occupy the same space, but at different times when the crank to cam relationship is correct. So, if you break the timing chain, the camshaft stops turning (which means that "some" valves will be held in the open position) and the crankshaft keeps turning (which means that one or more of the pistons will encounter an open valve as it reaches the top of it's travel) until it does some damage.

On these engines, if all you need to do is confirm that the t/c is broken, just remove the oil filler cap, and have someone crank the engine while you watch the valve train. If it doesn't move, you most likely are looking at a broken chain.

Ian

Les, Like you I was climbing a hill when mine let go . I heard something break, a definite metal but not a real loud noise. Car stopped dead and would crank but not restart. Fuel but no spark. No rocker movement while cranking. Ian answered the rest of your post the way to proceed is to install a new timing chain and do a compression test. If you have good compression in each cylinder (highly unlikely) then your ok to go. In my case I had two cylinders without any compression. Two badly bent valves. I had a friend repair mine so I got away cheap. The head has to come off the motor to asset the damage. The $1100 the dealer quoted does that include the timing chain plus internal motor damage?

Dealer quoted only for "timing chain kit". He said it was involved as they would have to remove engine to work on it. But nothing else was included.

My brother says he never heard anything when it went.

Looking at the Haynes book and other sources the instructions are to remove alot of components to get to the timing cover: belt,water pump, alternator, driveplate access cover, vib. damper, oil pan ( though I came across some postings about workarounds for just loosing two front oil pan bolts and levering timing cover out).

JoJOo, did you and friend have to remove the engine to work on the valves?

These minivans are tightly packed. I see where folks have to undo two dogears(?) to angle(pull) the engine forward to access the back sparkplugs. What are... where are dog-ears? I read where one guy parks on a hill in neutral undoes dog-ears; then shifts into park which jerks the vehicle forward causing the engine to lift out/ angle -out -- so he doesn't have to wedge it out w/ a prybar. Whooo!

You can pick the timing chain kit up for less than $100 can. $1100 to install a new one seems very expensive to me. Shop around. My friend took about 2 hrs to install a new chain. The motor did not have to be removed to change the chain or replace the bent valves, but I drive a sedan (Corsica) not a Van. Not sure what's involved to get at the timing chain on your Van or where the dog-ears are but I am sure Ian can help you through step by step.

Yup the parts cost are minimal compared to the labor and tools. I started today but only got as far as the serpentine belt before the rains came.

I'm kinda going slow, lots of thinking about