Engine Problem: Timing Chain 93 Trans Port

Well, its more of a catastrophe really.

I had just got on to a road and was accelerating when all of a sudden the RPMs dropped sharply, went back up again and then there was a small noise from what i believe is the engine, not the transmission. The car was still on but the RPMs had dropped to zero which could only mean - dead engine.

We have narrowed the problems down a little bit but one of the worst cases ask that we ask this question: If the timing chain breaks will the pistons touch the valve?

A rare event: what is the mileage of the engine?
I'd think the chain can slip a few teeth....which would not put the valves at risk. I am not sure but push rod engines are rarely interference type. I'll see what I can find...
A completely broken timing chain is almost impossible...but in this case it would most probably fall in the bottom of the case and block the engine sprocket....with the momentum of the engine when it happens, this would cause probably severe damage...can you crank it with the starter?
Broken cams have shown on this forum, but with the 3.1....mmm..is it a 3.1 ?

A rare event: what is the mileage of the engine?
I'd think the chain can slip a few teeth....which would not put the valves at risk. I am not sure but push rod engines are rarely interference type. I'll see what I can find...
A completely broken timing chain is almost impossible...but in this case it would most probably fall in the bottom of the case and block the engine sprocket....with the momentum of the engine when it happens, this would cause probably severe damage...can you crank it with the starter?
Broken cams have shown on this forum, but with the 3.1....mmm..is it a 3.1 ?

Thats what my father said too (hes around here somewhere, username Cromer) about the timing chain being broken and falling in to the bottom of the case. Thing is, i didnt have that much momentum, the only momentum i had was that which i gained from coasting down a hill and pulling in to a nearby parking lot. I heard a noise when it happened, could that have been the chain falling to the bottom of the case?

When we tried starting it again, the crank wouldnt budge (im not that good with cars, but the part with the "harmonic balanacer" or such) but the battery is full.

The engine is a 3.8, with mileage somewhere in the vicinity of 300k kilometers on it, so your slipping teeth theory probably isnt impossible. So do you think that the push rods are damaged at all, or the valves?

Thats what my father said too (hes around here somewhere, username Cromer) about the timing chain being broken and falling in to the bottom of the case. Thing is, i didnt have that much momentum, the only momentum i had was that which i gained from coasting down a hill and pulling in to a nearby parking lot. I heard a noise when it happened, could that have been the chain falling to the bottom of the case?

When we tried starting it again, the crank wouldnt budge (im not that good with cars, but the part with the "harmonic balanacer" or such) but the battery is full.

The engine is a 3.8, with mileage somewhere in the vicinity of 300k kilometers on it, so your slipping teeth theory probably isnt impossible. So do you think that the push rods are damaged at all, or the valves?
You could also try removing the spark plugs and put a long breaker bar and socket on the crank shaft bolt. With the spark plugs removed the engine will turn more freely.

Remove the front valve cover and look at the valves moving. If it doesn't turn or no movement from the valves then their would be a problem with the timing chain.

:banghead: :banghead: :banghead: :icon16: Well, so far weve been able to determine that the crank shaft is probably broken in half but nothing is confirmed. We shall try everything you guys are suggesting, keep the solutions comin.

Thanks alot.

EDIT: Well, we got the pan off and took a look inside and to quote my father, the engine had a "catastrophic failure." It appears that the cam shaft snapped between cylinders 2 and 3 thanks in part to the timing chain or something. I dont know, its not me that really knows anything, its my dad. Maybe he will be along later to say something.

Thanks alot to you guys for your help.

Well....s...happens.
With 300k "km" it became indicative this was Canadian..checked profile...so where in or around Montreal?...

Well....s...happens.
With 300k "km" it became indicative this was Canadian..checked profile...so where in or around Montreal?...

St Lazare, a suburb really. And 300k km is nothing...our other van has 400k km:eek:

Well, Dad here (cromer). This was a great learning opportunity for my son. Being a teenager he has not had a big interest in mechanics, but this was a crash course. As he said it was a catastrophic failure of the type I have never seen. Actually the crankshaft snapped like a twig and it was obvious that it was at fairly low RPM's because there was no peripheral damage, just a clean break between cylinder # 2 and 3. Until now I had great faith in the 3800. My 92 lumina apv has almost 400k on it still running strong, but everythin else is starting to fall apart. I also have the 3800 series II in my 97 grand prix GTP and a 3800 series III in my 2004 GP. I have to admit though, We have had the trans sport for about 7 years and it always felt "less balanced" than the engine in the Lumina.

So now I must make a decision. Scrap the Trans sport or do an engine transplant. The car itself is in great shape and has lots of new parts. It would kill me to send it to the bone yard. Qustion is, how feasable is it to do? From what I understand the only way to do this is to unattach everything and then undo the 4 subframe bolts and lower the thing. Just for the hell of it, I tried removing the frame bolts, front passanger side seems to loosen and then just spins, front drivers side actually came out, rear passenger side broke my 1/2 in to 3/8 adapter so I gave up.

Anyone out there done an engine swap that may be able to provide some insight?

THis engine gives a tremendous feel of power at low rpm...but really does not feel confortable past 4500 rpm...so I wonder at what rpm the break occured during the "acceleration". IN any case, this very rare event shows "it can happen".
ANd Yeaah..getting the engine out is same procedure as transmission so...just for the record....
www.avigex.ca/xport/4T60photo.jpg
www.avigex.ca/xport/trans1.jpg
www.avigex.ca/xport/trans2.jpg
www.avigex.ca/xport/trans3.jpg
www.avigex.ca/xport/trans4.jpg
www.avigex.ca/xport/trans5.jpg
....very potent crash course, indeed....
Several on this forum have gone through this operation...Viala, others...they will surely help...

If you are going to rebuild this engine, please try to take some good close-up macro photos of the fractures faces. In all probability this was a fatigue crack that started a LONG time ago. It probably started at some orig. defect-a small sharp dent, a machining flaw, etc.

I study these failures for a living and also have a 3800 in my van.

I bought the van at 173, 000 k and was able to get all of the service records along with it. The engine had been replaced by GM at 150,000 k under an extended warrantee from the previous owner. I was never really happy with the oil pressure, although I fing the graduations on the oil press. guage on this van to be very wankey. I did connect a trusty mechanical guage just to have a basis of comparison and it did prove the stock guage to report a lower pressure by approx. 10 lbs. I replaced the sender unit ... but same results.... All this to say, I do not believe the engine was ever starved for oli and I did replace the oil and filter and added a can of Bardahl b1 every 4 - 5K. It was mostly my wife that drove, so it was not beaten... It mus have been a defect just waiting to expire. I estimate the RPMs at time of failure to be approx 2500. When I get around to the engine swap I will take a digital photo of the crank... It is actually quite facinating (if not amusing).

Thaks everyone for your help!