Knock in engine

[tempfixit]

Was the connecting rod half on the piston moveable or was it frozen to the risk pin????

Does the connecting rod look dicolored??

Do you have any pics you can post???

What does the clyinder wall lokk like?? Any scratches or marks from the broken rod???

[crom9111]

wrist pin and connection free and moving. Rod looked the same as the others. Piston had marks on the top where one of the valves hit it but valve does not look affected. Can still see the cross hatching on the cylinder walls and no other marks. I was really hoping to find a problem so I could fix it, now with no obvious reason and a failure I think I will be worried it could happen again. :0 Will try to post to photobucket later this evening

[crom9111]

Hope this work........http://s1273.beta.photobucket.com/us...20broken%20rod

[tempfixit]

How many miles on the engine???

Just wondering if timing chain jumped a tooth caused the failure, but would think other pistons would show signs also.

Hopefully someone else will share thier thoughts.

This photo link worked for me.

[crom9111]

It has just under 180,000. I would think if it jumped enough to cause damage, it would have caused it to more then just the 1 piston. Have to admit I am at a loss

[crom9111]

Looks like I am in for an engine swap. Can not find connecting rods any where. so since that is my best option at the moment, has any one pulled the engine in 1 of these thru the top? I replaced the tranny from underneath and I know thats how you are spossed to do it but I have no lift here at the house.

[12Ounce]

I have bought single pistons and rods from engine machine shops. I would certainly try to do a simple rebuild. It is possible you had a simple leaky head gasket ... and enough coolant got on top of the piston to pop the rod. One replaced piston, rod and rings ... along with new gaskets and head bolts. You need also to pass the heads thru a shop that rebuilds valves/seats ... and checks heads for defects.

You might have a fairly simple rebuild on your hands.

[crom9111]

Hydrolic pressure was my first thought also, but head gasket was fine ( no holes, burns ect. ) No water in oil that I have ever seen. There were no tell tale signs of a problem other then the broke rod. Nothing seized. The only thing left I haven't checked would be if the exhaust valve would not open but I can't imagine even with stuck valves it could build up the pressure needed to snap a rod. I am still stumped on this one. I can get an engine warranted ( 6 months ) with 77k for 750. Still looking for a place to get the rod only but am loosing hope I would still be worried that whatever caused the problem would return with the rebuild however

[olopezm]

Originally Posted by crom9111

Looks like I am in for an engine swap. Can not find connecting rods any where. so since that is my best option at the moment, has any one pulled the engine in 1 of these thru the top? I replaced the tranny from underneath and I know thats how you are spossed to do it but I have no lift here at the house.

My brother, father and I did it twice 6-7 years ago. It's not that hard, you only need to remove the wipers cowl and that will give you LOTS of space to work. We even pulled it with the transmission still attached to it.

Oscar.

[12Ounce]

The early 3.8's had a very narrow section between the water jacket and the cyls. Notorious for head gasket leaks. If most of the water ended up in the cyls, most of it would pass on through the combustion process ... and little would go into the crankcase. This could continue until a "lock event". Often a leaky gasket is hard to "see".

I bet if you sent a oil sample to Blackstone, they would confirm that there is coolant in the oil. It takes a tremendous amount of coolant in oil to be visible to the naked eye.

If you can't find a good used piston and rod ... that kinda seals the deal I guess. There may be some benefit in getting a later 3.8 anyway. Good luck!

[12Ounce]

BTW, I've removed and installed the 3.8. I prefer to remove it the way Ford installed it ... from the bottom.

[crom9111]

Finally got the heads off, delayed by weather and kids. Off to the machine shop Monday and hope to have it back together by this weekend. thanks for all the help guys

[crom9111]

Hi guys sorry for the delay in this response. Got the van back together and running ( so much better now ) Wound up being the head gasket after all. The machine shop had to take quite a bit off of the heads to get them flat. everything else checked out very well for a van this old. After a few issues with the manufacturer sending the wrong parts, it was a simple matter of putting it all back together, ( of course that would be during the freekish amount of rain and snow and cold weather we had ) It's been a few weeks and a few hundred miles with no issues so hope I am in the clear for a while. Thanks for letting me pick your brains and for the encouragement......

[12Ounce]

Thanks for the feedback. Yes (I repeat myself) head gasket failures are hard to see in the gasket itself ... especially for us novices. A failing area rarely looks like what you would expect. I'm sure the machine shop refitted the valves to the seats, replaced the seals, etc ... so you now have much better compression in each cyl.

Congrats on the success!