4.0 SOHC with coolant coming from tailpipe. Now it won't crank!

[shelbygt]

It smells to me like antifreeze coming from the exhaust and was spewing steam the whole way home, then it started running rough and by the time I got home, it threw a CEL. Turned it off, went in the house, came back out hooked up the OBD2 reader and it said misfire in cylinder 3 and 5. So I went to start it and it must be hydo-locked or something, it won't turn over at all, like the motor is seized. The radiator is now low, so I know it is burning coolant somehow.

I assume it is likely a blown head gasket, but how could 2 cylinders on opposite side of the motor be misfiring if only one side is blown. Is there something else that could be allowing water to enter the combustion chamber that would cause issues on both sides of the motor?
I plan to pull the plugs tomorrow and see how many have water in the holes.
Any help I would greatly appreciate it!
Dave

 

[2000StreetRod]

Don't trust the DTCs

Were you abusing the engine just prior to the problem occurrence?

I would not put a lot of faith in reported misfire codes. I can't think of any likely scenario that would result in engine coolant leaking into the intake manifold and being drawn into cross bank cylinders. Like you said, it is also unlikely both head gaskets would fail at the same time. If you had driven in deap water that could explain fluid in multiple cylinders but not the loss of engine coolant. I agree that the first thing to do is pull the plugs. I would place a rag or paper towel is each plug well to collect any liquid displaced by the piston as it passes thru TDC.

 

[shelbygt]

No just normal driving. I pulled the plugs and number 5 was full of coolant and 6 might have had a little in there. Nothing from the other side of the engine. I assume this is clear cut that the head gasket is blown? Looking at the Haynes manual, this going to be a ***** of a job, requiring a special tool to re-set the timing.

 

[2000StreetRod]

Check the rear cassette

It's a lot of work just to get the valve cover off. I needed two 1/4 inch drive wobble extensions to get the rear valve cover bolt loose. There is very little clearance around the rear camshaft bulge in the cover. I suggest that you examine the rear timing chain guide for wear and chain slack. I could almost lift the chain off the sprocket it was so loose. Most members pull the engine, at least one has pulled the transmission to replace the rear cassette. Another member claims his mechanic was able to change the rear cassette without doing either because the head was off.

I'm in the process of pulling my engine to replace the rear cassette and leaking rear main seal. I hope to avoid buying the special timing chain tool set. At least one member has timed his engine by placing marks on the chain and sprocket. He only had to replace the guide assembly.

 

[slammed98z]

It's a lot of work just to get the valve cover off. I needed two 1/4 inch drive wobble extensions to get the rear valve cover bolt loose. There is very little clearance around the rear camshaft bulge in the cover. I suggest that you examine the rear timing chain guide for wear and chain slack. I could almost lift the chain off the sprocket it was so loose. Most members pull the engine, at least one has pulled the transmission to replace the rear cassette. Another member claims his mechanic was able to change the rear cassette without doing either because the head was off.

I'm in the process of pulling my engine to replace the rear cassette and leaking rear main seal. I hope to avoid buying the special timing chain tool set. At least one member has timed his engine by placing marks on the chain and sprocket. He only had to replace the guide assembly.

I sucessfully timed my 4.0 without the timing tools it isnt all that difficult to do. you have to make sure the cams are lined up correctly. Both of the cams have a slot cut out of them for this purpose. Just make sure you have the slots in the cams even with the valve cover mounting surface. i was actually thinking about making a set of cam tools for alighning them.

 

[chapsdeva]

I think you are correct and that your head gasket is probably toast. Also could be a cracked block. I feel you pain man...had the same thing happen (head gasket) on a 93 Sable...started smoking like crazy and blowing steam/coolant out the back....

 

[shelbygt]

How do you tell if the block is cracked? Once I get it apart, should I take the head to a machine shop even if the gasket shows obvious damage? There was no overheating prior to this event and I wouldn't think that any damage beyond the gasket could have taken place. It has 190k on it, but I have recently rebuilt the rear end and it's in nice shape so I am debating replacing the entire engine or replacing just the gasket to get it back on the road. I just don't want to sink a fortune into a vehicle that might have another few years of life left on it.