I have a 97 4.6L with 182,000 on it. When I tried to crank it the starter acted as if it was hung up or a poor connection on the batt. I tightened the connection on batt and tried to start it again. On the first attempt the starter did the same think, just made a solid "clunk" sound. But on the second attempt the truck started, but had a loud rattle. It reminds me of a loose torque converter bolt hitting the dust cover. The sound was heavier than a lifter, but not as loud as a rod. The truck runs with out a miss and has good oil pressure. i have not run the engine for any length of time for fear of doing more damage. Are these engines prone to liquid lock? Any help would be greatly appreciated!

 

i would crawl under the truck first and be sure the starter bolts are tightened, including the wires and cables connected to the starter.

 

Do you smell any gas? This sounds like a possible hydrolock. What can happen is an injector can stay open when the vehicle is shut off allowing fuel to fill one of the cumbustion chambers. If the piston is on the upward compression stroke when this happens then a Hydro lock can occur. I am only guessing at this time that this is the problem. Before you run the truck anymore remove the sparkplugs and check for a plug that has gas on it. If you find one slowly turn the engine over (with ignition off) using a socket and breaker bar on the damper bolt. Gas should shoot out of the suspect cyl. If this happens do not start your truck. When a hydrolock occurs it bends the rod and the rod can break and punch a hole in the engine block ruining the engine. A compression test would also tell you if the rod is bent. I usually look for compression around 100-130 or considerably lower than the others as an indication a rod is bent. But that depends on the compression gage. Again other things can cause the symptoms you are seeing but I don't want you to completely destroy your engine if this is the problem. I know you have not detected a miss yet but that can also be deceiving when at idle. Also if the rod bends enough the piston skirt will make contact with the crank counter weights and break the skirt making a noise such as you discribe. The pieces will drop into the oil pan and block off the oil pickup screen causing oil starvation to the engine. Not good. Again I am not trying to alarm you but cyl head removal, with a new rod and piston are better than a new engine. Good luck.

 

I had the same thing happen to me, except I had 300,000 miles on mine. Last Sunday morning it would not turn over, but when it did, my wife heard it all the way in the house. The engine acted as if it was coming out fomr under the hood. the engine is now locked up, I found water on the spark plugs. I ordered a 60,000 miles engine and tranny today for $2150.00

Lucs

 

Sounds like you had a 4.2L that hydrolocked, a very common occurance with that engine for that year.

The OP has a 4.6 which was not particularly prone to this failure. However, given his description, I'd place a hydrolock condition near the top of the possibilities.....


Steve
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I finally moved the truck into the garage today and made a recording of the engine noise. I noticed the truck started smoking a nice white steam/smoke today as well.


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