D7E Loud clunk...black smoke....and died??

nontypical9 · Jul 9, 2018

Clunk sounded like bottom end...I pulled valve cover and found bent pushrod.....and 1 stuck valve where the spring was weak and slack...valve goes down but won't come back up......but why would it blow black smoke and just die....haven't pulled the pan....but drained the oil....0 metal in the pan....any ideas on this one?? Turbo spins freely also....and vains look fine??

Junkyard · Jul 9, 2018

Can you turn it over by hand? Any other broken valve train parts? Pull air filter and see if intake is clean....

Any other symptoms or issues leading up to this? Run hot? Low on oil? What’s the history of the machine? Quite a few things it could be.... :-/

Junkyard · Jul 9, 2018

You aren’t far away. Just went through there the other day. May have to come visit. You sure don’t need an ordeal like Steve had! Sheesh

nontypical9 · Jul 9, 2018

Junkyard....I'd pay u good?? Good oil....never got hot....good coolant.....valves needed adjusted bad right b4 all this....I adjusted them....and I guess I set them wrong.....valve train was tapping just b4 this happened....

nontypical9 · Jul 9, 2018

Yes.....turns over fine......

d9gdon · Jul 9, 2018

That sure sounds like it dropped a valve. Maybe set one too tight and broke a valve spring which then lost the keeper and let the valve drop which hit the piston and it smashed the broken valve and hammered it into the soft piston causing the momentary black smoke?

I would think that is the tapping sound that you were hearing right before it happened.

Junkyard · Jul 9, 2018

d9gdon said:
That sure sounds like it dropped a valve. Maybe set one too tight and broke a valve spring which then lost the keeper and let the valve drop which hit the piston and it smashed the broken valve and hammered it into the soft piston causing the momentary black smoke?

I would think that is the tapping sound that you were hearing right before it happened.

That’s where my mind was going...most logical explanation given the symptoms.

nontypical9 · Jul 9, 2018

That makes total complete sense to me....I wonder if I hurt a piston?? Or just dropped the valve??

nontypical9 · Jul 9, 2018

My guess is i destroyed a piston and sleeve....and maybe the front head??

d9gdon · Jul 10, 2018

Piston for sure, head more than likely, liner maybe. I would sure check that connecting rod too for bend.

It is possible to take the engine side plate off and remove the connecting rod cap and pull the piston and rod out the top if I am remembering right. It is not real easy to do.

Used heads should be about impossible to find now since it's been 15 years or more since I looked and I couldn't find a pair back then.

Good news is that a new aftermarket head is available, but hold onto your hat at about $2 grand per head.

Hey, look here's a used one:

https://www.ebay.com/itm/Caterpilla...hash=item25c673d740:m:mIvFfqoBZWcW9wDYi1OoCiA

I'm on a job site about 25 miles from Ft Gibson now. If Junkyard comes down, I'll go to lunch with you guys if I'm here. I have to go to a wedding this weekend though.

The front two cylinders are a whole lot easier to get to than the back two. The oil pan is two piece and the back has the oil pump and the equalizer bar in the way. You have to pull the engine to get the oil pan off in the back. You have that one thing going your way.

nontypical9 · Jul 10, 2018

Thx man.....I'm assuming that 2k per aftermarket head is bare....no valve train??

d9gdon · Jul 10, 2018

I looked it up this morning. For a new aftermarket 1M2960 loaded head from Off Road Equipment in Dallas TX they want $1205. They have a new bare aftermarket head for $861 in Dallas and they have a new Cat Classic 325-6105 head for $1039 in Wisconsin and I assume that's a bare head. I guess they have come down in price or I have mis-remembered like Hillary did with her missing emails.

I'm pretty sure that I still have a new head gasket kit with one cylinder's worth of stuff left over that I'll never use. Or will I, I found a D7E close to me with a hole in the block...hmmm?

nontypical9 · Jul 10, 2018

That's at least better news!!!!!

nontypical9 · Jul 10, 2018

I'm tempted to go RIP that front head off and have a looksie!!!!

d9gdon · Jul 10, 2018

Push it under a shade tree first.

Don k · Jul 10, 2018

I had a what I think was a 1965 D7 17A. I don't remember the serial #. Is that a d7E? Reason I am asking is that I may have a few parts for one.

Vetech63 · Jul 10, 2018

Spend the extra $ and get the genuine head. The classic stuff is turning into junk from my experience with it.

grandpa · Jul 10, 2018

17A's were known as D7D's.

Cat_man320 · Jul 10, 2018

I would check and see if crank never cracked off . My dad was using my HD21C , everything working great just travelling across my quarry and bang , black smoke and shut off . crank broke so clean it would run on three cylinders. It's the crank or what the guys said above .

nontypical9 · Jul 12, 2018

Thx guys!!

D7E Loud clunk...black smoke....and died??

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