New rebuild...I think I got problems!

TNford

Member
So I finally got my slow cranking starter problem fixed by putting on a new one. She cranked fast and hard! Got the lines bled and she fired right up! Throttle up and down just a little and all sounded perfect. Set her to slow idle to let it run awhile to warm up and after a minute or so, starts blowing smoke out vent tube from valve cover. Minute or so later she starts to bog down and konks out. Hit the key and she won?t even turn over...like it?s seized up again. Have no idea what might have happened, all new insides. Only thing I can think of is that the shop that ground the crank didn?t get it right and spun it spun a rod bearing...anything else might cause this?
 
Did you check bearing clearances as you assembled it? Monitor oil pressure & temperature after starting?
 
(quoted from post at 20:23:36 06/16/18) None of the gauges work, that is something I?m in (was) the process of fixing too.
aybe considered by someone as harsh, but at first starting of a new/rebuilt engine without being able to monitor oil pressure should be considered a "self inflicted" wound. Some lessons are hard....& costly.
 
Yea, when you get old enough you might forget to put oil in it before you fire it up. I have gotten to where I tag things for me brain.
 
Should have had a mechanical oil pressure gauge connected to block. Should have pressure while cranking. If not, STOP, then find out why.
 
1) You should have plastigauged the bearings.
2) You should have had an oil pressure gauge installed before you even cranked it.

Expensive lesson learned here, and no, you can't blame the machine shop, regardless of whether it's their fault or not. You should have caught a bearing clearance issue.
 
Set her to slow idle to let it run awhile to warm up and after a minute or so, starts blowing smoke out vent tube from valve cover.

I was taught not to low idle engines during break in period as oil pump doesn't develop enough pressure to maintain adequate oil film.
 

since you cant turn it over, you cant do a compression check.


Probably blew the head gasket, and filled the cyls up with water.

Therefore, may have bent a rod/cracked piston. drain water first, use block drain also!!!!! then pull head and see if cyls are full of water/fuel/oil

carefully pull head and inspect head gasket for blow ports.. if fluids in cyls. have head checked for warpage.
 
I had another thought...more likely what happened was that a rod or main cap was put on backwards. Usually, this causes a crankshaft to lock up while it's on the stand, but it doesn't always have to be that noticeable. It would explain the slow cranking.
 
It could be anything, can pull injectors to check for hydraulic lock, and pull pan to check for stuck rod.

No oil pressure gauge was a bad idea.
 
I fired up the rebuilt engine in 71 Ford 4500 TLB (diesel) last week. Before I started it I got a new oil pressure gauge, and hooked it up, then cranked the engine over until it got oil pressure. Put the injectors in, while the bleeding injector lines it got oil pressure, then I tightened the injector lines, and engine ran like a champ. When I put the engine together I checked the ring gap, the main, and rod bearing clearance, and set the valves, all were within Ford specs.
 

Did you rebuild it or did the machine shop do it for you?

In some of your previous post you mentioned it had started and run for a few seconds at a time and in 1 post you mentioned it having a good bit of blow by.

How much total time has the engine ran before locking up?
Was it full of oil and full of coolant?

I'm sorry your having this problem but like others I'm going to have to smack your hands for not having some way to monitor the oil pressure.

I just recently replaced the crank in my 4000SU, I had disassembled the oil pump to clean it and check for wear, during reassembly I accidentally installed the pump cover a 1/4 turn off.
After several 5-10 second cranks with the starter I never got a pressure reading from my temporary gauge, I removed the oil filter and nothing.
After draining the oil, removing the oil pan and disassembling the oil pump I found my mistake and corrected it. I reinstalled the oil pump, put the pan back on, filled it with oil and after a couple of cranks the gauge moved, at that point I started the engine and got 75 psi of oil pressure as it should have.

Had I not had a temporary gauge to show me the engine wasn't making oil pressure I would be looking at possibly the same issue your having now.

NEVER EVER start a new or freshly rebuilt engine without some type of way to monitor oil pressure and coolant temps.
 
even if crank was not machined properly the firm can deny it is their fault..... I said did you turn crank by hand after torqueing each bearing perhaps I should have said could you
 
(quoted from post at 15:29:40 06/17/18) I had another thought...more likely what happened was that a rod or main cap was put on backwards. Usually, this causes a crankshaft to lock up while it's on the stand, but it doesn't always have to be that noticeable. It would explain the slow cranking.
How is it posible to put them on backwards? They have groves.. I dont get it :D
 
(quoted from post at 15:29:40 06/17/18) I had another thought...more likely what happened was that a rod or main cap was put on backwards. Usually, this causes a crankshaft to lock up while it's on the stand, but it doesn't always have to be that noticeable. It would explain the slow cranking.
How is it posible to put them on backwards? They have groves.. I dont get it :D
 
(quoted from post at 15:49:30 06/22/18)
What groves?
Only grove I've seen in these engines is for the bearing tang to set in.
That's what I ment, I didn't knew what they where called in english ;)
 

Even though the bearing tangs should be on the same side it doesn't keep one from mistakenly installing a rod or main cap on backwards. The rear main cap is about the only one you can't get backwards.
 
(quoted from post at 21:44:22 06/22/18)
Even though the bearing tangs should be on the same side it doesn't keep one from mistakenly installing a rod or main cap on backwards. The rear main cap is about the only one you can't get backwards.
one of the bearings to my 4610 with a 201 engige had any markings on the bearings. The crankshaft bearings have oil holes on one side, those goes toward the engine block of curse. The conrod bearings only had the tangs :) no lube holes :)
 

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