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Compression Test Results

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Old 07-07-2019, 11:24 PM
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Compression Test Results

Well Men, the only thing positive I can contribute to this thread is a fuzzy picture of where to hook up your bump switch on the starter solenoid, so that you don't have to remove the fuse for your ICM or disconnect your 42-pin connector, or disconnect everyone of your injector electrical connections (and run the risk of losing those tiny little bales into the innards of the head):




So, after 7 years of the van sitting not running at home (we have moved three times since it broke on 8-15-2012), here are the numbers:

Front of Vehicle
Driver | Passenger
Side | Side

430, 425 | 185, 180
285, 310 | 385, 390
280, 275 | 350, 260
400, 390 | 395, 380

Symptoms were loss of power over the Sierra's pulling a boat back from Idaho where we drove ~100 miles on dusty washboard (the van air filter does not seal well) tons of white smoke (the vans had a galvanized tank which Ford painted and the paint delaminated in mine sending flakes macerated by the fuel pump into tiny little specks at least as far as the in valley fuel filter).

I will spare you the tears, the whining and the disappointment.

I am interested in getting this rig going again.

Any suggestions would be appreciated.
 
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Old 07-08-2019, 12:08 AM
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Ouch #1 not happy.

Significant disparity will show on a cylinder contribution test. You have a way to run that?
 
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Old 07-08-2019, 12:41 AM
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@aawlberninf350 Thanks for the reply. I have NGS with the appropriate card, so I can run all of the tests.

But to do that I have to basically put the engine compartment "back together." There is so little space under the van "hood" that to access the valve covers I had to remove allot of stuff. Before I put it all back together, just to make sure that I am not chasing multiple issues, are there some other things I should do first?

For instance, I thought that I would pull the injectors, pull the nozzles, blow some carb cleaner through them like @Cartel showed us, then put new "O" rings and copper washers on and re-set them.

Or maybe I should do a Cody test first?

And I think I will pull the fuel plugs off the back of the head and pump some diesel through and see if I catch any paint flakes.

What do you think?
 
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Old 07-08-2019, 01:09 PM
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Where'd ya get the NGS? That's BA.

If you pull the injectors there will be some fuel splashed around, you'd see flakes there I imagine. New o rings is a cheap way to rule out some issues, especially since it's already apart. It sounds like a reasonable investment of time and money, not a great loss if it turns out to be bad rings anyway.

Not necessary to have valve covers on when running at idle for the CCT test. I'd still cover the interior with something just in case. Or put the dog house back on, I suppose.
 
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Old 07-08-2019, 01:54 PM
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Thanks David. I bought the NGS years ago on ebay when I first had problems with the van. @Y2KW57 is the expert on NGS and the various cards and he guided me through the selection. Since then it has proven quite helpful with the Bronco. I have spent most of my learning repair and maintenance on the Bronco, my wife's Dakota and her Corolla, various 2-cycle vintage stand up jet skis and boats. And only now feel up to the task of tackling the 2002 E350 7.3 PSD. Hopefully I will be in touch with more observations and discoveries soon.
 
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Old 07-08-2019, 08:10 PM
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I'd make sure there isn't a problem with the rocker arms and pushrods and ensure the glow plug isn't loose. You know, the easy stuff.
 
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Old 07-08-2019, 08:22 PM
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Originally Posted by SRBF150
I'd make sure there isn't a problem with the rocker arms and pushrods and ensure the glow plug isn't loose. You know, the easy stuff.
Compression check was done without any glow plugs installed. Will check push rods and rocker arms for complete valve closing. I also can't wait to pull injector #1.

From Chris:


https://www.ford-trucks.com/forums/1...fo-please.html
 
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Old 07-08-2019, 08:45 PM
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Testing the high pressure oil system with air (post #3) won't help your low compression numbers. Skip that step and save some time. I have seen on more than a few occasions intake valve seat leaks due to worn guides or poor filtration or other foreign material intrusion. Having the proper tools helps and I would invest a little bit of time in doing a cylinder leakage test and finding out WHERE your compression is going. Low compression due to valve issues won't cause crankcase pressure (puffing out of the oil fill cap) while cylinder or piston damage certainly will.

Here's my latest project from the carnage thread I started a week or so ago; valve issues AND piston/cylinder issues. The only way to fix that is a total overhaul. Valve issues only really require head work so long as nothing else is damaged.

Powdered metal rods in a 1995 block going in a 1999 F350? Yep, I am one of those people! The only good parts from the donor engine were the crankshaft, camshaft, one cylinder head, rear cover, everything attached to the front cover (not the cover itself), pickup tube, and tin.





 
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Old 07-08-2019, 09:29 PM
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cleatus12r: This Cylinder Leak-Down Tester or something else?



https://www.harborfreight.com/cylind...ter-62595.html
 
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Old 07-08-2019, 09:47 PM
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That won't hook to most glow plug adapters. Most of them use 1/8" quick couplers and that one is either 1/4 or 3/8.

You really don't need anything fancy because the percentage of leakdown isn't really that important. It's where the air is going that matters. Just being able to put a regulator on your shop air and hook it to your glow plug adapter for your compression tester (without the valve stem core) with hose and a worm clamp will get you where you want to be. The worst part is that you want the piston slightly past top-dead-center (with both valves still closed obviously) and this will require you to use low pressure (hence the regulator) or you'll just make the crankshaft spin until the exhaust valve starts to open for that cylinder.
 
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Old 07-08-2019, 10:47 PM
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cleatus12r: This is my compression adapter. It will fit into my shop air. Should I get another adapter to spin the piston to top dead center from the opposing cylinder with shop air? Or will the engine spin without a screw in adapter if I just push another type of compression adapter up to the glow plug hole on the opposing cylinder? Do I have to somehow hold the cylinder I am testing in place while I pressurize it to check for leaking air? If so, how? I would have to remove at least the radiator shroud to get a socket on the crank shaft harmonic balancer bolt. Should I just remove whatever it takes to get to the harmonic balancer bolt to move the pistons to TDC and to hold them during the test? Seems like less work in the long run... Did I mention it is a frickin' van? Thank you, and thank you all for your help!

 
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Old 07-09-2019, 12:39 AM
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Originally Posted by cleatus12r

That magnificent cam gear still causes groinal enthusiasm. Sorry, back to your regularly scheduled programming. Sous please feel free to delete.
 
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Old 07-09-2019, 05:48 AM
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Originally Posted by Tim Hodgson
cleatus12r: This is my compression adapter. It will fit into my shop air. Should I get another adapter to spin the piston to top dead center from the opposing cylinder with shop air? Or will the engine spin without a screw in adapter if I just push another type of compression adapter up to the glow plug hole on the opposing cylinder? Do I have to somehow hold the cylinder I am testing in place while I pressurize it to check for leaking air? If so, how? I would have to remove at least the radiator shroud to get a socket on the crank shaft harmonic balancer bolt. Should I just remove whatever it takes to get to the harmonic balancer bolt to move the pistons to TDC and to hold them during the test? Seems like less work in the long run... Did I mention it is a frickin' van? Thank you, and thank you all for your help!

You'll be good with just that. 10-15 psi will be sufficient....you just need to get air into the cylinder and keep it flowing while listening to the intake, exhaust pipe, and crankcase. TDC will work but can hide big scores in the cylinder walls from broken rings if you have that problem. If the crank turns with 15 psi (shouldn't though), just install the other glow plugs while you do each cylinder.
 
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Old 07-13-2019, 01:44 PM
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Cleatus12r and others: This is not a leak down test per se. This picture was taken with what I am pretty sure are both valves closed with no rocker arm pressure whatsoever, and the inlet air hose open supplying ~30 psi. When the inlet valve is turned off, the outlet gauge drops to zero immediately. Dish washing detergent and water showed no bubble on the valve stems.

It seems to me that there are three places that the air could escape:

1. valve to exhaust or to intake if a valve is stuck open;

2. piston rings;

3. hole or crack in piston.

I don't understand how air could escape past a valve guide during this test. But I do understand how it could escape past the valve guides during the compression test.


At this point I am planning to construct a body lift.

Any other suggestions?
 
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Old 07-13-2019, 03:25 PM
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The only time you should get leakage past the valve guides is when the engine is running and under load. Boost pressure will push past intake valve guides and drive pressure will leak past exhaust valve guides.

You should never have anything leaking past the valve guides during a static leak down test or compression test unless the intake tract or exhaust pipe is plugged.

Cylinder pressure while testing compression or leak down is going to go in a few different places only. Past the valve seats out the intake or exhaust, past the Rings and cylinder wall, through a hole or crack in a piston, or into and adjacent cylinder or water jacket from a head gasket leak. I forgot to mention something that happened with a block I have sitting in the shop right now.... Cracked cylinder walls.
 


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