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i have a 99 crew cab f250 that is overpressurizing coolant system, going to test for combustibles in the coolant by using block checker, was thinking i could unhook injectors at valve cover plug and run test with 1 side of motor to determine which side to tear down first, has anyone tried this before. i was also going to check compression and was wondering what the procedure to do this was. i was going to buy a diesel engine compression test kit from harbor freight tools for $17, it said it had the glow plug adapters for ford, pull all the glow plugs on that side and run compression on all cylinders. does anyone know the correct procedure? thanks in advanced.
jason
 

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Before you remove the glow plugs use compressed air and blow the oil away from the glowplugs first, otherwise oil will enter the cylinder and give innacurate readings. I remove all the glow plugs first so the engine spins freely when cranking. I crank the the motor 6 revolutions when checking each cylinder. You should be close to 400 psi. Your lowest cylinder should be at least 75% of you highest reading. Heres a copy of Ford's procedure. It's for a gas motor but it's in there diesel section. Also included is a cylinder leak down procedure.

Compression Test—Compression Gauge Check

Make sure the oil in the crankcase is of the correct viscosity and at the correct level and that the battery (10655) is correctly charged. Operate the vehicle until the engine is at normal operating temperature. Turn the ignition switch to the OFF position, then remove all the spark plugs (12405).
Set the throttle plates in the wide-open position.
Install a compression gauge such as the Compression Tester in the No. 1 cylinder.
Install an auxiliary starter switch in the starting circuit. With the ignition switch in the OFF position, and using the auxiliary starter switch, crank the engine a minimum of five compression strokes and record the highest reading. Note the approximate number of compression strokes required to obtain the highest reading.
Repeat the test on each cylinder, cranking the engine approximately the same number of compression strokes.
Compression Test—Test Results

The indicated compression pressures are considered within specification if the lowest reading cylinder is at least 75 percent of the highest reading.


If one or more cylinders reads low, squirt approximately one tablespoon of engine oil on top of the pistons in the low-reading cylinders. Repeat the compression pressure check on these cylinders.

Compression Test—Interpreting Compression Readings

If compression improves considerably, piston rings are faulty.
If compression does not improve, valves are sticking or seating incorrectly.
If two adjacent cylinders indicate low compression pressures and squirting oil on each piston does not increase compression, the head gasket may be leaking between cylinders. Engine oil or coolant in cylinders could result from this condition.
Use the Compression Pressure Limit Chart when checking cylinder compression so that the lowest reading is within 75 percent of the highest reading.

Cylinder Leakage Detection

When a cylinder produces a low reading, use of the Engine Cylinder Leak Detection/Air Pressurization Kit will be helpful in pinpointing the exact cause.

The leakage detector is inserted in the spark plug hole, the piston is brought up to dead center on the compression stroke, and compressed air is admitted.

Once the combustion chamber is pressurized, a special gauge included in the kit will read the percentage of leakage. Leakage exceeding 20 percent is excessive.

While the air pressure is retained in the cylinder, listen for the hiss of escaping air. A leak at the intake valve (6507) will be heard in the throttle body (9E926). A leak at the exhaust valve (6505) can be heard at the tail pipe. Leakage past the piston rings will be audible at the positive crankcase ventilation (PCV) connection. If air is passing through a blown head gasket to an adjacent cylinder, the noise will be evident at the spark plug hole of the cylinder into which the air is leaking. Cracks in the cylinder block or gasket leakage into the cooling system may be detected by a stream of bubbles in the radiator (8005).
 

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You will get better results if you follow the procedure described by djsdiesel above. If you do one side, make sure to disable the other bank. The engine will start and run on one bank.

If you are overpressuring the coolant system, you likely have cracked injector cups.
 

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Discussion Starter #4
thanks for the reply, turned out it was a blown head gasket on the drivers side, head was warped .040. had head resurfaced and replaced gasket and head bolts and torqued in the 3 step sequence. thanks, been running great, 7,000 miles put on since repair now at 258100 on odometer, has been a great truck
 

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so you go through the glow plug wholes with the adapter? Does it fit in it or do you hold it on???
 

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Was about to start a new post but I might as well revive an old thread.

So I saw in the tech files this video: http://www.powerstroke.org/forum/7-3-repair-help/65982-cylinder-compression-test.html#post788478

Is the adaptor that they use for the ford glow plugs come with all compression testers, or is there a specific diesel compression tester? Can I trust a Harbor freight tester, or should I buy one at a parts store like Oreilly?

I am planning on testing my compression while I am under the valve covers next week putting in my Stage 2s from DIY, and will be changing the glow plugs while I am at it, might as well see how this 240,000 mile motor is holding up.

Also, what is the easiest way to disable the injection to keep the motor from firing? I am going to be pulling the injectors anyways, so should I just unplug the UVC harnesses or unplug something else to kill the injectors or PCM to compression test?

I dont have any issues, not burning or leaking any oil, besides now an HPOP line O ring is leaking, so I should add that to the list of things to change. I am pretty confident that the motor will be good, just want to verfiy, like the fact that I know my model year is a forged rods but I pulled the plug today just to take a look and smile knowing I have decent rods.


Also while I am ranting, what specficially is the contribution test? Correct me if I am wrong its testing the injector intensity through the OBDII port? If thats the case and I am putting in reman injectors I should have to bother with testing this, they should all be good?
 

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Was about to start a new post but I might as well revive an old thread.

So I saw in the tech files this video: http://www.powerstroke.org/forum/7-3-repair-help/65982-cylinder-compression-test.html#post788478

Is the adaptor that they use for the ford glow plugs come with all compression testers, or is there a specific diesel compression tester? Can I trust a Harbor freight tester, or should I buy one at a parts store like Oreilly?

Also, what is the easiest way to disable the injection to keep the motor from firing? I am going to be pulling the injectors anyways, so should I just unplug the UVC harnesses or unplug something else to kill the injectors or PCM to compression test?

I am planning on testing my compression while I am under the valve covers next week putting in my Stage 2s from DIY, and will be changing the glow plugs while I am at it, might as well see how this 240,000 mile motor is holding up.

I dont have any issues, not burning or leaking any oil, besides now an HPOP line, so I should add that to the list of things to change. So I am pretty confident that the motor will be good, just want to verfiy, like the fact that I know my model year is a forged rod block but I pulled the plug today just to take a look and smile knowing I have decent rods.


Also while I am ranting, what specficially is the contribution test? Correct me if I am wrong its testing the injector intensity through the OBDII port? If thats the case and I am putting in reman injectors I should have to bother with testing this, they should all be good?
specific tester and specific adapter for the powerstroke. I think a tester and adapter is around $150.

On your superduty, leave the keys out of the ignition. Remove the top wire from the starter solenoid on the passenger fender (top wire is a small, single, covered wire). After connecting the compression adapter to the head and the tester, make sure that the adapter is clear of the valve train. Use a jumper wire from the positive battery terminal to the solenoid terminal you just uncovered. Let the motor crank over a few times. You should be in the 400psi range.


Cylinder Contrib/balance is nothing more than the scanner telling the pcm/idm to "listen" or "cut" out each cylinder and monitor RPM changes. It also messes with fuel flow to do this.

Don't worry about different injectors unless you are going above stage 3.



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specific tester and specific adapter for the powerstroke. I think a tester and adapter is around $150.

On your superduty, leave the keys out of the ignition. Remove the top wire from the starter solenoid on the passenger fender (top wire is a small, single, covered wire). After connecting the compression adapter to the head and the tester, make sure that the adapter is clear of the valve train. Use a jumper wire from the positive battery terminal to the solenoid terminal you just uncovered. Let the motor crank over a few times. You should be in the 400psi range.


Cylinder Contrib/balance is nothing more than the scanner telling the pcm/idm to "listen" or "cut" out each cylinder and monitor RPM changes. It also messes with fuel flow to do this.

Don't worry about different injectors unless you are going above stage 3.
On that note does anyone have a tester I can borrow if its going to run me $150?:doh:
 

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There is a connector on the passenger side of the engine compartment that will allow you to diable the vehicle from running. you can crank it as much as you want, but it will not start. all you have to do is unplug it and touch it to the positive battery post to roll the engine over. when you take the glow plugs out, before you hook up the guage, just turn the motor over with that wire and it will blow all of the oil out of the cylinders. you want to take your reading after 5 revoloutions of the engine. The connector you are looking for is round and runs along the passenger side of the engine compartment.
 

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I'm a newbie. http://www.powerstroke.org/forum/images/smilies/confused.gif

This is my first diesel truck and my first post to the forum.

I just bought a 2001 F-250 ext. cab with a 7.3 and approx. 270k on the clock.

The truck starts and runs ok but it is really rough and smokes a lot (sort of a white or light gray smoke). It seems to smooth out once it gets up to speed on the highway but it really shakes a lot as it is accelerating and going thru the gears.

The PO told me he thinks the truck only needs new injectors but he seemed to be a BS artist so I fully expect something more major to be wrong with the engine. I bought the truck to pull a toy hauler that I hope to purchase next year after I retire (possibly).

The truck is in fair shape and has several goodies on it like a 3 position Bully Dog switch, new tires, tool box, remote start (not sure yet if it works), Automatic trans., block heater, Nurf bars, Tinted glass, bedliner.

My tentative plans are to change oil and have it analyzed, test compression, rebuild injectors, change / inspect coolant, change / inspect trans oil, change fuel and air filters. Of course if I find a major problem that is all subject to change.

I have a Haynes manual which covers a lot and I have learned a lot by browsing this Forum (Thanks to all!!!).

My question(s) are:

Am I posting this in the right place (where the right people are most likely to read/respond?)

Can I do the compression test with my automotive gauge that only goes to 300 PSI? I understand a good engine should produce close to 400 psi, but if I only allow a couple of "puffs", can I get an idea of how each cylinder is doing? Also, how about the cheap (approx $24.00) testers I see on eBay. Will they do the job? I also have a local Harbor Freight if they have a tester that will work.

Is there anybody close (within about 50 miles) to Tipton County, TN (approx. 30 miles from Memphis) that would be willing to drive my truck and give his opinion on what is the most likely problem?

My background is mostly electronic (I am a computer tech. by trade), and I have a lot (30 plus years) of automotive experience and many tools. Just no knowledge (yet) on diesel engines. http://www.powerstroke.org/forum/images/smilies/wink[3].gif

Thanks in advance!

Tom Spear (901-301-6456 if anybody wants to call)
 

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This is a pretty good place to post. its best to search a topic before you post it if you especially if someone already discussed it last week. If you find a thread you can jump in and start posting if your issue applies to what is going on.

In your situation if it is running rough and a lack of power with smoke, start with the fuel filter. There are other things I would look at too before I jump into replacing all 8 injectors, eventhough it has 270K on it. Look at "contribution test" or Buzz test, that will give you a clue if you have a bum injector, and then if half of them are showing up weak or bad you can start replacing acordingling. Things get expensive when you start replacing or rebuilding $150-300 injectors. There may be issues such as Cam sensor, and Injector pressure regulator that are alot cheaper fixes than injectors. A ford diesel tech that can do a good run over for you for a few $$$ may be worth it to see if what actually is bad.


Oh and :ORG welcome::ORG welcome:
 
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