Hi guys, I've decided to do a compression test on the Beast. I want to keep modifying her but I've decided that I should give her a physical first, and make sure her heart is beating good. I have white/blue smoke at startup and the turbo has some dusting to it so I just want to be assured she's healthy at heart.
Onto the important part...

From what I understand a compression test is a fairly simple ordeal. I have gotten the Harbor Freight kit and am working on collecting the other parts mentioned in this thread (https://www.ford-trucks.com/forums/1...sion-test.html) by BigAlsPSD. I also plan on having a charger hooked to the batteries.

However I'm not quite sure on the steps, do the following sound right?


1. Remove everything neccesary to pop valve covers then pop 'em.

• Air intake piping
• IC pipes
• Disconnect the 42 pin connector on DS
• Disconnect the little vacuum? hose running over the PS VC.

2. Disconnect UVC harnesses.

3. Pull all of the glow plugs.

• Only after removing the oil around the GP!

4. Install compression tester in glow plug port.
5. Spin warm engine 2 to 3 times to get good reading.
6. Repeat 4 and 5 for all holes.
7. Install glow plugs and connect UVC harnesses and 42 pin connector.
8. Make sure she fires and runs.
9. Put all other stuff back.
10. Celebrate good compression readings.

If I missed something or am completely wrong please let me know, I'm still a newbie.


Thanks,

Baatzy

 

sounds good to me.

 

It's been said to get the truck up to normal operating temp for the most accurate readings. I got everything taken apart and let it idle for a while so I wasn't working on a engine.

 

You left out a whole buncha stuff:

• Drop your socket wrench on the passenger side, so it can land across the starter, make lots of sparks, and leave an "autograph" on the wrench handle.
• Scrape your knuckles when trying to remove the IC tube, then spend 10 minutes locating the Bandaids.
• Forget to drain the oil from around the GP before removal, then have it all paint the garage and your face on the first crank.
• Get the compression test tool stuck in the #7 hole, then spend 2 hours and a few beers trying to get it back out with every tool you own... taking several Bandaid breaks.
• Fight installing the passenger-side valve cover past the AC compressor and heater hoses... all the while shouting "The !#&%$ came outta there, why won't it go back in?"

At least... that's how I do it.

 

make sure the moving stuff out of the way part includes disconnecting the 42 pin connector.

 

Big yes here... but don't let the key near the ignition until AFTER the 42-pin is connected again and your safety check says everything is ready to run.

 

Thanks guys!

For those who've done it, do you warm the engine up before tearing anything apart? Or how far do you tear it down before getting it warm? It seems like it would be a huge pain laying on top of the thing if its all warmed up. Also what is considered a good warm temp?

I will also add disconnecting the 42 pin connecter.

Tugly, you are correct I did forget about the oil around the GP, thanks for the reminder. Actually its my roommate that thanks you, he's gonna be the helper and he probably wouldn't take too kind to getting an oil bath. As for the rest of the stuff you mentioned, I was hoping I wouldn't have to face that stuff but according to Murphy though I'm gonna have a fun time.

Do you think the Bandaids are critical? Maybe blood has a high enough shear resistance.......Save on oil.

I appreciate all the help. Also any other tips people have would be very appreciated. I tried to find compression testing threads with how to's when I decided to do this, however I couldn't find one that answered all my questions. I just gathered the info from multiple threads. To give back to the brotherhood for everything I've received I would like to try to make a complete how to of this process, and any tips on the process or how to make the how to better, is very appreciated.

Thanks again,

Baatzy

 

I am looking forward to seeing what #'s/ psi you end up with. I am going to be doing a compression test on my truck hopefully in the a couple weeks. I have a new set of glow plugs to install and that is the time to do it. I am going to use the write up BigAl did as far as making my own compression tester.

Also I was wondering couldn't you just pull the pcm fuse to keep the IDM and glow plugs from firing up when doing the test ? This is a question?? Correct me if I am wrong but if you kill the power to the pcm, it can't send a signal to the GPR or the IDM.

 

I took everything apart (except pulling glow plugs of course) and then fired up and let idle until it was around 180*, then pulled glow plugs and did the test.

I used Big Als recommended setup and it worked like a charm.

 

Glad the test went well. So what kind of #'s/ psi did you end up having?

 

ACK! I don't use the key to crank it. I use the starter relay on the passenger fender wall - it has two big posts like a glow plug relay. Short the two big posts with a screwdriver or a remote starter button and the engine will crank with no power to anything.

 

Can't do that on a '02-'03 truck. BUT...a jumper wire works fine on those from the positive battery post to the connector (big single wire) by the vacuum pump.

 

I've purchased the kit & parts to do a compression test (following BigAlPSd's instructions) and was wondering:

1) how tight I will need to spin the M10 x 1.0 adapter with its o-ring into the GP hole since it seems I will be spinning it on with the grease whip? If I am wrong about spinning the adapter on with the whip, is there another method/tool I should use?

2) how likely is it that I will lose the o-ring when I remove the adapter from each GP hole.

3) if I get a low compression reading, could it be attributable to injector o-rings or are injector o-rings not a factor with this test?

Thank you.

 

Hope it all works out well for you, a quick compression check is a great thing and IMO should be done before replacing injectors as well as a general health check.

I still don't see why not to use the key though personally. You could unplug the connector or the cps and it's not going to do anything that much different...

 

In referring to the "connector", do you mean the 42 pin connector or the valve cover connector or ???

Sorry if this is a silly question but I'd rather get clarification than screw something up.