Compression Results

[gonecrazyi]

I got around to starting to check the compression on my 89 7.3 with 180000.

The results were worse than expected. I only go around to testing the drivers side and the number one on the passenger side.

2 - 280
4- 280
6 250
8 - nothing

1 - 300

I guess this would explain the miss and the inability to get it to fire off with my spare IP pump. I could prime the entire system and get it to white smoke out the tail pipe, but could not get it to fire.
I checked the guage and its accurate so now I think Im gonna be in the market for another motor or a 6.9 to rebuild.

 

[Classicfordguy]

That is cylinder that died in mine, the back one on the driver side. It knocked real loud for 5k miles then lost compression. All the rings were broken or in the oil pan and the cylinder and piston were very worn. The other 7 were fine.

-Rob

 

[DeepRoots]

sorry to hear it, reckon you need to change your signature now.

 

[gonecrazyi]

Deep roots, I think yer right!!!!!!!!

Well I guess Ill be lookin for another motor, for some reason, people here in Florida see the word diesel and think gold! I can buy a complete truck for the price people want for some of these motors. Heck, I only paid 950 for the whole truck, the only thing keeping me attached to it is the drivetrain that Ive rebuilt and the fact that I cant find an IDI crewcab 4x4.

Classic Ford, I might be bouncin some questions off ya if I plan on rebuilding another engine.

It never ends, if it aint one thing its def. another.

 

[farriswheel]

what do those numbers mean?

 

[BigDiesel]

They mean the engines worn out and needs rebuilding. anything over 400 is good, under 350 is getting into worn.

 

[Diesel JD]

Pretty tired. Technically 195-440 is normal in reality Big Diesel is right, it should be higher than 350 and many good motors have 500 or so on some cylinders, the main concern is you don't want any really low cylinders and the highest cyl. should be at least 75% of the best. Billy I'll put the word out around here. Whats your budget for the used motor?

 

[fastass350]

8 is the one I recently had troubles with too, had a miss, low compression on it, 125 compared to around 350 for the rest. Tore it down and found number 8 piston was cracked from the bottom of the skirt through the second oil ring...strange coincidences

 

[RLDSL]

The thing may not be a total loss. With the other holes so consistant, it could be that 8 has a real bad guide and the valve isn't sealing and all you need for now is to get the heads done ( although with those numbers, a rebuild is in your future, but you could get away for quite a while in your climate without one)

 

[Agnem]

That is cylinder that died in mine, the back one on the driver side. ... The other 7 were fine.

-Rob

Another reason to run a road draft tube. This is proof positive that the back cylinders run much hotter than the others, due to the CDR location.


Can anyone recommend a good source for a compression gauge online? I want to buy one.

 

[Exekiel69]

Here is one

Here is another one

 

[Agnem]

Wow. $25. China Freight. Not my favorite. Of course, then there is the $749 one from Grainger. Surely there is something in between. Do you actually have one of these EZ? I'm just not sure I can trust a $25 gauge.

 

[Exekiel69]

Wow. $25. China Freight. Not my favorite. Of course, then there is the $749 one from Grainger. Surely there is something in between. Do you actually have one of these EZ? I'm just not sure I can trust a $25 gauge.

No, mine is made in USA and I can't remember where I got it from.

 

[Fordsandguns]

Wow. $25. China Freight. Not my favorite. Of course, then there is the $749 one from Grainger. Surely there is something in between. Do you actually have one of these EZ? I'm just not sure I can trust a $25 gauge.

Mel, I bought one of those POS. The adapter that is meant for our engine doesn't fit. I found one of the others to substitute but then the gauge quit after a couple of cylinders! So I agree, don't trust a $25 dollar gauge!

 

[icanfixall]

Mel, I bought mine from Northern Tools and its great. I will bring it to the rally if you want to use it till I need it sometime down the line. Then you can just ship it back to me....