7.3 runnine bad
Thread Starter
|
Mountain Pass
Joined: Sep 2006
Posts: 157
Likes: 0
From: Plain City Utah
7.3 runnine bad
Hello everyone: I have a 1994 7.3 an I was driving it on a family trip an I was about 300 miles from my home an it started to run real bab I took it to the ford dealer an they say I have bad motor my # 2 cynilder had only 150 psi the others were at 300 psi . How do you check the conpresion on a 7.3 does anyone know , I am getting lots of blow be into my cracnk case an I am seeing lots of blue smoke coming out of am pipe . If I have a bad motor were is a good place to get a new one an what is the price ? Rick
Senior User
Joined: Dec 2005
Posts: 261
Likes: 0
From: Columbus, Indiana
Having low compression doesn't tell you why. You could have an injector not seated leaking oil into the combustion chamber burning causing low compression and smoking, and it would add pressure to the crankcase. Well, it is possible...
You should verify the compression test and do a leak down test. If it ran fine and all of a sudden started this it probably isn't a "bad motor". That would signify the block is so worn that it is leaking passed the rings. I would venture to guess that you have another problem since it happened all of a sudden.
Snap-on has compression testers and leak-down testers that fit our engines. If you don't want to spend snap-on's prices, and I don't blame you, others have the same tools as well. I haven't had good luck with harbor freight's compression testers or leak down testers. They were way too cheap and didn't work accurately. Although we can all take random guesses, the only way to find out what is wrong is to run these two tests.
You should verify the compression test and do a leak down test. If it ran fine and all of a sudden started this it probably isn't a "bad motor". That would signify the block is so worn that it is leaking passed the rings. I would venture to guess that you have another problem since it happened all of a sudden.
Snap-on has compression testers and leak-down testers that fit our engines. If you don't want to spend snap-on's prices, and I don't blame you, others have the same tools as well. I haven't had good luck with harbor freight's compression testers or leak down testers. They were way too cheap and didn't work accurately. Although we can all take random guesses, the only way to find out what is wrong is to run these two tests.
Thread Starter
|
Mountain Pass
Joined: Sep 2006
Posts: 157
Likes: 0
From: Plain City Utah
The bill cam to about 270 dollars , but when I was looking at the valve covers if looks like the were not removed because I can still see the that the bolt have some black on them that has not been rubbed off
Post Fiend
Joined: Apr 2004
Posts: 12,835
Likes: 3
From: Silver Lake Dunes, MI
Well from the sounds of it I would say they did do it. usually if they are going to tell you that you have low compression they will just say you have low compression and not actually give you numbers. But I would get a second opinion and a leak down test need to be performed. It could be the rings are worn, piston cracked, head gasket, vavle issue, injector issue. so they need to do a leakage test to find out where it going.
Post Fiend
Joined: Apr 2004
Posts: 12,835
Likes: 3
From: Silver Lake Dunes, MI
And just to verify this is a powerstroke engine and not and IDI right? electronic injectors, turbo, wiring everywhere. if its a 94 PSD it should be a 5sp and not an auto.
Just making sure to be sure we are talking about the right engines here.
Just making sure to be sure we are talking about the right engines here.
Trending Topics
Thread Starter
|
Mountain Pass
Joined: Sep 2006
Posts: 157
Likes: 0
From: Plain City Utah
Hello again sorry for not getting back to you. I have the 7.3 idi I do not have electronic injectors an I have a auto tranny . Rick
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalyptic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Post Fiend
Joined: Apr 2004
Posts: 12,835
Likes: 3
From: Silver Lake Dunes, MI
Well then since you have the IDI your valve covers don't need to come off to check compression. But I would still get a second opinion. Let us know what you find out. Those engines sometime have valve guides that go bad too so that could be your issue. Once you get your second opinion post here then post your findings one forum lower. Those guys know more about the IDI's
