91 7.3 IDI NON TURBO BLOWN HEAD GASKET. ONLY 70K MILES

HEY GUYS AND GALS I HAVE THIS F250 I ACQUIRED 3 WEEKS AGO. I BOUGHT IT FROM MY INLAWS THE TRUCK ITSELF ONLY HAS 35K MILES BUT THEY SEVERALLY OVERHEATED THE ORIGINAL MOTOR BEYOND REPAIR. I GOT ANOTHER MOTOR OUT OF A TRUCK THAT HAD BEEN ROLLED OVER AND ONLY HAD 70K MILES (VERIFIED BY CARFAX). NOW I AM A ASE CERTIFIED MECHANIC SO I HAVE QUITE A BIT OF KNOWLEDGE ANYTHING MECHANICAL BASED. TODAY I WENT TO GO START MY TRUCK AND IT BLEW WHITE SMOKE LIKE CRAZY AND WAS RUNNING LIKE COMPLETE CRAP IT EVEN BLEW MY UPPER RADIATOR HOSE OFF. I PUT IT ALL BACK TOGETHER AND TOOK THE CAP OFF AND STARTED IT UP AND IT BLEW PUFFS OF SMOKE OUT THE RADIATOR ON EVERY POWERSTROKE OF ONE OF THE CYLINDERS. I TOOK ALL THE GLOW PLUGS OUT AND BEGAN TO PUT THEM BACK IN ONE BY ONE WHILE CRANKING THE MOTOR OVER (NOT STARTING) UNTIL THE COOLING SYSTEM BECAME PRESSURIZED, IT PRESSURIZED AS SOON AS I PUT THE NUMBER TWO PLUG IN (IF INTERNATIONAL USES THE SAME CYL IDENTIFICATION AS FORD? ITS THE SECOND ONE BACK ON THE DRIVER SIDE.) SO I KNOW THATS THE HOLE BLOWN AS I TOOK THEM ALL BACK OUT EXCEPT NUMBER TWO AND IT STILL PRESSURIZED. NOW MY QUESTION IS WHY THE HELL DID THIS HAPPEN WITH SO LITTLE MILES? I HEAR THESE ARE A MILLION MILE MOTOR? I KNOW THAT IF THE CDR VALVE GOES BAD IT CAN DUMP OIL INTO THE THE NUMBER 7 AND 8 HOLES AND LIFT THE HEAD. I REPLACED MY CDR VALVE YESTERDAY DUE TO LOOSING ALOT OF OIL IN 3 WEEKS TIME. THIS TRUCK NEVER GAVE ME AN ISSUE PRIOR TO THIS I ADJUSTED THE TIMING ABOUT 1/16TH OF AN INCH ADVANCED AND AFTER THAT IS WHEN I STARTED TO GET ALOT OF SMOKE I ASSUMED IT WAS BECAUSE OF THE TIMING SINCE THE TRUCK NEVER EVEN HICCUPED A LITTLE AND NEVER OVERHEATED WHAT SO EVER. ONE MORE QUESTION I HAVE IS SINCE THIS THING PUMPED SO MUCH COOLANT DO YOU GUYS THINK IT COULD HAVE BENT THAT ROD? I WOULD HAT TO REDO THESE HEADS AND HAVE IT HAVE A BENT ROD. ANY INFORMATION WOULD BE AWESOME! THANKS GUYS!

Your ase! You know stuff happens.block or head may not be perfectly flat or a bad gasket. After all it only lasted 23 years

Luckily replacing HG's is easy with these engines, even if you do it in frame. A cherry picker is a must tho. I would go ahead and do both sides while its apart. Get heads checked @ machine shop & maybe even install ARP studs if funds allow. You can then be certain that you have a bulletproof Idi that will never blow a head gasket again. Just my .02

You...YOU...are ASE.....sorry I am a Simplle Canucklehead Canadian *** IS that.....no really whats an ASE anything like a backyard wrench?


Sounds to ke like it is time to read stickies and tech and learn to use the Advanced search....

Me being a loey canucklehead cant offer much to a ge uine ASE kinda guy....just sayin

please take the time to separate your posts. it would make it easier to read. and would help us help you.


oah, welcome to the forum.

sounds like a head gasket to me. I wouldn't have touched the timing without a meter. if you can I would recommend to pull the motor, then you can fix all the other leaks and further inspect the motor.

Your synopsis of what cyl is bad sounds right.

Changing timing without knkwing where it was or what it is now was not really a good idea.

A rod could be bent yes.

Hg go when they go...you say 70 k...how do you know this

Really what is an ASE never heard of it.

ASE = Automotive Service Excellence. Requires a minimum of 2 years experience pertaining to the certification being applied for, plus tests, plus yearly tests for renewal. Kinda is to mechanics as ISO certification is to manufacturing.

riotwarrior said:

Really what is an ASE never heard of it.

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known to shade tree mechanics as **** certified.

it is a certified mechanic.
certified for talking out their ass and thinking they know everything.
ive seen these types of people put lugnuts on incorrectly

IDIoit said:

please take the time to separate your posts. it would make it easier to read. and would help us help you.


oah, welcome to the forum.

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Sorry about that I re read my post this morning and saw that it looked terrible. I looked for an edit button but did not find one so I'll just summarize it to better explain.

Engine I put in was verified 70k miles. I drove the truck even, it was rolled over during a hunting trip last year and totalled. I replaced the cdr valve on Wednesday and did adjust the timing (I've done it a thousand times on different IH idi motors just a dimes width from the stock location) I drove it for 3 awesome weeks and it did amazing. I drove 30 miles to a friend's house Wednesday and came home and parked it. I rose my motorcycle to work Thursday and came home around 6 to drive to the store and that's when it went kaboom. Verified it was the number two cylinder. As I stated I am an ase certified mechanic (getting crap for that here on the forum not sure why) Now I have seen many has motors give up a head at 70k miles (mostly subaru due to a paper and steal gasket design) but never seen a 7.3 do it.

My main questions are as followed.

Are the 7.3 gasket designs all the same through all the years? As this is a 1991 motor in a 1988 I'm just curious on that part.

How often does this happen as seen on the forums? I did a search and saw a few blown up but none that blew as bad as mine did so I couldn't verify bent rods from them.

Bent rods? I know I saw that question answered but how often do these rods actually bend under n/a power?

I plan on doing these heads inframe. They look very simple and shop time calls for 12 hours.

I know I repeated myself alot here but I wanted to make it easier to read and not make myself look like a ******* with my grammer. I was dealing with a crying baby and a messed up computer haha. Thanks in advance guys.

IDIoit said:

known to shade tree mechanics as **** certified.

it is a certified mechanic.
certified for talking out their ass and thinking they know everything.
ive seen these types of people put lugnuts on incorrectly

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I can assure you I'm not an idiot and Thats a little narrow minded to put every mechanic in the same category as a shade tree mechanic who likes to Jack things up on their car before they bring it to me to repair it because they can't. I have plenty of stories to tell about do it yourselfers who tried to fix their car and f***ed it up beyond repair.

dont matter if its N/A or turbo, if you get water in a cylinder it will hydrolock.
sometimes bending a rod,
it all depends how much water, and what you do while there is water in a cylinder.
if you have a 1/2 a cylinder filled with water and you try to crank it, chances are youre bending something.

FYI water does not belong in your cylinder lol.

7.3 headgaskets are the same for the most part, the only difference is the 6.9 vs the 7.3, but they all can and have been used.

before you put those heads back on make sure you get them mag'd and pressure tested.
EGT's like to eat cast iron.

as far as a bent rod, youre gonna have to find out the old way, my snapon solus isnt equipped with an xray app yet..

with heads off, just measure piston stickout.

74montercarlo said:

I can assure you I'm not an idiot and Thats a little narrow minded to put every mechanic in the same category as a shade tree mechanic who likes to Jack things up on their car before they bring it to me to repair it because they can't. I have plenty of stories to tell about do it yourselfers who tried to fix their car and f***ed it up beyond repair.

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I dont think he was talking all mechanics, just ones puffing out thier chest and using a piece of paper to prove thier credibility/talent.

You obviously have good diagnostic skills, and It is ok to be proud of what you do for a living...

IDIoit said:

dont matter if its N/A or turbo, if you get water in a cylinder it will hydrolock.
sometimes bending a rod,
it all depends how much water, and what you do while there is water in a cylinder.
if you have a 1/2 a cylinder filled with water and you try to crank it, chances are youre bending something.

FYI water does not belong in your cylinder lol.

7.3 headgaskets are the same for the most part, the only difference is the 6.9 vs the 7.3, but they all can and have been used.

before you put those heads back on make sure you get them mag'd and pressure tested.
EGT's like to eat cast iron.

as far as a bent rod, youre gonna have to find out the old way, my snapon solus isnt equipped with an xray app yet..

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Yea we have an amazing machine shop up here so I will be having then done. I plan on using felpro gaskets. I dont have 400 bucks to spend on arp studs right now so I can't do that I'll just be using oem bolts. I was just thinking I will measure each piston at tdc to see if on is shorter to look for a bent rod. Thanks for the advice I really appreciate it. I'm not super familiar with these engines so that's the only reason I'm asking.