Engine/Transmission (1994 - 1998) head gasket r&r

[Mhannink]

so about 2 weeks ago i was going over the truck during some down time and found a coolant leak. looking more closely i found the leak between the head and the block under the thermostat housing. ordered a new head gasket and bolts and they arrived a few days ago so today i went about replacing it.



i was sort of looking forward to replacing the head gasket since i wanted to see how the inside of the engine looked. in short i have to say i am very happy with it but found some interesting things.



so im trying to upload pics but it may or may not be working. moving forward, the truck has 237k odometer miles. looking at the cylinder walls the has marks are clear and distinct, they felt glassy but its been a while since ive had to worry about such things and i cant remember if its ok or not. the engine has no visible blow by or use any oil, but the road draft tube is always a little wet. also the top of the cylinders and valves/combustion chamber had very lite soot, wipe my finger on them and they look new. also the injector tips are spotless, granted there is only about 10k miles on them, but ive seen them at that mileage with noticeable carbon buildup. the last thing, there is virtually no carbon ring on at the top of the cylinder as is normal in most engines. in all the engine seems to be running a little lean and very clean.



those are the things that looked good, now for the interesting stuff. number one cylinder has a lite imprint of the intake valve though looking at the pics im wondering about that. cylinder two has something embedded in it. it struck the piston on one side and the embedded in the other side. i dont know what it is, how long it has been there, are how it happened.

 

[Mhannink]

more pics

here are the rest of the pics i took. the results of doing the head gasket have been interesting. the truck is much quieter, smoother, and has more bottom end power. at first i attributed it to having adjusted the valves with only 8k before the scheduled time it seemed logical. after having driven it though i think the head gasket might have been affecting performance a little more than it appeared to be. after the repair the truck felt like it had a whole new engine in it. i cant even begin to describe how much better it feels putting around town, i cant wait to get out and push it harder and see how she runs. i am waiting to get a few hundred miles of warm up and drive cylces before i put the power down.



if i am right and the headgasket was more damaged then it seemed it just goes to show how much making sure everything is tip top shape before modifying makes a big difference. i was chasing a fuel leak a few days ago that really made a difference in performance as well. i have a lot of other little things on other trucks that make big changes too.

 

[Mhannink]

first post second pic is a really good view of the hash marks. they look really good and clear to me. pic 4 is the number two cylinder where something hit it. the last pic in post 1 is the head and valves prior to cleaning, not the finger swipe marks and how clean it made it.



post 2 pic 3 is cylinder two, it had a little high spot that i worked down before installing the head. the piston is still in there and i am going to run it till it blows or i reman the engine for whatever reason. pic 4 is a close up of the injector tip after 10k miles. the last pic in post 2 is the possible valve slap, its in the right spot and size for the valve but the pattern doesnt look right. the valve is smooth and the mark here has an inner and outer circle with some other faint circular marks. this showed up only after wiping the pistons with a shop rag while i was preping for assembly.

 

[DWeaver]

Given mine was run longer with the engine being in trouble. It was run till it died.



These are 2 of the cylinders that had to have the connecting rod replaced.

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Glad you were able to catch it quick and make the engine better.

 

[Nyoest]

Have you timed the engine in recent history? The witness mark on the piston 1 looks like it could be caused by the valve drop method.

 

[Nyoest]

Welp disregaurd that theory. Looking at DWeavers pics it looks like the piston grows into the valve and makes some crop circles.

 

[Mhannink]

ouch looks like that hurt. how do you think the pistons and valves made contact. i never heard anything funny on mine to suggest that.

 

[Bob4x4]

That Piston was VERY HOT

 

[DWeaver]

A very bad decking of the head contributed. It was decked at angle across the width.



I received the engine not running so I can only ASSuME that the bad deck, with a sloppy valve setting did it.



The black, crudded up piston was #1 cyl.

 

[Nyoest]

Hannick have you noticed any change in fuel economy since the repair?

 

[Mhannink]

im not going to be able to give you a good estimate of whether or not it affected fuel mileage. i just fueled today, it was down almost a whole mpg. however there was less than half a tank since the repair, we have had strong head winds the last couple of days, i have had extended idle times, i my in town driving is higher than normal this week, there are also several other mods i did about the same time. those being horton fan clutch and wheel and driveline balancers. also when i filled up today i added a quart of canola oil, i am testing an idea with small amounts of biofuel as an additive. all of these things are going to affect performance enough that anything resulting from the head gasket will not show up.



what i do notice is a far better running engine imidiatly before and after the repair. i think there was more than just the coolant leak that i noticed, no other signs of problems but i think there was something. i did notice, though it didnt click right away, there was a fair amount of rust build up between the block and the head down the passenger side of the engine. sop for me is to take a worn scotch brite pad on a die grinder and carefully clean the block and head before install so that it is shinny smooth metal contacting the gasket. i think that rust build up was lifting the head off the block.



on another note, i hoping someone may be able to confirm this. i read a post on another forum where someone said that since some year 10 to 15 years ago, that all 12v head gaskets are marine gaskets. i ordered a factory gasket and bolts from pure diesel power, they have two different numbers for the factory and marine gaskets. does anyone know anything about this? note that the new gasket looked somewhat thicker than the old one, and seemed to be built differently. however i did not measure the 2 nor did i put them side by side and compare them. its sort of a hindsight reflection of the details i noticed but did not pay close attention to.



nyoest, i will get back to you in a couple of weeks after i have burned a couple tanks of fuel. depending on conditions, mileage changes might start showing up that could be related to the head gasket.

 

[mwilson]

im not going to be able to give you a good estimate of whether or not it affected fuel mileage. i just fueled today, it was down almost a whole mpg. however there was less than half a tank since the repair, we have had strong head winds the last couple of days, i have had extended idle times, i my in town driving is higher than normal this week, there are also several other mods i did about the same time. those being horton fan clutch and wheel and driveline balancers. also when i filled up today i added a quart of canola oil, i am testing an idea with small amounts of biofuel as an additive. all of these things are going to affect performance enough that anything resulting from the head gasket will not show up.



what i do notice is a far better running engine imidiatly before and after the repair. i think there was more than just the coolant leak that i noticed, no other signs of problems but i think there was something. i did notice, though it didnt click right away, there was a fair amount of rust build up between the block and the head down the passenger side of the engine. sop for me is to take a worn scotch brite pad on a die grinder and carefully clean the block and head before install so that it is shinny smooth metal contacting the gasket. i think that rust build up was lifting the head off the block.



on another note, i hoping someone may be able to confirm this. i read a post on another forum where someone said that since some year 10 to 15 years ago, that all 12v head gaskets are marine gaskets. i ordered a factory gasket and bolts from pure diesel power, they have two different numbers for the factory and marine gaskets. does anyone know anything about this? note that the new gasket looked somewhat thicker than the old one, and seemed to be built differently. however i did not measure the 2 nor did i put them side by side and compare them. its sort of a hindsight reflection of the details i noticed but did not pay close attention to.



nyoest, i will get back to you in a couple of weeks after i have burned a couple tanks of fuel. depending on conditions, mileage changes might start showing up that could be related to the head gasket.

Congrats on scoring that Horton Fan Clutch offered a couple of weeks back, I know that you really wanted one.



Look at the Cummins Bulletin I posted in this thread, may clear up the head gasket question for you. It is fuzzy, I have yet to find a good way to move those bulletins over to the TDR. If you can't read it after printing or saving it please send me an e-mail and I will attach a copy to the return e-mail.

-- email address removed -- in case you can't find it in your address book.



https://www.turbodieselregister.com...mbers-head-gaskets.html?highlight=head+gasket





Mike.

 

[Mhannink]

Thanks mike, yeah I jumped on that fan clutch kit like white on rice. The seller was great to work with, sent me pics and gave me good information. It was a real pleasure working with him. I was even able to txt him during the install about the wiring and he responded right away even though it was evening where I was and he's 2 hrs ahead of me. Clutch works great and I absolutely love it. Now I just meed to work on the a/c part of the setup. I will be calling turbo auto diesel soon and figure out how to set it up. We exchanged some thoughts already but I wanted to wait till I had the clutch installed before I started messing with it.

Also thanks for that h. g. info ill look at it more closely when I get home and will email you if I have problems.