6.9 Very un-happy lifter?

[IHcornbinder]

Ok so my 85' has an odd issue. It has a lifter tick(more of a knock), but there is nothing usual about it. I started off by going through all of the push tubes and rockers to make sure nothing was bent or out of shape. All was good. I had a new set of rockers out of a 7.3 i swapped to because they were like new but that didnt change anything. So this is the odd part. It is completly opposit of any lifter issue i have ever had before, it is completly quiet untill the oil pressure get to it then it starts ticking. The motor it self is very happy and hasnt had any internal problems. Currently has an old non-wategated sidwinder and had no problems pulling 10psi on a cold day. I just recived my new lifters from an 01 PDS and will be swapping them as soon as i get the chance, i just thought id throw it out there and see what ya'll think.

 

[gonecrazyi]

Are you sure it isn't an injector?

 

[icanfixall]

Sounds odd being the lifter noise is only when the oil pressure comes up. How many miles are on the engine. A nosie like this could be an injecter but only after it runs till the pressure comes up. Might just be a coincidence too. When the valve covers were off running the engine at idle and touching each rocker would have told you whish lifter it might have been. Or at least rule them out. You posted the replacement lifters are from a psd... does that mean they are used or thats what they were called when you bought them... These engines share lifters with many chevys and hummer engines along with many psd engines. They do not only fit our idi engines so they are easy to find all day long.

 

[Knuckledragger]

I had a very similar sound in my old white truck, turns out the oil was a couple of quarts low.

 

[IHcornbinder]

I was thinking a broke piston, but the more i started driving it i noticed that it would go away after it sat and the lifters pumped down. I cracked each injector one at a time to try to isolate a piston/injector problem and had no change in the sound. It seemed like the tick would go allong with the miss on the #8 cyclinder and when i put it on the scope the tick was at half speed of the motor, so i figured it was valve train. I guess ill know soon enough but i just found it so odd that it would tick with oil pressure. Rollers are ususally noisy untill the oil get there.

 

[IHcornbinder]

O, miles are unsure. Previous owner had the motor gone over when the oil cooler blew an oring and filled the collent with oil. Kinda nice to have a whole new colling system. The truck only has 157 on it but im not to sure what the motor has. I havent run the numbers on the block but it is one of the cleenest IDI's ive ever seen and you can leve it parked in the driveway for a month without an oil spot. Id bet it was swaped at some point, but like i said i havent looked at the numbers to see. Can anyone tell me how to identify if it is a 6.9 or 7.3. Or what code would identify the year it was cast?

 

[IHcornbinder]

O and yea on the lifters, yes on used, no there not in the motor yet. They are from an 01 PSD and are really good looking. Got them for $25 on ebay(free shipping too). I would doubt they have 150k on them from the wear but hard to tell with the deisel. I gues i thought i would just give eveyone a bain tease or see if anyone had a simualr issue before i tear it down and throw the old ones in the garbage(unless someone wants them).

 

[6.9man]

be interested on to see if its the problem. my pickup has the same ticking problem.

 

[icanfixall]

We have two easy ways of determining a 6.9 or 7.3. Most easiest way is look at the block serial numbers just to the drivers side of the injection pump gear housing. Right in the numbers it will say 6.9 or 7.2. the other is to fit a socket to the head bolts. The 7.3 uses a 5/8 socket to remove them and the 6.9 uses a 9/16 ... About the 6.9, I really have not worked on one so my socket size might be incorrect. Someone that has worked on them will chime in with the correct size. Now thats the simple way... The hard way is to remove a head bolt and measure it.. The 6.9 uses a 7/16 diameter bolt or stud and the 7.3 uses a 1/2 inch bolt or stud.

 

[IHcornbinder]

Thank you for the reply. That is very clear and ill know what i have as soon as i go to lunch. I say im unsure what it is because im prety sure it has been swapped. The engine that is in it is probly the cleanest IDI ive ever seen and it doesnt leak any oil (is that a first). The paint is nice and grey and looks new. I just wish this tick would decide to go away on its own. Im excited to know if it is just a realy clean 6.9 or a newer 7.3. Thanks again, you guys have been a great help.