Hammering noise in OKC area, Help!

[spitfirenut]

I just put a Diesel Depot takeout in my truck. Drove it around for a couple of weeks and headed to Oklahoma(about 1100 miles). When I got off of the Interstate last night I heard a rattle that didn't belong while coasting. Sounds like it's in the bottom end. I had the pan off before I put the engine in, it was in great shape. The oil pressure is good. Coolant temp is good. Power is good. Rattle goes away when the engine is under load. I'm getting ready to do an oil change just to rule that out and make sure nothing comes out with the old oil(about 2000 miles). I'll also try cracking the injectors one at a time. I'm puzzled by the fact that the oil pressure is good. Pulling the pan won't be an option due to lack of a place to work on it. Any thoughts? I've got six weeks before I'll have to rent a uhaul and trailer to get it home. Anybody know a good mechanic in the Norman, OK area? Any members in the Norman or OKC area want to have a listen?

[diesel65]

Check your torque convertor bolts.

[spitfirenut]

Well, I crawled under again and checked all of the torque converter bolts(just checked the two on the bottom the first time,)anyway, all of them were good and tight. Also checked the balancer, good and tight. Kind of hard to get a torque without my torque wrench, but they weren't lose at all. After I got done, I grabbed my factory service manual out and brought it up to my room. Under Diesel engine diagnosis it says "Noise - "rap" from one or more cylinders(sounds like rod bearing knock) - Nozzle(s) sticking open or with very low nozzle opening pressure. That sounds like what I'm hearing and jives with the oil pressure still being good. I was always under the impression that if a bearing got bad enough to knock, you'd have an oil pressure drop. So, I guess tomorrow afternoon I'll crack the injector lines and see what I find. Thanks for the reply William, I'll keep everybody posted on what I find.

[spitfirenut]

I think I found it! I got out there and loosened injectors with no luck. Each one lowered the idle and caused a miss. But, when I got to looking around some more I found 2 bolts on the injection pump that were so loose I could slide a piece of paper btween them and the pump. The third was not that loose but was not tight. Anyway, I lined up the marks and it quieted down considerably. Still a little off, but I'm not as worried. Anybody within 6 hours or so of OKC got a timing meter that's willing to check it for me? Thanks,

[arveetek]

I'm 4 hours from OKC, and I have a timing meter for a short time....

If you look on the map, you can take I-44 East to Joplin, MO. Then I'm southeast of Joplin about 30 miles.

Let me know if you're interested....

arveetek AT j s c o m m DOT net (leave out the spaces)

Casey

[spitfirenut]

Originally posted by diesel65:
Check your torque convertor bolts. Well, the correct answer is: the torque converter bolts. I got back under the truck today and started taking the torque converter bolts out to try and run it with the torque converter unhooked and see if the noise went away and when I got down to the last bolt, bingo, the rattle made itself obvious. Apparently, I put the wrong bolts in when I hooked it up and they were just snug enough to not make a noise until the miles added up. Anybody know what the correct bolts are for a 700R4 torque converter? If not, I'll call GM tomorrow. Thanks,

[john8662]

I'd call a tranny shop, they're bound to have em.

Glad you found your noise!

I've had a groaning noise on my '86 truck that I NEVER could figure out, it would only come in during acceleration at about 1800 RPM and then go away (yes, I've got a Tach). I basicaly would accelerate harder to avoid the noise. I replaced just about everything I could, new engine mounts, drive belts, tranny mount, crank pulley, harmonic balancer. Well, as of this weekend, due to other engine problems (awaiting to be diagnosed) I pulled my engine out. When I got to the tranny I discovered the 3 bolt torque convertor. I proceeded to disconnect two of the bolts and then spin the engine back over to get to the third. Then I noticed that it was loose already. The third bolt didn't want to come out, but wasn't holding the TC to the flex plate securely. I got it out to find the threads on the bolt as well as the nut on the convertor were stripped. I guess since this is the original tranny that the bolt was too long or the nut on the convertor had a bur that didn't allow the bolt go in all the way, so it never anchored itself to the flexplate. Thats where noise was coming from, if I was a betting man. The bummer is that the flexplate is grooved (size of a washer) and the torque convertor stub is now shorter than the rest on the one bad one. So, I guess I'll be buying a flexplate AND a Torque convertor for a tranny that has 150k miles on it, kinda scary.

[spitfirenut]

Originally posted by john8662:
I'd call a tranny shop, they're bound to have em.Wound up going to the dealer. Weren't too bad. He only had 5, but I twisted one off trying to get it out last night, so I could only use 5. I also elected to leave one of the long ones in because it wasn't feeling too good when I tried to back it out. I figure I'll just check it a few times between now and the trip home and pull the tranny when I get home. At least now it's not rattling.
John, I would say to just have the tranny gone through while it's out but my last rebuild was about $850, so that's kind of an expensive preventive. Probably right about the growl though.
Just remember Kids, if it's a 700r4 with the threaded nubs on it the bolts are .590" below the head. Otherwise, they make a lot of noise. Unhappy noises at that.
Later,

[arveetek]

Hey Don!

I just wanted to say that I enjoyed meeting you last weekend. It's always great to meet fellow DP members and put a face to the name. I'm sorry I didn't have more time to spend with you, but I really had a great time. There's just something about being with your 'own kind.' :D

Casey