1990 noise like a rod knocking

[Debreke]

I am very new here and recently bought an old U-Haul van on a 1990 E350 chassis. 7.3 idi no turbo and C6 tranny. It has been a very good truck and I am running W85 in it. It has always been pretty noisy to me but recently it has gotten much louder, if it was a gas engine I would swear it had a rod about to come out through the block. Since I am very new to diesels I just don't know what to think. I have tried all the tricks like cracking each injector line. It definitely drops the cylinder when I do that but the noise does not change at all. I have been all over the thing trying to figure out for sure where it is coming from with no luck. The only time the noise changes is at about half throttle it seems to get much quieter. I've been all over it with a stethoscope but the noise seems to be everywhere, especially on the back two injectors and the bell housing. I pulled the bell housing inspection cover and found this has a heavy cast more like a flywheel than a "flex-plate" like on a gas engine. So I am thinking it is not likely cracked causing the knocking. I do not have a way to post an audio but if you have ever heard a rod out in a gas engine that is just what this sounds like. Much louder than a fuel pump or lifter knocking. More like a clacking.

Any ideas how to know for sure without pulling the motor and tearing it down? Remember this is an Econoline so pulling anything without pulling the motor is not going to happen.

Thanks in advance.

 

[FarmerFrank]

Have you read the "CHUFFING" artical by Riotwarrior? might be your troubles. Whats the oil pressure? Whats the miliage?

 

[rattleonby]

First...Welcome to the forum!! Alotta good ol' idi owners here for sure.

First is first...since your down there and ur bell cover is off you might as well check those converter bolts for looseness right? Can cause a "knocking" like noise at different rpm's and loads.

Second: Have you switched her back to diesel quick also? I'd try that also because from my experiences running WVO and WTO in my truck it can and does change the engine sound from fill up to fill up. Essentially your changing the cetane "octane in gas" rating without adjusting timing i assume...(more of a pain than a quick turn of a gasser distributor)

Another couple quickies would be to check oil pressure with a live gauge. Slap a new oil filter on and some fresh oil for giggles...Dont ever overlook the stupid stuff. Also do a UOA (used oil analasys) to see whats going on in that engine whenever you purchase any used vehicle really.

Welcome aboard and i hope i helped a tad....Merlin

 

[Debreke]

Have you read the "CHUFFING" artical by Riotwarrior? might be your troubles. Whats the oil pressure? Whats the miliage?

I am trying to find this "Chuffing" artical you speak of, but very new here. As for the oil pressure it is running the same as it always has about half way on the OEM guage. The mileage is unknown but believed to be just over 200,000. Thanks.

 

[Debreke]

I have checked the converter bolts and this one has a cast iron "plate" rather than what I am used to being a "flex-plate" like on a gas engine, seems unlikely that would crack. I have ran it very low on W85 and put in a half tank of diesel and no difference. As for the live gauge oil pressure I have not done that yet but will likely. I am also thinking about replacing the back two injectors to see if that will make any difference even though cracking those made no difference but seems to be louder than the others with a stethoscope.

 

[Debreke]

Have you read the "CHUFFING" artical by Riotwarrior? might be your troubles. Whats the oil pressure? Whats the miliage?

I did finally find the "Chuffing" artical but sure hope this is not my problem. he he he As this is a van I can't even take of the passenger side valve cover without dropping the motor. Going to try changing the back two injectors with new ones hoping that makes some difference. If not then I guess it will be time to pull my first diesel out and apart.

 

[OLDBULL8]

Before you change the injectors. Disconnect the fuel solenoid (FSS) on the IP, pull the 6 and 8 glow plugs out, plave a heavy rag over the GP holes, crank the engine over about 20 revs, check the rags for coolant. If coolant shows up it's cavitation making the clacking. Certainly hope not. Had a 90 doing the same clack, not good.

 

[vegas39]

I am trying to find this "Chuffing" artical you speak of, but very new here. As for the oil pressure it is running the same as it always has about half way on the OEM guage. The mileage is unknown but believed to be just over 200,000. Thanks.

I doubt the motor has 200,000 on it, Uhaul went through a few motors on these diesels, mostly due to driver abuse.

 

[riotwarrior]

Welcome to Oilburners, please, take some time to go through the FAQ, Tech, and Hall of Shame sections, those first two offer a lot of good info, then get into the hall of shame before spending money! You don't want to purchase from companies in there!

Also fill in your signature with your information so we know details about your vehicle.

Unless you hear a CHUFF from the exhaust and it's quite distinct so you'll know if you have it, or one from the intake opening, I doubt you'll have an issue with the valves as I did.

As Oldbull mentioned remove the two GP"s and crank engine over but use a heavy rag/s over the holes, and don't try to keep them in place to much with your hand, use a board or something incase a GP tip gets shot out or something!!!!

This knock you say was always there and got worse progressively, correct? For how long and how many miles?

As mentioned get some type of oil pressure gauge on that engine that provides a real reading! This is important for diagnosis of issue.

If cracking ONE injector line does not change the knock, what about TWO injector lines at one time?

We will help you as best we can, but do the digging n readin through the threads, SEARCH should become your NEW best friend here too BTW


Again welcome to OB

Al

 

[ToughOldFord]

You can pull the valve covers and the heads off a van with the engine in place. Not all that hard really, just time consuming.

 

[Knuckledragger]

Oil level? I had a very pronounced knocking sound on my first 85 for a day, but the culprit was that I had not checked oil in a while and it was about 2 quarts low. The noise was emanating from the lifters because they could not stay filled.