The Stovebolt Site Forums The Shop Area Engine Shop Weird noise

Ok Gents,

After figuring out that my ‘54 235 was mechanical lifters (not hydraulic), I have the valve lash set (cold) and then adjusted once hot (including a rechecked).

Issue: I have a sound coming from the top end (?) that reminds me of the lifters/valves clattering on an old diesel engine. I can’t figure it out.

It originally started under load at around 2,000 rpms (guessing) and will now start and extend into the idle (clutch in). The sound fluctuates with RPMs but will not do it when parked (when reving) or at idle. The top end has oil dripping from the lifters and it maintains oil pressure.

Any thoughts or ideas are appreciated! I will report back all findings if I know how to do it!

Chris

Chris, you may have to strap a Go-pro under the hood and post a link to a video for us to help much. Otherwise, it's just it sounds like "clack-clack-clack".

Thats the problem with diagnosing over the internet.

I have a video from when I was driving it. But not sure how to post a video. Ultimately, I’m just trying to figure out what I need to start checking to diagnose the issue.

I’m going to get new rocker arm shafts in case the oil pressure is low or they are badly worn out. I’ve considered popping the head off and looking at the valves. Etc

I realize it’s like walking into a mechanic and trying to imitate the noise.

Are you absolutely sure you have hydraulic lifters?

I have solid/mechanical lifters

Sorry, I mistyped. I meant are you sure you don't have hydraulic lifters?

I only ask because I have seen an inline 6 (Ford) with hydraulic lifters that someone seemingly adjusted as if it had solid lifters. Not good.

Otto,

I originally adjusted them like hydraulic lifters and she wouldn’t run (no compression), I backed them off as if they were mechanical lifters and she runs great. Every cylinder is spot on as per the manual. Even tightening them up slightly more and they still make the diesel lifter clacking sound

Do you have any history on the engine? If the pistons and/or rods were installed 180 degrees out ("F" mark toward the back) the engine will rattle like a diesel- - - -piston slap due to the wrist pin offset being in the wrong direction. If the rods are numbered, the numbers should face toward the camshaft. That's easy to check by dropping the oil pan.
Jerry

I have zero history on this engine. When I test drove it and ran it for the last 18 months, it drove nicely. It started to make this sound over the last 3-4 months.

Here's an old diagnostic trick- - - -try retarding the ignition timing about 10 degrees- - - - -so the spark happens when the BB is about 1/2" to the right of the pointer, toward the inner edge of the timing hole toward the pushrod cover. If the pistons happen to be installed backwards, the noise will diminish, or maybe go away entirely. Performance will be lousy due to the late timing, but there should be a noticeable difference in the noise.
Jerry

Chris, around 1980 I had a situation that sounds sort of similar. One thing: the noise showed up suddenly and it wasn't exactly constant. At low speed and at idle, I didn't notice it. It turned out to be a single valve spring that had broken oddly at the very final spring winding (not where I would expect that to ever happen and I've never seen one break like that since). It caused the spring to continue to "sort of work" but not as it should. At least that's what I finally decided happened. It made the noise like you described but not for long enough for me to figure that part out and such a small part had broken I thought that might be why I didn't notice it running much differently. The same spring soon also broke pretty close to the center of the winding coil and when I removed it, there were three pieces...one strange small piece down at the bottom and then the two larger broken pieces when the spring finally gave up the ghost. All springs had been replaced when a valve job was done a couple of years before that and I figured one of them was defective. More proof of that idea: Around 1990 another of those springs broke but not down at the bottom. At that point I went ahead and replaced all of them. May not be your problem but good luck! Might also be a sticking valve, I suppose.

Also, Chris...after all that happened on mine I bought a cheap stethoscope so I could listen to each valve. You can see those for around $10 or so at Hazardous Fright Tools. If you hold the little needle on top of the spring retainer, you can hear what's happening with each valve.

Thanks Jon!

When I go out today, I will do an inspection. I considered that it might be something like that, but was unsure what the symptoms would’ve been or how to narrow it down since I don’t want to just throw money at it

Chris

I’ll report back!

If you can get it to make the noise whilst idling in the driveway….one easy check you can do.

Pull one plug wire at a time and see if you can make the noise change. This wouldn’t tell you exactly WHAT is wrong, but might help you isolate it to one cylinder.

This test might also tell you absolutely nothing but it’s super quick and easy and you aren’t out anything trying it.

Findings:

I took off the rocker shafts. They had pretty good grooves in them and loose chunks of stuff inside them. I replaced them!

Rocker arms looked very good and minimal marks (fingernail couldn’t feel it). I had some better rockers so I used them and inspected everything.

Valve springs were tight. I was able to move them 1/8” max. They were all equal tension (used my calibrated lack of strength)

Once I get the broken thermostat housing painted and replaced, I will set the valve lash and test drive.

If it still does it, I’ll try pulling plugs and what Jerry stated earlier. I don’t want to do everything at once or I won’t figure out what it is.

More info to follow!

Chris

I would bet you have it licked with the rocker shaft replacement. But keep us posted

Will do I will post the results!

Update: The whole engine is assembled, minus the lower radiator hose that was no longer pliable enough to stretch over the water pump outlet. I just valve lash set cold, I can run it and reset it hot. I am going to run a ton of water through the old radiator as I saw a brown colored fluid come out of the lower hose.

More to follow!

Chris

Update: wrong hose was sent so I’m on standby until next week!

Please don't trash those worn shafts- - - - -I grind them to a smaller diameter and put Torrington roller bearings in the rocker arms. The shafts can also be turned upside down, new oil holes drilled, and the original oil holes blocked with pressed-in brass plugs. The shafts only wear on the bottom.
Jerry

I tossed them, but I’ll go pull them out of the trash for you!

Chris

Update: the thermostat housing I bought broke. So I’m waiting for a Stovebolt brother to send me another. Just need to get back from my US tour to install it!

Chris

You'd better not have passed through Ft Payne w/o telling ....

How does a thermostat housing break? I assume it didn't break while you were installing it due to over torquing but rather in use?

The first one was cracked when I removed it. The second one cracked when I threaded a bolt into the hole. I was snugging it up and the threaded portion broke. I assumed it was a manufacturing defect.

Something isn't right if they break at the mounting ears. Maybe the mounting surface isn't flat?

One had a broken ear where it screwed to the block, the other had the threads break where the upper housing screws to lower.

Completely different places!

If the thermostat doesn't stay in its little groove, it will stick out on the bottom and cause the housing to break because it's no longer a flat surface.

It’s still in the groove. I was careful of that. I will post pictures of where it broke once I get back home from our vacation.

Picture of where the ear broke

Not the best place for a ground cable.

Looks like JB Weld is going to pay you a visit

Otto,

I already got the new one painted. The gaskets should arrive today!

BC59,

I agree. Previous owner had it there. As I have money, I’ve been fixing his shade tree mechanic stuff. If I told you what I found and what I’ve fixed, you would say that ground is nothing compared to it!

Chris

You should be able to find the lower housing here on the swap meet. Never seen a ground located there, and for good reason!

I may have both the upper and lower thermostat housings if you can't find them locally.

I’ve already found the parts and gaskets. Parts are painted and back on the 235. I’m going to check torque on bolts and fill her up so I can start her, recheck all the adjustments/upgrades (?), and then get her up to temperature/test drive.

More to follow!

Chris

After full installation of the following, the noise is still there!

1. Replaced rocker arms (I had a second set)
2. Replaced rocker shafts with new ones.
3. Replaced water pump and added a larger diameter fan (has nothing to do with the sound)
4. Fixed a broken thermostat housing
5. Reset valve lash

So far, I bought new gaskets (fixed leaks), painted parts, and new rocker shafts. The rest are extra new parts I had laying around for emergencies.

I’m starting to think that I have a lifter that is not moving through the whole range of motion. Maybe a weak valve spring?

It sounds great at an idle when I can have the hood up. I’m tempted to zip tie my phone under the hood so I can record the sound!

Info added; I’m not hearing a misfire or feel like I’m losing power like expect from a stuck lifter or bad spring.