Troubleshooting from the road - valve/rocker noise - before you lose an engine

[OnDaRoad]

Looking for a silver lining here fellas - so PLEASE lend a hand with advice & pictures
so the next guy like me has an easier time:

1990 7.3 IDI w/ATS factory turbo
Rebuilt w/ 400K plus miles
Complete valve job 150K ago

Symptoms:

Lifter? rattle or loose rocker arm noise seems to come from top end
Slight loss of power - slight miss at idle when hot
Let sit overnight - started up in morning - no noise

Suspect:

Failing/failed hydraulic lifter
Breaking/broken valve spring


So - let's start by taking off the valve covers which I plan
to do tomorrow because it is raining like HELL right now

Troubleshooting sequence:

What specific things do I look for once the covers are off?


CHIME IN HERE

 

[OnDaRoad]

Anyone have ideas?

Any ideas on how to proceed?

Jim
(260) 570-7286

 

[LCAM-01XA]

I'd think it ain't no broken valve spring, if it were the valve would drop down and the piston would beat it to hell, the noise associated with which would be something that turns your hair white rather quick. Once the valve covers are off verify the rockers are tight, you'd know if one is loose right away when you touch them. Is the rattle your hear really loud, or is it more of a tick? If it's a tick I'm thinking you may have an injector issue... Also are you still on the side of the road, or you moved her to a safer place?

 

[OnDaRoad]

That is a start

Raining solid here the past two days
Before I pull the covers - the rain has to stop

I am off the road
I am in no hurry to lose my engine

I will try to pull the covers in the morning

I agree a valve has not dropped - yet


Jim

 

[LCAM-01XA]

Do you know which side of the engine the noise is coming from? Driver-side valve cover is easy, the passenger-side tho requires removal of the filter tower, which in turn requires alternator removal... And the more I think of that concept, the more I'm considering moving my filters to some other location - for that very reason, troubleshooting on the side of the road.

 

[OnDaRoad]

Good points

Good advice,

Not sure where the noise is coming from
I had planned on checking the driver side valve cover first

Thanks,

Jim
(260) 570-7286

 

[LCAM-01XA]

back on the injectors subject, if you have one slobbering it will cause a rattler and misfire. It may be that the injector needs to heat up (to normal engine temperate) before it loses internal tolerances and the issue manifests itself again, kinda like how when the IP's head is about to go... When it was acting up at first yesterday (or was it this morning?) did you try looseing the injector lines one at a time to see if one of them does not change the running condition of the engine? It's kinda like pulling plugs on a gasser, you will notice it run worse every time you loosen a line, except if one don't change how it runs, or happens to make it run smoother, then that injector may be your culprit.

 

[OnDaRoad]

Injectors replaced

I bought a set of injectors from (typ4) here from Russ & I installed them
about 3500 miles ago - Russ checks them before shipping
but it is possible that one is having problems

The problem started yesterday evening after I had been on the road about 2 hours

This morning - I only warmed up the truck about 10 minutes at idle
and moved it around to park in a different spot

You bring up a very good point ....


Jim
(260) 570-7286

 

[LCAM-01XA]

Still, give it a shot, I know Russ is good at what he does and stands behind his work, but mechanical things do act up sometimes even when they shouldn't.

 

[typ4]

So true, and it is nice to see that some get this concept, nothing more irritating than bad new parts.

 

[LCAM-01XA]

Russ, I've worked as an 18-wheeler driver, then a design validator for a major OEM supplier, and now I'm a mechanic - trust me, I've seen so many bad new parts it ain't even funny...

 

[damac]

I am no techie and am dealing with a truck right now with an unknown history. I was just about to rip into things today actually to get to the bottom of what we thought was an exhaust sounding tick that happened all of a sudden on the freeway towing a trailer, mixed with some blue smoke.

After searching here I have seen people mention injectors so the first thing I did was warmed the truck up to see where the noise was coming from, sounded like up top passenger side. With the tick it sounded like the intake was gulping as well?

Shut the truck down, took the fuel filter off and filled it with atf. Truck fired right up and within a few seconds the tick was gone???

I let the truck sit there and warmup, then we hooked the trailer up for fun and took it on some hills to try and beat it up. Didn't do anything for 20+ miles under load.


So all I can say is start at square one like me, you never know what could have happened even with "new" injectors?

This makes me wonder, lets says yours was an injector as well. Do we just keep running a little atf in our fuel fillups or is it expected that they will keep misfiring, etc. and must be replaced asap?

Ours are original part numbers, 230,000+ miles

 

[19jackal90]

got ticking in mine now. thinking i might have an exaust valve not seating. everything under the covers is good and the injectors are fine (swaped them out for the g codes).

 

[Diesel JD]

Where are you at? Someone might be able to lend a hand. I think the exhaust valve getting ready to drop usually has a slight miss at idle along with an abnormal popping in the intake or out the exhaust depending on which valve it is. There isn't any chance anything is laying on the injection lines like the throttle cable is there? Anything at all on there is going to make noise. Otherwise you might have to break down and pull those valve covers.

 

[geonc]

Give the dollar bill trick a try----with the eng idling, hold a dollar bill by the end right up against the exh outlet---it should constantly be blown away.

If it is being sucked back against the outlet then a exh valve is the culprit.

There isn't any chance anything is laying on the injection lines like the throttle cable is there?

JD brings an important piece of info Had a similiar issue on my old IDI and I was yanking hair