Engine/Transmission (1994 - 1998) "Clackity" noise during accel, valves adjusted; springs?

[DPadgett]

98 12v auto around 200k. 4" exhaust, FASS adj pump 90gph, injectors. During acceleration after the engine is warmed up there is a very noticable clackity sound that slows and speeds up with engine rpm. I know its a diesel and they make noise but this is higher in pitch than the low end, grunty, tones of the motor. I would compare it to a little 4cyl like in an older toyota pick up, real thin, clicky, etc. Just had valves adjusted which reduced noise slightly but not much, as well as new overflow valve. Had 4k gov spring kit installed a year or two ago, could that be it and if so is that normal? Thanks

 

[fest3er]

How many miles? How old is the lift pump? Give a listen; if it sounds like it is coming from the general vicinity of the lift pump, that's probably the source.

 

[DPadgett]

200,000 miles. No mechanical lift pump, it died around 15,000 miles ago and replaced with FASS mounted on frame near fuel tank. When I did have the mechanical lift pump it made the tapping sound, this is different. Sounds like its coming from the top of the engine or close to it.

 

[Mikey-KE7LBB]

Possible that one of the jamb nuts that keep valve lash has backed out a bit and is making a racket. I found this out on a 93 while setting the overhead and missed my mark then rotated engine backwards to set the valve lash on #6
started and run fine, but had a ticking that I couldn't figure out. Next day, I checked the lash and it was off by . 040 and I set it again. The noise went away and all was well.

 

[1tuffram]

98 12v auto around 200k. 4" exhaust, FASS adj pump 90gph, injectors. During acceleration after the engine is warmed up there is a very noticable clackity sound that slows and speeds up with engine rpm. I know its a diesel and they make noise but this is higher in pitch than the low end, grunty, tones of the motor. I would compare it to a little 4cyl like in an older toyota pick up, real thin, clicky, etc. Just had valves adjusted which reduced noise slightly but not much, as well as new overflow valve. Had 4k gov spring kit installed a year or two ago, could that be it and if so is that normal? Thanks

Have you figured out what the noise is yet. I have been chasing the same type of ticking/clicky/clatter sound for awhile and still yet to figure it out. Mine sounds like upper valve train noise and last year I adjusted and re-adjusted the valves 3 or 4 times over a weekend and the noise persisted regardless if I set to the factory specs or a few thousands tighter. I could not see anything visibly broke, excessivly worn, etc while the valve covers where off. I replaced the fuel pump hoping by chance that was the problem, but it was not.

I seem to notice the rattly sound more if the engine is cold and more around 1800-2000 RPM under very light acceleration. The sound is most noticable when letting up on the gas pedal a bit after light accelartion around the 1800-2000 RPM range (engine with very little load on it).



I had the truck in for an emissions test a few days ago and the test center uses a mustang dyno to load the engine. Something I noticed when the engine was loaded during the test was a constant pretty heavy black/greyish haze from the exhaust and about every 3 or 4 seconds a heavy puff of blackish smoke. The emission center said I barely passed with 22% opacity and power is low (203 hp) for typical older 12v trucks they see. Last year my emissions test at the same place opacity was 15% and power was 209hp and no puffs of smoke coming from exhaust even thought I was having this ticking/clatter sound with the motor at that time. One thing I would like to mention is during the emissions test the cat converter must have got good and toasty because the exhaust had that funny "hot" diesely smell and while driving home I COULD NOT get the engine to make the ticking/clatter sound, but the following morning when driving to work the sound was back. My question is what can be going on? Could I have a bad valve or maybe a bad injector?????? I don't know what type of problems one would see if an injector or valve was bad.

 

[DPadgett]

1tuffram, unfortunately I have not located the noise yet, although it seems to have quieted a little bit. A very little bit. Good news is it seems that we are indeed describing the same noise, mine is also more prominent when the engine is cold, though it seems to never quite go away even after warm and with the engine idling, and is also most noticeable in the 1400-1900 rpm range under light acceleration or letting up on the accelerator like when going down a slight grade. Like in your case, doing a valve adjustment did not really make a difference on mine. As far as the emissions, I live in Georgia and currently diesel pick up trucks 2006 and older I believe are not required to have emissions just yet anyway, that could change soon. But I have never had an emissions test done on the truck. As far as the injectors being the culprit in my case anway I hope they are not simply because they are more HP than stock and were changed just last year. I could be mistaken but I want to say that it didnt make this noise at all before I had the timing adjusted. Does anyone know if there are any parts/adjustments to the timing that if not done exactly or whatever could result in a noise like this? I like Mikey-ke7lbb's suggestion concerning a valve jam nut but it seems after adjusting the valves and rechecking numerous times like you did surely something like that would have been discovered and corrected.

 

[Lonestar]

My 98' has a very similar noise, which I fear is a slightly hurt piston. I have read before about guys with similar noises having minor scarring from a damaged piston that creates a very distinct tick or knock in some cases. I am going to pull the head off my truck and see if my thoughts are correct or not. I hope not, but I feel that is the answer. If so, I guess its time for a shortblock.



Corey

 

[1tuffram]

My 98' has a very similar noise, which I fear is a slightly hurt piston. I have read before about guys with similar noises having minor scarring from a damaged piston that creates a very distinct tick or knock in some cases. I am going to pull the head off my truck and see if my thoughts are correct or not. I hope not, but I feel that is the answer. If so, I guess its time for a shortblock.



Corey

OH boy that's not what I wanted to hear. Do you think a bad piston could be causing the puffs of smoke from the exhaust during my emissions test?

Does the head have to come off to check for this or can a compression tester be used to verify a bad cylinder or bad valves?

I sent off an oil sample last year and from what I remember everything seemed ok.

For me the clattering noise seems to be coming from under the dash on the passengers side and is only reproducable while driving, it won't do it parked in neutral (which makes it next to impossible where it's coming from) I wish the emissions center would let me in the shop while running the test so I could listen in the engine compatment while the operater slowly load the engine until the clatter sound appeared then maybe I could figure out where it's coming from.

 

[DPadgett]

Lonestar, please let us know what you find out when you pull the head. If it is a hurt piston, and I would imagine this would be worst case scenario, anyone have any idea how much it would cost to have the problem piston replaced? Would the fix stop there or would other parts/components need to be replaced as well?

 

[38flathead]

I had a chatter from my 96 12v after using a stethescope I found the noise comming from my vacuum pump I removed the pump found 6 broken teeth on drive gear pulled timming cover removed broken teeth replaced pump and it's back to normal. sure was amazing some of the bs people on this sight people were telling me, like these motors are noisy {duh!} to begin with and that it sounded like #5 piston is scorned . the whole time it was making the noise the motor still preformed flawlessly . so take alot of this advise lightly. It was hard for me to believe that all these opinionated people that look and comment on this sight never even mention the vaccum pump!! 120. 000 miles good luck

 

[DPadgett]

38flathead, thanks for the advice! I am gonna PM you with some questions concerning the noise you had and removing/replacing the vacuum pump

 

[SFPADGETT]

If you pull the vacuum pump to check for broken teeth, then go ahead and replace the seals while it is out. I have the plastic "tools" to put the seals in with if you need them, or you can come down and we will do it here at the shop. If broken teeth on the gear, then more is involved in pulling the timing cover and removing the broken bits. Have you done the KDP fix, if not, now is the time with the timing cover off. Let me know if you need any help. Uncle Steve

 

[1tuffram]

any updates?

 

[Gene Arnold]

I may be way off in imagining your noise, if so, discard the following.



I had an irritating noise that I put up with for a long time. It was a tinny rattle that I just could not figure out until one day I put my hand on the decorative cover that sits atop the rocker covers. The rubber grommets had deteriorated and were allowing enough play to give me the sound. My remedy was to take it off and it still sits on a shelf in my garage. Someday I may find (or make) new grommets and reinstall it, but right now I'm OK without it.



Gene

 

[ChrisOlson]

Hello
my 2 cents
Before going to the taking off the head try a simple fix.
try an injector cleaner Like schafers or howes not a cleaner with alcohol.
if you injectors are a little gummy you would get a puff of smoke and early deteonation that might cause pinging of which could be interpreted as ticking.
Also I have heard that the # 6 piston oiler tube has a tendency to clog causing a ticking sound that resembles valve ticking

hope some of this helps

Chris

 

[DPadgett]

Chris, how do you check the # 6 piston oiler tube? Is it fairly easy to do? Thanks

 

[1tuffram]

Hello

my 2 cents

Before going to the taking off the head try a simple fix.

try an injector cleaner Like schafers or howes not a cleaner with alcohol.

if you injectors are a little gummy you would get a puff of smoke and early deteonation that might cause pinging of which could be interpreted as ticking.

Also I have heard that the # 6 piston oiler tube has a tendency to clog causing a ticking sound that resembles valve ticking



hope some of this helps



Chris

I run amalgamated TDR formula fuel injector cleaner/lube in every tank for past several years, if anything I usually add more than what the recommended amount per tank.



The dodge decorative cover that goes over the valve covers has been sitting on my workbench ever since this ticking sound started and I was frequently re-adjusting the valves.



The ticking sound seems worse before the engine gets up to temp when driving to work in the mornings. Is there a way to determine if this could be an injector problem vs say a valve-train issue?

 

[DPadgett]

1tuffram, I am also beginning to think that it is possibly an injector issue. I have been trying to remember if my truck made this noise before I had some aftermarket injectors installed. I don't know the make of the ones that where put on, but I am pretty sure I didn't hear the noise before they were installed. One thing that leads me to think that it is injector noise is some of the posts I have read in the 3rd gen 24v forums concerning "injector knock", where guys are discussing new injectors sometimes resulting in a tick or a knock that seems similiar to the noise that we have and are trying to figure out.

 

[fest3er]

Stethoscope (or looong screwdriver w/handle to the ear if you don't have a 'scope handy). Listen to this 'n' that on and around the engine whereever you can reach: injectors, delivery valves, valve covers, et alia. You ought to be able to detect *where* something doesn't sound right.

 

[Lonestar]

My story certainly hasn't improved. I was trying other options to eliminate my noise before removing the head. The first thing I decided to do was install new injectors as mine were at roughly 210k miles. I changed the injectors with no difference in noise. My truck has always run great. I took the truck to Amarillo on a work trip, and blew something while I was in Amarillo. The truck was running fine, pulled into a truck stop for fuel, shut down to fuel, and on restart the motor went to h$ll. I have been too busy to pull the head, and plan on taking the truck to my mechanic next week for repair. I fear it is what I mentioned in my first post and that my luck ran out. I will advise as I make progress. Hopefully we are describing different noises!!



Corey