[arisley]

First off, long post, but you gotta know wher I am.

OK, here is my problem first. My truck has a wicked vibration under engine load. It does this in park, neutral, reverse or drive. In park or neutral it happens at ~1200 to 1400, in Drive or reverse, it happens at 2000 to 2200. (kinda scary in reverse). I can run up to 3500 RPM's in park or nuetral. Always has a miss (almost like a dead hole but not quite). This vibration will make the front bumper vibrate so bad you gotta make sure not to stay away from it (bet it would hurt if you barely touched it).

What I have checked to date.

Took it out and drove like a madman and did not blow it up. (not a rod or anything else like that)

UVCH pulled both VC, pulled harness, folded, spindled and mutilated and could find nothing but 0 ohms on any wires (SOCG=system ops check good)

Did the same to gasket connector. SOCG

Replaced fuel filter, only 3k on old filter and it looked good, replaced anyway.

Changed oil, only 3k on old oil and it was full and looked fine.

Tested fuel pump flow, 1 quart really fast (less than 30 seconds, probably 15 or 20) SOCG

Disconnected EBPV sensor ot the turbo. no change

Disconnected wastegate. No change

Blocked go pedal at vibration and crawled all over the engine with a steth. Could not find the vibration.

I have been sleeping (sometimes I go to sleeping with a problem and dream the fix, true, you can even laugh if you want. I do) and reading everything I can. Have come up with three more possible problems.

1. IPR, gotta find a socket that will fit, take it apart and see.

2. Clogged (from previous episode with bad fuel) CAT.

3. I did the pre tank mods,Guzzle's version (if this is the problem, it's my mistake, not Guzzle's). Could I have put the intake line to close to the bottom, causing fuel starvation that gets really bad at load put engine off will give good flow. Or used inferior (O'Reilyy's Auto fuel line for fuel injected vehicles (they said it was OK for diesel)) fuel line that is breaking down (causing tha all the time miss) and actually collapsing under load (causing the vibration from [email protected]$l).

Or could I be missing the boat completly and this is an engine that is (stick a fork in it) it's done.

Help.

 

[action4478]

Have you looked at the HP oil system? ICP ,IPR & EOT as it compares to ambient air temp?

 

[arisley]

Not yet, on the list, in fact, it is on the top. I did unplug IPR, no change. EOT seem about like normal, just by feel, no guage.

Thanks

 

[Kanman]

[ QUOTE ]
Or could I be missing the boat completly and this is an engine that is (stick a fork in it) it's done.


[/ QUOTE ]

Naw, it's something simple, that's just hiding really well /ubbthreads/images/graemlins/bleh.gif /ubbthreads/images/graemlins/biggrin.gif. These engines are tough, they don't give it up that easy.

I would rebuild that IPR and then move to the ICP. Any smoke while all of this is going on? Disconnect the ICP sensor while it is running see if there is any change.

 

[arisley]

[ QUOTE ]
[ QUOTE ]
Or could I be missing the boat completly and this is an engine that is (stick a fork in it) it's done.


[/ QUOTE ]

Naw, it's something simple, that's just hiding really well /ubbthreads/images/graemlins/bleh.gif /ubbthreads/images/graemlins/biggrin.gif. These engines are tough, they don't give it up that easy.

I would rebuild that IPR and then move to the ICP. Any smoke while all of this is going on? Disconnect the ICP sensor while it is running see if there is any change.

[/ QUOTE ]

IPR is next on the list, already tried unplugging ICP, no change. No smoke at all. The only time I have ever seen smoke from this engine is when I was hooked up to a overloaded tractor trailer and pulled him off the road. She was smoking then. But she got the job done. Even with this problem, she is still making good power, but not normal power. If I have to slow down from freeway speed to like 50, when I speed back up, she downshifts. Never used to do that. Don't suspect tranny though, just a power thing. Seems to be a fuel system problem.

 

[ddog]

You didn't mention it, but I take it no codes or SES light? Try the "finger" test from cold start. If you have an injector not fueling that cylinder will be colder than the rest to the touch. Touch the part of manifold nearest the head for each cylinder, you can reach them all through the fender. Before I scanned mine, this told me #5 was the problem and scanning turned up the 1275 code confirming the finger test. Other than wiring checks,Haven't narrowed mine down any further though yet.

What your describing sounds like a dead cylinder, mine vibrates like crazy while driving , at idle it just shakes like a V8 with plug wire off, not as bad as what your describing. What about cracked flex plate or harmonic balancer problem? Hope you get it figured out.

ddog

 

[arisley]

No light or codes/per Snap On scanner.

I did try the finger test. All cylinders are firing, that is why I am leaning towards an issue with high pressure oil. I think the IPR is dirty. Got to find a 1 1/8 socket that I can modify. All my cheap sockets are either to little or too big. Missing 1 1/8. Running by a couple of pawn shops tonight. IPR is not leaking.

Hope it is not a flexplate or harmonic balancer problem.

Thanks

 

[arisley]

OK, going to pick up the IPR rebuild kit from International tomorrow. Will post results. Hope to finish off this thread.

 

[ryanPSD]

Yes please let us know. I have some similar issues you do, but also low ICP when towing, setting CELs, even in stock programming. The motor shakes like whoa... mostly at the top end, and a bit around 1000 and 700. No stumbles though. As far as my check engine lights are concerned I am suspecting the IPR, and am hoping to clean and rebuild it when I have time in the next month (busy and need the truck the next couple weeks). I just today made a tool to remove it in fact...

 

[arisley]

Have not had the time to do this yet.

 

[skylinedan]

Hay, mine has a little shake to it too, did you do a cylider contribution test. I did one the other night when the CPS went south and found #8 not carrying the load. Also if you have one, a themo gun is a great way to find dead cylinders, I have one and use it a lot to diag. misses in cars that come here. I paid around 100 bucks for it and I think its already paid for it self.

 

[skylinedan]

I went out and checked the temps of all the cylinders at the exhaust manifolds, heres what I came up with.

#1 190.0
#2 219.0
#3 212.0
#4 212.5
#5 203.0
#6 207.5
#7 215.0
#8 216.0

I started on the pass side front to back then to drivers front to back, I don't know the actuall firing order on these motor so I did it this way. Hope this may shed some light on your problem.

Dan

 

[arisley]

Got my IPR out and apart, the piston and cylinder was hard to get out. I betcha this is my problem. The next step is (temp) removal of the cat to see if it is plugged. Found a piece of 3 1/2 ID tube to replace the cat (FOR TESTING PURPOSES ONLY) to see if that fixes it. I bet this IPR fixes it though.

 

[arisley]

Got it put back together, in between honey-dos. Still there. On to option 2. Cat delete (FOR TESTING PURPOSES ONLY).

If a TC messes up, can it cause a vibration in neutral? Really think this is fuel related though. It is a continuation of by bad fuel episode.

Am really hoping that my bad fuel stopped up my cat. I know I have one on there, but I have searched all over for a label on my truck that says it has one. I cannot find it. Not on either VC, both clean. Not on a label like you usually see under the hood.

 

[klhansen]

Andy, I think you're barking up the wrong tree with fuel and exhaust issues. Although an injector miss can cause some vibration, it's not really noticeable at the higher rpms. I've cut out injectors on the highway, and other than a little roughness in the sound and SOTP, it's really not that much. A clogged exhaust would just cause low power and high egts, not vibration.

I'd be leaning toward a mechanical problem, such as TC or harmonic balancer, or even possibly something driven by the serp belt. You can run it for a short time for diagnosis without the serp belt installed (I've even done this at highway speeds) and not hurt anything. If the vibration goes away, you can concentrate there. If it doesn't, you'll have to keep looking. And, yes, a trashed TC could cause problems in neutral, although I think you'd find more issues than just vibration if that was the case.

A compression test would be a good step, although, again a low cylinder won't cause severe vibration, unless maybe it's zero and there's a chunk of piston laying in the oil pan. /ubbthreads/images/graemlins/frown.gif But you've pretty much ruled that out with the cyl exhaust temp test, indicating that all holes are at least firing. [insert Graemlin wiping his brow in relief]

I believe the early 99's didn't come with a CAT. Mine (99.5) didn't although it's a manual tranny.

One other thought. Does your SES light work? (should come on when you key-on and wait to start)?

Good luck with it.

Kevin

 

[arisley]

Yes, my light works, had codes pulled, no codes. There is a round thingy on the exhaust that looks like cat, and is sitting where a cat is supposed to be. Is there something else it can be? Not being a smart aleck, just double checking myself. I had heard that early '99 did come with one but cannot find any reference to it.

I did run the motor without the belt, vibration still there.

TC still locks up like always, tranny shifts normal, downshifts a little sooner, I am assuming because of the power loss. Does seem to be a LOT more heat from under the hood, engine temp is normal. That is one of the reasons I am suspecting the "cat".

Can I run the motor without the harmonic balancer??

Thanks for the help.

 

[klhansen]

Andy, I was just trying to make sure you checked everything. If I suggested something you said you already checked, it's just me not reading closely. /ubbthreads/images/graemlins/crazy.gif If you've got a cat looking thing in your exhaust, it's probably a cat.

If you have an infrared thermometer (aka temperature gun), you can use it as a pyrometer. At idle you should see between 200 and 250 at the up-pipes (turbo inlet). Kind of hard to use one of those at higher loads (under way), unless you have a friend willing to strap himself to the undercarriage when you drive. /ubbthreads/images/graemlins/phoney.gif If you run the rpm's up the EGT should go up over 300 pretty quickly. Sorry I can't give you more specific numbers.

No, I don't think you can't pull the harmonic balancer and run the engine. All your oil would probably squirt out thru the hole where the balancer was. That's where the LPOP is. You might be able to inspect it in place for any evidence that the outer portion of the pulley has slipped in relation to the inner portion. They're separated by a rubber ring bonded to both pieces, and it could have lost it's grip. Not sure how you would tell it's done that though, and on second thought, the harmonic balancer should be "balanced" anyway. It's really there to dampen torsional (in the direction of rotation) vibration. Someone else may be able to give you some more info on the balancer.

 

[arisley]

[ QUOTE ]
Andy, I was just trying to make sure you checked everything. If I suggested something you said you already checked, it's just me not reading closely. /ubbthreads/images/graemlins/crazy.gif If you've got a cat looking thing in your exhaust, it's probably a cat.

If you have an infrared thermometer (aka temperature gun), you can use it as a pyrometer. At idle you should see between 200 and 250 at the up-pipes (turbo inlet). Kind of hard to use one of those at higher loads (under way), unless you have a friend willing to strap himself to the undercarriage when you drive. /ubbthreads/images/graemlins/phoney.gif If you run the rpm's up the EGT should go up over 300 pretty quickly. Sorry I can't give you more specific numbers.

No, I don't think you can't pull the harmonic balancer and run the engine. All your oil would probably squirt out thru the hole where the balancer was. That's where the LPOP is. You might be able to inspect it in place for any evidence that the outer portion of the pulley has slipped in relation to the inner portion. They're separated by a rubber ring bonded to both pieces, and it could have lost it's grip. Not sure how you would tell it's done that though, and on second thought, the harmonic balancer should be "balanced" anyway. It's really there to dampen torsional (in the direction of rotation) vibration. Someone else may be able to give you some more info on the balancer.

[/ QUOTE ]


I understand about missing something or forgetting an earlier step in a post. Sometimes I get posts mixed up. I think it's a cat but it might be a dog, LOL.

I need a temp gun, but I can tell SOTP that my EGT's are significatly higher. When I open the hood there is a LOT more heat coming from the back of the engine bay. Not sure how much.

Think I will skip trying to run the motor with a harmonic balancer. I have seen that problem on gassers, I feel pretty sure that's not it.
Gonna keep it in mind and not rule it out.

There's a kid down the street I think I can talk into strapping to the frame rail. That's my next move.

Thanks for the pointers, you are one of the many guys on here that I trust there opinions and instincts.

Andy

 

[ryanPSD]

Have you checked your motor mounts?


I am suspect of mine, but they "look" okay, not like what I would think they would look like for as much shake as I have. I tested it once with a friend looking under the hood while I revved it and slipped the clutch to load the engine, and he said he could see one side of it rise some and said it looks like motor mounts are shot... but I'd think they would look broken or something? Last I checked they looked solid, so I am not really sure how to test or check them. I have thought about the possibility getting of a fluidamper but I don't want to mask the symptoms if the issue isn't an out of balance engine (aka mounts or something else).

 

[arisley]

Never crossed my mind. Motor mounts are now on the list. Doesn't feel right though.

Thanks.