# 2001 Silverado 5.3ltr shudder



## Mrbuilder (Nov 15, 2016)

Hello all, I have a 2001 5.3ltr that has begun to shudder while under low load, and in overdrive any speed, about 1100-1200 rpm. cleaned my throttle body of carbon from reg fuel, installed a new TPS about a month ago. any ideas guys ??

thx in advance :vs_cool::vs_cool:


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## ukrkoz (Dec 31, 2010)

What kind of shudder is it?
Engine, transmission, wheels, body?


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## 123pugsy (Oct 6, 2012)

Every time I've developed a "shudder", it's been that it was running on seven cylinders.

Hold it, I lied, once a chunk of fan blade broke off and gave it a good shudder.

Out of balance condition. 

Whoops, lied again, the other time was the rubber bushing in the drive shaft, hanger bearing, was toast and the drive shaft was jumping around.


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## ukrkoz (Dec 31, 2010)

Yeah, and idler/Pitman/end links/hub bearing/locking caliper/slipping transmission.
So, back to my question?


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## Mrbuilder (Nov 15, 2016)

feels like an engine shudder gang. but, I take really good care of 30-40k priced vehicles. this one has 376k on it. 2 trannys, 1 rear dif, new throttle body, lubed religiously every 3k, sat radio (lol) When I'm on level ground cruising and press throttle lightly, it shudders. When I release throttle it stops. If I put it under heavy load,(passing gear) it doesn't shudder. could it be the throttle body again ? I still use regular fuel. Last cleaned in SEPT.

P.S. just got up here in TN was up really late.:vs_coffee::vs_coffee::vs_coffee: Mr. George Dickel and I had a wonderful time last night !!! :smile::smile:


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## 123pugsy (Oct 6, 2012)

Throttle body is not like a carb that needs to be kept almost spotless.
It's just a big air valve.

Check your spark plugs/wires.


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## 123pugsy (Oct 6, 2012)

ukrkoz said:


> Yeah, and idler/Pitman/end links/hub bearing/locking caliper/slipping transmission.
> So, back to my question?


Never seen half the things mentioned above shudder. Interesting.


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## lenaitch (Feb 10, 2014)

Does it do the same thing if you drop it out of overdrive (either by button or pulling selector down a notch). It might be your torque converter trying to lock up like it should but can't. How's your transmission fluid level?


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## ukrkoz (Dec 31, 2010)

123pugsy said:


> Never seen half the things mentioned above shudder. Interesting.


Yeah, you just read about GM truck death wobble. Took 3 inter related suspension and steering parts to fix it. On, surprise, 2000 Silverado with 5.3L Vortech - which is basically his car. So I sort of have 1st hand on this, you know.


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## ukrkoz (Dec 31, 2010)

123pugsy said:


> Check your spark plugs/wires.



Second this. You do not tell how many miles on your car. 2001? 15 yo, 15 x 12000=180 000? 
Get truck some dark place, pop hood open, spray soapy water onto wires. Hear any crackling? There you are. Leaking wires will give you hell of shudder.
Next. If it's consistent with speed, I'd go for hub test. Is it tracking straight or snaking on the road?
Next. Power train mounts.
Fuel supply.
Can you reproduce that shudder with truck NOT MOVING? Simply held at those rpms? If yes, it's engine/transmission. If no, It's drive train. Hubs, all the good stuff I mentioned.


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## Mrbuilder (Nov 15, 2016)

thx lenaitch, Fluid level full and no burnt smell at warm idle pard. thought that might be prob, but not an issue. actually haven't used selector to test yet. great idea though !! thx get back to ya soon And, thx ukrkoz doesn't appear when not in gear.


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## lenaitch (Feb 10, 2014)

I think it might be important to determine if the shudder is related to vehicle speed, engine speed or drivetrain speed. I'm little help in providing answers to the answer but others no doubt will.


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## Mrbuilder (Nov 15, 2016)

UKRKOZ feels like an engine shudder gang. but, I take really good care of 30-40k priced vehicles. this one has 376k on it. 2 trannys, 1 rear dif, new throttle body, lubed religiously every 3k, sat radio (lol) When I'm on level ground cruising and press throttle lightly, it shudders. When I release throttle it stops. If I put it under heavy load,(passing gear) it doesn't shudder. could it be the throttle body again ? I still use regular fuel. Last cleaned in SEPT.


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## Bondo (Dec 8, 2007)

Ayuh,.... If ya think it's the motor skippin',.....

How long has it been since the spark plugs have been changed,..??
Do a compression test while yer changin' the spark plugs,....

A compression test is a _Great_ way to determine the motor's general overall health,.....


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## SeniorSitizen (Sep 10, 2012)

If you can avoid the clutter and get to the individual exhaust manifold connections, take their temperatures at lo idle and again at hi idle to see if one or more cyls may be sick with low temperature.


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## ukrkoz (Dec 31, 2010)

Mrbuilder said:


> UKRKOZ * feels like an engine shudder *gang. but, I take really good care of 30-40k priced vehicles. this one has 376k on it. 2 trannys, 1 rear dif, new throttle body, lubed religiously every 3k, sat radio (lol) *When I'm on level ground cruising and press throttle lightly, it shudders.* When I release throttle it stops. *If I put it under heavy load,(passing gear) it doesn't shudder. *could it be the throttle body again ? I still use regular fuel. Last cleaned in SEPT.


So we have 3 pieces of information.
1. feels like power train shudder.
2. shows under low load
3. does not show under high load.

Engine skipping? What is THAT? Missing? We already advised OP on wires/plugs. So far, he ignored that.
I say it's fuel supply related OR EGR valve. Every time I had EGR dirty, it will manifest itself with engine jerking at low RPM/low load.
I'd go for EGR. Not much of trouble getting to it, it's in your face. Easy removal, he he, if you have ample supply of Quick Wrench and are lucky not to break corroded flare nut. :vs_mad:

No, throttle body ain't got none to do with it, take your mind off it. 
Plugs.
leaking wires
EGR.
Fuel supply. Pump/filter/pressure regulator. 
Btw, those pumps are known to have bad ground that is total PITA to get to to clean. But then they simply die. Also, pump has pre-filter on it that gets dirty.
You realize it is not $40K vehicle anymore, right?


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## Mrbuilder (Nov 15, 2016)

Yup not a 40k truck anymore, just 30-40 to replace it, lol BTW gang, it's an extended cab. prob makes no dif but more info if needed. sorry about not getting back to you guys till now, had a small family issue to deal with. it was my 40yr old son, he came and "borrowed" my level and story pole without my knowledge while the wife and I were out to dinner. :vs_mad: and yes guys, he's still walking around no worse for wear, just his feelings are bruised........wife was with me when we went to visit him luckily......:biggrin2:
now thx ukrkoz, wasn't ignoring. women get hard to deal with when hungry. checked the wires w/soapy water, no clicking, no shudder when not moving. so, tomorrow I'll check or replace the EGR and get back to you guys. Thx for all your help so far. it's a hunt and peck thing, and i'll do more pecking on the morrow. Thank You All


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## Brainbucket (Mar 30, 2015)

Check ignition coils. That what it sounds like. Runs fine cept under load. Could be fuel injector needing cleaned but it points to ignition coil. Check engine light on? Check misfires.:vs_cool:


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## 123pugsy (Oct 6, 2012)

SeniorSitizen said:


> If you can avoid the clutter and get to the individual exhaust manifold connections, take their temperatures at lo idle and again at hi idle to see if one or more cyls may be sick with low temperature.



I use a squirt bottle with water. Works good on headers, I've never tried it on manifolds.


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## Brainbucket (Mar 30, 2015)

Mrbuilder said:


> feels like an engine shudder gang. but, I take really good care of 30-40k priced vehicles. this one has 376k on it. 2 trannys, 1 rear dif, new throttle body, lubed religiously every 3k, sat radio (lol) When I'm on level ground cruising and press throttle lightly, it shudders. When I release throttle it stops. If I put it under heavy load,(passing gear) it doesn't shudder. could it be the throttle body again ? I still use regular fuel. Last cleaned in SEPT.


oops...full throttle and doesn't shudder eliminates coils. An egr flying open will cause that. Does it do it cold and hot? Just when warm? If only when at operating temps could be a dirty injector. hhhmmmm check engine light on?:vs_cool:


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## Mrbuilder (Nov 15, 2016)

Ok guys, I drove it today, did all the testing stuff suggested, and now it's not doing it !!!!! :vs_mad: guess I'll wait till it starts being difficult again, then try to figure it out. Just hoping it's not the torque converter. 

Thanks guys for all your time trying to help. Hope your Holidays were great, and the new year serves you well ..........:smile:


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## Mrbuilder (Nov 15, 2016)

P.S. Filled up this morning with Premium, maybe cleaned a couple injectors ?? hmmmmmm......


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## ukrkoz (Dec 31, 2010)

Well, why don't you run 2 cans of Seafoam - it's a large engine, right? - through 2 tankfuls in a row? That will clean any **** out of anywhere gas goes. Proven good medicine. Not much expense.


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## ukrkoz (Dec 31, 2010)

Remember, you said - no shudder with transmission disengaged? How it will then be torque converter?


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## Brainbucket (Mar 30, 2015)

Been thinking on this. I had one doing this and it was an ignition coil. It would do fine until just lightly pressing on peddle. Full throttle did fine. In overdrive it would show it's ugly head. Just cruising and light throttle and boom, it would start missing. No other time did it miss. Cold it wouldn't do it. Just at operating temps so the fuel was more lean than a cold engine. Now I ask again. Is check engine light on?:vs_cool:


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## SeniorSitizen (Sep 10, 2012)

Replace the distributor cap and rotor.


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## Mort (Nov 26, 2008)

SeniorSitizen said:


> Replace the distributor cap and rotor.




The 5.3L doesn't have those.


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