2000 5.3 liter Silverado runs rough until warmed up

[bruceb58]

Re: 2000 5.3 liter Silverado runs rough until warmed up

My 5.3 showed lean condition codes when my intake manifold warped.
The intake manifold is a very common problem with the 5.3.

What is the cause of the intake manifold warping? I have a 5.3L engine as well.

EDIT: looks like a good idea to eventually change the intake manifold gaskets to the updated ones.

Very interesting post here regarding similar symptom to OP and intake manifold:
http://www.dieselplace.com/forum/63...-lly/56634-warped-intake-manifold-5-3l-2.html

To the OP, if you happen to have an oiled air filter(K&N type) these can cause this problem as well as the oil from the filter can contaminate the MAF. I stopped using these types of filters a long time ago.

 

[dockwrecker]

Re: 2000 5.3 liter Silverado runs rough until warmed up

The 5.3 plastic manifold weighs maybe FIVE pounds is all. The replacements are supposedly thicker around the ports to prevent warpage. Mine was so warped around the ports they looked like potato chips. Just replacing the gaskets won't last very long.

 

[rogerwa]

Re: 2000 5.3 liter Silverado runs rough until warmed up

The 5.3 plastic manifold weighs maybe FIVE pounds is all. The replacements are supposedly thicker around the ports to prevent warpage. Mine was so warped around the ports they looked like potato chips. Just replacing the gaskets won't last very long.

Thankfully, mine has 110k+ on the new gaskets and running like a top. I'll make sure to watch the for the symptoms to re-emerge..

 

[bruceb58]

Re: 2000 5.3 liter Silverado runs rough until warmed up

The 5.3 plastic manifold weighs maybe FIVE pounds is all. The replacements are supposedly thicker around the ports to prevent warpage. Mine was so warped around the ports they looked like potato chips. Just replacing the gaskets won't last very long.

Do they say why they warp or is it just because of the material and its bound to happen eventually.

 

[bruceb58]

Re: 2000 5.3 liter Silverado runs rough until warmed up

One more thing, I keep thinking of more stuff after I hit the submit button, anyway, are you leaking any coolant around the plastic intake. If so, your going to have to replace it and that could be causing your issue. Pull the oil dipstick and see if any coolant is mixed in with the oil if it looks milky looking like a cup of coffee with alot of creamer in it then that could cause issues.

Is this really true? I thought there were no coolant passages through the intake manifold on these engines.

 

[dockwrecker]

Re: 2000 5.3 liter Silverado runs rough until warmed up

Do they say why they warp or is it just because of the material and its bound to happen eventually.

I was told it's a little of both.

"Is this really true? I thought there were no coolant passages through the intake manifold on these engines."
I didn't do the swap, I thought I saw cooling passages on my old manifold tho. Was more amazed at the time with the port warpage and how light it was.

 

[mscher]

Re: 2000 5.3 liter Silverado runs rough until warmed up

Is this really true? I thought there were no coolant passages through the intake manifold on these engines.

My 2001 5.3L Silverado, has NO coolant ports, through the air plenum (intake manifold). I fell for bad (but free) "advice" and changed the gaskets for nothing.

I believe it's the 5.7L (and others) that suffered manifold coolant leaks

It's NOT the 5.3L

 

[mscher]

Re: 2000 5.3 liter Silverado runs rough until warmed up

I just bought a 2000 Silverado with the 5.3l for a work truck. It has 150k miles and runs great after running for 2 minutes or so, but until it warms up a slight bit, it idles very rough and the RPMs fluctuate quite a bit. Any obvious things to check first?

I second checking for intake air leaks.

 

[bruceb58]

Re: 2000 5.3 liter Silverado runs rough until warmed up

I believe it's the 5.7L (and others) that suffered manifold coolant leaks

It's NOT the 5.3L

That's what I thought too!

 

[snowforfun4]

Re: 2000 5.3 liter Silverado runs rough until warmed up

Thanks for all for the suggestions. The MAF cleaner reduced the rough idle at startup by about 90%. I think a tune-up is in order and it should be good to go.

 

[MH Hawker]

Re: 2000 5.3 liter Silverado runs rough until warmed up

Run a can of sea foam through it to clean up the injectors, that should just about fix it. I also have that truck, I got it used and it wouldnt idle when cold and cleaning the MAF and running 2 cans to a full tank brought it from 12 mpg up to 15 mpg and adding a K & N filter added 1 more MPG