26th Jun 2006, 21:39

Clunking is a very annoying problem. I looked into it a while back (friend had same problem on his '02 Z71 - he now owns a Ford). As for my '00 Z71, I grin and bear it. The culprit is a flange? (can't remember for sure) in the drive shaft. The play is intentional, from what I've heard. If it drives you batty, your dealership should offer a zinc-plated alternative for about $400.00 that is supposed to quiet the superior engineering.

27th Aug 2006, 15:18

I had to look into the clunk in the rear end of my '97 GM, I was told it was the slip yoke and that the repairs would be very expensive. My brother in-law changed his himself, not fun.

12th Sep 2006, 10:17

I have a 97 GMC Z71 I have already placed 2 rear ends in it and I'm going to put a 3rd in there tomorrow... any idea why the rear end keeps going out?

4th Oct 2006, 08:40

I have a 2000 GMC Sierra that has 57000 miles the only problems I have are the rough idling, I have changed out the spark plugs and spark plug wires and it still idles rough. Other than that the truck has been doing good and as long as you do the regular services to it, it will keep running just fine because I haven't had a problem with it since I bought right out the dealer with 3 miles on it. Does anyone know what I can do to get rid of the rough idle?

13th Oct 2006, 22:35

My 1997 GM idled rough only slightly until I had to put in my third fuel pump. This time though, I went with a GM certified part and the rough idle seems to have stopped.

5th Feb 2007, 20:53

I have a 2000 GMC Z71 obviously with the 5.3L in it. In regards to the engine/valve clatter, I am hearing that the intake manifold gasket is the culprit which may relate to anyone having issues with low coolant (no visible leaks) and the rough idle. I told my mechanic who was trying to help me troubleshoot this issue, that I had heard from a couple other people who had the same problem. Apparently this is common because he has had numerous customers come in with coolant lose and no explanation of where it is going. Since I am no mechanic and can't quote his exact words, his thinking is that once the engine is shut down, the oil seeps down into the lifters and sits there. Once the motor is fired up, that is why it clatters since the oil is pumping back into the lifters. Since it is such a small amount of antifreeze, that is why the 'check coolant' light only comes on about 2x a year. My question as to if it is contaminating the oil was answered that it most likely burns off after driving and isn't a threat to shortening the life of the motor. Since I am selling my truck and wanting to get it fixed before I do, I will keep you posted as to if the problem was solved. Any donations would be accepted to be the guinea pig. lol.

2nd Apr 2008, 01:28

I have a GMC Sierra 2000 z71, but I don't know what model it is.

Is it a 1500 or a 2500?

How do I find out, so I can get the right part?

4th Aug 2008, 07:41

I have a 2000 Z-71 and clunking is my problem!

This happens after about 15 minutes of driving. As if it only does it when the transmission is warm.

From a stop, when I accelerate and it shifts into 2nd. I feel a drop and hear a clunk.

Does anyone know what the problem is?

Any help is greatly appreciated.

20th Jan 2009, 23:27

For the drop and clunk guy, check your trans mount and keep an eye on your U joints.

28th Nov 2009, 21:52

The clattering in the engine is the famous piston slap. Coolant does not go through the intake on a 4.8 or 5.3.

22nd Dec 2009, 12:55

I have a 2000 GMC Z71 I purchased new and now have 190,000 miles on it. The piston skirt slapping is somewhat embarrassing as stated before, and people ask if I have checked the oil, and I always have to explain what the deal is. I also have experienced a rough idle and changed plugs and wires. Then today it quit idling and just cut off. I am guessing it is a fuel related problem, so I would suggest if you have a rough idle, to get it fixed before you get left stranded.

Long story short, I have enjoyed this truck and would definitely look at buying another one.

The only other things I have had to do is change a battery and do brake work. My experience with GMC has been wonderful.

14th Jan 2010, 19:17

I have a 2000 1500 Sierra Z71 4 wheel drive. The problem I have is intermittent and drives me crazy. Sometimes the truck just won't start. It acts like it's starved for gas. I think it has to do with the factory alarm's fuel shut off mechanism sticking. It has no rhyme or reason as to when it will happen. I've gone months without it happening, and also had it happen multiple times in a week. Very inconvenient. Any help would be VERY much appreciated.

21st Apr 2010, 14:24

I have a 2000 GMC with a 350 ci gas. It powers out when warm, and won't rev past 3000 rpm. Any suggestions?

30th Apr 2010, 00:29

I just purchased a 2000 Z71 ex-cab 4x4. Beautiful truck, but from reading these comments, I don't know if I should keep it or sell it.

25th May 2010, 11:35

For the person with the fuel problem... 14th Jan... check your connections on your alternator and battery. I had the same issues and cleaned them. Now it runs like a dream, minus the piston slap every now and then.

30th Jul 2010, 03:30

I have had a 2000 GMC Sierra 4X4 extended cab, and now own a 2001 GMC Sierra Z71 extended cab...

BOTH trucks had the "clunk" problem when starting and stopping... It is the Yoke (yolk) sp... I had mine repaired at a GM dealership at a cost of $365 with a 1 year warranty... 1 year and 6 days later it started the clunk again... I AM NOT SPENDING THAT MUCH MONEY to have this clunk fixed every year... so I just live with it...

BOTH trucks had/have the steering shaft rattle... I have yet to be able to have the shaft repaired... Also have the cold start clacking issue as well... Took this up with the wonderful folks at GMC... NO RECALLS, and they said they are NOT responsible.!.!

I tell you what, if there are so many trucks with the same problems, why is there NOT a recall or mandatory repair call issued for this?? I can't begin to tell you the number of folks who have this same exact problem with these two year models... and MORE!!

I was considering buying another GMC truck, since mine now has 180K miles, but have decided that GMC will not stand up for their vehicles, so they will get no more of my hard-earned dollars! May consider a Ford or Dodge next... Just don't know... LOVE the GMC Sierras if GMC would just be honorable and not honor-less. I figured with the bailout monies they got, they would be a bit more consumer-friendly... NOPE... just padded their pockets...

I am really ashamed of GMC right now... Been a long LONG time fan of the Sierra, but the kinship has sunk now... SHAME ON YOU GMC!!!