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Discussion Starter · #1 ·
Anyone know a good mechanic in Huntington Beach or around this area?

I used to take my truck to DR. J's on Gothard and Talbert, but he has ripped me off one too many times.

I have a misfire in my tahoe. Its a 2000 Old body with the 5.7L Vortec.

Ive changed the plugs, wires, cap and rotor. I need some motor work.

HELP PLEASE.

I need to get my truck running good so I can sell it and then go see Mr. Photoglou for a new Silvy or Sierra.
 

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have you narrowed down what cylinder it is?

i can walk you thru the diag if ya want, i know em like the back of my hand;)
 

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tell me all the symptoms , did it start gradual and get worse or did it happen all of the sudden? is it a misfire or is the motor just down on power?
 

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Guy at C&G Automotive in the Gothard and Talbert area. Good guy, no pun intended. He has worked on my family's stuff for a very long time. Not the cheapest guy but he gives you options and shoots you straight.
 

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Discussion Starter · #6 ·
Well for the last 9-12 months or so I have had what I though was a blown exhaust manifold (header) gasket. You can hear the ticking from the exhaust manifold or that area. I didnt think it was too bad.

About 2 weeks ago, I changed the gasket. It didnt look blown out, but it definitely had some carbon build up. I have JBA headers on my truck. The gasket looks to have been sealed with no leaks, so im thinking maybe a weld on the header is blown at the flange, or the flange is warped or something.


This is of the #7 Cylinder all the way in the back on the driver side.
The side showing in the picture sits against the header flange. The other side is clean, like it should be.

When I pulled the plugs, the #5 plug was a pain in the ass to get out, and it looked dirty. So right now im thinking it is the #5 cylinder giving me the misfire or whatever.

Since the exhaust leak, I have had to change the #7 and #5 plugs periodically from them burning up and giving me the rough idle at start up and under load.

I think it is a misfire... when driving up a hill or hard excelleration you can feel it cut power slightly. It was idling rough in the mornings, so I used some fuel system cleaner which made the rough idle go away. After the tank of gas with the cleaner was gone, I changed the header gasket. I still have the same sound of an exhaust leak with the new gasket.

Now with fresh parts it is still giving me problems.
 

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Discussion Starter · #7 ·
Other than this problem, my truck is in really good condition with a lot of work done to it as far as visuals, suspension, and sound system. Im hoping to get it running decent enough to sell it to someone who can deal with the problems. My original plan was to swap out the motor with a 383 GM crate motor, but I need a new reliable truck with a warranty.

Im hoping for a cheap repair that will last a few months.
 

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those injectors are known for sticking from time to time. go buy yourself a can of pour in top engine cleaner from the dealership, it'll clean the injectors and intake better than any shit you can buy at a parts store.when the injector poppet sticks, it'll misfire all the time though.

if it misses under a load, its ignition. is it possible you cracked a plug during installation? also if that truck has over 100k on it, the top bushing in the dizzy will be almost worn out and let the rotor get all wobble'n during operation. its easy enuff to check, just mark the dizzy, pull it up and turn the rotor while checking for play in the top bushing.

sounds like ignition issue to me, just because of it happening under a load.
 

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those injectors are known for sticking from time to time. go buy yourself a can of pour in top engine cleaner from the dealership, it'll clean the injectors and intake better than any shit you can buy at a parts store.when the injector poppet sticks, it'll misfire all the time though.

if it misses under a load, its ignition. is it possible you cracked a plug during installation? also if that truck has over 100k on it, the top bushing in the dizzy will be almost worn out and let the rotor get all wobble'n during operation. its easy enuff to check, just mark the dizzy, pull it up and turn the rotor while checking for play in the top bushing.

sounds like ignition issue to me, just because of it happening under a load.

x2

The GM "fuel system cleaner" is what you want. I beleive its the same as the bottle of techron they sell at the Chevron station.

Those poppet injectors are a failure prone pain in the ass. Check with a GM dealer. A couple years ago I beleive that they extended the warranty on the injectors to 10 years and 100K or 150K miles...I can't remember.
 

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Discussion Starter · #13 ·
found out it was a broken spark plug. Put another new one in and it is running okay but still misses at idle and underload periodically, just not a constant miss like before. My father-in-law pointed out a some smoke coming from my exhaust. It appears i have coolent getting into the exhaust.

Im thinking i need a new head gasket.

Whats a job like that normally cost? a grand or so?
 

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found out it was a broken spark plug. Put another new one in and it is running okay but still misses at idle and underload periodically, just not a constant miss like before. My father-in-law pointed out a some smoke coming from my exhaust. It appears i have coolent getting into the exhaust.

Im thinking i need a new head gasket.

Whats a job like that normally cost? a grand or so?
more than likely its the intake gaskets leaking coolant;) i've never seen that motor leak externally from a headgaskets unless it'd been overheated badly! look around the area where your starter is at and see if there's coolant there, if there is, have someone replace the intake gaskets, check the dizzy bushing while its out, and put in some ngk plugs gapped at 35
 

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Discussion Starter · #15 ·
I just had the intake manifold gasket replaced about 5000 miles ago.

Smoke is coming out the exhaust, and it sounds like there is an exhaust leak.
 
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