99 TAHOE bogging down

**NE1469** · 08-13-2007, 04:51 AM

My Tahoe is sputtering when you give it gas. If you give it slow when it is in park it revs up just fine. If you try to rev it fast then it bogs down. When it is in drive the engine shakes and it gets a lot worse on the bogging down. I changed the plugs and plug wires and also the fuel filter but that did nothing, any suggestions?

**unplugged** · 08-13-2007, 07:59 AM

Welcome. I helped a friend with the same problem last week, and the trouble was the plug wires. He changed the plugs first, and I came along with a set of wires that smoothed out the engine under load. You didn't mention if there were any DTC (check engine) codes.

**GaryL** · 08-13-2007, 10:05 AM

Probably should change cap and rotor as well.

**Steve** · 08-13-2007, 10:24 AM

How many miles on that '99 and what's the engine in it?

**Chevy1997** · 08-13-2007, 10:38 AM

Well, i changed plug wires, spark plugs, cap and rotor and i don`t solve the problem. somebody recommended me that i must to put dielectric grease in porcelain surface of the plug to eliminate the less of electric power to the plug. Check your engine at complete darkness and observe if you have electric lights in any parts (plug wires, sparks plugs, cap, etc) .

I don`t use dielectric grease yet because it`s very freak product in my country yet (i hope that Loctite help me as soon as possible).

i have a silverado 5.7 vortec small block. Maybe it`s simillar than your truck.

**Crawdaddy** · 08-13-2007, 10:44 AM

PLEASE oh PLEASE do NOT use Loctite on your plugs. It's not the same and you will NEVER get the plugs out of the heads. Dielectric grease and Loctite are nowhere near the same. I can't believe you can't get it in your country for some reason, but I guess there's some weird ban on it. Good lock

**Chevy1997** · 08-13-2007, 10:50 AM

crawdaddy, you mean that i use dielectric grease but no loctite or anyone else?

the product it`s overselled know, Loctite say me that the product arrive the next week probably.

**Chevy1997** · 08-13-2007, 10:52 AM

Because the use is only in electric generation at industries. Nobody use dielectric grease in truck or car engines.

**NE1469** · 08-14-2007, 12:08 AM

Problem solved! I changed the dist. cap and rotor button and she runs like a scalded dog. I guess when the platinum plugs go out they take everything with them. I had the truck in at 100,000 miles and the the plugs showed no wear at all. It now has 203,700 miles and they look like they had been run for three times as long. The gap was out to .075 and some were .083. They should be .060. It is a Vortec 5.7 V8. Thanks for all the posts and glad I found you all.