A few questions about my Tahoe...

[98_2DR]

Sorry for the several questions I am about to ask but I need some direction and I'd rather ask all at once than be a post whore.. I hope I describe everything well, if not just ask..

1. I replaced my thermostat today and the temp theme gauge still hovers around the bold line in between 100 and 210, I have replaced the cluster with a spare I picked up and same issue so it's not the gauge is this normal for the tahoes or could the temp sensor be bad?

2. I just had dual exhaust added Monday, it's borla brand and they "dumped" the pipes right at the rear axel. Since then when you rev it up,it sounds great when you open it up on highway it sounds like a NASCAR, however when you let off the throttle it sounds like crap, almost like an exhaust leak. Took it to autozone and another shop and they told me its normal when you have dual exhaust because "your hearing both sides of the engine separately"... Sounded like crap to me but I know nothing about exhaust systems. I took it to another muffler shop and they said don't worry about it, so I took my new knowledge and my Tahoe back to the shop who installed it said the mufflers are good, and he showed me with a dollar bill where one muffler in "blowing" and one was "sucking".... He put the truck on a ob2 scanner and no codes were being thrown or even pending, he did say it sounded funny but only thought it may be a leaky intake manifold gasket, a bad exhaust valve, or a ton of built up carbon... Any ideas????

 

[squeasel]

re: Water Temperature gauge - FWIW, my 1996 5.7L runs 1 1/2 notches (small lines) above the Bold line you described. It is always consistent unless I run low on coolant. I believe I run the standard thermostat but don't know what it is off-hand (180F ? maybe).

 

[samotahoe]

normal. optimum operating temp for most of these trucks is around 195 to 210 F. as far as the exhaust issue, see if they can connect the pipes somehere along the line, did you want them to be dumped in that area? mine runs like the factory one and has a nice tone to it not too loud.

 

[lesterl]

Does it kind of cackle at you when you let off?

Could be the new thermostat is bad, have the OBD2 temp checked thru the scan tool to verify 195* or whatever your stat was.

 

[98_2DR]

Yes it does crackle when you let off of it.


I drove the truck today on a 3 hour drive, used real mid grade fuel and added some chevron fuel treatment to the tank, when did good on trip, when it idles now it makes the same "crackle" tone mixed with the rumble... What could this be?

 

[lesterl]

Hows your fuel pressure? Timing alright?

 

[98_2DR]

Not sure about either.

It idles fine, seems to run fine. The fuel gauge doesn't work due to a bad sending unit so in a few days ill have a new Delphi fuel pump installed. Other than that I don't know how to check anything else.

 

[lesterl]

Fuel pressure guage on the schrader port under the hood to test pressure, but wait till after the pump, or would be nice to have a before and after pump pressure reading.....

Timing would require a Scantool..... and if the distributor (high voltage switch) has been removed it would most certianly have been put at least a little out of time.....

 

[Beeker702]

It sounds like that cause you have the exhaust pipes dump right at the axle instead of going all the way back. You'll get a better sound and better performance if you make the exhaust look stock looking, might even get better gas mileage. I've always hated boria exhausted and never heard anything good about it. If your still worried about your temp and know someone who can install a temp gauge so you can see what the actualle temp is then I would do that route for now. And I believe putting on full exhaust tips will take care of your funny sound

 

[Tex99Tahoe]

re: Water Temperature gauge - FWIW, my 1996 5.7L runs 1 1/2 notches (small lines) above the Bold line you described. It is always consistent unless I run low on coolant. I believe I run the standard thermostat but don't know what it is off-hand (180F ? maybe).

My temp guage settles in exactly the same position (1999 5.7L), standard factory thermostat, my Scanguage reports 193°F...

 

[98_2DR]

So today I went to muffler shop and had them install a y pipe and stock looking exhaust pipe, WOW what a difference! Still has the weird sound when it idles down tho, maybe just because its so "open" as the muffler tech says. As for the temp it reads 195 on scope but found that the sensor that sends that info to the computer is malfunctioning so I bought a new one today and will install tomorrow or Saturday along with another new (better brand) thermostat since the two are right together... I'll post info as soon as I have some.

 

[Beeker702]

Glad it sounds better. But yea you'll never get away from that sound of once you take your food off of the gas until you put a magnaflow, flowmaster or dynomax muffler. You'll still get a great sound and performance but I'm willing to bet you'll get better gas mileage as well. Best of luck

 

[squeasel]

re: Water Temperature gauge - FWIW, my 1996 5.7L runs 1 1/2 notches (small lines) above the Bold line you described. It is always consistent unless I run low on coolant. I believe I run the standard thermostat but don't know what it is off-hand (180F ? maybe).

I attached a scanner after the engine was warm. Live Data shows 189F with the gauge needle at 1 small line past the bold line (between 100 and 210). I imagine gauges can vary. IMHO it is irritating having a non linear gauge without additional annotation. Cheers!