BlackBeauty

I have a 2007 Tahoe that was purchased last September. From the get go the Tahoe has stunk. At first we chalked it up to new engine, exhaust, and alot of the preservative on the truck. We expected that it would burn off eventually. We are now at 8500 miles, and the tahoe still stinks. It smells like rotten eggs. What are the chances that a brand new tahoe could have bad catalytic converters already? Has anyone else had any issues with this?

ZX1100F1

Pretty slim but could happen, usually the smell that you describe is from a rich air/fuel ratio and not a catalytic convert problem. Have you done any modifications that would effect the air/fuel ratio?

BlackBeauty

The only modification has been the E85 fuel update. Otherwise it is as exactly as it came from the factory. The smell was there long before the E85 fuel update. If you remember ZX, you had informed me of the preservative on the tahoe, that you said could be causing the smell. It actually comes and goes really. I havent noticed any differences when it does come and go. Today for instance, there was no smell, however yesterday there was. It has not been driven any differently today then it was yesterday. However, yesterday my wife states that she pressed on the gas to speed around a car, and it took about 3-5 seconds for the engine to actually kick in from stepping on the gas. This has never happened before, and there has never been a delay. Could a bad catalytic converter switch back and forth like this? Or do you possibly think its bad gas? We always fill up at the same Company, and here lately have been using the cheapo gas which is 87 octane. This is my only vehicle, which my wife uses during the week, so I cant be out of a vehicle. The dealership is open on Saturdays, but they are always so busy, and Im not entirely sure they take the time to resolve any issues. I just feel rushed out with when they decide there is no problem.

Any advise as to what might cause this? Any ideas to resolve? What should I tell the dealership? Afterall it has 8500 miles on it now, I would think the engine has been broken in by now. We typically get around 13mpg in town...

ZX1100F1

After 8,500 miles I think it's safe to say that it is not the cosmoline preservative any longer and it doesn’t smell like rotten eggs, it has a nasty hot odor.

If it were my Tahoe my next course of action would be to run this tank of fuel as near empty as practical and then refuel at a different station that gets their stock from a different refinery if possible, the grade of fuel used should be of no concern provided it is 87 octane.

A hesitation of .5 (half) a second can seem like an eternity when you are trying to get out of another vehicles way but I am willing to bet that your wife experienced the transmissions Torque Management System which will slow the opening of the throttle blade to allow for a 1st gear downshift (without damaging the tranny or your molars) if you are coasting to a near stop and then reapply the throttle abruptly.

TahoeGirl

I just was searching this forum due to the exact issue. I was having a horrible rotten egg/natural gas smell coming into the cab area.

My 07 Tahoe is at the dealership right now because of this and apparently there is a service bulletin. I just spoke with myservice writer told me it has to do with the rear differential, so they have ordered all the parts and are hopefullygetting me fixed up.

I was wanting to read exactly what the service bulletin says...does anyone have access to these???

***Val***

ZX1100F1

Document ID# 1888812
2007 Chevrolet Tahoe - 4WD
[hr] [align=left]
Subject: Propane Sulfur Or Foul Odor From The Rear Differential - keywords axle fluid vent #PIP4027 - (01/18/2007)[/align] [align=left] Models: 2007 Cadillac Escalade, Escalade ESV, Escalade EXT[/align] [align=left]
2007 Chevrolet Avalanche, Silverado, Suburban, Tahoe[/align] [align=left]
2007 GMC Sierra, Yukon, Yukon XL[/align]
[hr] The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI. Condition/Concern: Odor or repeat odor from the rear differential with no other noise symptoms. Recommendation/Instructions: [ol]Drain and disassemble the rear differential by removing the gear case and axle shafts. Clean the rear differential completely with a suitable solvent make sure the housing is clean and dry prior to reassembly. Replace the rear differential vent hose and cap. Relocate the vent to either near the spare tire or evap canister area. Cut the new vent hose approximately 6 inches from the vent cap end and install filter part number 5651682, secure the filter with clamps supplied. Fill the differential with the appropriate fluid listed in eSI [/ol] Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed. GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.


[hr]
Document ID# 1888812
2007 Chevrolet Tahoe - 4WD

TahoeGirl

Oh my gosh...your awesome!!

Thank you soooo much!!

***Val***

TahoeGirl

Okay,unless I am reading this wrong, there are really no "parts" required except for a filter. Is this a special filter? Wouldn't they normally keep filters in stock??

My service manager told me they order the parts (he specifically said parts not part)yesterday overniteand as of 3:30 p.m. the parts weren't there yet. Are the feeding me a bunch of b.s. because I'm a girl??? I sure feel like it!!

ZX1100F1

Not sure, probably not.
This fix actually requires the replacement of the 2 items and installation of an additional item (3 items total).
The vent hose is a stock item cut to length from a roll type part however the vent cap and filter may not be in stock, this filter is a specific use type element and not widely used.

There is a chance that this fix does not make your odor go away, I have rarely came across a stinky rear end.

TahoeGirl

Thanks ZX...I hope this fixes it because I don't think they have a Plan B!! They have already changed out the battery because the said if failed their load test and that didn't work either. Well see...

***Val***