Ok I looked down the TB and indeed there's a pool of Mobil 1 in there, it frequently pings on 87 octane while under load, and in 3000 miles I went through a little bit under 2 quarts of oil. I'm pretty sure the gasket is leaking. Would it also cause a loss of power? I'm wondering because other 5.9 owners seem to have traction problems on dry pavement whereas I don't. Also, I've got a 100k mi extended warranty so the dealer will be doing the work on this, my question is this: Are they going to put the same gasket in that fails or have they fixed the problem and will they put updated parts in? Should I order something out of pocket and have the dealer put it in?

 

If nothing else, just call and ask them what type they use. If its a cork gasket, I'd recommend getting other gaskets yourself, even if they are going to be doing the work.

 

I have the same symptoms. Has your mileage fallen off as well (you may not notice inyour 5.9)? Mine has. Used to average about 16-17. Now it is aobut 13 no matter what. How many miles are on yours? Mine has 113,000.

 

hughes engines makes a 1/4 thick billet plate that replaces the stock piece it comes w/ gasket and fastners its also stronger than stock or u can weld the factory one on

 

Ext Warranties Require factory replacement parts. Its all theyll pay for and they wont even pay the right price for em usually so the dealer ends up loosing some profit (Dont worry they make it back on the sale of the contract anyways!). Im sure you could talk them into putting a supplied gasket in though

 

I've got about 55k on mine, and my mileage on the computer has been 12mpg average since I bought it, about 13k miles. I get a bit over 14 average on the highway, and dismal in town. Maybe I need to work for a gas station part time.

 

Well I dropped it off at 8 this morning and they started in on it. Sure enough, plenum gasket is faulty and they're swapping it out. I greased the wheel a bit by having them do my 60k service as well and damn. It's not cheap. But maybe I'll get my truck back tomorrow and it'll have more power, better fuel economy, won't ping, and won't consume oil at odd intervals. And then I've got a shiny new set of 50-state legal ceramic coated shorty headers to put on, for even more power.

 

the gasket that will be put back in it should not be the one that failed the first time. ive done quite a few lately and all the new gaskets are made of metal. the old ones are paper.

 

Well I got the truck back yesterday, everything seems a little tighter, maybe it's my imagination, but the front end just seems more connected.

Whatever. This afternoon I installed some shorty headers. Seems odd to me that the factory iron exhaust manifolds don't use a gasket at all. There was evidence of the exhaust leaking too, but apparently not enough for it to be a big problem. So it's sealed up, my intake is sealed up, I've got headers, and now I just need to save some coin for a high flow cat and a 40 series flowmaster to complete the exhaust. This truck I'm keeping emissions legal, gotta have at least one that I can take with me if I move someplace civilized.