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First off I want to say im new, and ive been searching but couldnt find much. I just bought an 87 F250 with a 6.9. The guy that had it before me put a 2 1/2 inch exhaust on it (one single pipe dumping in front of the passanger side tire with a turbo muffler). I know it wasnt drove much after he put it on, maybe 30 miles. The truck is extreamly loud in the engine compartment now. It kind of sounds like the exhaust manifold is off the engine. Will putting this small of exhaust on crack the manifolds, or is it more likely that its just a gasket. its so loud that its hard to really pin down what part of the system is making the noise. Any ideas or helpfull sugestions would be greatly apreaceated as this is my first Diesel.
Welcome to FTE. I think that is the original size. My exhaust is 3 inches and I was told that was upgraded. I am sure more people will chime in shortly.
The air cleaner and assembly is on the engine right? That can make a lot of noise as well.
The former owner liked cheap chrome. The original air cleaner is long since gone. It currently has a cheap edelbrock style with a 2" tall 16"? round filter (something that should be a small block with a holly). Could this be the cause of all the extra noise?
That may be it. My truck is loud when the air cleaner is open. There are some threads on here about the "soup bowl" mod wich removes a soup bowl type piece from the air cleaner assembly. They said one of the reasons that it was there was for noise reduction in the intake. I did notice a difference when I removed mine. I know yours is gone, but it may just be intake noise.
trucknut25, do you have an "open" type filter arrangement, or is it still hooked to ducting that draws in cold air from the front of the truck? Diesels need as much air as possible, but not from the engine compartment.
tbone. its got an open style on there now. im trying to find the factory one in a junk yard, but thers not many of these trucks in the yards im finding around here.
trucknut25,
Welcome to FTE and the IDI diesel forum.
Stock exhaust pipe size on the 6.9 was 2.25" ID pipe.
3" is a much better size to make the engine happier.
Diesel engines like lots of air, both in and out.
when i got my 7.3 the right manifold was cracked and it was prety loud if your manifold was cracked or if a gasket was leaking you should see lots of black sut around the leak
It smokes a lot right now (i believe an injector is stuck). And i discovered it has a leak on 2 of the injectors, so im working on getting that fixed, and finding a factory style air intake/filter (cant find any junkyards around here that have an old diesel). I belive once i have that fixed it will be alot easier to pin down if its a gasket of the manifold. I would have just assumed that being a diesel it would come factory with atleast 3" exhaust. As i said I dont know much about them, as this is my first, but for the 250 bucks i got in it, i think its worth learing some about. Anybody know of any other vehicle that had this engine i can pull the filter off of? I thought maybe an old school bus since a lot of them were diesel. These trucks are few and far between around here. From what im told, seams like soon as one gets in the junkyard somone buys the whole thing before you can blink around here.
well I can tell you for sure its not the location of the exaust.I have a 5in that dumps infront of my right rear tire and my regular cab is very nice noise wise.