Dieseling/Marbling/Exhaust noise under acceleration?

[rvitek]

Ever been in an old car that when under acceleration in the heat, you would hear that dieseling sound (that's what my dad always called it, or he said there were marbles in the tank causing that noise), but at idle or under constant cruize speeds, no sound on the driver's side of the engine. Well, I tried the mid-grade and the premium grades and they didn't work as that was always the fix when it happened to my dad. It's cold out now, and I think my theory isn't valid, as I still get the sounds.

So I was in a freinds 96 5.0, and his 'exhaust tube?' is cracked on his passenger side and when he accelerates, it's loud as heck. I was wondering, do you know what this exhause tube is, and is there one on the drivers side? Any way I can test for a crack?

Thanks!

Ry.

 

[section525]

The problem is his (and probably your) exhaust manifold is cracked. It's a problem with all 5.0 Explorers. You have manifolds on both sides of the engine and the passenger one seems to be more prone to leaking.

What you'll need to do is get some headers on there! Or you can replace the manifold for twice as much money. Since you have the GT40-P heads you'll need to modify the headers a bit. All you need to do is have someone add an EGR tube on them.

Search the board because I know a handful of members have done it.

 

[rvitek]

Thanks 5 - I'm still under warranty, so I'm going to take it to the dealer and have them check it out. But let me ask, should I ditch the KKM when I take it in? I remember somewhere on here that the KKM (or any modified intake) may cause some dieseling? I don't want the dealer to claim that's the problem, but then I don't want to swap out my air box either?

Thanks again 5!

 

[section525]

It might be worth your while to put the stocker back in. It all depends on the dealer. When I lived in LA my buddy bought a new F150. He added a 4" suspension, 3" body, 38" meats, headers, intake, exhaust, chip, and shift kit. The dealer was way cool and acted like it was a stock vehicle. But others get upset if you change your tire size or grille.

Have you delt with your local Ford Service Dept. yet?

 

[grtexplorer]

Hi guys,
I've got the same problem as rvitek, but mine's a SOHC with only 18k on it. I've checked other threads and the only solution I could come up with is the infamous cam chain guides. Am I on the right track?

The dieseling sound I get only happens under acceleration and then only from 30mph - 45mph. Do I need to take it to the shop?

Thanks in advance,

Jim

 

[james t]

if you have a "dieseling" sound, thats not an exhaust manifold leak. the 2 sounds are very different. if its the manifold, it will be a "tick" that will rise/fall with rpm's. the dieseling sounds, well, like a diesel. best thing (if its still under warranty) would be to take it to the dealer.

and just as a precaution, put the stock intake back on. dealer may be cool, or he may not. since its an easy swap, eliminate dealer hassle and put stocker on for now.

 

[grtexplorer]

James -
thanks for the info. I still have the stock intake, but I intend to get a KKM after I get the Apten chip and see how it works for me.

Unfortunately mine is out of warranty so before I take it to a dealer any thoughts on what they might tell me it is?

Thanks,
Jim