EGTs and smoke, out of nowhere

trevdalocal

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Been enjoying the upgrades, 366SXE, 250/200s, SD efuel with RR. Pretty much out of nowhere, the truck has been smoking under moderate-heavy acceleration, even in a heavy tow tune. Hotter tunes give more smoke. The hot street tune that would previously give a few wisps before the turbo lit will now make a fat cloud that keeps billowing even with the turbo lit.

Before this problem occurred, the truck ran very clean. It would only smoke if you were a gear or two high and stomped on it (ZF5), and only until the turbo lit. Predictably, EGTs are also higher now. Not alarmingly high, but higher than when I first installed everything. At 65 cruising, I'm around 650-750, a minor hill will put it at 800-900. Bigger hills, I can reach 1000-1100. These are in heavy tow tune, unloaded, except a 50 gal transfer tank in the bed.

I checked for boost leaks and found the boots at the plenum Y weeping. I tightened those and all of the other intake clamps, except for the ones at the intercooler, in front of the radiator support, behind the grill. I did find very small leaks at both intake plenums (Beans billet), on the short side of the plenum closest to the inlet. Running my hands around the manifold, you can hear a very tiny wisp of air as your finger waves past it. Same place on both. I swear I cleaned the heads meticulously and ran a good bead of Ford gasket maker, but I guess that wasn't enough. How much boost leak is too much?

While trying to chase a rompy idle, the CPS was replaced with no real change. Don't know what happened, truck seems to idle okay when fully warmed up now. Instead, between 180-190F (according to ISSPRO temp gauge), idle "surges". Goes about 600 RPM and blips up to 650-700 RPM and settles back down, every 3-4 seconds, pretty rhythmically. Idles fine when cold after a few initial romps. ICP and IPR look fine under all driving conditions. Only thing I can think is UVCH and VC gasket, as those were not changed when I installed the injectors. Kicking my self now for not replacing them.

Passes a CCT according to Forscan, I'll try to make a video of a CCT running when I get a chance.

Thanks for the advice that's gotten me this far!
 
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trevdalocal

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How about leaks on the exhaust side? How are the MAP/EBP values tracking? Just throwing those out there. Cheers!

Don't see any soot marks anywhere on the firewall or block. Had a loose manifold to uppipe bolt a week after I installed it, probably forgot to torque it all the way down, got very loud on the way to work one day, haha. Don't hear any exhaust leaks now either. MAP and EBP track well until the boost fooler starts opening up. See screenshot below

Has boost dropped off? Don’t have a back pressure gauge?
Boost seems okay, maybe a little lazy down low if anything. Still hits hard once it spools up. No aftermarket BP gauge, but the EBP sensor is new and I can reference that. See screenshot below

The first screenshot is at idle, EBP and MAP read almost identical. Second screenshot is at 7/8th throttle or so, 5th gear, going up a slight incline. Pressure on the ISSPRO gauge was around 30PSI.

Here's a link to a CCT I did today. Engine is hot, drove 15 miles to work.
https://youtu.be/I4KbPNv_Gvo

Thanks for your help in figuring this out, it's driving me mad. I feel like fuel consumption is up too...
 

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glovemeister

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Clean your EBP sensor tube.

It sounds like a boost leak to me. With your sticks, and turbo you can outpower a boost leak, in total amount of boost.

I'd start with the easy things, and pressurize your intake tract.
 

trevdalocal

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Clean your EBP sensor tube.

It sounds like a boost leak to me. With your sticks, and turbo you can outpower a boost leak, in total amount of boost.

I'd start with the easy things, and pressurize your intake tract.

52 psi for back pressure is a lot for me I feel

Yeah, another reason I am leaning that way. 2:1 drive ratio is likely a boost issue.

Since it is easy to fix/text for boost leaks I am thinking why not.

I will do another, more comprehensive boost leak check this weekend and keep everyone updated. It seems to have gotten worse, so hopefully it'll be easier to find this time around. Guess I'll try resealing the plenums too, hopefully the tube of sealant is still good!
 

trevdalocal

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Okay, did another leak check this weekend. Definitely leaking from around the plenums. Pulled the piping and turbo last night, popped off the plenums and resealed.

I see why they were leaking. The Beans billet pieces have a groove milled around the edge, like a o-ring groove for your head gasket. Naturally I laid the Ford sealant in the groove and installed the plenums. Well, on the narrow side of the plenum with the slotted bolt, the groove completely misses the corresponding sealing surface on the head, it's too far in. As a result, the bead of sealant was doing nothing for that whole side of the plenum, it was still there, looking just like I laid it down. This time, I laid RTV on the heads themselves.

I wrapped up just before midnight, so I didn't have a chance to leak check it again. On the way to work this morning, nothing seems to have changed. EGTs might be slightly lower under steady cruising, but they still spike up exactly as before. It was dark out, so I couldn't see if it was smoking like before, but I would hazard a guess it is. I'll leak check it again and see what else I can find, now that plenums aren't hissing away.
 

JCart

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I’d crawl underside with bright light and check e manifold to block interface especially towards rear of heads. Not uncommon for exhaust manifold bolt heads to pop off, causing leaks. As you are aware no exhaust manifold to head gasket on these engines so look real close on the bottom side typically it’s the drivers side that leaks, least what I’ve found on my trucks.
Cheers,
j
 

ghohouston

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Check your map sensor hose for cracks. In your log, the map sensor reading would equate to roughly 15 p.s.i. boost after you subtract atmospheric pressure, at least here in Texas it is usually just below 15 on the atmospheric pressure.
 

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