so i posted before about an issue with my swap, went from 4.6 to 5.4 and didnt get my torque converter in properly, so we now have a differnt trans. I have only been able to fire it up for a couple minutes at a time. last night i finally got to drive it after the swap and somehting is still not right. when i took it out of the shop and put the motor under load, it blows white smoke, as if i were a a tractor pull. im running g05 antifreeze so im not sure it will give that sweet smell. knowing that there is moisture in the exhaust and everywhere else from the swap i gave it a chance an drive it a bit. it feels like im missing a cylinder, when idling under torque ( in drive stopped) it idles down to 500 rpm and is non responsive when accelerating until it clears out, shaking the whole time. it does clear out and anything over 1500 rpm is ok, but stil not correct.

i checked the coolant level after driving 20 miles city, level is where id expect after purging the whole system, less than half a resevoir drop. i pulled the oil fill cap and there was a touch of milky oil but again with condensation in the motor, it wasnt an alarming amount. checked the oil dipstick and it is as clear as when i put it in. i do not have a sniffer, but seeing my other truck with a known head gasket im pretty sure there is no exhaust in the coolant.

so my simple question is, how do you tell if you have a blown head gasket vrs intake gasket?

also, seeing i just replaced the intake gasket, are they easy to crack? ever use sealant on them?

 

so on my way home tonight i got a p0174 code, bank 2 lean code. i did some searching and saw somone posting, similar problems, runs rough and the code, they say 99% intake gasket, due to a vaccum leak.
so my next question, since i did the swap and changed around the vacum lines, (everthing found a home) whats the best way to finding vaccum leaks?

 

you need to do some testing and narrow down the problem. Is it using antifreeze or not ? The 174 code is "lean" and that could be a vacuum hose on a good engine.. It could also be a leaking intake manifold if you have known antifreeze problems. Looking for vacuum leak is not a bad idea, but checking if you have additional problems is also warranted. Rough idle, stumbling, could be bad COP or leaking antifreeze into the cylinder. Since you have NOT seen a COP code yet I would not lean that way, but don't discount it until you get the stumble figured out. Small vacuum leak on a hose is not causing the rough run and stumble.

 

Some comments:
Antifreeze does not burn.
That much passing through exhaust too often will kill the cats and cool them so much they will not heat to operating temperature and coat with Ethylene Glycol from the antifreeze...
Fix the cooling system first.
174 code is a shift in fuel table for bank 2. Coolant remotely could cause this code for one bank if the OX sensor is detecting excess oxygen from the cylinder that is not firing (passing the coolant) because the spark plug is swamped from firing.
The mode 6, test 53 could be used to fine the missfing cylinder/s passing the coolant.
The 174 code could suggest that bank has a gasket issue of some sort if code 171 is not present..
Good luck with it.

 

thanks ill be doing some testing today, will post what i find

 

a question i had while taking it apart? tps? is that zerod out when its intalled onto TB or is it zerod to the computer with its reading?

 

The TPS has a min. voltage range as it's mounted and therefore non adjustable.
When you turn on ignition each time the computer uses what it measures as the floating zero point for that drive cycle.
This way the system automatically takes into account wear and changes until it either gets out of limits, open or shorted, then a code is triggered.
BTW, if the Idle stop is changed the TPS position also changes so the idle stop is also non adjustable as far as the operating system is concerned.
.
Back a ways in earlier times, the 5L guys thought there was a performance gain by setting the TPS a preferred value but they did not know it only stayed for that drive cycle and was negated the next time they started the motor.
Good luck.

 

Check the EGR valve. Some symtons you are having are related to EGR. Hope this helps.

 

whats the best way to check EGR valve?

i pulled the intake, and didnt find anything wrong, tried to do a compression test but i couldnt get the tester to thread in, darn rubber hose. put it back together, and nothing has changed, id say the soking has gone down, but the rough running is the same if not worse.
When i pulled the plugs, number 5 Drivers front plug was wet- ish. all 4 were pretty clean, all 4 on the pass side had a bit of carbon buld up on the casing id call it, inner diamerter of the threads.

couple questions, i put bosch platnium 4 plugs in it, so with such a small electrode i can see where it would be sensitve, not sure if i should ditch them, but obviously theres another issue.

before i pulled the intake, while running i pulled wires off the coil packs one by one, and id say i could only hear a difference on 4 or 5 plugs. hard to tell when its running bad already. which leads my to another question, from my knowledge the 4.6 and 5.4 have the same firing order correct? i dont think the 99 PI heads should matter since they are both 2V. i will be double checking plug wires, but cant se that being the problem, since i left them clipped together when i swapped the whole harness as one.

firing order is 1-3-7-2-6-5-4-8 the only ones i could see being a problem and still run are 6-5 but you would think it would throw a misfire code, speaking of that what senses any misfire?

 

To search for leaks I spray short bursts of carb cleaner around the manifold joints and vacuum hoses while engine is idling. If you hear an increase in rpm, keep narrowing down the possibilities till the leak becomes apparent.

Todd

 

What senses misfires/
A good question, so ride along because it's not so simple.
Being a computer controlled system, the crank sensor is the system Tach sensor. it tells the computer what the RPM is at all times.
Besides RPM it measures rotation time for every cylinder every time every plug fires and keeps track of it all.
This being the case, it measures the time of rotation and compares it to a table of times developed as an 'average' for all the cylinders.
Anytime the rotation is measured as too slow as compared to the table, a stroke count is recorded in memory.
When the count exceeds a total to a limit, a code is set that turns on the CEL.
The code will indicate what cylinder by a P 030x code.
Any fault that results is a slow rotation time will be considered a misfire.
The faults can be a spark plug, a coil, a coil driver, the harness/plugup, missing fuel, fuel injector, missing/weak spark, cylinder fault etc.
It never fails to see a misfire.
Good luck