jdoyle

iTrader: (27)

hey i got my car tuned today at the same place i got the motor built at and he said that it blew a headgasket, cuz of the 14.0 A/F ratio across the whole mf'in graph, what else can be wrong, cuz this ****** motor is brand mother ****** new.

appreciate the help

EDIT: By the way, i left the shop with a knock sensor problem code, could this make anything worse?

Bandit28

iTrader: (28)

yeah i doubt it... ideal afr is 14.7 so i mean its not that far off, sounds like there is another problem.

LS1-450

iTrader: (33)

I'd re-post & tone down the emotional outburst. Not trying to rile you up even more. It's just that you'll get more feedback with details about what has happened. List the the motor build spec's., max. motor speed (RPM), injector size, timing advance,...etc.. Something is strange. 14:1 is lean @ WOT, but, there's more to it.

calongo_SS

iTrader: (7)

14:1 is a little on the lean side, but it's not going to blow a gasket. If you have a knock sensor problem, maybe it was detonating

slowpoke96z28

iTrader: (2)

yeah, at cruise not WOT. that is way lean for WOT. i dont think you hurt anything else, but you won't know for sure till the heads come off. what code you got ? P0332? if the tuner saw the A/F that lean, the fuel should have been adjusted before anymore runs were made. can you post up the dyno graph and A/F ratio graph were the gasket blew so we can see it?

LS1-450

iTrader: (33)

Build spec's., compression, head bolts, were they tightened correctly, timing advance @ WOT.

jdoyle

iTrader: (27)

Motor Build Specs:
2005 6.0 liter block, crank, rods and pistons. Stock hardware (head bolts, etc.)
Mellings Ported Oil Pump
TR224/112 cam
LS6 IM/Ported TB
Stock 99 injectors (to my knowledge)
Crane Billet Double Roller timing set, i believe the cam is set normally (straight up), but doesnt the cam have the advance ground into it? so im guessing its +4 because of the grind of the cam, but please correct if im wrong.


I didnt get a good enough look at the graph for max engine speed but i made 310/350 through the stock 10 bolt. Last time i dynoed with the same setup, i made 387/398.

that should cover everything, the motor ran VERY well during the break in period, with a normal amnt of oil in the catch can after 500 miles.

jdoyle

iTrader: (27)

P0327 actually, knock sensor bank 1. low circuit or no connectivity or sumn?

I dont have the dyno graph with the A/F graph beneath it, but he def. pointed out the 14.0 A/F to me after the first baseline pull. It was a fat 14.0 the entire graph, except there was a little time when it dipped into normal (down closer to the stoichiometrically (Sp?) correct line) somewhere in the high 3000-anywhere in the low 5000 rpms. Then 2 more pulls were attempted and then aborted prematurely i guess due to leaning out?, then a 4th and final complete pull was made. Then he told me the news.

slowpoke96z28

iTrader: (2)

14.7 to 1 is stoichemetric. thats what the PCM shoots for during closed loop cruising. its NOT what you want when you are on the dyno. that is leaner than you want. when you pull the heads, check for warpage on the block's decks and the heads' machined surfaces. how did he diagnose the popped head gasket?

jdoyle

iTrader: (27)

yes exactly, 14.7 is good for idle and cruising, but not WOT

he told me that his wife saw some liquid on the ground coming from the car and tasted it and said that it wasnt water, which led to the conclusion of blown headgasket.

He said that there was coolant in the oil?

the work done will be covered by warranty, so i will not be doing any of it.

Asmodeus

Tuner sounds suspect, and wtf is wife doing drinking car fluids?

Bandit28

iTrader: (28)

yeah like i said IDEAL

slowpoke96z28

iTrader: (2)

i didn't want to be the first one to say it. never do a wot pull after you KNOW the A/F ratio is that lean. WTF was the tuner thinking. i guess everybody is entitled to a brain fart evry now and then. at least he's going to fix it free. good on him in that regard.

LS1-450

iTrader: (33)

99 injectors? If the same injectors were used to make 310/350 are used in the "new" set-up, 387/398 & the tuner couldn't get better than 14.0 in four pulls, then I'd look into injector size. There may have been room in the 99 injectors to fuel the "new" set-up. However, no way for us to what the injector efficiency is @ WOT. The injector size should be looked @.

+4 advance @ 14:1 A/F would likely pre-detonate (knock). Don't know for sure if this caused the gasket failure, but, it didn't help.

As mentioned above, check the heads for warpage or any gouges that may have lead to a coolant leak, check the injector size (am guessing he is maxed on injector efficiency). I'd ask the tuner to start w/ +0 advance until fuel curve is 12.8 on a dyno jet dyno, then go +2 & listen for knock, if not knock (pre-detonation) then +4 .
Good-luck.

TTPMatt

iTrader: (18)

Your A/F should be around 13.0:1 across the board. Whenever I put a car on the dyno I don't just whack it all the way to redline, we check a/f across the board. If I see a lean mixture for a span of around 800-1000rpm's I will dump fuel across the board into the program before making a full pass.

I honestly dont think a 14.0:1 a/f would blow the headgasket, could be improper installation, warped heads, etc. Could be a lot of factors actually. If there is coolant in the oil (a/k/a "milk-shaked") then it probably is the headgasket.

Check the heads for straightness and any damage, even the smallest chip/crack especially near a water jacket can cause a blown headgasket.

The shop should have a tool to test for leaks. We have the Snap-On and Matco testers to do these tests.

You said stock hardware, did they reuse your stock head bolts/gaskets??

Kraest

iTrader: (3)

Aren't stock 99 injectors 26#? Those are way too small, mang.

jdoyle

iTrader: (27)

hmmm ill ask about 42 lb injectors, i hear they are easy to tune.

LS1-450

iTrader: (33)

If 99's are 26# injectors, you need to keep a close eye on the guy you have working on your car. When I mentioned the injectors as suspect above, had no idea what size 99's were. Maybe even have him fix it under warantee & then have someone else double check the work & do the dyno pulls.

jdoyle

iTrader: (27)

that sounds good to me, but im sure will cost alot of money, correct?

could you recommend a way to go about having someone else double check the work and do the pulls, this seems to be a sort of gray area.

jdoyle

iTrader: (27)

i like your procedure alot better.

to be honest, at first i did, and then i did some more investigation, and now i dont think it blew cuz of the A/f either. i believe improper installation to be the culprit, since what i and others saw of the workspace environment, was in no way a condition to be building motors in, it was too dirty. i doubt warped heads, but it could be, i had then milled by a good machine shop so im pretty sure the mating surfaces are flush. he mentioned coolant in the oil, so ya, milkshake.

i would love to check the heads, but he will be doing the work since it is warrantied, and i have work, then school, then back to work all 5 days of the week.

to my knowledge, they are brand new headbolts and gaskets. i sure hope he didnt re-use em.