99T/A

As you can see in my sif I have a 99 T/A A4. Mods in sig also. Just put this thing back together. The car was stock with stock tune before hand. I got the mods done and fired the car to check for good oil pressure and any leaks before tuning. Note the car did not get driven during this time. The car would not idle so I had to keep it running. Oil pressure up around 80psi at 2k rpm. I guess something tried to adjust and the car started idleing at around 650 on its own. Then started running like **** and making a chirping noise from underneath and backfiring out of the headers (open). Come to the conclusion that there was a lot of raw fuel in the headers from the computer trying to adjust. I sent the computer to Jason at TSP for a mail order tune since it is their cam and stuff in the car.

Got the computer back today and put it in. Fire it up and tune is great. Car idles on its own at 850 and after 30 sec of run time the backfiring quits completely. At idle there is no chirping noise but anything remotely over idle it occurs. Hear some ticking in the rockers (which I know is common) but decided to double check anyways. Completely reset all the rockers and now the ticking and chirping sounds louder. I put the cats on the headers to start mocking up the exhaust and decided to see how it sounded w/cats on it. Fire it up and at operating temp the passenger side cat is glowing red. Brand new highflow cats and a bunch of exhaust coming out so I know the cats arent stopped up, so why is it glowing red?

Any help with this issue or any suggestions would be greatly appreciated.

brad8266

iTrader: (23)

check your plugs, one could have a hairline crack in it. If its doing exhaust backfiring there is fuel getting into the header and its most likely from the fuel not firing off due to lack of spark rather than just too rich. Id check the entire ignition system before doing anything else.

99T/A

I will check the plugs but the backfiring has quit completely now it is just chirping over idle.

99T/A

Anyone else have any input or suggestions?

99T/A

Well I have went over everything I possibly know of. My next step is to pull it back out and go through and double check everything in the entire motor. If anyone has any advice before I tackle this tommorow evening please let me know asap. Thanks

Rebelord

iTrader: (2)

Like they said, check your plugs and wires. swap your coil packs from driver to pass and see if it follows. If it does, track down the bad coil or possible connections. Are you throwing any codes? Are there codes stored but not setting off the SES light? I would check that also. Check your injectors to incase on or a few are sticking.

Ski

Rebelord

iTrader: (2)

OH..////..grounds!!! Make sure you have good grounds. Thats cause some issues with others before too!!

slowassta

iTrader: (12)

especially the ones on the drivers side head, mine were loose and the car backfired really bad at WOT, and ran like ****...

99T/A

Ok just to clarify incase there was a misunderstanding when the first post was read. Now that the car is tuned the backfiring has quit completely and it runs great. There is a chirping/ticking sounding that is still happening anywhere over idle. When the car warms up it idles at 850 and there is no noise, but if I slighty crack it and I mean 50 RPM the noises comes out from hiding. Also both cats glow red at operating temps. I sent these to Jon @ Texas Speed to see what they thought. Let me know what you think.

Rebelord

iTrader: (2)

I watched the vid. Pull your valve covers, check all your springs, rockers, pushrods EVERYTHING. Sounds like a FUBAR'd valvetrain, possibly bent vavle from hitting a piston. Reading your sig, are the heads milled any?

Ski

99T/A

Here is a quote from the original post. Already went through the valvetrain. Only thing I haven't checked in the valvetrain is for a bent valve. Haven't pulled the heads back off yet but as far as I can tell the valves look fine from up top. The heads are straight out of the box PRC CNC LS6 heads with upgraded springs all which was purchased from TSP. I asked them before the purchase about PTV issues and they told me with my setup there would be none. Running out of options here so I might just have to tear it all down again Also can't figure out why the cats are glowing red hot at operting temps.

99T/A

Found the prob tonight. Bent valve on #7.

SPRAYED 01

iTrader: (22)

I just had the same problem. Mine was from low spring pressure and hitting the rev limiter a bunch of times. I replaced the valve, cleaned up the heads and used the proper shims to correct the spring pressure. You need to find out if that cam is just too big for your heads. Good luck.

Rebelord

iTrader: (2)

There you go. Talk to TSP about the springs possibly being weak and having to shim them.

Ski

Irocss85

iTrader: (1)

what springs do you have? you "should" have the platinum or extreme springs in there with the LSK lobed cam. and find out what installed height. they told me 1.800". mine were w/n .005 all the way around w/o any shims. wonder how that valve got bent like that? also dont miss the spot where the intake valve also hit the piston. something not right here. I think you should measure piston to valve clearance too. you could also take the springs out from that cyl. and have them tested, and see what the installed height was on those springs.
another thing, you cant run that car w/open headers. the 02 sensors are all F'd up due to reading all that fresh oxy. the headers are pulling into there. you need to atleast have the ypipe on it IMO.

LS1MCSS

iTrader: (18)

What is your pushrod length, rocker arm ratio, and head gasket thickness?

808ws6

iTrader: (6)

99T/A

Any updates on your findings?

Curious o see why the exhaust valve kissed the piston. I would have thought it would have been the intake. Is that a light impression of the intake valve on the piston?

Did you run stock GM MLS head gaskets?

99T/A

Ok I found a small peice of debris that was apparently in the back of the intake. The best that me and TSP both can come up with is it fell into that cylinder. When the piston came up it bent the spark plug electrode against the center electrode. Then when it tried to blow out the exhaust valve it got stuck holding the valve open enough for the piston to hit it. As far as the heads go, I ordered all of this as a package deal (at one time). When I called to place my order TSP told me they would have to build the heads. I told them everything I had and wanted so they could build them accordingly. Everyone at TSP especially Jon Reynolds have been extrodinarily awesome with me on this whole project so hat off to TSP, you guys have my business from now on. The gaskets I am running are Cometics and P/R are TSP 7.400. The spring are upgraded to the PRC double springs and the heads have a CNC Comp valve job on them. I am sure that everything else is right just one of those freak deals but I guess weirder things have happened Car should be back together by monday so I will keep ya'll posted.

99T/A

That mark that looks like the intake hit had me wondering. I did some researching and pulled som pics when I tore the motor down from it's completely stock state and that mark was there so that put a lot of ease to my mind

808ws6

iTrader: (6)

Thanks for the update.

The cometics you are running are .040" or thicker?

Thanks!