fernandito7

iTrader: (2)

I guess u can now add me to the list of failed engines with FI.
However, at least i hope, my damage aint that bad. Here is what happened.
I took my car to my tuner to have the ignition harness installed and so that he can initialize it and retune. So the install goes perfect. He starts to road tune. Tuning goes well. 6.5 psi no problems,7psi no problems 7.5 psi no problems. After a while of road tuning he does on final run and hits 7.3 psi and hears something pop. Luckily he was a block away from his house. He stops the car and immediately pops the hood to see if he had blown the engine. There is no hole on the block. Oil pressure is fine, water pressure is fine, car idles perfect. However, theere is this one clicking noise coming from inside the block. Like if somethin is hitting or rubbing. Kinda like a "clunk clunk" noise. So he calls a couple of people and tells them the problem. We do a compression check and noticed that cylinder #2 was at 90 and cyliinder #1 was at 160 degress, The other ones were fine. We chekc the spark plugs and they are all fine.
WE know think its probably a messed up valve. At this point im already saddened and worried about the damage that happened to my car. He ruled out the possibility of the damage being a rod or piston because if it was the car wouldnt run at all.

I towed my car to my house and will be calling a couple places to see what they think it might be.
Does anybody know what it might be? If its a valve, is it expensive to fix and time consuming.
ANy help would be appreciated. Thanks
PS Should have just lefted at the stock greddy level.

KShep

iTrader: (4)

Very sorry to read about another one having problems. I hope that it is nothing too serious.

Sharif@Forged

iTrader: (92)

Fernandino...sorry to hear about this. I cant remember...have you upgraded your fuel system before attempting the higher boost levels? Tell us a little bit more about the tuning process and fuel enrichment. You said he initialized the eManage...did he then load the stock values before begining his road tuning session. Did you have a wideband connected? Sorry for all the questions...just trying to understand a little bit more about the failure.

That clunking noise may be a valve, but it could also be a bent rod, and the noise you are hearing is the clanking sound of the piston/rod not working nice with one another.

The best course of action would be to remove the head first, and then check that valve. If's its not the valve, then you'lll need to pull the motor and rebuild it. Forged Internals.

whosdady

iTrader: (6)

It sounds like your tuner was driving/working on it when it "popped." Why is he not taking care of it? Why was he boosting so high? I would be pretty upset if my tuner was hitting 7.5PSI (with a turbo) and my engine popped. This is why they carry insurance. Maybe if he told you he didn't want to do this and you said it was OK? That is the only reason I can think of that he could get off the hook.

Is it overheating? Is it leaking anything? Is there any smoke coming from the tailpipe? I would call your tuner back.

How many blown motors from turbos do we have? I can think of 3. The other 2 were rods

Zcool

Fernandito, I'm really sorry to hear that you may have a serious problem with your engine. Who was your tuner and like the previous reply I would like to know why he isn't taking some responsibility since he was driving your car and pusing the boost into dangerous territory.

Sharif@Forged

iTrader: (92)

Blown TT engines to my knowledge.

1) ZRAYGO: Accidental overboosting to 10psi+ level; headgasket
2) Joenismo: 6.6psi rod snapped at the wrist pin.
3) G35: I cant remember this guy..but I guess he has a shop and blew the engine at 6-7psi...not really sure here....lots of sketptics...and an extensive post on the matter about 4 weeks ago.
4) Fernandino: 7.5psi while road tuning.


These are ones I know about...maybe there are others.

I am ordering my forged stuff NOW!

Sharif@Forged

iTrader: (92)

Blown TT engines to my knowledge.

1) ZRAYGO: Accidental overboosting to 10psi+ level; headgasket
2) Joenismo: 6.6psi rod snapped at the wrist pin.
3) G35: I cant remember this guy..but I guess he has a shop and blew the engine at 6-7psi...not really sure here....lots of sketptics...and an extensive post on the matter about 4 weeks ago.
4) Fernandino: 7.5psi while road tuning.


These are ones I know about...maybe there are others.

I am ordering my forged stuff NOW!

fernandito7

iTrader: (2)

GQ, yes he did load the stock values and started from there. I also have the walbro 255 wideband o2. My tuner is gonna get that taking care of. He is working on that.
Whosdady, the car is not smoking, overheating nor leaking anything. My tuner also retarded the timing and everything was fine. I guess its just one of those things that some engines are better than others because others are running 8-10psiwiht no problems. I really hope its not a bent rod because that is gonna cost me a lot to fix and i dont have the money to fix it. I'll keep u updated. THanks for all ur help. Keep it coming.

fernandito7

iTrader: (2)

Also how much time does it take to remove the engine and take everything apart?

etx

After looking over a stock Z at the body shop and working with mine I don't think it would be hard at all. The entire front end of the car comes off! You can drop the trans, bolt up an engine mount, then lift the car and slide the motor out the front/bottom. Then the motor is on the stand and ready to be torn down!

I'll probably be doing this over the winter. 1 bar here I come.

Darren

Notice how Nissan has gone out of their way to keep this engine spinning slow and running rich? Nothing against Nissan, but it sounds like they don't put these engines together with a great deal of care. Personally, I would not consider making any major changes to this block (i.e., flywheel, UR pulleys, FI) without first pulling the motor down, installing forged and nitrided rods and pistons, and then reassembling taking care to have the entire rotating assembly carefully weighed, balanced, and all clearance specs tightened up.

350Now

sorry to hear about your car fernandito. Was your tuner datalogging during the runs. If so, how did the A/F look when he heard the pop? Based on your description since the motor still cranks and run it could be a valve issue making the clunking noise. I would be interested in seeing how the A/F is.

fernandito7

iTrader: (2)

He was data logging but i do not know what the AF was. He told me that it was running rich. We will be taking it to a shop that specializes in Z's and hopefully they will tell me good news instead of being somehtingl like a bent rod or broken piston. Just one word of advice to others, leave ur car at the stock boost level if u dont want to deal with any problems. It is safer this way. Now i understand y Greddy locks their emanage.
350z now, can u explain to me y do u think its a valve and not a bent rod as GQ mentioned? I mean the car turns on normally idles ok just that noise its making.

Sharif@Forged

iTrader: (92)

Is it more of a metal tapping noise or a clanking thud. Realistically, its impossible to diagnosis this over the interenet, unless you record a sound clip or something. Either way, at least the head has to come off, and this is very expensive, in and of itself.

If you are going to go through that, I'd do what ETX suggested and just pull the motor and rebuild. The parts are relatively cheap, compared to the labor you are going to incur..even just to fix the bent valve. I can source you Pauter Rods and Aria LC pistons for about $1700 for the set...complete!

stangme01

i had this problem with my mustang and the rod bolt was partially busted. it may not be that bad. I recommend NOT turning that car back on. can't you just pull the oil pan and look underneath?

man I need to get J&S on my altima NOW

g35tt

fernandito it is bad to hear that, and from what i read i could be saying that your rod went bad and thats y u have that ''clunk clunk' sound . and for repair i think it will be better if u build the bottom end of the motor. i am runnig my car at 8psi with no problem ( thanx god) so keep us inform and updated on this.

little_rod

OK, now this is starting to scare me and probably anyone else who has thought about a TT. We can go through our lists of things it might be, but point blank, it is still just an engine that was messed up by a TT.

SCs, especially the Vortech, are becoming a lot more attractive. Good luck to you fernandito7, this is really bad news, hopefully it is not too bad. Please keep us updated.

phunk

iTrader: (21)

What you have said about your compression test results... that made no sense HOWEVER if you meant to say "that cylinder #2 was at 90 and cyliinder #1 was at 160 PSI " ...

if thats what you meant to say, well... that motor is done.

hopefully you meant something else tho...

the last thing you want to do is tear down a motor if nothing is exactly wrong with it... what if its just some BS problem? Could be something weird with a pump, could be something weird with a timing chain pulley... i dunno... but make sure its definatly something that the engine has to be torn down for first.

Here are some things to consider...

a valve... i highly doubt you dropped a valve or lost anything at all in the valvetrain. the valvetrain on the VQ35 motor is pretty much the indentical bulletproof layout to the VG30 motor, toyota 3SGTE and 2JZ motors, not to mention just about every cylinder head on a motorcycle. The only thing I dont like about these VQ heads is how tiny everything is... but i would have to say that the chances you messed up anything on the head are next to nothing... not only that but if something was wrong there the car should run like total crap since a dropped or bent valve would mean 0 compression on that cylinder.

First thing first I would pull off the lower oil pan and see if you can see anything at all going on, or any debris. Take off the oil filter and cut it open and look for debris. A thrown rod is outright obvious, a bent one should be also.

If everything looks normal and you cant find debris, i have one idea to check for a bent rod... pull out all your spark plugs. get something long and thin like a piece of welding stick. put it down the spark plug holes one at a time and mark the height of the stick with the piston at TDC while spinning the crank by hand tools via the crank pulley. If there is a bent rod than its center to center length would be shorter and the height of the welding rod would be lower on the cylinder with the bent connecting rod.

it can be next to impossible to dianose this kind of problem over the internet....

i have seen engines with pistons that had melted ring lands runs completely normally at idle and cruising and also compression test fine.

try a leakdown test also.

im just trying to help you out... hopefully its just some ******** going on there and nothing too extreme.

-Charles

spazpilot

iTrader: (2)

little_rod


If its tune right it will run right. 9000 plus and still going strong

phunk

iTrader: (21)

spaz said it.

a motor can blow even under wing of the best of tuners... it is, however, much less likely. The VQ motor seems to be building a rep for shitty internals... i can understand the pistons... but weak rods is really some ********.

i mean with piston design a lot of it has to do with emissions and long engine wear... but i cant think of an excuse for crappy rods. Nissan needs to take a lesson from toyota on connecting rod design.