booger

iTrader: (6)

No...no oil

Mia...I was on your side , thats for sure . Hoped it would have over heated with out boosting to confirm T-stat

Ep3

iTrader: (10)

damn good luck booger see this thru

failsafe306

iTrader: (38)

I'm still not 100% convinced we're all seeing headlift, at least those of us under 600whp. Hell, I've always got a little bit of coolant on the top of my APS overflow can after hard runs, and the level in that can is usually higher than I'd like to see, but until someone can show me trashed head gaskets, oil analysis proving coolant in the oil, or proof of stretched out head studs, I'm going to have to say that our motors are just running too hot under boost due to an inadequate cooling system.

Again, I'm only saying for those of us well under the 600whp mark. Over that, anything's possible I suppose.

booger

iTrader: (6)

Any one know where the temp sensor is , that the ECU reads ? If it's coming out of the motor or going into the motor ? If the sensor is located on the water coming out , I can log water temps and see how hot it runs when Im boosting . If the sensor is taking temps if the water going into the motor , it wouldnt do much good to log them

failsafe306

iTrader: (38)

It's in the rear of the motor, monitoring the outgoing coolant, pre-radiator.

booger

iTrader: (6)

Then it would show exactly how hot it is running then . I'll do that next time

martin320

mine is doing exactly the same thing.overflow is full after a run. i did change the rad cap to a nismo one after steam was coming out of the stock one.once the motor cools down and i take the rad cap off the rad is still full.
going to try bleeding it to see if this works out.my car has only done 500 miles since my aps tt install.

failsafe306

iTrader: (38)

Is yours FULL, like literally overflowing, or just high enough to cause the sloshing of the coolant around to come out of the small hole in the top? Mine is doing the latter, it's not what I'd consider overflowing by any means. If yours is overflowing, you most likely have air in the system.

barthelb

I wonder if APS has experienced this. Cuz this is only been a problem since the install. Im sure they must have seen something like this.

martin320

first of all it dumped a load of coolant when i put the car in the garage after a run. then i noticed steam coming from the rad cap.even though i have lost some coolant cannot get any back in the radiator as it is full.which may point to air in the system. now its not losing coolant.but the overflow is at the top with a small amount of coolant coming out of the hole on top of the overflow tank.

Z350Lover

iTrader: (2)

ok.... when I said my radiator cap was bad.... I can actually see some coolant trapped in between the clear film on the nismo logo sticker... and right after I swapped the cap, it never happened again though. Never have the coolant overflow issue again and the overflow tank stays just slightly above the max. level mark (and sometimes it is just get a little bid lower).

but I did notice one thing before I swapped the cap, I would only have heater when I gave the engine some gas and as soon as I let go of the throttle, heater would be gone.... probably mine was the simple problem since my heater just didn't work over night (not gradually becoming colder).

cheers,

richie

350zDCalb

iTrader: (21)

i just pulled my motor...headgaskets looked perfect (granted i was over 600whp-sae corrected)...but the head lift does exist, you won't necessarily see anything with the gasket, i did see a marked residue around the intake and exhaust side of the block/head surface of cylinder #3...you could see also where coolant had oozed out onto the block, on the medial side of the block and laterally...
i did have black residue in my coolant, but no milky oil...

failsafe306

iTrader: (38)

Did you take your studs to your machine shop to be accurately measured to see if they're stretched out, by any chance? Not doubting your theory, just curious. I'd think if they were stretching, there would be tell-tale signs. It would be interesting to see the results.

Audible Mayhem

iTrader: (48)

sorry i didnt read everything here.


take out your thermostat and gut it out. i gutted out my thermo and filled half of my coolant with water and it runs 40 degrees F cooler all the time. i think everyone with FI should do this. the only downfall is that your car takes a bit longer to warm up.


much much safer cause i have heard of a few people overheating their cars...

G352NV

iTrader: (13)

This is why I suggested that. It would also be easier to get all the air out of the system. I did this back in my V8 days.

350zDCalb

iTrader: (21)

i will be analyzing the studs for any stretch soon, but understand, the studs do not need to stretch to allow the heads to lift...

a few of the other possibilities allowing head lift:

-head studs not being re-torqued (as recommended by ARP)--this is a very grueling procedure, as one would have to remove the timing cover and cams

-mating surfaces between block and heads are not redecked..therefore not sealing completely

-detonation dramatically affecting cylinder pressures and forcing the heads to lift- possibly pulling the studs slightly out of the aluminum threaded block


...a few possibilities
-head gaskets compressing and crushing

Gman2004

iTrader: (8)

did you happen to check to see if yours needed to be re-torqued?

350zDCalb

iTrader: (21)

i should have but didnt..but, they were still very firmly torqued down, took just as much to pull the nuts off of the studs surrounding the affected cylinder as compared to the other cylinders

failsafe306

iTrader: (38)

I suppose if detonation were bad enough, it could warp the mating surfaces, correct?

350zDCalb

iTrader: (21)

it is moreso an issue of detonation creating extreme pressures within the cylinder, forcing the head to seperate from the block (in thousandths of an inch)

detonation is not the only answer here, there becomes a limitation of matter...the standard arp studs do provide a tremendous amount of clamping force between the heads and the block. Greater amounts of torque to the studs will decrease the instances of cylinder head lift, the choices are; stronger studs, steel inserts in the aluminum block, larger diameter studs...or all of the above.

GT motorsports claims that there are a few vq35's that are in a drag race platform making 1500+hp and do not have a hint of cylinder head lift issues (these motors are built with 14mm studs)