2 unrelated (I think) problems Ive been having are too much crankcase pressure popping my dipstick out, and losing coolant into the overflow bottle and ultimately onto the ground.

The dipstick tube is pretty tight... not tight that I have to use much force to pull the dipstick out, but tight enough that I think theres too much pressure in the crankcase causing it to pop. What causes this, what might the problem be, and what can I do to fix it?

Also, the coolant thing... I was driving around earlier and the temps started climbing towards 205F, even the fan couldn't bring them back down. I pulled into a parking lot and popped the hood. The overflow bottle was full, and there was coolant on the frame under the rad, dripping out of the overflow hose. I had some coolant in the backseat so I dumped a full 4L into the rad to fill it back up... meaning it was about half empty. What causes all this water to go into the overflow? It was full.

Headgasket is my guess.

Its impossible... its a brand new metal headgasket. There isnt even 100km on it.

You have new parts in there like PCV and rad cap, thermostat etc?

I hope I'm wrong, but pushing coolant like that is a CLASSIC symptom of a blown HG. (Ask PPG).

The dipstick popping out kinda goes along with it. Perhaps it's not "blown" but not sealing properly??

$2 on the head gasket.

You could check head bolt (stud) torque, and perhaps re-torque to spec, and see if that helps.

Did you use the copper "spray"?

-double post -

I'd check the thermostat and rad cap first.. Is the coolant boiling over in the overflow bottle?

Darko, were you running high boost under lean conditions?

It takes a fair amount of abuse to blow a metal headgasket.

Maybe you had some air trapped in the cooling system.......

I noticed on my extremely old stock rad cap I'd push a lot of coolant into the bottle. I switched to a 300ZX TT rad cap and now I never really see much fluid coming out the overflow. If the car is really hot and you turn it off then it will push some out.

I just went out there and checked the thing again... I let the car run without the rad cap on, and there is absolutely NO bubbling or soaping up of the coolant. If the headgasket was shot or not seated properly, the coolant would bubble and soap up for sure... so Im gonna be optimistic and rule the headgasket right out.

When Nick and I tuned the car the other day it didnt have a rad fan. We hit a bit of traffic so the temps went up to about 205F (haltech and water temp gauge are both accurate, so i know it didnt overheat)... at this point the water would've boiled over into the overflow. We installed a rad fan after we were done tuning (went out to buy one). At this point tho, the overflow must've been full already. I drove the car the same night without problems but it was cool outside. When the little mishap happened yesterday, I had to fill up 4L of water to top the system up. What I think happened is that we lost half the water while tuning and never filled it back up... this made the water that was already in there heat up a lot faster since there was so little of it. Thats my theory anyway.

I might have a small leak or two as well, so Ill be sure to check for that... Im gonna keep driving it over the next few days and keep a close eye on the coolant level.

Edit: we were tuning with a wideband and never going over 5psi... there was no dangerously lean condition, and no abuse whatsoever.

205F shouldn't be a problem. I'm usually around 206-209..

If there's a leak in the coolant system, it's possible it won't draw fluid back in from the overflow bottle as it cools.

After some sleep, I'm now thinking it might be your rad cap. If it's not sealing properly, it could do the same thing.

Well actually I just realized that my overflow hose (the one that sits inside the overflow bottle is only about 1" long... I must've cut it for use with something else and forgot to get another one in place while the car was off the road.

So even when the coolant cools back down, the hose wasn't long enough to suck it back in.

So did replacing the overflow hose fix the problem?

I would fill your rad, blow out the air, put on a new rad cap, then go for a good drive. Thats what fixed my coolant problems after changing the head gasket for no reason.

At least I got to see that my cylinders still have a good cross-hatch on the walls!

Steve you just made my day

I was all worried about my temps that get to 198 on hot days in traffic. But you say you go 10deg hotter?? YAY

if a guru like you lets your car go that high, Im ok

You are worried about 206?
>230 is where I would get concerned.

Actually the ecu shuts off the A/C at 239F as long as the coolant temp switch is working.

Temps from Manual?
Fans on - 185
Fans off - 172

My experience - > 200 On, off around 197

As for coolant out the overflow?
I went through a HUGE problem with that.
Mine WAS HG and load dependent.
Actually - wasn't the HG - I fixed the problem by re-torqueing the head - go figure.

If the coolant is BOILING under 250F you have serious problems with either a cap that doesn't hold pressure, or the HG is blown, or your head is on loose which pressurizes your cooling system.

Is your head on right?

Im not worried because the temperature itself reaches near 210F, Im worried about what's causing it and whether its a bigger problem.

Its funny you mentioned that I should retorque the head down, because another member told me to try this earlier. Its a fresh motor and it may have needed retorquing after the initial startup and first few KM of driving. Im very much hoping that this is the problem because it will save me a whole buttload of money and time.

The day I posted this thread, I heard the coolant boiling in the overflow... the temp was below 210F. My rad cap is fine, but there may be another leak in the system at one of the lines that goes to the t-stat housing. I could be losing pressure there?

Anyway, Im probably gonna retorque the head tomorrow, and pick up a new tstat, gasket, and rad cap just to be sure... as well as tighten up and clamp down all the lines again to ensure its not leaking anywhere else.

Thanks for the suggestions. Im hoping that retorquing the head will solve the problem. Im using a metal headgasket so I very much doubt its blown. I don't see how its at all possible. Guess I'll find out tomorrow.

ps. anyone wanna confirm the torque specs for the head? Im using ARP hardware... 80-85 ft-lbs okay?

80-85 FT-LBS WITH ARP LUBE, with oil its 100, since the engine has been ran theoretically the lube has came in contact with oil so I am not sure what value to use, when I retorque mine I'm going to go to about 90 (ARP studs, Cometic metal HG)

Metal Schmetal!

If the block and head aren't perfect the metal won't seal it....

I've experienced the EXACT same problem with a similar amount of prepwork and care and this weekend after pulling my head off the gasket told all...

The gasket looks fine however you can see carbon tracks on a sealing surface to the water holes in the block on cylinder's 2 and 3.

It was dead center between the studs and a retorque with ARP lube made absolutely no difference.

I could have got the head decked and tried again but it's not worth the hassle..

I just bought a core and am going all out on it.