dipstick blown out, bad valve?

[Billy_Jack]

So, a few days a ago i picked up my r33 from the shipping company, boost wasnt set too high, but it did smoke a little while driving for the first bit. after driving it for two days, i changed the oil and dropped it off at the shop for its OOP.

anyways, the mechanic said he didnt have much time to look at it but he did say that he thinks the rings are cracked, lifted the hood and boom, the dipstick is blown out and oil all over. GREAT. limped it the short way home and did a compression test. here are the results as follows:

Dry (psi): #1=148 #2=145 #3=142 #4=98 #5=147 #6=150
Wet (psi): #1=158 #2=157 #3=155 #4=106 #5=160 #6=170

So im thinking it isnt the rings, but would a bad valve cause the dipstick to blow out and spray oil everywhere? it really doesnt burn that much oil but the crankcase vent does blow quite a bit of smoke.

Thoughts?

[bobbo]

Stuck PCV valve maybe? What's done to the car? If it doesn't smoke/use oil and it idles and drives well I wouldn't suspect valve or ring damage although #4 doesn't look too happy.

[Billy_Jack]

I can't tell you what it has for internals but here is a short list:

Hks gt25 x2
Hks fcon vpro
Hks IC piping kit
Hks evc
Hks mushroom AF
As far as injectors go, couldn't tell you anything other than the denso stamp on them

And I'm pretty sure it isn't the pcv valve, the hose will let off pressure when you hold your thumb over it ( it just vents underneath the car)

[cortexx]

Cylinder number 4 has issues , either broken rings , cracked piston preassurizing the crank case OR blown headgasket pressurizing the oil galleries , either way its an engine out , take it apart and show and tell scenario.

[Billy_Jack]

Ok, well I'm gonna go ahead and do a leak-down test before I start ripping it apart

[RSTuning]

Nissan service limit is 120-130 psi.

at 98psi i would remove the motor.

[jrhdohc]

whom did you purchase the car?
have you spoke to them?

[Billy_Jack]

I brought in from japan, so I don't know if there's much I can do.

[dark_sky]

your rings are gone. how many km on the car?

[Billy_Jack]

68000km

[fenris]

Ring blown at 68km seem your car got a 'haircut' in japan. Were did you bought it so no one here deal at that place?

[frankiman]

combustion chamber pressure is escaping trough cyl #4 into the crank case making the dip stick blow out

[mcase]

Sorry but you will have to pull the motor out. Maybe melted piston from cyl 4 or scored bore maybe, but in short bad news.

[Billy_Jack]

well, did the leak down test came up with a ~75% loss on cylinder 4 and a heavy amount of air coming out of the oil filler cap, so on to the next step.

anyone have have a ball park figure for a refresh (assuming the pistons and bore check out fine)?

[cortexx]

Pistons and bore will not come out fine given the symptoms , i suggest you yank the engine , take it apart and start making a shopping list .

This isn't a platform thats cheap to play with , if cost is a major factor and you can't really cheap out on an engine rebuild.

You might even consider cutting your losses and selling the car off as parts and then using the cash to buy a good running car , or buy a complete dropin engine from one of the JDM engine importers .