240z-PART II--if it's not the head gasket, then...

[73rebzcar]

hold those horses, nellie.

as previously posted, white smoke and the aroma of the sweeeeeet nectar of antifreeze led me to what was thought would be the head. after getting the head back (no cracks, but warped and two passes for a max. of .008" being taken off-btw, the gasket was not compromised during the inspection process), installed with the new gasket kit, etc, etc, the car started but still fluid out the tailpipe. appears that water is in the oil as well (it was idled for a period of time, not driven).

anyway, leads me to something in the block (water jacket, cylinder walls....something). from reading many of y'all's posts, these blocks are very reliable, so it might be a 'simple' bottom end rebuild. would like to have it torn back down and focus on the block; if nothing visual, then have it magnafluxed.

i was asked by a friend if the new head gasket was installed incorrectly....can that actually happen without it being obvious to someone that is being paid to know 'which side is up'?

thanks so much again for your thoughts.

btw, some addl. background on the car:

l-24/e88 head; all stock, 3 row radiator, 5 speed from a zx, msa 6>1 headers. second engine in the car so do not know the history of the switch. compressions range from 120-133 for four cylinders, with a 110 and 105 thrown in for good measure. i've put 24k miles on the car over eight years and gotta tell you, starts, idles, and runs like a newborn. good oil pressure, never runs hot even with the a/c.

[evildky]

What 2 cylinder had low compression? Yes it should be obvious which side is up, it's also possible to get a bad gasket. Had this happen to me on an mr2, had a metal ring around an oil passage that was too tall and the gasket could not seat around it, spewed oil at high rpm. Low compression in those cylinders needs to be figured out, is it leaking past the rings? valves? into another cylinder? this will help you narrow down the source of the issue, a leakdown tester makes this a lot easier, an air regulator and a compression tester with the schrader removed can do the job in a pinch.

[73rebzcar]

thankx,ev.

not sure which cylinders were on the low side of the readings. will have them confirm as well as performing a leak down test. I'm expecting a rebuild of the bottom end so as to ensure I'm not in there later, thus my desire to ensure this block is rebuild-worthy.

will keep u posted. I think I've forgotten how to drive this car so it might be necessary to post a thread for driving instructor referrals in my area...

[73rebzcar]

ev

based on a firing order of 1(closest to fan, correct?)-5-3-6-2-4, compression readings are 129-133-130-120-110-105

[evildky]

firing order has nothing to do with it, the cylinders are numbers front to back, 1 2 3 4 5 6 , they do not fire in that order but I'm guessing that still means that 5 and 6 are your lwo cylinders, now you need to find otu if the compression is leaking between the 2, or into the exhaust, or the intake or the oil or the coolant

[73rebzcar]

thnks for the guidance, ev.

will report back with the verdict.

[73rebzcar]

...there must be a PART III.

well, after what appears to have been a lifetime out of my 240, i was fortunately reunited with my 30 yr friend and z car guru(funny story about how we lost contact the past four years, but i shall not digress).

as noted herein, i was chasing symptoms on the combustion side of the equation. turns out it was diagnosed (over the phone no less!) as a casting flaw in the e88 head that is not readily apparent through normal aluminum head diagnosis/work. as i understand, it's in an area of the head nearest the thermostat cover. anyway, while it can be repaired, one never knows if it will hold. so...'off with his head'

he had an early version of the e88; did a valve job, replaced all the seats, etc and back on the engine. what a magician.

thankx, ev, for your posts throughout this. been out of the car for a few months, so hope i can remember how to drive it.


best to all.

[evildky]

you never clarified where your compression was low, if it was in fact 5 and 6 thats the opposite end of the head form the thermostat housing. I've never heard of a mfg defect in the E88 head that takes 40 years to surface. A cracked head should have been found by any competent machinist. There is no point repairing an e88 head, especially when an N42 or E31 are readily available and both would improve performance.