240z....if it's not the head gasket, then ?

[73rebzcar]

i appreciate the responses to my post last week regarding water out the tailpipe. again, operating temps were good, oil pressure good, then the smell of antifreeze and subsequent water out the back. the next day, i had added approx 1 qt of water before driving two miles to my guy.

anyway, had the head pulled and the gasket was not compromised. my guy is gonna send the head out to magnaflux for cracks as well as checking it's true.

interestingly, when they drained the oil, it was not milky and no bubbles (i had driven maybe four miles; two home, two back to the shop), but he said water came out then the oil. he also said the radiator was down, so the water i added two miles prior escaped as well.

any thoughts of a direction i should be looking towards, assuming the head comes back good?

thankx, as always

[evildky]

When you say water out the tailpipe are we talking about little spotty suitty spittle? If so thats normal just running a bit rich or have a weak spark. These cars didn't have a cat, newer cars with cats don't have this issue.

If the HG is blown you get huge plumes of smoke especially at start up, and or your exhaust passes into the cooling system forcing coolant out the overflow. The 73 didn't come with an overflow reservoir but one might have been added. Hows the rad cap? Hows the coolant mix? A poor mix and a weak cap will cause your car to spew coolant out the overflow hose as it heats up, if there is no overflow container to catch it you won't see the raised level nor will it have any way to suck the coolant back in as it cools, which is the benefit of an overflow.

These engines are not prone to loosing head gaskets unless boosted to the 300 whp range. They are prone to corrosion of the head near the lower thermostat housing which can leak, right onto the hot exhaust and burn off before it hits the ground.

You referenced an earlier post but this appears to be your first post.

[73rebzcar]

thnkx, ev..

nope, it started as smoke out the tailpipe and the smell of antifreeze. at the time, water and oil pressures were normal and remained that way through the two mile drive back home. i do have an overflow tank. cap/mixture are fine. the water out the tailpipe was more than you referenced. in fact, it trailed backing out the drive. while at first i thought it was oil, it did evaporate so it's possible some carbon or other byproduct was mixing in giving it the look of oil.

as mentioned above, if the head comes back fine, and there was water in the oil, does that lead to a crack in the block? can't imagine that for these iron blocks are extremely strong, so would be interested in any additional thoughts.

[evildky]

These blocks are actually incredibly strong, the stock blocks are known to make 600 whp, they are made with a higher quality metal than your domestic blocks of the same time period.

So you did get huge plumes of smoke at startup? Just because no "smoking gun" was spotted in the HG doesn't meant it wasn't at fault. The blown area might have damaged or distorted in the separation process, you should still be able to spot some proof but if it was a small leak for a short time it might not have left much evidence.

[73rebzcar]

thnks again,ev.

The jury still out as the head is being checked. Smoking is only on acceleration through normal driving. I don't really pay attention at startup but the interesting thing is it atill starts perfect it idols perfect it accelerates perfect so my feeling is it's on the exhaust side of the combustion process dumping straight into the headers. if it Were on the intake side of the process then my feeling is it would be difficult to start as the cylinders might have fluid in them. I appreciate your thoughts that the gasket could be compromised and I just can't see it. It's going to get replaced regardless. I will come back and post once i find out. if you have any other wild thoughts you know how to reach me
thankx again

[73rebzcar]

ev-update status

well, my boy will be coming home...under his own power, not in any auto-bodybag.

got the head back; no cracks but some distortion. i believe they initially pulled .005 off only to have to go back for another .003. i find that a pretty significant amount. i really like the e88 head and the shop is well respected.

thankx for your interest in my issue, ev.-best to you

[evildky]

If I had known you had an E88 I'd have suggested an upgrade

[73rebzcar]

yeah, i bet you would have, along with a few other nice pieces...

other than msa 6 into 1 headers and typical mild upgrades; three-row radiator w/overflow, 5 sp, toyota 4 piston calipers, and '79-'83 era distributor, pretty much a stock beauty. even running 14" rubber on a set of konig rewinds.