Ever blow a Freeze Plug while Driving?? I did....

[Zs-ondabrain]

So Me and Z_Tyler_Z were at the local Pull A Part stripping a 71' 240Z before they crush it tomorrow. Weirdly enough, got a couple parts for $12 and headed home. Traffic absolutely sucked, so after sitting in the driveway for 5 minutes waiting for a break, I floored it and hit about 6KRPM's and a burst of steam "Puffed" out of the hood to fender area.

Nowhere to pull over till I got around the corner. The whole time, I'm thinking "Please be a hose, Please be a hose" "And not the $300 aluminum radiator" So I shut it off and popped the hood to have a steady stream of hot water shooting onto the drivers side inner fender between the coil and the strut tower. So after a closer look, I spot the colprit..... One of my freeze plugs had rusted through and the hi RPM's pushed the metal enough to finally burst the rust wall of the freeze plug.

Upon further inspection, the center freeze plug also has rust on it and a small rust stain could be seen below that plug as well.

So my question is, before I go and try and find 2 new plugs, is...

Does anyone know the size of the Freeze plugs on my 70' L24 block??

Just wanna be prepared for the hunt tomorrow.

Thanks in advance.

Dave

[Zs-ondabrain]

And a BIG thanks to Tyler for going back to the Pull A Part and getting me a gallon of "Recovered Antifreeze" and then following me home to make sure I actually made it that far.

It never over heated but the dam towel that I put near the front SU, to keep the water out of the carb, got socked into the front SU.... Causing me to basically run on 3 cylinders all the way home. And he was back there sucking up the fumes of an OVERLY rich 3 cylinders and all the water going into the rear carb.

Fun Times, Fun Times.

[Nigel1943]

So Me and Z_Tyler_Z were at the local Pull A Part stripping a 71' 240Z before they crush it tomorrow. Weirdly enough, got a couple parts for $12 and headed home. Traffic absolutely sucked, so after sitting in the driveway for 5 minutes waiting for a break, I floored it and hit about 6KRPM's and a burst of steam "Puffed" out of the hood to fender area.

Nowhere to pull over till I got around the corner. The whole time, I'm thinking "Please be a hose, Please be a hose" "And not the $300 aluminum radiator" So I shut it off and popped the hood to have a steady stream of hot water shooting onto the drivers side inner fender between the coil and the strut tower. So after a closer look, I spot the colprit..... One of my freeze plugs had rusted through and the hi RPM's pushed the metal enough to finally burst the rust wall of the freeze plug.

Upon further inspection, the center freeze plug also has rust on it and a small rust stain could be seen below that plug as well.

So my question is, before I go and try and find 2 new plugs, is...

Does anyone know the size of the Freeze plugs on my 70' L24 block??

Just wanna be prepared for the hunt tomorrow.

Thanks in advance.

Dave

Dave: I ones you need are 35mm and are available in brass which I would recommend.

[prilofx]

and pick up a couple of the rubber-sandwich temporary ones in case another one blows on you if you aren't going to do all of them at once. To keep in the glovebox for an emergency.

Edited May 27, 2010 by prilofx
it's 4 minutes to 6 am

[S30Driver]

As bad as it was Dave, better now close to home, then half way to Canby in a few weeks ....

The rubber freeze plug is a good idea, I may pick one up & put it in the kit with the spare tire for emergencies.

[Zs-ondabrain]

That's a great idea and yes, "Better close to home" I'd be screwed had it happened on the way to Canby.

Thanks guys, 35 mm it is. Guess I could also pull the bad one and take it with me to the store for simple comparison sake.

Dave

[preith]

This is a very real concern for racers. I toasted a fresh race engine my first time out at the drivers school, 4 laps into it, because of this. The only hint of an issue was a small amount of water on the windshield, which I thought may have been from the car ahead of me. The temp gauge never climbed because there wasn't any coolant on it. I've added a low pressure coolant switch since and am religious about adding Permatex high tac sealant around the edge. The good news is the issue hasn't presented itself again since '04.

The same thing happened to a fellow 510 racer too.

Edited May 27, 2010 by preith

[Darrel]

why only replace the 2 that are showing rust?

[Zs-ondabrain]

Actually, I ordered 6 Brass 35mm Freeze Plugs from Napa. I tried everywhere else but nobody had them in stock. Napa has them in their Seattle Warehouse and will have them up here tomorrow morning. At $1.99 each, I figured "why not do all of the exterior plugs while I'm at it.

Dave

Edited May 28, 2010 by Zs-ondabrain

[Pop's Z]

Hi All,

I read this thread last week and thought "that's interesting", but....Then this weekend I was testing my "new" F54/N42 cammed, shaved head combo at high rpms and POP then great clouds of steam erupted from under the car. Long story short I, too, had blown out a brand new core (freeze) plug, the first one back from the alternator on the rt. side of the block. The temp guage did not register the changed situation, either. Fortunately, I had a rubber temporary plug in the car. So I filled it back up with water and went on my way. I thought I had put the core plugs in correctly, but now I'm totally paranoid that another one will blow when I'm off in some remote area. To install them I used a socket that just fit and bapped them in with a BFH. Is there something I missed? I did not use any kind of sealer/adhesive as the NAPA guys said they weren't necessary. Any advice will be appreciated. Dave, did you put yours in yet?

Cheers, Mike

[Diseazd]

Mike.....Same thing happened to me a couple weeks ago. The culprit from what I can figure out is hard runs before the thermostat has opened. In other words if you get on it before the engine has fully warmed up and allowed the thermostat to open, the water pump is building maximum pressure. If the thermostat is open, your radiator cap can release the pressure......Make sense? Guy

[Zs-ondabrain]

didn't mean to Jinx ya. Mine were on the drivers side so I ended up pulling the intakes and header, JUST to pound in 3 new plugs. The center one (near #4 piston) had a small misty leak to I pounded it in a little more with a 3/8 x 8" extention in the area of the leak (about 1 O:clock)

BUT, aparently I did more damage, as I found a small leak under the water pump. I had blown the bearing seal and called NAPA to buy a replacement unit that I'll put in tomorrow. I'm suppost to drive this car to Canby and have a new set of ZTHERAPY ZT's put on. Hoping this is the end of the issues till I get back. Don't ned a break down between here and there (500 mile round trip)

Dave