There is a hole!

[myWRXtacy]

Ok so right behind the L20B under the valve cover I found a hole, and yesterday while filling up antifreeze it spill from back there, that made me realize something is suppose to be there.... What's missing and what am I doing wrong?

 

Thank you!!

 

 

[flatcat19]

You're not giving pics is what's wrong.

[BRE510]

...Freeze plug???

[]2eDeYe]

Yep, sounds like a freeze plug did it's job.

[LenRobertson]

I agree with the freeze plug (core plug) guess, at least until we know more. Can you prop a mirror against the firewall and get a pic of the hole? If you have trouble with pics, I can post a pic of what the back of the head should look like. Is this an engine you are just getting running, or one that has been running and just started leaking? More info will help.

 

If the core plug is leaking or gone completely, anyone have a clever trick for sticking a new one in there without pulling the head? I have a random idea, but my ideas tend to be waaay too involved and complicated.

 

Len

 

[]2eDeYe]

If it's the one in the back of the head, I would pull the motor mounts so the motor drops down to get room to maneuver back there.

[myWRXtacy]

I picked up the car last year. here..

 

http://community.ratsun.net/topic/55827-my-very-first-datsun-and-very-first-post/

 

 

And so I didn't have a clue that there is a freeze plug, seems like it hasn't been one in there for a while.

 

Here is the picture

 

 

So what's the easiest way to take care of it and also where would I get a plug?

 

Thanks for the input, it will be greatly appreciated!

 

Luis

[]2eDeYe]

Yep, freeze plug. You should be able to pick one up at any auto parts house.

 

As I posted before the easiest way is to pull the motor mounts and lower the engine to gain room to maneuver. You will want to clean up the hole a bit with a scotch bright pad before installing the new plug. Should just tap in with a small hammer.

[banzai510(hainz)]

they also make a rubber expanable kind to get you by. but I know they make it for the larger 40mm size. dont know about soemthing smaller.

 

has this motor been running with out this or whats the story?

You change heads and didnt notice this?

[LenRobertson]

Guys, am I seeing this correctly - looks to me like a rusty round thing in the center of the round inspection mirror? So the core plug is still in there, but leaking, maybe from rusting through? Not that it doesn't need changing, but if it is still there, the old one has to be removed. May not be easy with limited working room.

 

I like the remove the motor mound idea, except isn't the pan really close to the cross member on at least some of the cars (maybe not so on Datsun trucks)? I'll look at my 200SX, since it is the same vintage as Luis' 510. I'm remembering my '72 510, the pan just clears the X-member.

 

I'll try to post a pic of the core plug in the back of a head I have off when I get back from work this afternoon.

 

Len

[Stoffregen Motorsports]

If you can get a small chisel in there, hit it on one side so it kind of turns in the hole, then pull it out with a pliers. But since it is rusty, it will more than likely come apart when your trying to chisel it.

 

Best to do it with the motor out, but if you can try first with the motor in, just be careful. If you try to remove it and screw it up, you could cause irreperable damage.

 

Good luck.

[]2eDeYe]

Guys, am I seeing this correctly - looks to me like a rusty round thing in the center of the round inspection mirror? So the core plug is still in there, but leaking, maybe from rusting through? Not that it doesn't need changing, but if it is still there, the old one has to be removed. May not be easy with limited working room.

 

I like the remove the motor mound idea, except isn't the pan really close to the cross member on at least some of the cars (maybe not so on Datsun trucks)? .

 

Len

 

 

That's possible, hard to tell in the pic.

 

The trucks have a removable cross member that the pan fits through. Not sure on the late model 510's.

 

[LenRobertson]

Luis - A quick pic of the plug on the back of an extra head. I'd love to see a shot without the plug if anyone has one they can post.

 

 

This appears to be a steel plug with a flat bottom and straight sides which press against the hole in the aluminum head casting. I've never changed one of this type in aluminum, so I'm really unsure of how to do it, or if any sealer is used on a new plug. Since the surrounding metal is aluminum, I'd be quite careful about attacking it with chisels and pry bars, like you could one in an iron casting. If no one posts a fool proof idea for R&R in this thread, you might start a new thread asking how to do the head freeze plug.

 

If the the hole in the back of your head doesn't look like my pic, it could be the plug is gone on your head. If you aren't sure, stick a small magnet back there and see if it sticks to the steel plug. If it is gone that may make the job easier.

 

I know you don't want to hear this, but I keep thinking you may need to remove the head, and maybe even take it to a machine shop so they can replace the plug. You might search YouTube for vids on freeze plug replacement and see what info you can find. I may be be imagining this is more difficult than it really is.

 

I'll keep thinking. Let us know if the old plug is in there or not.

 

Len

 

 

 

[Ranman72]

if the motor has been sitting for a long time it might be worth it to replace the head gasket at the same time you do the freeze plug

otherwise you can pull the tranny mount and motormounts and maybe get enought clearance to do in the car

[LenRobertson]

Yeah, good chance to replace the head gasket. For that matter, it would be a good excuse  to abandon the smog cylinder head and stick on a closed chamber head and some sidedraft carbs. :P

 

Len

[myWRXtacy]

they also make a rubber expanable kind to get you by. but I know they make it for the larger 40mm size. dont know about soemthing smaller.

 

has this motor been running with out this or whats the story?

You change heads and didnt notice this?

 

I got the car running late spring this year after rebuilding the carburetor, replace fluids, and other little stuff (That's what I was told it needed). Not sure about the past or history of it :(

 

So that makes me realize that it won't be moving nor going anywhere this summer until it gets fixed, and most likely go full throttle on rebuilding the engine this winter so it is ready to roll next summer, I was thinking on a swap but I'd like to keep it original and collector status as far as legal status states. 

 

Thank you all so much for the input it is greatly appreciated!!

 

Luis