Head Seeping Coolant After Swap... Re-Torque?

[metalmonkey47]

Seems like I'm posting issues more then usual. I think my car's  on a breaking streak after begin driven more in the last few months then she has in years.

I swapped in my rebuilt N47 head onto my L24 to help my compression issues and after driving it about 3 months I've noticed after my last oil change a few weeks back that the center of the head is starting to seep antifreeze. 

 

The head was checked and seemed perfectly straight. The block as well, however the motor could have been overheated several time before, and had a blown head gasket when I got it early 2014 (which is why the E31 head isn't on it) so there is no telling. I had no seeping issues on the worn out MN47, however I guess at this point it may have just been coincidence. 

I have ARP studs in this motor. Is it worth a re-torque to help solve this issue for a short time? I'm getting ready to throw an L28 together and build a racey head for it, but since this is currently my DD I can't afford any extended down time. And it's cold as $^!# this week (13 degrees) so working on it for long periods is out of the question.

 

 

Note: I've yet to do a compression/leakdown test however I have both so I may take the time out of my day tomorrow and do it. 

 

 

[siteunseen]

"Is it worth a re-torque to help solve this issue for a short time?"

 

That's about your only short time option.  Hopefully those APR studs are newer and won't break.

 

You had a 2.8 head on prior right?  Smaller block was notched for the 2.8 valves?

 

It is cold as hell down here, 32 degrees when I woke up and I think that's the high for the day.  It's supposed to be around 10 degrees tomorrow morning.  I'm being a d***, my northern buddies.   

[cbuczesk]

It looks like it's spraying out. Look at all the drops on the starter and oil filter. I'd check that hose first to make sure that it doesn't have a pin hole leak. I doubt it's that simple but I'd hate to replace a headgasket if I didn't have to.

 

I'd try to retorque it. It might work. What's the worst that could happen? Hmmm...stud breaks, head warps beyond repair, attempt to drill out broken stud but drill at an angle into cylinder wall... Forget I said that!

 

Temps getting down to 8 degrees here today.

 

Chuck

[madkaw]

Bad part is that the leak is right where the oil supply hole is for the head, so keep an eye on things. So did the leak come with the cold weather?

Might as well try a retorque!

[240260280z]

Antifreeze replaced when head swappped or just water?

[siteunseen]

I've been reading Blue's vacuum gauge results page and thought you might try that test, simple.

http://atlanticz.ca/zclub/techtips/vacuum/

 

 

Idle (with constant large fluctuations)

This action usually indicates a leaky head gasket.

[Zed Head]

I swapped in my rebuilt N47 head onto my L24 to help my compression issues and after driving it about 3 months I've noticed after my last oil change a few weeks back that the center of the head is starting to seep antifreeze. 

 

The head was checked and seemed perfectly straight.

I have ARP studs in this motor. Is it worth a re-torque to help solve this issue for a short time?  

 

site asked an interesting question about valve clearance.  Wouldn't be your problem source but still interesting.  The big bore heads can have problems on the small bore L24 engine.

 

How did you check the head?  You should have an actual number.  I think that they tend to bow in the middle.  There's a flatness spec., it's .002" max. for the N47 head.

 

I think that the ARP site will tell you if the studs are multi-use or one stretch only.  What kind of HG did you use?  Some of the older ones recommend a retorque.  And re-torquing the head bolts is actually a maintenance item in the early FSM's.  Finally, although distasteful to many, some Bars Stop-Leak might do the job.

[71Nissan240Z]

I'm betting there is a crack somewhere.

[bartsscooterservice]

Only option is to take the head back off...

[Zed Head]

There is a lot of spray there.  It's even on the starter.  The pattern looks like it's coming from the head but it would be worthwhile to double-check.  You should be able to see it spraying at some condition,  Maybe warmed up with the engine revving.

 

Note that the cylinders, the coolant, and the oil all have different sealing systems, combined in to one gasket.  The cylinders have steel compressible sealing rings, the oil passage has a copper ring, and the coolant uses the gasket material.  Some people recommend smearing RTV around the coolant passages.  In case you do have to change the gasket.

[metalmonkey47]

Hey guys, so i don't have a lot of time to reply to all the questions so I'm gonna try and cover it all here in one big post. 


Regarding the L24 w/ L28 head, I've had no clearance issues in fact i never even thought to check. I had an MN47 head on it for a while, but the valves were leaking like a siv so I cleaned up an L28 N47 and slapped it on there. That's what's leaking now. FYI, this is fresh coolant and distilled water in the radiator.

There is no spray, it's leaking from the head for sure. I was going to re-torque today but ended up going to a local yard to check out a couple Z's with a buddy and look for salvageable parts. Found goodies! I'll post those later........ 

 

Anyways, I haven't been seeing any coolant/oil mix yet. I'm going to do a leakdown test tomorrow and retorque if it gets warm enough. It's 17 degrees out now. 

Another thing to note: I have coolant on the floor and I'm a little pissed at my 240 even though i shouldn't be. Driving back from the grocery store, I turned right merging into traffic and put my foot down. Prior to this, I had no reason to suspect the compression rings were also leaking although now I fear they are. During the 1-2 shift I heard what sounded like it might have been a little pop and started smelling antifreeze instantly. Windows started to fog, etc etc bad news etc.... Pretty sure I popped the heater core, and my only guess is that it's the result of compression leaking into the water jacket and over pressurizing the cooling system. I parked the car and gave up for the night but it looks like tomorrow I'm going to be troubleshooting that too... I'm in for a busy day. Hoping it's just a loose hose that's spraying. They're all brand new so I doubt it... 

[siteunseen]

-3 with the wind right now!  Daaaum that's cold for here in the North, of Alabama.   

 

Man that sucks popping a heater core in the dead of winter.  Can you borrow a car from a friend until you get it figured out?  I sure hope so.