question about head gasket!

[mk3tattoos]

so i have been having a problem with water coming out of my rad cap when i open. I used arp studs and a titan gasket and after doing some research found out that some people forget about the rivets. so i called my friend that rebuilt my engine and asked him about the rivets, he siad they were crush style.

so my question is are there crush style on the titan gasket?

i alredy have the head ready to come off.

---------- Post added at 01:20 PM ---------- Previous post was at 01:17 PM ----------

sorry posted twice, can someone take off one please

 

[CyFi6]

Theres no such thing as a crush type rivet, but the newer gaskets dont have issues with being crushed, make sure its actually holding it up before you pull the head. If you are removing the radiator cap when the coolant is warm, coolant is going to come out as its under pressure unless its cold.

 

[mk3tattoos]

Theres no such thing as a crush type rivet, but the newer gaskets dont have issues with being crushed, make sure its actually holding it up before you pull the head. If you are removing the radiator cap when the coolant is warm, coolant is going to come out as its under pressure unless its cold.

it is always cold when i open it and it flows out for a second. thank you for you quick response

 

[IJ.]

Theres no such thing as a crush type rivet, but the newer gaskets dont have issues with being crushed, make sure its actually holding it up before you pull the head. If you are removing the radiator cap when the coolant is warm, coolant is going to come out as its under pressure unless its cold.

Are you sure about that?

Never seen one of these mythical later design MHG's that have the rivet issue corrected...

 

[mk3tattoos]

good to know IJ, so does that mean i have to take the head off and redo the jod? thanks agian

 

[IJ.]

You should be able to see if the rivet is at fault before you go to the effort of pulling the engine/head.

Do you have any pics of the Deck surface without the head?

 

[mk3tattoos]

i will check right now and see if i have any good angles on the pictures that will show it.

 

[mk3tattoos]

i do not have any with the head off but i have a few with it on and out of the engine! so lets see if we can get anything from these.

 

[IJ.]

What we need to see is circled.

 

[mk3tattoos]

so do i need to take the head off to show you, or can i strip everything off on the exhaust side in the front with the head on and still take pctures? thank you so much!

 

[IJ.]

You should be able to see it with the head on (just)

I'd be doing a Comp and a Leakdown and possibly a Napa Combustion gas test long before I'd think about pulling the head as if the block hasn't been surfaced much the rivet doesn't affect anything as the stock block casting drops away there, it's not until you cut it xx amount that it becomes an issue.

 

[mk3tattoos]

i had a compression test before we moved to a new house, then lost the sheet when we did. it was all good with that, but i will do all test this week on the engine. thanks again man! i will get going on this asap

 

[IJ.]

No probs, it's always a good thing to confirm you have an issue BEFORE ripping into it

 

[CyFi6]

Are you sure about that?

Never seen one of these mythical later design MHG's that have the rivet issue corrected...

Not exactly mythical just going based off research

Older Cometic/Titan

Newer extended front rivet Cometic/Titan

It was the Cometic (and rebadged Titian) that had this problem, most new versions have been corrected. To be sure, just lay the MHG on the block deck. If any rivet touches the deck surface, remove it.

Sorry if there is a such thing as a crush style rivet on MHG's but as far as i know you dont want anything interfering with the MHG seal between the head and the block deck

 

[IJ.]

Just said I'd never seen one, thanks for posting the pic, good to see someone's finally updated the HG design now if HKS will follow suit we'll be golden.
(Cometic make the TMS MHG)

Bit of a hint ALL rivets are crush rivets excluding Pop rivets that leave the steel pin inside and aren't crushable.

I think that's the distinction the OP's mechanic was trying to make without realising that even the crush rivet is enough to cause an issue on a decked block.

 

[grimreaper]

with the radiator cap off, even cold it will slowly begin to overflow as it heats up... Test the cap too if your seeing hgher then "normal" water levels in the overflow tank. I had two NEW fluidyne caps that tested bad right out of the box.. On held 13 psi and slowly leaked it off and the other held 9psi solid.

 

[mk3tattoos]

what also led me to believe i had a leaking HG is that i kept blowing out the older rad hoses that seemed ok and didnt need replaced. so there must be alot of pressure on them. my rad cap is very old. \
grim can you give me a good source to get a cap from.

thanks for everyones help. i value this site so much!

 

[grimreaper]

Apparently fluidyne uses stants re labeled. After i found my caps to be $50 pieces of trash i called fluidyne and they gave me the stant part number instead of replacing them. Sad huh? Same cap used on the 84-89 300zx for 13psi. Stant 11227, napa # 703-2443. If you want a 16psi cap its the one for the 90-96 300zx stant # 10233 $6.50 out the door... Id bring a radiator cap tester in with you. Make sure to test it before leaving! Good thing is the new cap has a MUCH beefier spring when compared side by side to the fluidynes. Hopefully it will last a while.

Id love to get my hands on 5 or 6 HKS or Spoon caps and see if they have same quality control...

I never had an issue with to much pressure. My first clue something was a miss was a softer then "normal" upper rad hose after shutdown. Also had funky water levels in the overflow tank. It never hit consistent levels even when driving day to day in nearly identical conditions. Now it does or close enough to hardly notice with out a tape measure (ya i can get a bit anal sometimes)

 

[mk3tattoos]

that is great info! thanks for all of that buddy, and you cant be to anal about that stuff, its just love

 

[IJ.]

Keep in mind also that there are 2 different height caps in that diameter..