Blown Head Gasket

[tsunari]

Did some headwork about 24k miles ago (Engine now has 156k on it) . . . 3-angle valve job, new belts, mits. head gasket, etc . . .

Just did a compression test & leak down test and got the following:

1, 2, 3, 4 [Cylinder]

140, 180, 180, 180 [psi Compression]

60, 6, 9, 5 [% leakage]

From the sound of it, I have a blown head gasket between cylinder 1 & 2 (sounds like air is coming out #2 spark plug hole). Questions are:

1) What would've caused the head gasket to blow with only 24k miles on it?
2) What should I replace when I get everything apart? (Arp head bolts, aftermarket head gasket, PT Cruiser HLAs, etc. . . )

Any and all SANE suggestions/ideas are greatly appreciated.

 

[RoasT BeeF]

How much boost are you running? Did you have the head decked? Did you tighted all head bolts to spec?

 

[tsunari]

Originally posted by RoasT BeeF
How much boost are you running? Did you have the head decked? Did you tighted all head bolts to spec?

Still running stock boost (~14 PSI) . . . did have the head decked, but not a whole lot- just enough to get everything nice and flat. As for tightening everything to spec- yup! Did it by-the-book . . .

Only thing I can think of that 'went wrong' with the engine is I had my waste gate lines hooked up wrong when I initially put everything back together. Luckily I was still running the stock BOV/Pop-off valve . . . so nothing blew up.

 

[NOSNUSE]

What type of head gasket did you use?, the Felpro ones are crap and will give out.

 

[tsunari]

Originally posted by NOSNUSE
What type of head gasket did you use?, the Felpro ones are crap and will give out.

Hmmm . . .brand. . . brand. . . .brand . . .

I think it MIGHT'VE been Felpro . . . but do not remember for sure. I just know I got it from the local Mits. Dealership.

So since I most likely have to get a new one- What brand should I get? I'm already thinking of getting ARP head bolts. Anything else I should do while she's torn apart?

 

[sound227]

Felpro is good to me. I had mine on for about 20,000 now at 16psi, but when I change my turbo I will be getting teh mitsu 4 layer metal head gasket with ARP head bolts, that should be good for what I plan to run at (22psi). If I were you, I would make the same investment, it should cost around 200 or so, but you shouldnt have any more problems after that.

 

[tsunari]

So here's the list of things I'm thinking of doing while she's torn apart:

Kevlar Timing Belt
Balance Shaft Removal
Mits. Head Gasket
ARP Head Bolts
Updated Lifters


Any other suggestions? And is the Mits. Head gasket pretty much the best for our engines? Also . . . am I going to need to replace my intake/exhaust manifold gaskets as well? Perhaps even my Valve cover gasket and all the gaskets for the turbo? (I.E. - just get the whole engine gasket set from Mits?)

 

[Djcubinlinx]

i don't see a point in putting in the kevlar belt if your gonna have to change the pulleys anyway after 60k. Might as well just put the regular one in and save the cash. IMO.

 

[AL92]

There are some better gaskets cometic are supposed to be very good and about same price as mits mulitlayer but not sure if you have to oring block or heads to use them.I have heard of some guys blowing the mits metal gasket out too so not sure what to use.Obviously some arp head studs are a good idea.

As for the kevlar belts well they are supposedly unbreakable and don't stretch and probably could be used for 120,000 miles .Heck even 60,000 miles is going to be like probably 10 years for me since I have other vehicles to drive.

Why take the chance on a timing belt breaking.I say buy the kevlar one.

 

[tsunari]

Since i have almost 10% leakage on #3 cylinder . . . and I'm going to be doing the BSE kit while everything is apart. . . think i should go ahead and get a set of ARP rod bolts and maybe even a set of new rings? Or would that be a waste of $$$ at this point?

 

[tsunari]

This just occurred to me . . . *IF* the headgasket was indeed blown, wouldn't the adjacent cylinder suffer the same fate of low compression?? So #2 would be low as well?

BTW- The head gasket that was put on was the OEM composite gasket from Mits. . . . not the 4-layer metal one :-(

Originally posted by tsunari
Did some headwork about 24k miles ago (Engine now has 156k on it) . . . 3-angle valve job, new belts, mits. head gasket, etc . . .

Just did a compression test & leak down test and got the following:

1, 2, 3, 4 [Cylinder]

140, 180, 180, 180 [psi Compression]

60, 6, 9, 5 [% leakage]

From the sound of it, I have a blown head gasket between cylinder 1 & 2 (sounds like air is coming out #2 spark plug hole). Questions are:

1) What would've caused the head gasket to blow with only 24k miles on it?
2) What should I replace when I get everything apart? (Arp head bolts, aftermarket head gasket, PT Cruiser HLAs, etc. . . )

Any and all SANE suggestions/ideas are greatly appreciated.

 

[sound227]

Originally posted by tsunari
This just occurred to me . . . *IF* the headgasket was indeed blown, wouldn't the adjacent cylinder suffer the same fate of low compression?? So #2 would be low as well?

It depends where it is blown at, could have blown into an oil sleeve or water sleeve. It might not have blown across the cylinders. It is wierd that it blew only after 24,000 miles. I would just make sure that is teh problem and it isnt anything more serious. there should eb some signs like maybe oil in your coolant or engine pulsation in your coolant. I would go mitsu 4 layer with arp head bolts as I stated earlier, they are both reusable for the most part and pretty cheap, If you are concerned about blowing it again, look into a HKS gasket, but Id rather dump that money elsewhere. I dont know what other help you need. If you are gonna replace your rings, you should check them first. If you place a small square of printer paper over the oil fill on the valve cover (maybe like 4" x 4"), it should flap around with your engine pressure but not fly away. If it dosnt hold itself on, your rings are most likely worn and it is allowing part of the compression to leak by and cause excess pressure in the top of the engine. My moto is dont fix whats not broke, but then again I didnt replace my water pump in August when I had the engine out and I had to replace it last month. $40 then could have saved me 5 hrs now. I regasketed my engine right away when i had it out, felpro kit and it cost me like 120 bucks at autozone.

 

[tsunari]

Nope . . . no oil in the coolant. . . guess I'll have to try and do some more troubleshooting to pin-point what the problem is

Thanks for the advice- I'll try the paper test. So if the paper stays put and just pulsates. . . rings are probably 'OK' ?

Originally posted by sound227

Originally posted by tsunari
This just occurred to me . . . *IF* the headgasket was indeed blown, wouldn't the adjacent cylinder suffer the same fate of low compression?? So #2 would be low as well?

It depends where it is blown at, could have blown into an oil sleeve or water sleeve. It might not have blown across the cylinders. It is wierd that it blew only after 24,000 miles. I would just make sure that is teh problem and it isnt anything more serious. there should eb some signs like maybe oil in your coolant or engine pulsation in your coolant. I would go mitsu 4 layer with arp head bolts as I stated earlier, they are both reusable for the most part and pretty cheap, If you are concerned about blowing it again, look into a HKS gasket, but Id rather dump that money elsewhere. I dont know what other help you need. If you are gonna replace your rings, you should check them first. If you place a small square of printer paper over the oil fill on the valve cover (maybe like 4" x 4"), it should flap around with your engine pressure but not fly away. If it dosnt hold itself on, your rings are most likely worn and it is allowing part of the compression to leak by and cause excess pressure in the top of the engine. My moto is dont fix whats not broke, but then again I didnt replace my water pump in August when I had the engine out and I had to replace it last month. $40 then could have saved me 5 hrs now. I regasketed my engine right away when i had it out, felpro kit and it cost me like 120 bucks at autozone.

 

[gnes100]

you could have a burnt valve

 

[tsunari]

Originally posted by gnes100
you could have a burnt valve

What would cause a burned valve? Reason I ask, is I bought this car a year ago and it had one (#3 cylinder I believe). Is there some underlying problem that I need to hunt down so I don't continue this cycle?

Also, am I going to need to get an entire head gasket kit from mits. when I tear this head off again? I did last time, but am not sure if the gaskets/seals are re-useable.

 

[billdo_83]

Every gasket that you are taking off the car replace with a new one.

Get new ARP hardware for the head. I would replace the springs and retainers with Crower Titanium while you are in there also.

Make sure that its the headgasket and not rings before you do anything.

 

[tsunari]

Hmmm . . . I went ahead and did another compression test about 5 min ago. Also followed up with a wet test in all cylinders. Here are the results:

Cylinder:....1......2......3......4
Dry:........135...185...175...185
Wet:........155...205...205...210

With the jump of ~ 20-30 psi per cylinder, I'm guessing that would rule out a burned valve and leans more towards rings?

I also did the "paper test" suggested by SOUND227 and the paper was vibrating fairly violently in rhythm with the engine . . . but didn't fly away.

So does that sound about right? Or do you guys have some other insight?

 

[billdo_83]

Your rings are worn.
Time for a rebuild it looks like.

thats a huge difference in PSi between the #1 and the rest of them. It shouldnt be more then 15~

 

[tsunari]

So I'm looking at:

Head Gasket
Arp Head Bolts
Rings (Hone the cylinders while I'm there)
Arp Rod Bolts
Rod Bearings
BSE Kit

And anything else I might want to do while I'm in there . . .? (Rods, Lifters, etc . . .)

 

[Flybiyou]

Hold on im confused how could you have 180 compression on a 4g63t 7-bolt thats stock compression and the other you did you got 185 are u sure you know what your talking about. NOT TALKING SHIT just curious why you think your compression is low when it looks like you have better than brand new

 

[tsunari]

I completely agree! #2-#4 Cylinders are looking great . . . it's the compression on #1 cylinder that worries me. It's down around the 130-140's. (40 PSI difference).

And if I remember correctly . . . the LARGEST difference between cylinders shouldn't be any larger than 13-14 PSI. and NO cylinder should be below 133 PSI.

As for the history of the car, I had a burned exhaust valve in #3 cylinder last year so I tore the head off and got all of the exhaust valves replaced . . . did a 3-angle job on 'em and did some light porting. The head was also milled just a bit so the mating surface was nice and flat.

When I put everything back on, I used the stock composite head gasket (didn't know about the 4-layer metal one back then). So here I am now with my compression #'s. If I could just figure out why there is such a HUGE difference between #1 and all of the rest . . .

Part of me wants to say rings, but why the rings in just ONE cylinder?? Wouldn't they tend to wear a bit more evenly?

Head gasket? Why am I not seeing oil in my coolant/coolant in my oil? And when I did the leakdown test, why wasn't #2 cylinder affected?

This might sound like I've no idea what I'm talking about, but none of this is adding up. None of the symptoms clearly point to one problem or the other . . .

So I'm doing another leakdown test in a few days and hopefully I'll be able to pinpoint where the air is escaping from.

Originally posted by Flybiyou
Hold on im confused how could you have 180 compression on a 4g63t 7-bolt thats stock compression and the other you did you got 185 are u sure you know what your talking about. NOT TALKING SHIT just curious why you think your compression is low when it looks like you have better than brand new

 

[tsunari]

Alright . . . one last question-

Instead of pulling the head off . . . I was wondering if perhaps I could just replace the stock head bolts with an ARP set and torque everything down- maybe that'll re-seal everything . . .?

 

[datsun510dude]

no can do. if its blown, its blown, u cant jus retorque it with different bolts.

 

[tsunari]

If using the copper gasket spray for the 4-layer head gasket is HIGHLY recommended, would it also be wise to use it on:

+Intake Manifold Gasket
+Exhaust Manifold Gasket
+Turbo Gasket, etc . . .

Pretty much all of the metal gaskets?

 

[tsunari]

Ok, got the head taken off and have some pix

http://www2.msstate.edu/~msa8/PiX/

Looks like #1 and #3 exhaust valves aren't seating . I'm hoping it's just because of the buildup of carbon.

I'm wondering about the markings on the cylinder walls. Should I be worried about them? The walls aren't scratched at all . . . nice and smooth and still some pretty decent cross-hatching. Could the markings possibly be from heat? Or is this normal . . .

On a side note - What size socket am I supposed to use for my new arp studs? 13mm 12pt?