Blown Head Gasket - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

Goldfinger95 · 02-08-2021, 01:15 PM

I had posted a thread not too long ago about an overheating problem I've encountered while building my KA24DE. I've had my head gasket pop twice now, the first time was because I thought the clutch fan and some sensors were bad. This time I'm thinking it's because I'm cheap and used the original head studs as well as a eBay head gasket, I'm running flat-top SOHC pistons in the motor so I'm thinking it had too much compression for the cheap combination. When the head gasket blew each time, it was on the road and under load (taking it for a test drive), but it would run like a sewing machine in the garage. I checked compression and I had 215-220 in cylinders 1-3, but cylinder 4 had like 180, so I'm thinking that loss in comp is where the head gasket blew. The block itself could be wrapped but I doubt that, it was freshly decked with new freeze plugs and everything. I bought an ARP head stud kit with a felpro gasket rebuild kit, as well as sending one of my other heads off to get decked with a new valve job, etc. Has anyone had a similar situation? I'm at a loss if this doesn't work.

relaxamigo · 02-08-2021, 02:47 PM

No, I haven't taken an engine apart only to put junk parts on it and use stretched stock head bolts with hundreds of thousands of miles on them.

Your new combo should work just fine. Learn from your mistake and get the head decked/cleaned at a machine shop and clean the block surface up nicely before you put your new studs and the Felpro head gasket.

good luck

Goldfinger95 · 02-08-2021, 04:20 PM

Thanks man will do, just dropped a head off at my local shop earlier today and should be getting it back by the end of the week. Gonna check for wraps on the block, clean all the surfaces up real good before I stud and gasket her back up.

Goldfinger95 · 03-07-2021, 07:36 PM

Got my head back and put everything together today, going to let everything set overnight and do a compression test tomorrow. I'll post back whenever she's either road-worthy or popped another head gasket.

Original post - https://zilvia.net/f/showthread.php?t=678173

Goldfinger95 · 03-08-2021, 01:39 PM

Did a comp test today, cylinder 4 now has 225 compression yet cylinder 2 magically has less than 125. I guess the next step is to completely start from scratch with a new block, going to try and run factory pistons. Does anyone know where I could find good replacement rings for a factory piston? A company called DNJ was where I bought my last two sets, I don't wanna run them pieces of crap no more.

DiscountPirate · 03-14-2021, 12:50 PM

Good effort but sounds like it's time to get a professional involved or just start from scratch.

Goldfinger95 · 03-15-2021, 09:45 AM

I fired the motor up to get it out the garage, let it sit for about thirty minutes to an hour, after a few minutes of initial startup it stopped smoking out the tailpipe, and the radiator was holding water which it didn't before. Ran a compression test and cylinder 1 & 4 had 215 psi, while 2&3 have a matched 200, so it's definitely holding compression. My only problem it seems now is a noise coming from the exhaust side of the motor, put a pry bar up to the exhaust runners and heard the noise moreso on 2 & 3. Uploaded a video on youtube, sound fimilar to anyone?
https://www.youtube.com/watch?v=gPLy-7bZbvU

Goldfinger95 · 03-15-2021, 03:32 PM

Hoping it was valve ticking, but I adjusted all the valves and the noise persists, going to start over from scratch and have a shop set up the bottom end.

DiscountPirate · 03-15-2021, 04:32 PM

I dunno but at the least it doesn't sound like knocking in the vid. If engine is all together and has compression and is not mixing fluids just go with it for the moment and keep an eye on it until you have the opportunity to figure out your next step. Kind of weird that you would have a low compression cylinder that magically fixed itself. If you did it yourself maybe it wasn't accurate. Maybe pay a shop to at least do a leakdown test and inspection and see what they think.

02-08-2021, 01:15 PM	#1
Goldfinger95 Join Date: Nov 2020 Location: NC Age: 25 Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	Blown Head Gasket I had posted a thread not too long ago about an overheating problem I've encountered while building my KA24DE. I've had my head gasket pop twice now, the first time was because I thought the clutch fan and some sensors were bad. This time I'm thinking it's because I'm cheap and used the original head studs as well as a eBay head gasket, I'm running flat-top SOHC pistons in the motor so I'm thinking it had too much compression for the cheap combination. When the head gasket blew each time, it was on the road and under load (taking it for a test drive), but it would run like a sewing machine in the garage. I checked compression and I had 215-220 in cylinders 1-3, but cylinder 4 had like 180, so I'm thinking that loss in comp is where the head gasket blew. The block itself could be wrapped but I doubt that, it was freshly decked with new freeze plugs and everything. I bought an ARP head stud kit with a felpro gasket rebuild kit, as well as sending one of my other heads off to get decked with a new valve job, etc. Has anyone had a similar situation? I'm at a loss if this doesn't work.

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02-08-2021, 02:47 PM	#2
relaxamigo Zilvia Member Join Date: Feb 2015 Location: mid atlantic Posts: 181 Trader Rating: (1) Feedback Score: 1 reviews	No, I haven't taken an engine apart only to put junk parts on it and use stretched stock head bolts with hundreds of thousands of miles on them. Your new combo should work just fine. Learn from your mistake and get the head decked/cleaned at a machine shop and clean the block surface up nicely before you put your new studs and the Felpro head gasket. good luck

02-08-2021, 04:20 PM	#3
Goldfinger95 Join Date: Nov 2020 Location: NC Age: 25 Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	Thanks man will do, just dropped a head off at my local shop earlier today and should be getting it back by the end of the week. Gonna check for wraps on the block, clean all the surfaces up real good before I stud and gasket her back up.

03-07-2021, 07:36 PM	#4
Goldfinger95 Join Date: Nov 2020 Location: NC Age: 25 Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	Got my head back and put everything together today, going to let everything set overnight and do a compression test tomorrow. I'll post back whenever she's either road-worthy or popped another head gasket. Original post - https://zilvia.net/f/showthread.php?t=678173

03-08-2021, 01:39 PM	#5
Goldfinger95 Join Date: Nov 2020 Location: NC Age: 25 Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	Did a comp test today, cylinder 4 now has 225 compression yet cylinder 2 magically has less than 125. I guess the next step is to completely start from scratch with a new block, going to try and run factory pistons. Does anyone know where I could find good replacement rings for a factory piston? A company called DNJ was where I bought my last two sets, I don't wanna run them pieces of crap no more.

03-14-2021, 12:50 PM	#6
DiscountPirate Zilvia Member Join Date: Jul 2016 Location: SoCal Posts: 189 Trader Rating: (0) Feedback Score: 0 reviews	Good effort but sounds like it's time to get a professional involved or just start from scratch.

03-15-2021, 09:45 AM	#7
Goldfinger95 Join Date: Nov 2020 Location: NC Age: 25 Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	I fired the motor up to get it out the garage, let it sit for about thirty minutes to an hour, after a few minutes of initial startup it stopped smoking out the tailpipe, and the radiator was holding water which it didn't before. Ran a compression test and cylinder 1 & 4 had 215 psi, while 2&3 have a matched 200, so it's definitely holding compression. My only problem it seems now is a noise coming from the exhaust side of the motor, put a pry bar up to the exhaust runners and heard the noise moreso on 2 & 3. Uploaded a video on youtube, sound fimilar to anyone? https://www.youtube.com/watch?v=gPLy-7bZbvU

03-15-2021, 03:32 PM	#8
Goldfinger95 Join Date: Nov 2020 Location: NC Age: 25 Posts: 16 Trader Rating: (0) Feedback Score: 0 reviews	Hoping it was valve ticking, but I adjusted all the valves and the noise persists, going to start over from scratch and have a shop set up the bottom end.

03-15-2021, 04:32 PM	#9
DiscountPirate Zilvia Member Join Date: Jul 2016 Location: SoCal Posts: 189 Trader Rating: (0) Feedback Score: 0 reviews	I dunno but at the least it doesn't sound like knocking in the vid. If engine is all together and has compression and is not mixing fluids just go with it for the moment and keep an eye on it until you have the opportunity to figure out your next step. Kind of weird that you would have a low compression cylinder that magically fixed itself. If you did it yourself maybe it wasn't accurate. Maybe pay a shop to at least do a leakdown test and inspection and see what they think.