whats up with KA24s blowing up

[nightwalker]

I have to be honest, I am a little worried about my own motor, because I have seen (as well as heard) of a lot of KAs blowing up. My friend bought a S14 with the rod sticking out of the bottom end, another friend blew his up very similiarly, and also two other friends bought cars with blown motors. These were bought from everyday people, not gear heads like the lot of us. Why would these motors be blowing up like this? Anyone have a logical explanation, or know what I'm talking about. My KA24E ran fine until a couple months ago when it started to burn oil really bad. So I swapped it out for a DE. DE runs perfect, with only 65K on it. What are your thoughts?

[TrunkMonkey]

These were bought from everyday people, not gear heads like the lot of us. Why would these motors be blowing up like this?

everyday people don't maintain cars as well as they should. something as simple as not checking your oil on a regular basis can lead to disaster. the KA isn't the problem, it's the owners.

-demetrius

[Nathan]

I bought one with a blown engine...I still don't know how Syntax360 managed to do it

[s13ofdoom]

my ka was just smoking. the valve cover leaking so i got thinner bolts and torqued em down good . also i know plenty of people who drive hard on there ka's and properly maintained have 200k on them so!?!?!?!?

[Biggs2004]

speakin of blown KA24Es does anyone know where I can get a good built ka24e, ported, polished, blueprinted, bored, total seal rings.... the list goes on.... anyway, if you do please let me know, thanks!

[Nathan]

I'll sell you a built DE fresh out of the machine shop for 5 grand next week

[Biggs2004]

I wish, but I'd really rather keep the sohc, and not have to change ECUs, and harnesses, + I don't have 5 grand on me right now, heh, thanks though:)

[MidnightSlide]

i have a freshly re-built ka24e block ... i am planning on throwing some arias pistons in there if i keep my turbo kit. I am still trying to find some good rods for a low price.

[Biggs2004]

here's my deal, my valves chatter horribly, my engine guzzles oil, yet my compression is 140psi in each cylinder, and the thing runs 95mph in the quarter...... what's the freakin deal?

[Altiman94]

fix the head and your in business. Probabyl bad valve seats.

[Biggs2004]

I agree, I'm pretty sure it's all in the top end, yet, I'm still not confident enough to take the head off, though I haven't found someone to give me a good valve job cheap enough, my last quoted price was $1,300......... a little much considering I can get a rebuilt for $1,900.

[TachyonS14]

I thought with a valve job they just replace the shims? Or are you talking about getting all new ones installed?

[Biggs2004]

to me a valve job means reseating the valves along with new shims, or lash adjusters, depending on engine type

[groundhogday1976]

Isn't the lash on the e adjusted automatically (hydraulic)?

[Biggs2004]

Yes, but after time they wear out, and do not adjust by themselves any longer. So, you have to replace them every-so-often.

[s13ofdoom]

go sign up at ur local jc take the engine class and rebuild ur head urself its not that hard. well rebuild the whole motor if u can deal with the lack of that car.

[Biggs2004]

go sign up at ur local jc take the engine class and rebuild ur head urself its not that hard. well rebuild the whole motor if u can deal with the lack of that car.

I'd love to, except that I live in Oklahoma...

[Rev_D21]

Only dead KA I ever saw was a direct result of the driver, no oil=kaboom!!! Only lack of care will send KA's to their grave.

[Altiman94]

^ He's right, but no engine will last forever. When you get over 200k, during the course of the engine's life itll just eventually stop running. Mechanical parts do fail.

[ride4lame]

i have boughten 2 s13;s both with bad head gaskets, that is the serious weak point in the KA motor. Any other serious problems are most likly due to poor ownership.

[TrunkMonkey]

i have boughten 2 s13;s both with bad head gaskets, that is the serious weak point in the KA motor.

not true. my fastback had 221k miles on it before i got rid of it, and it still had the original head gasket. i'm sure there are other members that can say the same thing. poor maintenance can cause all kinds of problems, including a blown head gasket.

-demetrius

[TrunkMonkey]

...and let's not forget, the stock head gasket has been proven to hold 20+ psi.

weak point?...nah.

-demetrius

[Rev_D21]

Almost every 4 cylinder Nissan motor has had one weak spot, the head gasket between the 3 and 4 cylinders. This goes way back into the past too. Something about the manufacturing process that makes it needed to retorque the heads after so many miles. The KA can suffer from this too.

[absolute]

ok so say a large percent of it is owner neglect and a smaller portion of it would be a manufacturer's defect. My aunt has a running 88 honda accord with 280000+ original miles and no overhaul or rebuild of anykind but i just killed a 99-2000 model with under 90k 3-4 months ago :o my bad, not something I do often but the car had a bad gasket leak and i raced it, then overrevved it one dumb night after a party.

[McAdam]

Only KA I have ever seen blown up was when I put a rod thru the block on my old SOHC. saw the exact same thing happen on a 91 4WD hardbody pickup.. both times it was the result of the timing chain tensioner breaking away , then the timing chain tensioner can get out of its little hole it sits in allowing for a MASSIVE internal oil pressure leak, and before you know it, one of your conrods can't take it anymore. usually the #3.

McAdam

[95hardbody]

Dang. How long do you think the connecting rod failed after the tensioner failed? Was it like a catastrophic failure all at once, or did the oil pressure light at least come on to attempt to warn you?

[95hardbody]

poor maintenance can cause all kinds of problems, including a blown head gasket.

That's true. Regular coolant drains/refills can go a long way to ensuring long life for your cooling system, which includes the head gasket. Remember that the standard "green" coolant has silicates for corrosion inhibitors and this package will be depleted over a period of a few years (which is why they normally say to replace it every two years or 24k miles; I think Nissan recommends every 30k miles). Running on the same stuff for years and years and years can help accelerate corrosion in the cooling system, which can weaken any head gasket over time.

[McAdam]

uhm, since I was at highway speeds, it was too late by the time the engine started to sound funny. A chunk of rod flew out the bottom of the car and I caught a glimpse of it in my rear view mirrior. that happened as I was slowing down and pulling over. damn thing still ran on 3 cylinders with the clutch in. I knew it was on its way out, it was a tired SOHC, plus I was 30 miles out of town, plus I had a line on a REALLY cheap bolt in DOHC. like cheaper than the parts + hassle of putting in new tensionsers. but, yeah, muh bad!

McAdam

[95hardbody]

That sucks; glad you had something already lined up when it happened. I understand they started using a steel tensioner/guide in the later engines? I have a '95 (SOHC) with the plastic parts and I pulled the cam cover a few months ago to check everything out and from what I could see, everything looked as new. I guess I'm lucky -- either because the stuff has lasted this long (181k miles) or because it was all replaced before I bought the truck!

[McAdam]

well, heres my theory.... in the early 240sx and truck SOHC's, they used a bad plastic only compound for the tensioners. In frigid states, like North Dakota, the plastic becomes very brittle when its cold outside (-30), which causes them to break. In the later motors, I understand they started using metal backed tensioners, which did not flex and crack. So i think it was just on the earlier motors, but don't quote me on that, lol!

McAdam