Whoever designed the KA24DE is an shiny happy person.

So a friend of mine had a timing chain guide let go on his '00 Altima, pretty much wiping out all the valves. I get to rebuild the head and put a new timing set in it. No big deal, I've done this 100 times.

Pulling the head was pretty much straight forward, other than the fact that the intake design is completely retarded. I usually like to unbolt the intake from the head when I pull a head, just so I don't have to disconnect so make things. Not going to happen on this one.

Now for the timing cover. While unbolting it, I realize the PS pump is in the way, and the whole mounting bracket has to come off with it, because the frame rail is in the way. No big deal. Oh, now I realize that two bolts go up into the bottom of the cover from inside the oil pan! Dumb, but I was planning on dropping the lower pan anyway to get the broken chunks of chain guide out. I get the last two bolt out and commence prying it off, since the dowel pins and silicone have a pretty strong hold on it. I get it loose but it still won't come out. Oh look, the oil pump is bolted to the timing cover from the inside! Of course it is. Now if they would have made the pump just a little smaller you could have just taken the pick up tube off and been done, but that would have been too easy. Now the upper oil pan has to come off. I get half of the bolts out before I notice that I have to remove the center subframe piece, which means that I also have to remove the front and rear motor mounts, which also means I have to brace the engine so it doesn't fall on me. I get those out and notice that the AC compressor bracket is bolted to the oil pan, so now the AC compressor has to come off to get to those two bolts. Why the hell not, I've taken everything else off of the stupid engine! Now that those two bolts are out it's time to drop the pan, or so I think. I to go pry it off, because it's also glued on pretty well, and it doesn't seem to want to break free towards the back. I then take off the torque converter bolt access door and there's two bolts way up in there, at a funny angle, that need a network or swivels to get to them. Ridiculous.

None of it was particularly hard, but never in my life have I had to remove SO MUCH E36 M3 just to get to a timing chain. I'm really just venting, but if the designer of the KA24 is reading this, I owe you a serious punch to the giblets.

Time for an SR20 swap

I think the people that make the motors must not talk to the people that make the chassis. My example the PT Cruiser, you have to take the intake manifold off to do anything it goes right over the valve cover. Then one you get that off there is nothing you can even reach with your hand. The few things you can get to with the motor in the car need extensions,wobble ends, and luck. I feel your pain

I thought a lot of FWD car timing chains were like this?

The Saturn timing chain is an absolute whore to get to/service wit the engine in the car. But since it should out-last the rest of the engine, it's not a big deal :)

How many miles were on the Altima that the timing chain let go? Neglect?

i have done this job on a KA. i feel your pain.

if it was just the chain, i MIGHT do it again.

if the chain had already fragged like in your case, i'd just swap in a junkyard motor.

They used a chain because they don't expect it to have to be replaced. The Z-24 engine in my truck wasn't near this much trouble, but its north-south.

belteshazzar wrote: if it was just the chain, i MIGHT do it again. if the chain had already fragged like in your case, i'd just swap in a junkyard motor.

That had already happened once. The chain went a couple of years ago (at 150k) and the owner (not a car guy and didn't know me very well back then) had a shop put a junkyard engine in. Well that lasted 30k miles before the junkyard engine chucked the chain. I would NOT put in a junkyard KA24 without putting a new chain kit in it, and if I'm going to put a new chain kit in one I might as well do it to the engine that's in the car. Rebuilding the head is the easy part. If I didn't have all the head tools, I might feel differently.

jere wrote: Time for an SR20 swap

pretty much applicable in any automotive situation

Nissan seems to be able to make most of their stuff inaccesible, particularly on the intake side. My B13 Sentra with the SR20 is really jammed up back there.

My nephew had one of these Altimas as his first "adult"/bought it myself car. When the chain went, he dumped the car for a used Element as the cost to fix the Altima made it cheaper to "throw away" the car.

In the '80s and '90s just about every car company had at least one model that was a pain in the butt to re-build.

Wait 'till you have to do a valve cover gasket on an Atlas engine.

I'm fairly certain to do a thermostat on a VG30 Maxima you need to unbolt some motor mounts and either raise the engine 4-6 inches or lower it about a foot.

Wasn't there some GM car in the late '80s with a transverse V6 that backed up to the firewall in such a way that replacing the back bank of spark plugs meant dropping the engine?

16vCorey wrote: I'm really just venting, but if the designer of the KA24 is reading this, I owe you a serious punch to the giblets.

I betcha the designer(s) gotta an "atta boy!" for saving .9 kg of aluminum on each engine by using such a design...

Wow, and I thought the chain on a GA16DE was bad...

It seems chains on most modern OHC engines are bad. It's as if they were designed to be a "lifetime" part that would never need to be replaced. at least with a timing belt, they know going in that it's a service item so at least some thought is given towards getting to it without a bazillion disassembly steps.

Twin_Cam wrote: I'm fairly certain to do a thermostat on a VG30 Maxima you need to unbolt some motor mounts and either raise the engine 4-6 inches or lower it about a foot. Wasn't there some GM car in the late '80s with a transverse V6 that backed up to the firewall in such a way that replacing the back bank of spark plugs meant dropping the engine?

I had an 89 Maxima with this engine and pretty sure did not need to to do that.

The mid 80s Bruick wagon with 3.8 engine had to have motor mounts removed and the engine jacked up a bit to get to the rear plugs. I would almost bet that the old Monza with v8 had the same scenario.

Ian F wrote: It seems chains on most modern OHC engines are bad. It's as if they were designed to be a "lifetime" part that would never need to be replaced. at least with a timing belt, they know going in that it's a service item so at least some thought is given towards getting to it without a bazillion disassembly steps.

Pretty much what I was saying. You think Nissan cares that the chain is difficult to service at 300K miles? Nope. Nor do 99% of consumers. I think the real issue here is that the chain is failing early, not that it is difficult to work with.

Twin_Cam wrote: I'm fairly certain to do a thermostat on a VG30 Maxima you need to unbolt some motor mounts and either raise the engine 4-6 inches or lower it about a foot. Wasn't there some GM car in the late '80s with a transverse V6 that backed up to the firewall in such a way that replacing the back bank of spark plugs meant dropping the engine?

the only GM engine that i can think of that almost fits that description is the DOHC 3.4 that was put in the Lumina Z34/Euro 3.4 and Grand Prix GTP. i've seen 2 different cars that had notches cut out of the cowl right over the rear plugs that allowed a straight shot with nothing but a 12" long straight extension- but they were hidden under the cowl weatherstripping and i only found it on the first car by accident.

you are supposed to drop the engine cradle to swap alternators on those cars, and you are driving a ticking time bomb if you get over 100,000 miles on the timing belt.

Knurled wrote: Wait 'till you have to do a valve cover gasket on an Atlas engine.

or an Olds Aurora V8.. took almost an entire weekend to do valve covers, alternator, and serpentine belt on one. just a PITA design no matter what you are doing to those things.

Twin_Cam wrote: Wasn't there some GM car in the late '80s with a transverse V6 that backed up to the firewall in such a way that replacing the back bank of spark plugs meant dropping the engine?

Nah, you just undid the torque mount(s) going from the engine to over the radiator and rocked it forward a few degrees. They even provided a third hole in the mount(s) so you could slam the bolt in to hold the engine there. Takes maybe 30 seconds to do it. BFD.

It was some of the REAR wheel drive vehicles where it was a PITA to access the rear passenger bank plugs. IIRC it was Olds-engined A/G bodies with A/C. It was definitely A/G body. Still, they weren't nearly as bad as, say, a 4th-gen F-body with headers.

I know it was a real PITA on the "downsized" DeVilles with the 425ci engine. Needed an open end wrench on the end of the spark plug socket to get to the two back there.

novaderrik wrote:

Knurled wrote: Wait 'till you have to do a valve cover gasket on an Atlas engine.

or an Olds Aurora V8.. took almost an entire weekend to do valve covers, alternator, and serpentine belt on one. just a PITA design no matter what you are doing to those things.

I did an oil pan gasket on a Northstar. Also did the "cradle" (main bearing cap/block half assembly) while we were in there.

To pull the oil pan, you need to remove the exhaust crossover.

To remove the crossover, you need to remove the transmission.

Nobody ever fixes their leaky Northstars. We only sold this job because the trans had to be out anyway....

FWIW - Valve cover on an Atlas involves pulling the intake manifold back/off. And the valve cover gaskets always seem to be the cause of misfire codes, from oil getting into the plug wells.

every nissan engine that I can think of right now you have to remove the pan to take the timing cover off for some strange reason.
When I was in Nissan training, the instructor called them "screw you bolts"
there are usually some cleverly hidden bolts up in where the lower pan was, holding the cover on, too.
such a pain in the ass, for no reason.

Knurled wrote: Nobody ever fixes their leaky Northstars.

QFT.
I've literally NEVER seen a northstar that didn't have an oil leak. NEVER.

corytate wrote:

Knurled wrote: Nobody ever fixes their leaky Northstars.

QFT. I've literally NEVER seen a northstar that didn't have an oil leak. NEVER.

That's what happens when oil pan is two farking pieces! Cadillac techs joke that the Northstar replaced the B series (or whatever the designation for Cadillac's V8 was) because the B series couldn't pass an emissions test. The N* will pass an emissions test but will pollute anyway by continually oiling down road surfaces

I am suddenly really sorry that I've never gotten into Nissans or old GMs.