KA24E Question

jadcock · Jan 22nd, 2003, 05:09 PM

I have a question on a KA24E in a Hardbody truck, but I'm really hoping that someone else out there (like with a 240SX) might have had the same problem or know what it might be. We can't figure it out in the Hardbody forum and I hope maybe SOMEONE has an idea.

There's a ticking sound coming from the engine, and it's a very particular sequence. It's always the same pitch...it starts out quiet, gets louder, gets louder, gets louder, then it quits. tick-tick-tick-TICK-TICK___ Then wait 5 seconds and it'll start again. tick-tick-tick-TICK-TICK____. It seems to repeat this cycle over and over. The speed of the ticking and the cycle is directly related to RPM, although I don't think it's in the upper end. It sounds like it's coming from underneath the engine somewhere.

When it was running, I opened the oil fill cap and the noise didn't change in volume, pitch, anything. It was definitely NOT coming from under the valve cover. I don't think valves or chain guides are the culprit here.

It sounds like it's a valve or a switch ticking, but I just can't find it. Interestingly, it seems to be louder INSIDE the cab than under the hood, but it's definitely coming from the outside the cab. At first, I suspected the AIV valve or associated reed switch, but I'm pretty sure it's not that. I'm next thinking about the EGR valve. Is it operated by vacuum or a motor? It sounds like it's a motor that's trying to operate something and the shaft is bound...and the gear will slip and make a tick sound until it quits trying. And then start again. But as I think about that possibility, I remember that the ticking is directly related to RPM. As the engine revs faster, so does the tick. I wouldn't think the EGR motor (if it is a motor) would run faster with engine speed, and I don't think it'd be operating at idle either (the tick is present, idle or running).

It doesn't sound like an exhaust leak because the tick will start and stop in a cycle -- rather than sounding like a physical, omni-present leak.

It's annoying the stink out of me and driving me batty trying to find this thing. Of course, it's also about 15 outside, so crawling around and checking on stuff isn't easy nor comfortable to do at these temperatures and with snow/ice present.

I would GREATLY appreciate anyone's ideas here. Again, I think I'm looking at something OTHER than the valves/chain, but I'm not familiar enough with the truck, and Nissan systems in general, to know what to check.

Dwntyme · Jan 22nd, 2003, 07:18 PM

I see you said you open the oil cap up when running and didn't hear it there,,did you get your ear full of oil

. Jokin aside it sounds like you have a weak lifter or you may have (in the timing chain area) slack side guide broken, I also have a ? for you, What weight oil are using? the reason I ask this is the KA24E has had trouble using 20w50 and never use PTFE stuff in your ride especialy the KA if you will change too 5w30 for winter time and 5w 50 summer you'll notice a big differance and maybe the tick will go away,,also it could be injector making the tick. But sure it's the lifter...Good luck...also Goto this site lot of cool rides.
www.4x4parts.com goto forum do a search on your problem lots info there...

slowr6 · Mar 13th, 2003, 04:08 PM

Hey jadcock my truck just started doing the same thing. I start it up and maybe after 30 seconds that ticking starts in the weird pattern. It goes away shortly after I start driving (I haven't been able to tell how quickly it leaves yet). Anyways, I was curious if you ever found out what this noise was? Thanks.

jadcock · Mar 15th, 2003, 08:21 AM

Slowr6, mine is completely dependent of ambient air temperature. If it's in the 20s or 30s outside, it will usually do it, following that random pattern. Recently, since the weather has been in the 40s and 50s and 60s, I haven't heard it at all. I think it's a function of oil temperature. When the oil is really cold, it just doesn't get to the top of the engine quick enough maybe. Dunno... ??

slowr6 · Mar 15th, 2003, 09:20 PM

That's odd, I thought mine was temperature dependent as well but I've noticed it happen in single digits as well as 50 degree weather. It's completely random as far as I can tell, as long as the truck hasn't been driven in a while (1st thing in the morning or when I get out of work). Also, it usually kicks in 20-30 seconds after the truck is running and continues even when the truck warms up, until I drive it and it shortly goes away. I guess it could be a weak lifter or something. Anyways, good luck and if you find out anything new let me know.

allmotormax · Mar 31st, 2003, 09:50 AM

you are hearing the fuel injector pulses stop by trophy nissan or courtesy nissan and they will confirm this

BUZZ!#(& · Jul 24th, 2004, 04:32 PM

The a/c has an actuator that moves the device changing the airflow patterns. I had one go out a couple of years ago and it did cycle through that series of clicks you describe. The number of "clicks" corresponded to the airflow options. The actuator doesn't cost much and it was not too hard for them to get to under the dash of my 240. I ope it worked out for you. I see that this post is several years old. Hopefully you fixed the prob or sold the truck by now.