Noisy KA24DE in a 2000 Frontier

[Robert8096]

I did a welcome post in the general area about me and the truck. Here is the condensed version. Son blew up first engine in the truck. Wife had engine replaced with junk yard engine by very poorly skilled mechanic. I am now seeking the forum's knowledge to help me get the truck back on the road.

I also downloaded the service manual for this truck.

I did a compression test and oil pressure test on the engine. I have 185 lbs of compression all cylinders and 17 lbs of oil pressure with the engine warm and transmission in drive. Have about 22 lbs at operating temp and in park.

Here is a video of what it sounds like hot or cold. I'm thinking a timing chain job is next on my list. Opinions greatly appreciated.



HAVING A ERROR WITH THIS FORUM. Even though it states to the right I can post video and images and everything shows up in preview when I submit I get YOU ARE NOT ALLOWED TO POST URLs. Just copying in the links to video and pictures without using the buttons up top.

Well that didn't work so can a Mod or admin please fix the issue of not being able to post video or pictures or someone point me to a post that tells how to post video or pictures.

Thanks

[Robert8096]

One more try to post pictures and video.

[centralcoaster33]

We had a thing about not letting new people post images for a while, like they had to have 5 or more posts to be able to embed images. It was to prevent spamming and dumb stuff. I don't know if we're still doing that or not and I don't know if another mod fixed your links or not. The images show up fine on your posts now.

In the video I hear timing chain rattle and/ or exhaust leak. I saw hose missing from Valve cover to intake, oh, the whole intake is missing. Okay. The top and side guides get removed and the upper and lower tensioners get a bit of a cleaning. The front upper cover comes off for that. You can look at the underside of the valve cover and see if the chain is rubbing on that since you say the upper guide is already removed.

[Robert8096]

I was not aware of the time restriction on images so that was most likely my problem. As you can see above all is good now.

When I did the above video I had the air cleaner assembly removed which is why the hose to the valve cover was disconnected. Of course the mechanic did break the mounting point of that hose on the air cleaner side so I had to do a backyard fix on the cleaner.

I did remove the valve cover and saw no signs of the chain hitting the cover or anything else that jumped out at me for the cause of the noise.

I don't think this engine was ever equipped with the tensioner that is mentioned in other threads. There are no bolt holes for said tensioner. The only one I see on the upper chain is the one that is pressured by oil.

It did have an exhaust leak between the manifold and the down pipe. The master mechanic who was working on it before me installed this little jewel in the pic below. I removed it and installed the correct gasket and that fixed the exhaust leak.




Timing set is on order and hopefully I have it by the weekend, if not I'll go ahead and start the teardown and finish it up when I get the parts.

[centralcoaster33]

Wow, neat um stuff in the exhaust! Glad you got that replaced. The oil pressure thing IS a tensioner. Here are links to two articles. The engine FSM page (shows chain, tear down, etc.) You can see the chain and both tensioners and such starting on page EM-17. You'll likely use that during your timing set installation. Also, attached is a basic rattle article. It appears that your engine doesn't have the second guide on the upper chain, nor maybe even the top guide. I think by 2000 they figured out they didn't need them in the KA24DE. Cleaning the upper and lower tensioners is probably what you need I would think.

http://www.nicoclub.com/service-manual? ... tier-KA/em
http://www.nicoclub.com/archives/fix-yo ... attle.html

[Robert8096]

Thanks for the links. I found this site by searching for the service manual and been studying it for the last few days.

[centralcoaster33]

The service manuals are one of our treasured assets. BTW, I did run into an article recently where someone had a rattling water pump. That's a bit odd I think. But, I mention it because it's in the same vicinity as the timing chain. They used a stethoscope to isolate the source of the sound. You'll be using a new water pump during your teardown and rebuild I figure.

[Robert8096]

Water pump looks new but will most likely change it while I'm there. I removed all the belts and started the engine and it did nothing for the noise issue.

[centralcoaster33]

That's good process of elimination. I'm hoping your timing kit solves all the rattle issue and breathes some new life into your truck.

[Robert8096]

Thanks

[Robert8096]

Had time this weekend to work on the little truck. Started disassembly and other than two missing and one stripped bolt in the power steering pump area it went well. Once I got clear access to the crank bolt I did a valve clearance check and all readings were within the specs. I did notice the upper chain was snapping when I was hand rotating the crank while doing the valve check. Looks like the upper chain tensioner is stuck, lower one looks to be in working order. Timing set will be here today but I won't get a chance to work on it again until this weekend. Going to be a slow process reassembling the engine because I want to clean up the parts before I put it back together.

My oil pan had a cork gasket but the service manual refers to using RTV. Do I need to see about a new gasket or just use RTV?


Some pictures for your viewing pleasure.

[centralcoaster33]

Your choice with the gasket. They're out there but I've used RTV each time.

[jonjon20xx]

im having the exact same problem with not being able to post urls

[Robert8096]

im having the exact same problem with not being able to post urls

Give it a few hours and you will be able to post pics and urls

[Robert8096]

Finished the chain install this weekend. Still got a few issues to work out.

One is my knock sensor is disconnected and I cannot find the connection for the sensor on the wire harness. The sensor was disconnected when I got the truck back from the so-called mechanic. I checked around where the grounds and water sensor connect on the intake manifold and also looked from underneath the engine and don't see the connector. Did some research and found two places it may be, one near the front where all the grounds connect to the manifold and the other is behind the throttle body. I didn't check around the throttle body so I'll canvas both areas again. If someone has a picture of where the connector is on the harnesses please post it.

Second is when the engine is warm and I shut it down for a few minutes (like running into the convenience store to by a drink) when I start the truck it will start, run for a few seconds then shut off. Now if I rev the engine once it starts then it will idle like normal.

Here is the after video. In the video you can hear a knock when I rev. This was with the timing set at the manual recommended 20 degrees. If I drop the timing to 15 degrees then I don't get the knock but the engine is a little sluggish. Timing was set with the TPS disconnected.

[centralcoaster33]

On my 240sx, the knock sensor is actually plugged into a short um, mini harness, and that in turn plugs into the main harness near the ball of plug that is closest to the throttle body. I'd guess yours is similar. Perhaps the mini harness is on the bench at the mechanic's shop?

I'm not sure about knock, but for proper timing and idle, you'd first set the voltage/ resistance on the TPS with a voltmeter, then adjust your idle close with the TPS disconnected, then set the timing at 20, then reconnect all. If there is knock after that, I think something else is wrong.

[Robert8096]

From doing a Google search I ASSUME I have the mini harness. It is hanging off the knock sensor. The intake and throttle body is a different setup on a Frontier. My TPS still has the factory paint marks on it and if I remember correctly the idle screw is capped. Once I get the knock sensor connected, check the fuel pressure and clean the throttle body I'll revisit the idle and timing problem.

Thanks for the advice.