Timing chain question

rbo1577186

rbo1577186

Well-Known Member
Joined
Aug 12, 2005
Location
Winston Salem
97 Nissan Pickup
KA24E engine


I'm FN stumped. We replaced the timing assy and all timing marks look correct. The cam/crank sprockets are keyed and they have a timing mark on them. 2 silver links on the chain line up with these marks to line everything up. It will crank up but sounds awful..... I didn't even run the motor 7 seconds. No sputtering/ stalling, just sounds awful. I'm gonna check the oil pump to make sure it full, but other than that I'm stumped. This is the second time we've done done this in 2 days. We didn't put any belts/radiator/air breather/power steering back in.

First time we put everything together using marks off the key on the cam/crank in relation to a mark on the block/cam. Didn't use the silver link/mark on the sprocket method. He said he didn't really change anything as far as the mechanical timing is concerned.. We turned it over by hand several times to make sure everything sounded/looked OK. Turned the key and it would only turn over for a second and stop. Took Dist/and oil pump back out to realign the 2 (they're keyed together and drive off the crank) Then it would turn over constantly, but never fire. Everything looked good.

I guess my question is..... if something were off could we bend a valve or something by turning the motor over by hand???

I'm going to recheck the oil pump, but I never got an oil light when I did fire it.
 
Did the chain break ? is this the reason for the replacement ?

If you are reinstalling after a chain break, you may well have had parts meet internally.

I know Toyotas are good for it, and so are some Nissans.

interferance engines gotta love 'em !
 
That motor is an interference motor, so if the chain let go before then you prolly have some valve/head issues. Make sure you didn't but the sprockets on backwards, it is possible to do that on alot of motors and that will cause all sorts of problems.

Also, did you let the cam or crank turn at all with the chain off? I had the cam spring back on a neon i was working on and that was enough to bend the valve.

Easiest/quickest way to rule out valve damage is a compression check.

I have also seen quite a few cars throw the belt and break the valve off inside the cylinder and do all sorts of damage to the cylinder wall , piston and combustion chamber. I also had a ford throw the belt and it bent the piston ring groove enough to have poor compression (ask me how long that took to figure out!)
 
No chain breakage, just Maintance. It had rattle noise on a cold start that had gotten worse and worse that we thought was worn guides. It was the tensioner. I know it common to change the timing assy around 100k for Nissans/Toyotas.

Didn't put the sprockets on backwards, the timing marks are only on one side. Neither moved. We jammed the cam up with a socket extension while removing the bolt. It moved slightly as we were loosening/tightening the cam bolt, but it came right back to the spot where it was. I'm thinking that's normal.

Another guy I posted with today said he had a similar situation. He thought he ruined it, but ran it anyway. He said it began to sound normal in a "while". Don't know what a while was.
 
Got time today, compression test is good. 190 ish on all 4 cyls.
I guess the oil pump isn't primed. It's outside the oil pan at the bottom of the front cover. I'm gonna pull the plug wires off the distributor and let the starter prime the pump for a few seconds, let the starter cool off and repeat.
 
it should get oil pressure pretty quick, i do rember the pump and dist are a pain in the ass to get lined up by yourself, what a stupid design. if you fire it and it doesn't get oil pressure in 10 seconds you have another problem, oil pump quit was not engaged into dist, or screen is stopped.
 
I know on the Toyotas a common problem is making sure the distributor lines up correctly with the cam sprocket (making sure it lines up exactly as it came out). Easy to forget to mark it beforehand. If it's off the firing will be all jacked up.
 
Well I just about give up........

I put everything completely back together, coolant air intake and all. Fires right up but is still loud as hell. I let it run for about 10 minutes at idle it seemed like it got a little quieter, but not much.

I'm guessing oil pressure is good, no red oil light. I can take the fill cap off and my hand gets lightly splattered with oil while holding my hand over the fill hole.

It did miss every once in a while, I'm guessing because I haven't got the ignition timing set??

With my timing light at 0 degrees... I'm on 10 degrees according the the marks on the crankshaft pulley. I twisted the distributor trying to get it better, but that's the best I could get with the distributor turned counterclockwise as far as it would go.

I'm going to drop the oil pump and realign it with the distributor as a last ditch effort. It looked good according to the picture in the service manual, but I'm ready to do anything but break it back down and if I can't find anything wrong, pull the head.

I'm gonna let the engine warm up and re try my compression results..... Yesterday I got 190 ish on 3 cyls, but one cyl # 3I got 175, I just assumed I didn't tighten down the plug enough. If my compressions OK then WTF?? It can only be my ignition timing, correct??

I did find a little piece of metal on top of my oil draining pan. It's round, about .400 in diameter and it has a little ding on one side of it. I'll try to put up a pic later. This scares me....
 
OK, I got it...... I had to walk away for a minute and cool down. Everything was right, I just started freaking out a little bit. It just took a long time for the hydraulic lifters to bleed. I knew by dropping the oil pump I would get air in the system but I had no idea it would take that long to bleed... I let it run for a grand total of approx. 40 minutes to get all the air out and now she sounds like a champ.

The piece of metal I found appears to be an oil galley plug. I'm guessing it's been in the oil pan from the day I bought from the dealership.
 
if the whole oil gallery plug is out that would be a cause of low oil pressure and it would knock. If that is in fact a gallery plug it may have been able to gain enough pressure over the time you let it run but if you let it sit and pressure bleeds off it will start making noise again.
 
Cperry, I see your point and tried it out. After sitting for over 24 hours it fired right up and truck sounds good.

I'm guessing it's been there since I bought it. It was the first time the oil pan has ever been pulled.
 
Back
Top