Pomorza

Hey guys. This past weekend I installed a new timing chain kit on my Z. As I'm going to run the valves this weekend and have the valve cover off I would like to reassure myself I did it right. First off I used the #2 hole in the cam gear to set the chain. This was the way it was when I took the old one off. Is that OK to do. Timing at the moment is 12@1000 RPM (idle). Secondly I have two manuals that have two different torque readings on the cam gear. The FSM says 90-100 ft lbs while the Haynes manual says 40 ft lbs. Which one is right? I set it to 40 ft lbs as the 100 just didn't seem like the right number to me. Thank guys Jan

Yea welcome to the PO mistake fixing club. My Z has paint over rust, radio wiring that isn't attached to anything, missing speakers, no heater, timing was off, AFM was set so rich the car barely idled the list goes on and on. Its a matter of finding and fixing said mistakes. Jan

I second this explanation and reasoning. I live in Arizona so I use VR1 20W50 as it gets rather hot here in the summer. My only advise to you is once you choose an oil stick with it. Don't switch back and forth. Jan

There's a multitude of things that can make rattling noises in an engine. I know that's not the answer you're looking for but I can't really get really into detail. Remember that an engine is made out of hundreds of parts so it rather hard to answer your questions. Here's a try. Hypothetically speaking let say that your chain is slapping the cover. This would indicate that the chain is stretched enough to slap around. Stretching can lead to the cam and crank to be off time a bit. If the chain is stretched enough it could in theory skip a tooth or more on the cam leading to issues. In the most extreme case it can snap completely and cause the piston to meet the valves. After rereading your first post you said that "The 4th plug is fouled wet and black, and I'm sure it's not firing because the engine doesn't bog when I remove the plug wire, but it is getting spark." Now for what I remember if you remove the plug wire from a plug you should hear a difference in engine RPM as it is running on one less piston. So here's my concern. If the engine is running on 5 cylinders it is possible the noise you are hearing is a dead cylinder as suggested below by Johnny'O. This could be cause by either a weak spark or a fuel issue (too much or not enough fuel). Hope that helps mate. Jan

I have check many of the things mentioned in the link you posted. Thanks a lot though. The noise does not occur when the engine is cold though if that helps anyone eliminate anything, it only occurs at or near operating temp. Jan

Well sadly replacing the timing chain did not fix said sound. I'm not saying it wasn't needed as the old chain was about an inch longer than the new one and the tensioner spring was roughly a third of the size of the new one, so it wasn't all a waste. Atop that the cam was off time and there was about an inch of sludge in the oil pan, so it was most definitely needed. Anyhow the sound has now become more localized from when it first appeared. For what I can determine (and my mechanic I go to) the sound appears to be coming from the mid to rear section of the valve cover. Before I go further this is what occurs. The sound only appears between 1 and 2K on the tachometer. Only does it on deceleration (not on acceleration) it doesn't really vary with pitch or frequency even if I go up to 5k and release the throttle, it seems to be rather constant and only occurs at said specified ranges. My mechanic suggested that maybe one of the rocker arms in the motor is wobbling or moving when decelerating (that is load being taken off). Any ideas guys? This is rather annoying. Jan

The only advise I'm going to give you is, if YOU don't feel safe driving your car for any reason don't. I can't tell you that it is safe or not. I'm not there and I don't know your driving style or the condition of the car. There are literally hundreds of things that could go wrong with a motor and all of them in one way or another can be unsafe. (A broken fan belt could in theory lead to a crash) Hope that helps Jan

Thanks for the info. I would first determine the frequency of the sound (how often if occurs). Knowing this will give you a bit more information to work wit (duh) but it can also let you know what part of the motor is occurs on. What engine RPM is that video at? It sounds to me a bit high 1500 or so? Jan

First off. What oil did you use and what oil was in there prior to the said oil change? How much did you put in? How does the sound act? Is it present at all RPM ranges, does it change pitch, noise level, area where it seems to be coming from? To answer a number of your questions. Sounds tend to travel in metal objects so don't trust your ears. My advise would be to either pull the cover or the chain inspection cover and have a look at the chain. Pull it and see how much of stretch you have. If you have a remote starter hook it up and slowly crank the motor with the distributor off. See what the chain does where does it go, how does it act those kinds of things. Also look at what your valves do. Now I'm not in any way a trained mechanic (I'm 22 and owned two cars in my life) but to me that sounds like an exhaust leak or air leak of sorts. I can't really tell you exactly as I've never owned a carbed car. Have a look at the exhaust and intake manifolds and see if there isn't any leaking air. Check the vac lines. The one thing I've learned on Z's is to go step by step and rule things out as you go. Just because the parts "looks" good doesn't actually mean it is. Hope that helps and let me know what you find. Jan

The coolant lines on picture one are rather odd in my book. I would take them all out and go back to the standard way it should be. (which on my 280 is the lower hose attaches to the water inlet and then to the lower heater core hose. Then from the lower heater core hose it will go into the engine block via the rear intake) As for the second pictures. I'm not a 240z guy (nor expert in any means) but I believe that is either the outlet for the coolant lines that run through the intake or its for somekind of sensor. I'm not 100% positive on which one as I own a 280. Hope that helps. Jan

What fuel injector cleaner did you use? How much of it did you run and what gasoline did you use while using it? Jan

Thanks. By the looks of it I'm missing one piece that allows the water to flow back to the engine when the valve is closed. As the temps here are getting rather warm I'm not really worried. I'll get it fixed when winter comes again. Thanks a lot guys Jan

So while working on the heater I inadvertently grabbed onto the glove box door and broke most of it off. Does anyone know how to fix said broken door. The "Hing" is where it is broken its torn about 90%. Any advise would be great. Jan

I will advise that you replace the bolts on the water pump also. They have a tendency to break if they are reused to many times. I'm talking from experience here as I broke on when I replaced mine on my 280. Luckily it was only the head so most of the bolt was outside and I pulled it out. But please buy new bolts. You don't want to spend hours trying to get a broken bolt out of your engine block. You can get both (pump and bolts) from MSA. They work rather well from what I can tell. (I'm running one at the moment) I'm not sure what electric pump you have but I've been told by many Datsun guys that the electric pumps are fairly loud. Mine is rather loud all the time but but again its on a 280z so it could be different. Jan

Here is a photo of what is located in my car. I'm just a bit confused on how the water flows through all this plumbing when the heat is off. I understand it when its on and coolant flows just not when its off. Someone please shed light on that. Secondly the blower motor that I pulled out of the Z. Is this out of a Honda? For what I was told the one in the Z has a metal fan, the one I have is most definitely plastic. Thanks Jan

Thanks for the pic. I wish I would have taken a pic of the disaster that was down there. I sat there for a good ten minutes going "huh? what?" By the looks of it I'm missing a pipe something. I'll take a look at it tomorrow more closely. Jan

Hello all After months of procrastinating I finally forced myself to pull the old broken heater core out of my 280z. After removing the blower motor and it's housing I find that the hoses leading to and from the heater core are well a mess. I don't know which one goes where and how they are at all set up. I pulled everything out, cleaned and replaced. Now I'm at the moment where I need to pipe the system but I have no idea where what goes. The two manuals I have are little help but not really as specific as I would have hoped. Does anyone have any picture(s) of the plumbing down there? To and from the heater core, how they hoses go? Please its getting rather cold here in Arizona and driving in 32 degree weather with no heat is rather um...cold. Jan

Hello guys A friend of mine has a L24E (810 motor) that is sitting on his property. This next week I'm going to be replacing the oil pan gasket on my L28E (280z) and I'm wondering if the two oil pans are interchangeable. I was going to remove one (off the 810) clean and paint it and put it on when I replace mine. Thanks Jan

As quoted above it is in fact the timing chain rubbing. Thanks guys for all the help Jan

Am I positive? No. As I said I couldn't really pinpoint the sound as it started raining. It was loudest at the rear of the motor on the flat part of the transmission. Now is this where it's coming from I can't tell you. I will be doing more tests tomorrow or later this week so I'll know more as the weeks progress. Jan

Nope noise stays.

Update. I went over to a friends house last evening and pulled out the old stethoscope. Walked around the entire valve over from front to back and the sound was nowhere to be found. Finally I placed the stethoscope on the flat top part of the transmission. BINGO the sound could be heard. My efforts were then disturbed by some nasty rain so I couldn't pinpoint the noise but it sounds like its coming from that area. Ideas? Jan

Yup cam has little holes. Made sure of that when I was looking at the top of the engine. Not sure if there's block off plates as there was a huge puddle of oil but I'll look next time I have the cover off. Thanks Jan

1. I'll more than likely do that. 2. I'm going to check the valve lash this upcoming week or weekend. 3. Its an L28 so it is possible that it went to an internal cam oil system. I'm not positive but its not there I'm sure. I was rather stunned when I saw it. Jan

Awesome I actually have one laying in my garage someplace. I will dust if off and get to work. Thanks Jan