Turned 88 yesterday and see 90 approaching in the not too distant future. My wife turned 91 on March 1st, is healthy, and her memory problems are stable. I’m putting less than 1000 miles a year on the car with present mileage of 138,700. Solved the tire sensor problems I mentioned last year by having them all replaced as suggested. Have a new problem that I think may be related to low use. When I start the car there is a light tapping sound on right rear part of the engine. It lasts for a few seconds and then is gone. It happens from a cold start and also when the engine is warm. I suspect it may be due to the fact that the car gets so little use. I change oil twice a year. The shop uses a synthetic blend. Is there anything I can do or is it possible more serious work is needed? Any suggestions would be appreciated. Aside from that the car is running fine and I still get that chill of pride as I walk toward the Z in the parking lot.

 

I always enjoy seeing your yearly post sir !!

 

Hey Bob! Happy to see your yearly post/update once again.

That tapping sound is probably valvetrain noise. If the vehicle sits for extended periods of time, the lifters are probably going a bit dry. It takes a few seconds for the oil pump to circulate oil to the valvetrain. A little test you can try is putting the vehicle in clear flood mode and cranking it for 5-8 seconds before starting. This should be enough revolutions to build up some oil pressure. To activate clear flood mode, simply push the gas pedal to the floor and hold there, then turn the key to to the start position. This should disable the fuel injectors, allowing the engine to crank but without starting. I use this little trick whenever my Z sits parked for extended periods of time.

What's a bit strange is that it also does this when the vehicle is warm (meaning recently driven). Lots of things could cause this. Fuel dampers, injectors, valvetrain noise, exhaust leaks, spark plug not fully seated (loose).

Cheers!
-Icer

 

Thanks for your response Icer. I think I will have my mechanic check it out, mainly because it occurs often when the engine is warm. Thanks again for your thoughtful feedback.

 

You're welcome!

I also just had to replace all 4 of my TPMS sensors. My rear wheel sensors were constantly dropping in and out, which of course meant the TPMS dash emoji would start flashing at me while driving. It was very distracting and irritating. When I checked the sensors with my Autel TS501, they all check out "Good" but clearly something wasn't right with the batteries. I noticed the rears in particular were very lazy when reporting to the multi-gauge display, the fronts would register immediately (within the 1st 30sec of driving), but the rears could take 3-5 min if they even registered at all.

I finally pulled the trigger and had more modern aftermarket replacements installed instead of the older OEM design (way cheaper!), so far so good. Not a single issue (knock on wood). The new sensors all report in within the 1st 30 seconds or so of driving (speed does matter when waking them up).

Hope you can pinpoint that ticking noise, fingers crossed it's nothing serious.
Cheers!
-Icer

 

Hey Bob nice to see your updates. Happy belated birthday.

I am currently having a very similar issue trying to figure out a ticking/tapping noise on my 04. Mine just started out of no where about a month or so ago. Still trying to see where this is from. Follow my thread as I plan to update it with my findings as i go along. May not be the same issue your having but who knows.

 

After I get the car looked at I will come back on this thread and make a report.

 

Bob- always a pleasure to hear of your adventures and birthdays! One other question to ask about your twice a year oil changes: in your dry climate, is it really needed? Unless you're running the engine extremely hard or long, the oil just sits in the crankcase. I'd think there's other ways to spend your money to keep your Z in good shape.

 

Don’t call me Sir! It makes me feel old. Bob

 

Recent picture of my wife and me to show you what we look like.

 

You 2 look great! Thanks for sharing this photo. Now you need to share one with the Z

 

I will take one!

 

Me and my Z five minutes ago. Pic taken by my wife.

 

My mechanic says the tapping noise indicates need for valve adjustment. Unfortunately there is no way to adjust valves on this engine. Says only way to solve problem is major overhaul of right |rear valve lifters. Total job $4000. Says oil pressure is fine. Suggested changing oil and additive to coat lifters. Periodically have him check lifter action with stethescope to see if there is any deterioration. Considering my limited use of the car he does not feel any major overhaul is needed.
How does this sound to you.

 

Thank you for the update on the valve train noise. I still havent figured out exactly where the tapping noise is coming from on my car. I fear it maybe the same as yours. In your case it would make sense what your mechanic suggested. Im also going to try an additive with my next oil change and go from there. I had plans on getting a low milage VQ to have around as a spare. I think I may start looking to get one and have it on hand. Although my son is taking over the Z next month the car will stay in the family. Our plan was to keep it regardless and restore it in the future. I would love to get my hands dirty on a VQ rebuild and what best to do it on the motor that came with the Z. Thanks for the update Bob

 

I am going back for a check up in about month and will follow up regularly. I have been with this mechanic for almost 30 years. If it ever gets to the point where he recommends an overhaul I will do it. As my wife says, where are you going to get a car like that for $4000.

 

its true though, when i broke a lifter that trashed my head and cam in the vette, i opted for the $8k fix because cheaper than a new car.. and added some horses. win/win

 

Thanks for the update Bob! You guys look great, I was thinking no older than 75, not pushing 90+!

As for the lifter situation. If that's the case, there might be a cheaper/easier method to adjust the valve lash without the need to remove the heads, which your mechanic might be interested in (if it ever comes to that). But it does require purchasing a special tool from JWT. You can get this tool for around $100. Here's a LINK to the MFG's website. This is definitely something I want to have in my tool kit for future use. Like bre240z is planning to do, I already have a spare longblock ready for a rebuild (was an oil burner).

As stated, these engines have non-adjustable valve lash. The "adjustment" is set at the time of assembly by a stud/post on the underside of the spring buckets. I don't believe there are shim kits that work with the stock valve springs/lifters. The spring buckets themselves are inexpensive individually, but a complete set (24 total) will get a little pricey. Nissan sells these with precise thickness machining, so you need to do the teardown/inspection work before ordering. While the work is being done, replacement of the valve guide seals should also be tackled (super cheap, well worth it).

Downside to using this kit, you would still need to remove the cams + cam gears, which AFAIK, requires a full timing job to be done. Now maybe there's a cheat somehow to pull the cam gears off and hanging the chains without having to pull the entire front cover. But If I was replacing worn out spring buckets, I would also be replacing the chain as it would be worn as well (assuming it's original). This does save the added effort of pulling the heads off, which will save a lot of extra labor/time/money.

Sure you would still need to refresh things like cam seals, valve covers, seals, etc. But this is probably the best option assuming your heads (valves, guides, & cams) are in good shape. If it's discovered that the valve guides are worn beyond tolerance or there's a burnt valve, or something else that's odd/unusual, then at the point you have to pull the heads for a complete refresh.

Just wanted to share!
Cheers!
-Icer

 

This gives me hope that in 55 years i'll still be into cars. Lets see if my 240 and 350 last that long.

 

@icer5160 thanks for that link for the JWT tool and for your input. Im going to run the current motor until I start seeing some odd stuff. Car seems to run really well with no issues but that tapping sound. After adding an additive, I was also thinking of replacing the cat gaskets and cat to y pipe gaskets to see if maybe its an exhaust leak causing this tapping sound as it sounds its coming from the bottom of the car more than the top side. I doubt this is the cause but its worth a shot since ive never replaced these gaskets