Hello guys.

This past Friday I did an oil change in my Z. Decided to give 20w50(VR1) weight oil a try as the temps here in Tucson are getting a bit warmer. Went to the local store bought six quarts of oil (one spare) and a Bosch oil filter. Put everything together added 5 quarts oil and away I went.

When I rev the car up now to about 4k and let the throttle go it will make this rather annoying rattling sound from the valve cover for a few seconds. Any ideas? Is the oil just too thick to lubricate the cam at idle. The pressure is sitting exactly where it needs to. I pulled the fill plug out and the cam is most definitely covered in oil. The sound was not present this morning when I drove to school or before I did said oil change.

I did figure out where all the oil I was loosing was going. To my dismay my mechanic who did the valve clearances for me didn't tighten the valve cover enough and caused leaking from the cover. Just noticed this issue this past week.

Thanks

Jan

Edited March 6, 201015 yr by Pomorza

It may be time to re-adjust your valve lash.

It may be time to re-adjust your valve lash.

Here's a bit of an update. I took the Z out for a ride a few hours ago. Engine temp was just to the first line (the low line) and oil pressure was just past the halfway point. Car was rather loud, as I could hear the cam moving. (rather louder than usual). When I revved the car up 3k or so and released the throttle the said rattling sound was present for about two seconds. Took the car for about a ten mile drive. It felt rather sluggish, which I guess could be explained by the far thicker oil (I used 10w30 before). Didn't really push the car, did reach 4k a few times but mostly kept it below that area. The car sounded and drove fine the entire time. As I reached home I revved the engine once more and the rattling noise was there but not as loud or long lasting as before. I parked the car and checked the oil level. By the look its just about a few cm above the H line. About 5cm or so. Could too much oil cause noise?

What can cause a sound from the cam to just appear? Could the new oil just not be lubricating it enough? I'm a bit scared here to drive the Z as I may damage something important (like the cam). I'm also just lost here. I've never had this happen to me before where sounds just appeared after oil changed. Its not like I drove the car with no oil.

As for your suggestion. The valves were adjusted in September when the car had 240k. Car now has 242k, but I'll give it a look tomorrow.

Jan

Edited March 6, 201015 yr by Pomorza

By the look its just about a few cm above the H line. About 5cm or so. Could too much oil cause noise?

Jan

5 cm????? That's like 2 inches! That can't be good. Perhaps you mean 5mm?

Here's a bit of an update. I took the Z out for a ride a few hours ago. Engine temp was just to the first line (the low line) and oil pressure was just past the halfway point. Car was rather loud, as I could hear the cam moving. (rather louder than usual). When I revved the car up 3k or so and released the throttle the said rattling sound was present for about two seconds. Took the car for about a ten mile drive. It felt rather sluggish, which I guess could be explained by the far thicker oil (I used 10w30 before). Didn't really push the car, did reach 4k a few times but mostly kept it below that area. The car sounded and drove fine the entire time. As I reached home I revved the engine once more and the rattling noise was there but not as loud or long lasting as before. I parked the car and checked the oil level. By the look its just about a few cm above the H line. About 5cm or so. Could too much oil cause noise?

What can cause a sound from the cam to just appear? Could the new oil just not be lubricating it enough? I'm a bit scared here to drive the Z as I may damage something important (like the cam). I'm also just lost here. I've never had this happen to me before where sounds just appeared after oil changed. Its not like I drove the car with no oil.

As for your suggestion. The valves were adjusted in September when the car had 240k. Car now has 242k, but I'll give it a look tomorrow.

Jan

Are you saying 242,000. miles? That is some serious miles if the engine hasn't been rebuilt. I wouldn't drive an engine with that sort of miles vary hard. 10w30 is recommended oil for these engines and should be just fine in your local for both winter and summer. I recommend that you pull the valve cover off and see if you can see something that is wrong. If the oil is so restricted that the Cam is suffering the lower end will be also. At the vary least you need to warm the engine before driving the car .

Are you saying 242,000. miles? That is some serious miles if the engine hasn't been rebuilt. I wouldn't drive an engine with that sort of miles vary hard. 10w30 is recommended oil for these engines and should be just fine in your local for both winter and summer. I recommend that you pull the valve cover off and see if you can see something that is wrong. If the oil is so restricted that the Cam is suffering the lower end will be also. At the vary least you need to warm the engine before driving the car .

Yes I do mean 242,000 miles. The engine is in great shape starts and runs amazingly it just scared me a bit after the oil change. I don't drive very hard on this car. I've seen I6's engines run for 500k before they need work so I'm not all that worried. I might just get rid of the oil and go back to 10w40. I'm going to start the car tomorrow and see what it does and then pull the cover off and investigate that. I do mean 5mm...more like 10 though. I can't really explain it but it is just above the H line.

Not to start another debate here but is straight old fashion Castrol GTX oil fine in these cars. I've been running VR1 since I bought it as I've been told the zinc in it is good for the engine but it's rather heavy on the wallet.

I always wait a good five minutes before going anywhere in any car. Let the oil get everywhere first and then I'm off driving. I also keep it under 3k when the car is cold, usually shifting at 2.5k or less.

Jan

P.S

I'm the third owner of this Z. I'm not sure if the engine has been rebuilt in the past or not. By all the records I got with the car when I bought it, it doesn't seem as if it was rebuilt at all.

Edited March 6, 201015 yr by Pomorza

Let me get this stright. You didn't have any sign of this noise before you changed oil......right? You didn't change or touch anything else (however insignificant) except the oil filter......right?

I go with the regular Castrol GTX 10w-30 year round, works great for me!

20W50 is waaaaaay to heavy. 10W30 should be your all around oil.

20W50 is waaaaaay to heavy. 10W30 should be your all around oil.

NO it isn't and NO it should not.FSM says 20/50.Ya'll should bother to notice where Jan lives before posting advice.:stupid:

Yep, I used 20W50 in my Datsuns here in SoCal. I really don't think oil weight would cause the engine noise problem anyway. It may just have shown up coincidentally after the oil change.

Edited March 6, 201015 yr by sblake01

Not for nothing, sounds like maybe your mechanic might not have tightened down a nut or one loosened up or the setting was too loose? Seen it many times on Honda SOHC 750's. I would either pull the valve cover and do the work yourself or bring it back!

Is it possible the noise that you hear is more like a timing chain rubbing? Or does it have the clickity noise like a loose adjustment.

Sluggish feeling in this case would indicate to me my above suspicions as opposed to thicker oil. 10/40 to 20/50 should not make that big of a deal in the cars feeling. But if the temps are freezing and below, it could - been there.

Hey, change the oil and see if you can feel a difference - its $25 or so for POM!