clicking type noise when cold

[chadwick609]

my 92 z34 makes slightly loud clicking type noise coming from the engine when it is first started. The colder the ambient air temp is, the louder the noise is. As the car warms up, the noise goes away. Any idea what it might be and what can be done to remedy the problem?

[SappySE107]

Lifters ticking. There is a TSB on the oiling but I believe the kit is no longer available. What kind of oil are you using? Mine makes a little noise for about 1 minute when its cold out but im using different lifters (no tsb update done either). Mobil 10w30.

[chadwick609]

I think the oil im using is 5W30.

[GTP_MuNkY]

I noticed the same ticking when I first got my GP. I was pretty quick to swap all the oil for Royal Purples 5w30. The sound didn't go away completely, but it is less noticable and fades quicker, usually within a minute or 2. Aside from that I don't know what to try, maybe an additive?

Jamie

[Mach10]

Could be piston slap. Is it constant with load, or does it go away/change when you are accelerating?

If it's pretty constant, it's likely a lifter. You can try this trick for an oil change, but be VERY careful. I wouldn't do this except to try and clear out that sticky lifter. DO NOT do this if your motor already knocks.

You'll need the materials for *2* oil and filter changes. You'll want 5 quarts of 0w30 (if you can find it) and 5 quarts of your regular weight oil. Also, you'll want 1 quart (or so) of regular diesel fuel or engine oil flush. If your motor won't idle under 1200 rpm or so, DO NOT ATTEMPT THIS.

If you are really paranoid, you can get the same results by running 0w30 synthetic oil, and changing the oil every week (and the filter every 2) for a month.


I haven't changed a filter in a z34 or olds, but if you need to, pick the car up on jackstands first.

Spin off the old filter, replace with new one.

Start the engine, and let it warm up to operating temperature.

Pour a quart of diesel fuel/flush into the motor from the oil fill.

********DO NOT TOUCH THE THROTTLE!!!!*********

Let it idle for two minutes, then kill the motor. Let it sit for a good 10 minutes

Change the filter, fill the motor with the light oil, and let it idle for 15 minutes or so.

Drain the oil, then fill it again.



The diesel oil will loosen deposits in the motor. You have to replace the filter FIRST in case you manage to suck up a glob of sludge that will plug the filter. You do NOT want to trip the bypass when the deposits start to come loose. The new filter ensures that the crap will stay where it belongs.

Just be warned: I have heard of people eating bearings by doing this, although I suspect they tried revving the motor, or they had problems already. Also, if the motor is REALLY sludged, it'll plug the filter for sure.

If it IS sludged, you can also try this. You'll need a good 2 gallons of diesel

Bring the engine up to temp, then pull the cam covers. (both)

With a LARGE catch-can under the car, open the drain plug and drain the pan. Replace plug. Pour about a gallon of diesel into the motor over the cams on one head. With a brush loosen the sludge, and flush all the crap into the pan. When done a side, make sure that there is NO sludge on the tappets or cam lobes. Use compressed air to be sure, and with a small paintbrush coat the cam lobes and tappets liberally with assembly lube or gear oil. CLEANLINESS IS CRITICAL. You don't want to eat a cam 'cos you couldn't be bothered to take the 10 minutes to double-check.

Drain the pan, note the color of the diesel. (Black = good. Means the sludge is dissolving).

Repeat for other side.

Drain pan completely, change filter, fill with light oil, run for 15 minutes. Drain oil, replace filter (again) and fill with oil.

After doing this, I suggest increasing the frequency of oil changes for the next few months to get rid of any other crap. You don't need synthetic, but Synth DOES have better detergents. For economy, consider a blended sythetic.