Jerry 87 928S4

When I was checking my oil pressure with a guage,and after letting it idle for about 20 - 30 minutes, suddenly a loud consistent clicking started under the manifold.

My engine actually shut off and then did not want to start. It eventually started and after putting the sending unit in, everything seemed fine.

Now a few weeks later, the clicking sound is back and the car is running fine. Any ideas what this might be?

Mike Schmidt

Are you sure the sound is coming from under the intake, and not from the valve cover or covers? There really isn't much under the intake that could be making a loud clicking noise. The flappy actuator, idle stabilizer, and throttle switch are the only things under there that move. I can't really see any of those making a loud clicking though.

Did you try to locate the source of the noise with a stethoscope, of a piece of hose with one end held to your ear and the other moved around the engine?

Jerry 87 928S4

I actually used one of those car Stethoscopes to locate the sound - and yes it is under the intake and not the valve covers.

I guess I could check to see if my flappy is working - do you think that would tell me anything?

Anything else I should do?

John Struthers

Jerry,
We have different MY but when I lifted the hood one day - engine running - there was a loud clicking emanating from the top of my spyder.
When I moved around the sound moved. When I put my hand on the top of the spyder the noise just about stopped, move my hand and it was back again.
Long story short... there were several posts last year that identified the noise as the injectors.
Yeah, I know the clicking sounds like valves or an arcing coil wire but I put Pattycakes thru her paces regularly and the noise never increased or decreased . On rare occassions you can hear it inside the car.
Put the stethosope near/on an injector - try several as some may be louder than others.
HTH

Mike Schmidt

I guess checking the flappy operation wouldn't hurt. The actuator is pretty much just a vacuum diaphram connected to the bottom of the flappy shaft, so it sure wouldn't seem like a very likely source of a loud clicking noise.

The injectors clicking is a possibility, but that's usually a pretty consistent noise. If one of them was having some sort of intermittent problem, I'd think you'd have been able to isolate the noise to one side of the engine. Try the stethoscope on the injectors. If it seems like the noise is coming from one of those, disconnect the plug from it to see if the noise goes away.

Did you ever determine if your oil pressure really was low? Is the clicking noise only present at idle?

Brett Matthews

Now here's a thread consistant with what I've posted before! I also have a noise coming from the engine bay, is an intermitant occurance, is dependant on engine RPM, and I cannot locate it. I suppose you could call it a clicking noise, but I'd call it more of a knocking noise. Sort of a pocka-pocka-pocka. Not as heavy as a rod knocking, although Wally said that was what he might guess it to be, when he heard it, at SitM this year, '02. But it never increases in decibles, as in getting worse, and it has been with the car since I've owned it, May of '01. I am seriously going to be watching this thread, I'd like to get rid of this irritating occurance!

Greggg

OK, hears what I've been thru. When I first bought my shark I had 2 types of clicking noises coming from the intake/ cam covers. Both problems were caused from the car sitting too much. First the injectors were gummed up; so I removed them and mailed them off to Marrien Motorsports to have them cleaned and computer tested. This helped alot! 1st noise eliminated, also drivablity and power much improved. 2nd noise occured when first starting the car, would last for 2-5 minutes, sometimes would not go away unless I turned car off, let it rest, them restarted. After exhaustive reading, found a quick fix. I added 1 quart of trans fluid to my motor oil and drove the car for 300 miles then did an oil change. Now your saying, TRANS fluid- IN THE OIL?! Yeah, sounds scary. I guess it dissolves the gunk/ gum buildup in the oil check valves and entire engine. I kept checking for temp, leaks, noises, no problem. After first 10 miles with trans fuild in the motor quited down and smoothed out.This my not be for everyone, if you don't want to take this kind of chance-DON'T. So far no problems have surfaced, its been about 500 miles since the oil change. I'm curious to hear if anyone has done this with any serious aftermath? Hope this helps. <img src="graemlins/c.gif" border="0" alt="[ouch]" /> <img src="graemlins/icon107.gif" border="0" alt="[icon107]" /> <img src="graemlins/burnout.gif" border="0" alt="[burnout]" />

Mike Schmidt

If the noise is coming from the valve covers, the most likely causes are probably either a sticky oil check valve, or the cam chain.

If it's the oil check valves, the transmission fluid trick may help. If not, there's information on cleaning the check valves at: <a href="http://members.rennlist.com/v1uhoh/oilcheck.htm" target="_blank">http://members.rennlist.com/v1uhoh/oilcheck.htm</a>
<a href="http://ourworld.compuserve.com/homepages/nichols/tip473.htm" target="_blank">http://ourworld.compuserve.com/homepages/nichols/tip473.htm</a>

If it's the cam chain, it could be due to the plastic cam plugs coming out and reducing the oil pressure. It seems like whenever I hear about that problem it's on an '87. It may be more common on that model year for some reason, or it may just be a coincidence. There's some information on the plastic plugs at: <a href="http://ourworld.compuserve.com/homepages/nichols/tip578.htm" target="_blank">http://ourworld.compuserve.com/homepages/nichols/tip578.htm</a>
<a href="http://members.rennlist.com/v1uhoh/nasty.htm" target="_blank">http://members.rennlist.com/v1uhoh/nasty.htm</a>

If Jerry's noise is coming from underneath the intake manifold, I'm really kind of stumped on what's causing it.

Max

Jerry, try this; Start the engine, remove black rubber cap off of "Flappy's" shaft and with your thumb press down real hard.

Cheers

Max

Jerry 87 928S4

Max, you suggestion sounded kind of funny but I did it anyway to no avail.

Then I revved the engine to about 4k-5k rpms and the clicking went away for about 15 seconds.

Sounds like I need the stethoscope again, until then suggestions?

Max

I heard a strange vibrating noise one day while working on mine. It turned out to be the Flappy shaft vibrating. I haven’t noticed it sense.

I haven’t noticed if you said in any of your pervious posts if you ever fixed your oil PSI problem or not.

O-well, there's my shot at it

Back to my hole I call a Garage!

Steve Cattaneo

Jerry,
To check for an injector noise disable the injector by removing the feed wire from it. If the click is gone you have a bad injector. Another method is to use a stethoscope. The click could also be a lifter noise due to low oil pressure or a sticky oil check valve. Since you have an oil pressure problem I would remove the valve covers, clean the check valve and change the cam oil plug. While the covers are off have them powder covered along with the intake.




Cam oil plug

Jerry 87 928S4

Wow Steve, tempting to say the least. I just got done with my timing belt - not ready to dig into another project - but may have to.

Concerning low oil pressure, I have 1.5 bar at idle as registered on a seperate guage. The sending unit is set at .5 +/- .15 before it turns on the warning light - so I guess I do not really have a low oil problem.

Twice now I have seen both my oil guage and alternator guage drop at idle - this is what happened when I thought I had an oil pressure problem - not sure of the cause here either but maybe a battery.

Thanks for the help guys, I will keep you updated.

Steve Cattaneo

jerry,

My oil pressure at idle is2.5 to 3 bar, at 1500RPM it stays at 5bar. Go the extra step, is it worth you engine.


Corroded relays, fuses and bad grounds cause electrical phantom problems.

Low battery voltage or bad grounds, overcharging and undercharging alternator can cause an erratic computer control. Any input sensor, example, TPS, CTS (coolant temperature sensor), relay can malfunction or give a wrong reading under these conditions. With the ignition off turn on the headlights for one minute after one minute turn the headlights off; connect DVOM set to DC volts, negative lead to negative post, positive to positive. A fully charged battery should read 12.6 volts. Anything lower than 12.3 volts, you will need to charge the battery, with the main cables disconnected. With the meter connected to the battery positive-to-positive, negative-to-negative, start the engine; turn on the headlights, heater fan, and radio. This puts a load on the system. You should see 13.5 volts to 14.4 volts. Anything under 13.5 volts could be a bad alternator, bad diode, bad ground or high resistance in the positive cable. Anything over 14.5 volts is an overcharging alternator. With the car still running, lights and accessories still on, place the negative lead of the meter to the negative lead of the battery post, place positive lead of the meter to all of the ground wires. No more than 0.10 volts should read on the meter. A good ground is 0.00 or 0.01 volts. If you have 0.20 or more you have a bad ground wire. You can use a jumper wire for the negative lead of the meter to the negative lead of the battery post, so you can reach the engine compartment. Just be careful and use common sense when working in the engine compartment when the engine is running. You should check the alternator output directly at the alternator with the car running and all accessories on.
Make sure you have the decimal in the right place on your meter.


<img src="graemlins/beerchug.gif" border="0" alt="[cheers]" />

Mike Schmidt

[quote]Originally posted by steve cattaneo:
<strong>My oil pressure at idle is 2.5 to 3 bar</strong><hr></blockquote>

With the engine fully warmed up, that's the same as mine is at idle.