ticking sound its not the valves

911 2 · 07-23-2006, 08:49 AM

canged the oil and did a valve adjustment on my 1991 3.3 turbo have completed this i started up the car and it had a ticking sound it kind of comes and goes and i have been told its not there on the overrun, i thought may be the valves were adjusted loose so i reopened everything rechecked the valves using 2.7 racers method if anything the sound seemed to be coming around culinder 3 if iput a rubber tube to my ear on rechecking it was slightly tight, i have noe finished readjusting for the second time and have started the car and the sound is still there any ideas what it is

jmreiser · 07-23-2006, 08:55 AM

Was it making the ticking sound before the valve adjustment?

Too tight on the clearance is worse than too loose. When the valves heat up they expand, which means the valves will never be fully closed.

Using a torque wrench for the adjusters? I know its miserable for space in there.

911 2 · 07-23-2006, 01:07 PM

im sure it was there before but very slight thats why i thought the valves needed adjusting
either i know its there and thats why it sounds louder, if you are standing next to the car its hard to hear get underneath and you can hear it
if you apply pressure to the throttle the sound diappears and im sure you cant here it on overrun
can an exhaust leak or laek from the air pump to cylinders cause a ticking sound

jmreiser · 07-23-2006, 01:14 PM

An exhaust leak could do it, or a cylinder head gasket leak could too, though when rev'd, either way it should get worse.

How many miles and/or track events on the engine? Could be due to exhaust guide wear, especially if that one exhaust valve was out of adjustment for some time.

PJMARKOW · 07-23-2006, 01:31 PM

I have the same problem. I have adjusted valves, replaced valve adjusters and I definitely know it's NOT the valves now. I think it may be the ball bearing in the line that goes from the oil pressure sender at the back of the engine to the turbo. The ball bearing acts as a check valve when you turn the engine off and prevents oil flowing through the turbo when the engine is not running. That way you will have oil at the turbo as soon as you start up. My mates 3.3 turbo makes the same ticking noise. Seems to die off when you increase the revs. I've given up worrying about it. By the way, my engine is freshly rebuilt & my mates has about 200,000+ km on it so I think the noise is just something that happens with 3.0, 3.3 turbos.

Cheers

911 2 · 07-23-2006, 02:47 PM

im sure the sound was there before
the car has 60000 miles on it with full service history and drives fine,surley if it was head gasket or exhasut guide wear the car would not perform very well.
i have changed the oil grade from 0-40 to 15-50 mobil 1 i dont take it on tracks previous owner may have taken it a few times.

jmreiser · 07-23-2006, 03:34 PM

I will defer to the guys with the 3.0 & 3.3 turbos, I think they are on to something there.

911 2 · 07-23-2006, 04:18 PM

do i take it you think there is another problem
what does a broken valve spring sound like

Steve@Rennsport · 07-23-2006, 04:39 PM

Broken valve springs usually manifest themselves as a miss.

If your valve train is noisy and the adjustments are spot-on, its either worn rocker arms & shafts or worn guides which is VERY typical for a Turbo.

These engines run OKJ with worn guides so the only sure way to check is to measure the side-play in the valve assembly and that takes some experience to do, accurately.

As Joel said, loose heads and/or an exhaust leak can sound a lot like noisy valves.

911 2 · 07-23-2006, 04:47 PM

valve train isnt really noisy the sound can be heard when you listen to it from under the car difficult to hear if your standing next to the car

jevvy · 07-23-2006, 11:36 PM

At risk of sounding like an idiot (not sure turbos use fuel injectors) but injectors make quite a loud tic noise as they open and close - might be worth considering (if you have them)

911 2 · 07-24-2006, 12:08 AM

defo not the injectors does dound similar though

rotorhead · 07-24-2006, 12:26 AM

Quote:

Originally posted by PJMARKOW
I have the same problem. I have adjusted valves, replaced valve adjusters and I definitely know it's NOT the valves now. ...................... My mates 3.3 turbo makes the same ticking noise. Seems to die off when you increase the revs.
Cheers

Thats a relief my 930 makes exactly the same sound. It dies off when revs are increased. I have been trying everything to chase it down. Only recently had a top end rebuild. (oh I replaced all 6 injectors without affecting it but I doubt CIS injectors would make an opening/closing noise)

911 2 · 07-24-2006, 12:30 AM

i just hope its not valve spring guides anyone have this sound recorded or know how to do it so we can all have a listen

PJMARKOW · 07-24-2006, 03:35 AM

My engine has new guides, springs and one bank has new valve adjusters (elephants feet). When I checked the old adjusters there was nothing wrong with them. No it's not valve train related. When I get the chance I will take that ball bearing out from under the oil pressure sender and see if the sound disappears.

Cheers

jmreiser · 07-24-2006, 03:38 AM

Worn valve adjusters are hard to evaluate, since the wear in the elephant's feet is inside of a ball, it is hard to measure. Comparing the removed parts to each other would not be as clear as comparing them to new ones.

PJMARKOW · 07-24-2006, 04:04 AM

I did compare them with new ones. The new ones were looser than the old ones. I even pulled one of the old ones apart. Couldn't see any significant wear on the ball either.

jmreiser · 07-24-2006, 04:06 AM

Oh my!

911 2 · 07-24-2006, 04:31 AM

rotorhead does your sound come from the left handside rear ie the side the wastegate is that would be passenger side on a uk spec car
pjmarkow let me know how you get on will be interesting to see what happens to the sound

rotorhead · 07-24-2006, 05:12 AM

Quote:

Originally posted by 911 2
rotorhead does your sound come from the left handside rear ie the side the wastegate is that would be passenger side on a uk spec car

No the sound appears to be comming from the right side of the engine. I'll get a sound byte of it with my Ipaq tomorrow and post it.