clacking noise from #2 valve area
07-11-2004, 01:07 PM
#1
Racer
Thread Starter
clacking noise from #2 valve area
In case anyone forgot, or isn't aware of my project, I have a 1980 euro spec "S" motor with CIS installed in a 914.
The car is working out pretty well as an overall build. The biggest problems have been with the used motor I am using. I have several questions I could use some help with.
First, Is there a brand of seal that is better? I Installed new seals on the cams and oil pump. I have one cam leaking and the oil pump seal is leaking.
Anyone ever had a clicking or clacking noise for a few seconds of running after start up? The noise sounds like a hydrolic lifter in a chevy engine that isn't pumping up. The sound is in the area of #2 cylinder.
Second thing is I have oil fouling #2 spark plug. I think I must need a valve stem seal or something. Is there a common problem I should know about?
Is there an easy fix for this?
Or is it simpley time to tear the sucker down and rebuild it?
(approximately 85000 miles on a 10/1 compression motor)
Any suggestions on a good text publication or web site with the do's and don'ts when rebuilding a 928?
I am an accomplished mechanic but never pulled a 928 motor apart.
The car is working out pretty well as an overall build. The biggest problems have been with the used motor I am using. I have several questions I could use some help with.
First, Is there a brand of seal that is better? I Installed new seals on the cams and oil pump. I have one cam leaking and the oil pump seal is leaking.
Anyone ever had a clicking or clacking noise for a few seconds of running after start up? The noise sounds like a hydrolic lifter in a chevy engine that isn't pumping up. The sound is in the area of #2 cylinder.
Second thing is I have oil fouling #2 spark plug. I think I must need a valve stem seal or something. Is there a common problem I should know about?
Is there an easy fix for this?
Or is it simpley time to tear the sucker down and rebuild it?
(approximately 85000 miles on a 10/1 compression motor)
Any suggestions on a good text publication or web site with the do's and don'ts when rebuilding a 928?
I am an accomplished mechanic but never pulled a 928 motor apart.
Last edited by 918-S; 07-11-2004 at 10:11 PM.
07-11-2004, 02:19 PM
#2
Nordschleife Master
Not aware of different brands of seal being available. I did look into this but couldn't figure out what flavor of seal was needed after finding the right size.
The oil pump is tricky, at least to me, as I had one fail due to putting the seal too far in. It's supposed to be flush with the outside as there's no lip to seat it to.
Lifter noise at start-up in not uncommon. The manual calls for 20w50 oil if you're using thinner stuff.
Fouled plugs at not really common. Have you run a compression test? I'd be surprised if enough cam past the valve to foul the plug.
I don't know of a site with a whole rebuild described and early engines get less of that. The manual is OK if you have some idea what to do. Having recently rebuilt the same engine as you've got I'll share a few things:
Get the official block-half sealant from 928 intl. Use a little roller to apply. Check Home Despot or similar and you'll find some. Not too thick, not too thin. Hard to describe but it should give a bit of color and hold a few bubbles.
Don't touch the bores. Clean them and oil them but no honing. If deeply scratched then get it bored...or get a different block.
After removing the intake plenum and runners, the whole CIS system can be removed as a unit.
I _believe_ the standard Porsche gasket set for the 4.7l engine will work on the Euro S. I checked in the PET and it listed a lot of components that were needed for the CIS engine (K-jet). The US 4.7l have L-jet. I got the parts I needed for the engine job individually as the cam towers were still fresh. Anyone rebuilt a 4.7lUS? Were there a bunch of parts left over?
There's only one manufacturer of gasket sets. (Reinz)
Get the OEM rings. I got that advice from several places. (Goetze)
Check for getting the right main bearings. Some blocks use the "944" bearings, some do not. I needed a split front bearing which is not the 944 type.
Check out the advice on the lists for sealing the oil pan. The gasket is unusaIly thick and soft and tends to compress and then leak. I used some high-temp silicone and so far (3mo) so good.
HTH!
The oil pump is tricky, at least to me, as I had one fail due to putting the seal too far in. It's supposed to be flush with the outside as there's no lip to seat it to.
Lifter noise at start-up in not uncommon. The manual calls for 20w50 oil if you're using thinner stuff.
Fouled plugs at not really common. Have you run a compression test? I'd be surprised if enough cam past the valve to foul the plug.
I don't know of a site with a whole rebuild described and early engines get less of that. The manual is OK if you have some idea what to do. Having recently rebuilt the same engine as you've got I'll share a few things:
Get the official block-half sealant from 928 intl. Use a little roller to apply. Check Home Despot or similar and you'll find some. Not too thick, not too thin. Hard to describe but it should give a bit of color and hold a few bubbles.
Don't touch the bores. Clean them and oil them but no honing. If deeply scratched then get it bored...or get a different block.
After removing the intake plenum and runners, the whole CIS system can be removed as a unit.
I _believe_ the standard Porsche gasket set for the 4.7l engine will work on the Euro S. I checked in the PET and it listed a lot of components that were needed for the CIS engine (K-jet). The US 4.7l have L-jet. I got the parts I needed for the engine job individually as the cam towers were still fresh. Anyone rebuilt a 4.7lUS? Were there a bunch of parts left over?
There's only one manufacturer of gasket sets. (Reinz)
Get the OEM rings. I got that advice from several places. (Goetze)
Check for getting the right main bearings. Some blocks use the "944" bearings, some do not. I needed a split front bearing which is not the 944 type.
Check out the advice on the lists for sealing the oil pan. The gasket is unusaIly thick and soft and tends to compress and then leak. I used some high-temp silicone and so far (3mo) so good.
HTH!
07-11-2004, 03:30 PM
#3
The 16 valve engines had valve guides that were prone to early failure. If you pull the intake tube for that cylinder and see carbon on the backside of the valve, either the valve seal or guide has gone bad.
The cam carrier is prone to leak if the cam surface of the head is not machined at the same time as the bottom.
Dennis
The cam carrier is prone to leak if the cam surface of the head is not machined at the same time as the bottom.
Dennis
07-11-2004, 03:38 PM
#4
Inventor
Rennlist Member
Rennlist Member
What manner of crankcase venting are you using?
I had just a K&N breather on the oil fill cap for a while, and had similar problems with oil ejection at high rpm's. Worst was that my #1 spark plug kept building up oil crud on it.
I switched to an exhaust pilot tube vent and have had no problems since, even the spark plug is clean now.
I had just a K&N breather on the oil fill cap for a while, and had similar problems with oil ejection at high rpm's. Worst was that my #1 spark plug kept building up oil crud on it.
I switched to an exhaust pilot tube vent and have had no problems since, even the spark plug is clean now.
07-11-2004, 10:23 PM
#5
Racer
Thread Starter
[QUOTE]Originally posted by GlenL
The oil pump is tricky, at least to me, as I had one fail due to putting the seal too far in. It's supposed to be flush with the outside as there's no lip to seat it to.
I discovered that lip thing when I installed that same seal....
Lifter noise at start-up in not uncommon. The manual calls for 20w50 oil if you're using thinner stuff.
I'm using 20/50 GTX and added a quart of Barsdahl snake oil to see if this would help stop the oil leak.
After removing the intake plenum and runners, the whole CIS system can be removed as a unit.
I've had everything off the motor except the cam towers, heads, and short block. I replaced the seals and used Yamabond on the pan I developed some leaks within 500 miles of driving.
The oil pump is tricky, at least to me, as I had one fail due to putting the seal too far in. It's supposed to be flush with the outside as there's no lip to seat it to.
I discovered that lip thing when I installed that same seal....
Lifter noise at start-up in not uncommon. The manual calls for 20w50 oil if you're using thinner stuff.
I'm using 20/50 GTX and added a quart of Barsdahl snake oil to see if this would help stop the oil leak.
After removing the intake plenum and runners, the whole CIS system can be removed as a unit.
I've had everything off the motor except the cam towers, heads, and short block. I replaced the seals and used Yamabond on the pan I developed some leaks within 500 miles of driving.
07-11-2004, 10:30 PM
#6
Racer
Thread Starter
Hi Porken,
I ended up reconnecting the stock screen device. Because I no longer have the fill tube connected to the bottom of the can. I can't be sure it's working properly. I just capped off the hole in the can.
Do you have any photos of your exhaust type drag tube setup?
I ended up reconnecting the stock screen device. Because I no longer have the fill tube connected to the bottom of the can. I can't be sure it's working properly. I just capped off the hole in the can.
Do you have any photos of your exhaust type drag tube setup?
07-11-2004, 11:23 PM
#7
Inventor
Rennlist Member
Rennlist Member
I was worried about contamination of my oxygen sensor(s) so I put the tube in after the muffler (in place of the cat):
click pic for thread: Adjustable FPR and Exhaust Crank Evac
When I get around to it, I'm planning on putting either banjos or AN adapters on the cam towers, replacing two of the aluminum threaded plugs on each side (18x1.5mm?). I might also remove the oil strainer assembly, cap the crankcase opening, and run an external separator if necessary.
click pic for thread: Adjustable FPR and Exhaust Crank Evac
When I get around to it, I'm planning on putting either banjos or AN adapters on the cam towers, replacing two of the aluminum threaded plugs on each side (18x1.5mm?). I might also remove the oil strainer assembly, cap the crankcase opening, and run an external separator if necessary.
