944S taping noise from engine

1987944Sick · 10-29-2008, 03:52 PM

ok,so i still have this taping noise i know its coming from the engine..When i first start the car up it dose not make the noise when its cold then about a min later it starts to knock and get louder and luder then i turn the car of and wait a little bit start it again and the noise goes away in about 5 mins its get quieter and quier..then it turns off, and drive around and it dose not knock...also when i start the car the rmps jump up and down to 2k rpms and stop in about 10 sec...I THINK THE O2 SENSOR IS WORN AND DAMAGED COULD THIS BE THE CAUSE?

looneybin · 10-29-2008, 05:57 PM

where in the motor is the knocking coming from.
I had the oil pressure relief valve fail & it caused a knocking sound on the top of the motor.
I have also had a loose exhaust manifold bolt that caused a knocking sound

1987944Sick · 10-29-2008, 06:35 PM

Quote:

Originally Posted by looneybin

where in the motor is the knocking coming from.
I had the oil pressure relief valve fail & it caused a knocking sound on the top of the motor.
I have also had a loose exhaust manifold bolt that caused a knocking sound

sound like from the top of the motor...but it stops when the car gets hot and you wait a little then start it again it goes away and dose not turn on untill the next day i guess when it cools down..did yours go away?

looneybin · 10-30-2008, 11:13 AM

Sounds like the OPRV, that's what mine did until i replaced it

looneybin · 10-30-2008, 11:15 AM

I just noticed you said 944S
is your car a 16 valve?
It may be different than the 8 valve concerning the OPRV, but probably not

1987944Sick · 10-30-2008, 12:02 PM

Quote:

Originally Posted by looneybin

I just noticed you said 944S
is your car a 16 valve?
It may be different than the 8 valve concerning the OPRV, but probably not

yeah it is..
what oprv? how much dose it cost and where can i find it?

1987944Sick · 10-30-2008, 12:13 PM

Quote:

Originally Posted by looneybin

Sounds like the OPRV, that's what mine did until i replaced it

i am looking for this?

http://cgi.ebay.com/ebaymotors/OEM-Porsche-924-944-968-Oil-Pressure-Relief-Valve-NEW_W0QQcmdZViewItemQQcategoryZ46098QQihZ023QQitem Z360085385266QQrdZ1QQsspagenameZWD1V

holy **** that cost a lot this car is starting to piss me off..i already have stuff i have to replace..damn

1987944Sick · 10-30-2008, 01:24 PM

My oil pressure is normal tho????? it dose not go up or down or anything and is bettwen 2 and 3 bars..

looneybin · 10-30-2008, 06:50 PM

the pressure should be at 5 bars unless at warm idle, then should be between 2 & 3 at idle.
I don't have a part # but the OPRV is expensive, i think mine was around $300

1987944Sick · 10-31-2008, 03:28 AM

Quote:

Originally Posted by looneybin

the pressure should be at 5 bars unless at warm idle, then should be between 2 & 3 at idle.
I don't have a part # but the OPRV is expensive, i think mine was around $300

Yes thats how it...did your knocking turn off after u waited a little? maybe mine is a little dirty and blocked so when the oil heats up it flows normal...i dont understand this because it is not showing any oil problems..

looneybin · 10-31-2008, 07:40 AM

I had full pressure at the time of the knocking too.
The porsche mechanic told me that when the oprv fails it is intermittant, meaning that if you let the car sit for a while then restart it, it will be fine.
The problem is when it fails, it does not allow enough oil up into the valve area, causing the valve train noise.
I don't know if it's possible to clean this part, but it couldn't hurt to try

1987944Sick · 11-01-2008, 06:45 PM

Quote:

Originally Posted by looneybin

I had full pressure at the time of the knocking too.
The porsche mechanic told me that when the oprv fails it is intermittant, meaning that if you let the car sit for a while then restart it, it will be fine.
The problem is when it fails, it does not allow enough oil up into the valve area, causing the valve train noise.
I don't know if it's possible to clean this part, but it couldn't hurt to try

is the the big bolt next to the power steering? can i damage anything if it knocks for a while ? i am guess i could..should i not start it anymore untill i fix it?

Arizona_928 · 11-01-2008, 08:05 PM

when was the last time the timing chain was replaced?

1987944Sick · 11-02-2008, 05:28 AM

Quote:

Originally Posted by AZ_porschekid

when was the last time the timing chain was replaced?

you are talking about the chain under the valve cover? i dont know,but the car only has 52,000 miles..i checked it tho and it looks new...

1987944Sick · 11-02-2008, 02:44 PM

i just took out the oil pressure valve....how can i know that this is the problem? how can i test it?

looneybin · 11-02-2008, 06:22 PM

I don't know if it can be tested, but you may be able to clean it with brake cleaner or parts cleaner & reinstall it to see if that solves the problem

1987944Sick · 11-03-2008, 03:14 AM

i just need to know this is the problem before i spend the money

looneybin · 11-03-2008, 07:48 AM

I'm not positive that's the problem, but it would be my best guess based on the symptoms.
There are others on this board that are WAY more knowledgeable than me on the 16v motors.