Strange sound from rebuilt engine...
02-12-2013, 08:07 PM
#151
Burning Brakes
Thread Starter
Peter,
If the case is filling with oil you should check to make sure the soft line leaving the engine by the axle is not crimped or restricted. I have even seen someone forget to remove a plug placed on the line to the front cooler and put a hose right over it during reinstall. I would also consider changing the oil pressure relief valve and oil pressure regulator. They are not to hard to get to and if the relief valve sticks open you get low pressure and oil dumped back into the case. (see the diagram I posted prior). Pull the drain plug from the bottom and see how much oil comes out. You can always put it back in if it's perfect.
If the case is filling with oil you should check to make sure the soft line leaving the engine by the axle is not crimped or restricted. I have even seen someone forget to remove a plug placed on the line to the front cooler and put a hose right over it during reinstall. I would also consider changing the oil pressure relief valve and oil pressure regulator. They are not to hard to get to and if the relief valve sticks open you get low pressure and oil dumped back into the case. (see the diagram I posted prior). Pull the drain plug from the bottom and see how much oil comes out. You can always put it back in if it's perfect.
02-12-2013, 08:09 PM
#152
Burning Brakes
Thread Starter
02-12-2013, 09:19 PM
#153
Burning Brakes
Thread Starter
02-12-2013, 09:24 PM
#154
Burning Brakes
Thread Starter
Checked compression on 4-5-6.
All at 150 PSI. Will get to 1-2-3 tomorrow.
What should the compression be at this point? I would think it will increase when rings are seated at higher rpm's.
All at 150 PSI. Will get to 1-2-3 tomorrow.
What should the compression be at this point? I would think it will increase when rings are seated at higher rpm's.
02-12-2013, 10:17 PM
#156
Race Director
I'd say you would typically see between 180 and 220psi on an NA car.
For reference, my 8.0 compression ratio 993 Turbo returned 150psi in almost all holes.
02-12-2013, 10:33 PM
#157
Burning Brakes
Thread Starter
150 is low, but given all the cranking and limited run times, you may run down the battery a bit. A strong starter/battery can affect compression.
I'd say you would typically see between 180 and 220psi on an NA car.
For reference, my 8.0 compression ratio 993 Turbo returned 150psi in almost all holes.
I'd say you would typically see between 180 and 220psi on an NA car.
For reference, my 8.0 compression ratio 993 Turbo returned 150psi in almost all holes.
Yes, the battery was very low when I did this. Charging tonight.
02-13-2013, 11:02 AM
#158
Three Wheelin'
Most of my mechanical "talent" comes from listening to click and clack, reading the hack mechanic in the BMW CCA Roundel and the tech advice columns in the Roundel and Panarama -- in other words none. But, it seems to me from my years of busting knuckles and screwing things up on my DYIs and motor builds, that engines are really somewhat complicated version of simple things and thus the fixes are usually simple.
This is a long way of saying I would be very surprised if the sound and the low oil pressure were not related. Fix the oil pressure and you'll get enough pressure for the lifters and you'll be on your way, I bet. Of course, it's easy for me to bet, but there's no harm in fixing the pressure (in fact if there is harm it is in NOT fixing the pressure and cranking the thing).
Just my worthless opinion -- not even worth two cents.
But know we're all rooting for you!
This is a long way of saying I would be very surprised if the sound and the low oil pressure were not related. Fix the oil pressure and you'll get enough pressure for the lifters and you'll be on your way, I bet. Of course, it's easy for me to bet, but there's no harm in fixing the pressure (in fact if there is harm it is in NOT fixing the pressure and cranking the thing).
Just my worthless opinion -- not even worth two cents.
But know we're all rooting for you!
02-13-2013, 10:33 PM
#159
Burning Brakes
Thread Starter
I have some news... Good, not great.
Warmed up the car. Removed right chain housing heat shield and then right tensioner retention cap. Very little oil came out, about 1/2 oz, if that.
Imagine my relief/amazement/homer simpson moment when I found the tensioner UPSIDE DOWN! Doh! No little hole. Flipped it over, re-installed. Buttoned up the cap and re-installed heat shield.
Started up the car. Ran it for 15 minutes but the loud sound has remained. Hmm... Do we think running it could have damaged/collapsed the lifters?
Anyway, I looked under the car and there is a pool of oil.
Two steps forward, one step back. It's coming from the cap. I guess one can not re-use the gasket. I have one on order.
One other note. I noticed some loctite 574 sort of hardened around the side oil holes in the cap. I can see now how easily that stuff can break off and enter the vehicle bloodstream. Next time the gasket is going on dry or with a VERY THIN LAYER of loctite. Lesson learned.
Warmed up the car. Removed right chain housing heat shield and then right tensioner retention cap. Very little oil came out, about 1/2 oz, if that.
Imagine my relief/amazement/homer simpson moment when I found the tensioner UPSIDE DOWN! Doh! No little hole. Flipped it over, re-installed. Buttoned up the cap and re-installed heat shield.
Started up the car. Ran it for 15 minutes but the loud sound has remained. Hmm... Do we think running it could have damaged/collapsed the lifters?
Anyway, I looked under the car and there is a pool of oil.
Two steps forward, one step back. It's coming from the cap. I guess one can not re-use the gasket. I have one on order.One other note. I noticed some loctite 574 sort of hardened around the side oil holes in the cap. I can see now how easily that stuff can break off and enter the vehicle bloodstream. Next time the gasket is going on dry or with a VERY THIN LAYER of loctite. Lesson learned.
02-13-2013, 10:48 PM
#160
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During your 15 minutes, did the oil pressure look good?
574 only hardens without air contact, so it would just be carried in the oil - which is why you do a quick oil change after startup.
Cheers,
Mike
574 only hardens without air contact, so it would just be carried in the oil - which is why you do a quick oil change after startup.
Cheers,
Mike
02-14-2013, 02:07 AM
#161
Rennlist Member
Hey peter if you have isolated the noise to the area of the lifters then maybe that is the issue they are not "pumping up" as mine did not untill i drove it. Mike and expeciallly Steve you guys have done engine rebuilds and lifter replacements, did yours quite down while idling afterwards without driving? I know mine didnt even though i soaked them in oil overnight. I certainly dont want you to drive your car and damage it but that is what i did and it worked. When you did the top end work did you replace the oil pressure sender? my original one and a "new" replacement one didnt work properly both went to zero when i took my foot of the gas and the warning light came on everytime i stoped. My third sender seems to work fine.
good luck......maybe its overpriced Porsche mechanic time?
good luck......maybe its overpriced Porsche mechanic time?
02-14-2013, 02:55 AM
#162
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I have had a few cases of really late pressurization - one took a good 30 minutes of idling and some light driving. In that case, all we did was the lifters, so we knew that was the cause of the noise. Sometimes they just pressure right up, and I am not sure why there is a variance - I do the presoak and use the same procedure every time (like once installed I crank for a bit with the DME relay pulled to load the lifters even more).
In this case, it's not just the lifters that were replaced, so its a bit of risk to run it that long to pressurize, but it could just be that issue. However, at least one fault has been found so far, so its worth a bit more digging to confirm everything else is ok before its run in.
Cheers,
Mike
In this case, it's not just the lifters that were replaced, so its a bit of risk to run it that long to pressurize, but it could just be that issue. However, at least one fault has been found so far, so its worth a bit more digging to confirm everything else is ok before its run in.
Cheers,
Mike
02-14-2013, 08:13 AM
#163
Rennlist Member
I agree with Mike's first question. How is the oil pressure now? Lifters may be pretty dry at this point and take a bit to pump up. The bummer is I had suggested this after your initial post and you have had to struggle with it for a week now. Your oil level was high in the crank for a bit so you may see some leaks at the case through bolts etc. If the rest of your oil flow is good the leaks may subside completely.
Last edited by bobt993; 02-14-2013 at 08:30 AM.
02-14-2013, 09:24 AM
#165
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