996 hot start noise
#31
Three Wheelin'
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Have someone else start the car.
You should be able to put your ear by the "variocam" lettering on each side of the engine cam cover (chain box) during this start problem/noise and see if it is coming from there... which might indicate an actuator issue.
You can also take a long screwdriver and hold it against the engine in certain spots while cupping the other end in your ear. You'll be able to hear chains and ticks and things you can't hear with the naked ear.
When you have it on a lift that might be useful. BE sure to wear eye protection!!!
You should be able to put your ear by the "variocam" lettering on each side of the engine cam cover (chain box) during this start problem/noise and see if it is coming from there... which might indicate an actuator issue.
You can also take a long screwdriver and hold it against the engine in certain spots while cupping the other end in your ear. You'll be able to hear chains and ticks and things you can't hear with the naked ear.
When you have it on a lift that might be useful. BE sure to wear eye protection!!!
#32
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Thank you all again! ![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Macster, I have had only one head open at a time, and cyl 1-3 had the black solenoid.
And, I did remember to remove the bolt that I used to compress the actuators.
The time that the car needs to cool down is about 30mins to 4h, during this period the engine is noisy.
If I start the car after 10min's no noises what so ever, and engine purr's like a kitten.
If the engine is completely cooled down, there is (allmost) no abnormal noises.
Car was dynoed 4 months ago, 255hp at wheels, so I don't think that there is nothing wrong with the variocam system. This noise is more like the annoying thing (crazy frog)![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
This morning I listened the engine when I started it, and I think that startermotor did make some metallic noise. As the starter is easy to remove, I will check that one first.
Well at least next week, work and other hobbies take too much of my time...
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Macster, I have had only one head open at a time, and cyl 1-3 had the black solenoid.
And, I did remember to remove the bolt that I used to compress the actuators.
The time that the car needs to cool down is about 30mins to 4h, during this period the engine is noisy.
If I start the car after 10min's no noises what so ever, and engine purr's like a kitten.
If the engine is completely cooled down, there is (allmost) no abnormal noises.
Car was dynoed 4 months ago, 255hp at wheels, so I don't think that there is nothing wrong with the variocam system. This noise is more like the annoying thing (crazy frog)
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
This morning I listened the engine when I started it, and I think that startermotor did make some metallic noise. As the starter is easy to remove, I will check that one first.
Well at least next week, work and other hobbies take too much of my time...
#33
Race Director
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Thank you all again! ![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Macster, I have had only one head open at a time, and cyl 1-3 had the black solenoid.
And, I did remember to remove the bolt that I used to compress the actuators.
The time that the car needs to cool down is about 30mins to 4h, during this period the engine is noisy.
If I start the car after 10min's no noises what so ever, and engine purr's like a kitten.
If the engine is completely cooled down, there is (allmost) no abnormal noises.
Car was dynoed 4 months ago, 255hp at wheels, so I don't think that there is nothing wrong with the variocam system. This noise is more like the annoying thing (crazy frog)![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
This morning I listened the engine when I started it, and I think that startermotor did make some metallic noise. As the starter is easy to remove, I will check that one first.
Well at least next week, work and other hobbies take too much of my time...
![Smilie](https://rennlist.com/forums/images/smilies/smile.gif)
Macster, I have had only one head open at a time, and cyl 1-3 had the black solenoid.
And, I did remember to remove the bolt that I used to compress the actuators.
The time that the car needs to cool down is about 30mins to 4h, during this period the engine is noisy.
If I start the car after 10min's no noises what so ever, and engine purr's like a kitten.
If the engine is completely cooled down, there is (allmost) no abnormal noises.
Car was dynoed 4 months ago, 255hp at wheels, so I don't think that there is nothing wrong with the variocam system. This noise is more like the annoying thing (crazy frog)
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)
This morning I listened the engine when I started it, and I think that startermotor did make some metallic noise. As the starter is easy to remove, I will check that one first.
Well at least next week, work and other hobbies take too much of my time...
Sincerely,
Macster.
#34
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Finally had the time to do something else than driving the car (and working)
I got used "scavenge" oilpump for 1-3 cyl head from e-bay. Changed it and the problem is still there.
While the car was on lift, I had my friend to start the car. It seems that the noise is coming from, starter, flywheel or gearbox.
Soon I have used parts to build a nother engine :P
I got used "scavenge" oilpump for 1-3 cyl head from e-bay. Changed it and the problem is still there.
While the car was on lift, I had my friend to start the car. It seems that the noise is coming from, starter, flywheel or gearbox.
Soon I have used parts to build a nother engine :P
#36
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First startup noise, now the engine developed new symptoms. These noises cause me to do this
![](http://speedrii.kuvat.fi/kuvat/possu/11092011186.jpg/_medium.jpg)
![](http://speedrii.kuvat.fi/kuvat/possu/11092011187.jpg/_medium.jpg)
Like a marbles in a can
Took the gearbox out first and started, still making noises.
Took the aux belt off, sama thing.
Took the IMS bearing off, it was ok. I had all ready installed LNE ims bearing.
ims-chaintensioner was very soft. I mean that there was litle or no preload in it when i removed it. Should the ims-chaintensioner be like the camchaintensioner???
I will take the heads apart tomorrow and check whats lurking in there....
Just hate this, I love driving this car but the engine![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
so, new engine, buid new engine, put some other engine, or???
![](http://speedrii.kuvat.fi/kuvat/possu/11092011186.jpg/_medium.jpg)
![](http://speedrii.kuvat.fi/kuvat/possu/11092011187.jpg/_medium.jpg)
Like a marbles in a can
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
Took the gearbox out first and started, still making noises.
Took the aux belt off, sama thing.
Took the IMS bearing off, it was ok. I had all ready installed LNE ims bearing.
ims-chaintensioner was very soft. I mean that there was litle or no preload in it when i removed it. Should the ims-chaintensioner be like the camchaintensioner???
I will take the heads apart tomorrow and check whats lurking in there....
Just hate this, I love driving this car but the engine
![banghead](https://rennlist.com/forums/graemlins/banghead.gif)
so, new engine, buid new engine, put some other engine, or???
#37
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Ok, problem found. Connectingrodbearing on cyl. 5.....
![](http://speedrii.kuvat.fi/kuvat/possu/12092011188.jpg/_medium.jpg)
Engine on stand, cyl.head 1-3 removed
![](http://speedrii.kuvat.fi/kuvat/possu/12092011192.jpg/_medium.jpg)
Small scraches in cyl 5 and cyl 4 you can hardly feel those with finger, goingto use the blocks anyways. Block 1-3 is like new.
![](http://speedrii.kuvat.fi/kuvat/possu/12092011193.jpg/_medium.jpg)
Engine with the 4-6 block off
So end results, need a new or good used crankshaft and one connectingrod.
If enyone has these parts, please send me private message.....
![](http://speedrii.kuvat.fi/kuvat/possu/12092011188.jpg/_medium.jpg)
Engine on stand, cyl.head 1-3 removed
![](http://speedrii.kuvat.fi/kuvat/possu/12092011192.jpg/_medium.jpg)
Small scraches in cyl 5 and cyl 4 you can hardly feel those with finger, goingto use the blocks anyways. Block 1-3 is like new.
![](http://speedrii.kuvat.fi/kuvat/possu/12092011193.jpg/_medium.jpg)
Engine with the 4-6 block off
So end results, need a new or good used crankshaft and one connectingrod.
If enyone has these parts, please send me private message.....
#38
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wow, grats on solving the problem. Did replacing the rod bearing fix just the "can of marbles" problem or the original clatter problem as well? I would have sworn that was the chain tensioner sound I heard.
LV
LV
#39
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Hi LV
Engine is still in pieces, hunting the parts to put it back to gether.
But I'm quite sure that this was the cause of these noises.
If enyone will come up with an idea, that what could have caused this??
All the other bearings were in good shape.
Engine is still in pieces, hunting the parts to put it back to gether.
But I'm quite sure that this was the cause of these noises.
If enyone will come up with an idea, that what could have caused this??
All the other bearings were in good shape.
#40
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Looks like you have a nice shop to work in. I'm wondering if you are using a used shaft if you are going to have it turned and balanced with the rods and pistons on since you seem to know and be into engine performance. I'm not sure if porsche cranks can be turned (advice from porsche maker shadows) but as far as I know it’s generally the best thing to do with a crank that has been broken in with different rods and pistons to at least turn the crank. Some guys have just repolished the bearings areas which keeps from hunting new thicker bearings to make up for what's been turned off the crank. Could be best to check the tolerances of the block bearing areas for uniformity and get a good idea of the size bearings that might be needed to keep the problem area from coming back by possibly going with non standard bearing thickness’s. Regretfully it isn’t always going back to off the shelf part numbers.
Whatever the case have fun and enjoy.
Whatever the case have fun and enjoy.
#41
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Glad to hear you found the problem.
If I were in your shoes I would either look for a rebuilt engine.
OR if you want to salvage what you have:
Send block to autofarm.uk for 3.7 rebore and new pistons
Perhaps new connecting rods if required example: http://www.lnengineering.com/rods.html
Send crankshaft to reputable source to have it balanced if possible??? (or if money is not an object source a new one example: http://www.flat6innovations.com/shop/home.php?cat=301)
Valve job since you have the heads off.
Replace other serviceable items such as chains, ramps, aos, pumps, seals, gaskets, orings, washers, hardware, oil cooler, main and rod bearings, thrust washers, circlips, hoses, etc, etc etc.
Keep us updated!
If I were in your shoes I would either look for a rebuilt engine.
OR if you want to salvage what you have:
Send block to autofarm.uk for 3.7 rebore and new pistons
Perhaps new connecting rods if required example: http://www.lnengineering.com/rods.html
Send crankshaft to reputable source to have it balanced if possible??? (or if money is not an object source a new one example: http://www.flat6innovations.com/shop/home.php?cat=301)
Valve job since you have the heads off.
Replace other serviceable items such as chains, ramps, aos, pumps, seals, gaskets, orings, washers, hardware, oil cooler, main and rod bearings, thrust washers, circlips, hoses, etc, etc etc.
Keep us updated!
#42
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Pac, I thougth that there is no oversize bearings for these engines?
I have traced a good used connectingrod from England, only the crakshaft is still a mystery.
I try to make this engine work, and spend money little as possible. Reason for doing this, I was planning to build better engine next summer. And I don't have the fund's to do it properly now.
And for the money, I'm now at about 1600usd and only missing the crank.
So I hope to rebulid this engine for 2-2.5 k usd
But, does enyone have an idea, what would have caused this?
No over revs in ecu counter.
Rodbolts were tight
Everything else inthe engine is in good condition, including all the other rodbearings.
I hate to put this back to gether, if I dont know the cause.
I have traced a good used connectingrod from England, only the crakshaft is still a mystery.
I try to make this engine work, and spend money little as possible. Reason for doing this, I was planning to build better engine next summer. And I don't have the fund's to do it properly now.
And for the money, I'm now at about 1600usd and only missing the crank.
So I hope to rebulid this engine for 2-2.5 k usd
But, does enyone have an idea, what would have caused this?
No over revs in ecu counter.
Rodbolts were tight
Everything else inthe engine is in good condition, including all the other rodbearings.
I hate to put this back to gether, if I dont know the cause.
#43
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So, the rod bearing did not fix this noise....
I have been testing and finding the conditions that this noise occurs.
And this is what I have found.
When starting the engine, idle valve lets the engine rev to 2200rpm when this noise occurs.
If the revs stays about 1300 or less, there is no noises.
Could the idleairvalve be the cause?? If it lets the revs too high in the startup?
My car starts fast, it takes about one rev from the engine to get going, and when the IAV lets the engine run to 2200rpm, the noise will be there until the oilpressure is over 3bar...
Could some one check how high the IAV let's rev's go, when the engine starts?
I have been testing and finding the conditions that this noise occurs.
And this is what I have found.
When starting the engine, idle valve lets the engine rev to 2200rpm when this noise occurs.
If the revs stays about 1300 or less, there is no noises.
Could the idleairvalve be the cause?? If it lets the revs too high in the startup?
My car starts fast, it takes about one rev from the engine to get going, and when the IAV lets the engine run to 2200rpm, the noise will be there until the oilpressure is over 3bar...
Could some one check how high the IAV let's rev's go, when the engine starts?
#44
Three Wheelin'
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Doubt it's the IACV.
I think I read somewhere crank position sender might cause this overrev on startup. Or maybe throttle position sensor.
Perhaps clicking is due to not enough oil in some areas because of startup high rev?
Just ideas...
I think I read somewhere crank position sender might cause this overrev on startup. Or maybe throttle position sensor.
Perhaps clicking is due to not enough oil in some areas because of startup high rev?
Just ideas...
#45
Race Director
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So, the rod bearing did not fix this noise....
I have been testing and finding the conditions that this noise occurs.
And this is what I have found.
When starting the engine, idle valve lets the engine rev to 2200rpm when this noise occurs.
If the revs stays about 1300 or less, there is no noises.
Could the idleairvalve be the cause?? If it lets the revs too high in the startup?
My car starts fast, it takes about one rev from the engine to get going, and when the IAV lets the engine run to 2200rpm, the noise will be there until the oilpressure is over 3bar...
Could some one check how high the IAV let's rev's go, when the engine starts?
I have been testing and finding the conditions that this noise occurs.
And this is what I have found.
When starting the engine, idle valve lets the engine rev to 2200rpm when this noise occurs.
If the revs stays about 1300 or less, there is no noises.
Could the idleairvalve be the cause?? If it lets the revs too high in the startup?
My car starts fast, it takes about one rev from the engine to get going, and when the IAV lets the engine run to 2200rpm, the noise will be there until the oilpressure is over 3bar...
Could some one check how high the IAV let's rev's go, when the engine starts?
I've kind of lost the context of this thread, being on the road and all.
Have you used a mechanic's stethescope to try to pinpoint the location of the source of the noise? Knowing where the noise comes from can help with a diagnosis.
Idle racing from cold start is not unknown. I can't recall what rpms level is hit upon startup with my cars but it is over 1K and possibly closer to 1.5K. The tach in your car may not be reading the right level at startup so you need to hook up an OBD reader/data logger and capture the actual rpms that is obtained at engine start.
The ticking might be due to a noisy (even leaking) fuel injector. If it is leaking not only can it be noisy it can add too much fuel and the engine can race.
Long and short fuel trims can provide a clue.
Also, check the intake air temp and coolant temp at engine start. If these are wrong -- due to sensor/sendor problems -- the engine controller can add too much fuel which can result in an abnormal engine rpm level during engine start.
Sincerely,
Macster.