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Wonder if a variation of a scavenger valve installed in the exhaust right after
the muffler above the tailpipe junction would provide enough air flow and suction
to evacuate the catch can? It would need a "purge valve" that opened only above
3000 most likely but in the old days it worked really well to vent a drag engine..
Nick, I don't track my car for one. I didn't want to clutter up the engine bay any more and felt that as long as the AOS can be monitored with a Manometer all will be fine (for me) as it's just another wear item like many other parts.
As for the IMSS, that's the way to go, if I could I would, but I have the 997 type bearing.
I remember reading a post or two from Jack Raby that he tried using the knock sensor to detect a failing intermediate shaft bearing and the data was not reliable enough to make this work. I like your enthusiasm but most of what you are posting has already been tried in the past. I've used a self sourced intermediate shaft hybrid bearing and the end results were not good at all. The bearing was coming apart at the 12K kms mark. I have posted this on my engine repair thread but my pockets are not deep enough to keep trying this. Did it once, got lucky enough that the engine didn't grande and I am able to fix it.
Last week I received the spark plug tubes so that I could get started to put everything together.
The only hick-up was that the heat shield over the coils didn't fit perfectly. The new coils(NGK) are a bit beefier and the fixation screw heads protrude from the unit and these touch the heat shield. If you look at the picture you'll get the idea how the heads protrude. I didn't do anything about it, just added some loctite and fastened reasonably. The new coils are also around 20g heavier.
With everything together I started refilling the oil. After 8 L the stick indicated completely full, time to start and circulate the oil. The car have been sitting for over one months and had a complete oil drain (filter out and 24h drain period) so I was expecting a bit of rattle from it. On top of this it was rather cold, around 5 C only. Turned the key and it came to life with a lot of rattle and a loud tick from the cylinders. I knew that these engines make a lot of rattle but it was quite discerning, especially the ticking. The ticking was clearly not an injector or lifter, it was coming from the cylinder. I let the car run for 5min and then turned off. I'm treating the engine with tungsten disulphide so I have made an oil mix which is 1% wt ( 34g of WS2 powder to 3400g oil) mix which I will slowly put in there. I was able to put 1L of this in before the dip stick read full. I will do a new filter change shortly which will drain some oil so that I can fill more.
With the engine full I let the car idle for around 5min (still loudly ticking) before slowly going to the petrol station. Since the car had been sitting I was afraid the cylinders was completely dry and thus I wanted some oil on them before setting off. It's only 2km to the petrol station and by the time I arrived the ticking was almost gone. After setting off from there It quickly disappeared. Due to the WS2 treatment I needed to directly drive the car(the stuff sinks, so after sitting still for a week it will separate from the oil and not do much) so I had planed a 1 hour drive. Dark, cold and rainy...it wasn't the perfect drive weather but the car pulled very strong and smooth.
At arriving home I let the car idle at the drive way while I listened. When properly warmed up it runs silky smooth(!), the only ticking is from the injectors doing their job.
The day after I started the car again, to circulate the oil before the WS2 sinks, and it's making this ticking noise again. Day after that I tried to pre-heat the engine before starting and this clearly made the ticking less. My idea is that the clearance for the rings are so tight that when the engine is cold they have too much pressure causing the tick. Could also be the AOS not properly evacuating the pressure from the crank case causing it. I guess there is a thread somewhere where the reason have been found?
The new Mann+hummel AOS have arrived and I have been testing it. It's very similar to the original, so similar that it might be possible to use it sans modifications. I still built a pressure regulation adjustment for it if needed. I will let the short term fuel trim guide me. I bought the 200 size but I guess a smaller 150 or even 100 will work well also. At idle the blow-by should not be much more than around 60l/min so a size 100 would in theory work.
The knock sensor have arrived also but it will need an amplifier and a band pass filter to bring out the relevant signal.
The engine makes ticking noise just at start up from cold, but that's it, 2-3min. Spark plugs look perfect. No excess sot. Engine runs perfect and strong. No CEL.
I took it for a drive yesterday (almost 2h of high RPM driving in the mountains, 3k-7k) and it ran perfect. After I check the spark plugs again, still perfect. No excess sot on either exhaust.
I did a filter change and re-filled some oil and went for another 1h drive. All Perfect. In the evening I dissected the filter and checked the small amount of oil that drained during the filter change: nothing.
When I bought the car it made no start up noise (I felt the engine before first start, it was cold). I also checked the exhaust pipes for sot.
Since I bought it I have replaced/done the following to the engine:
*Coils
*Spark plug tubes
*Checked all spark plugs, all in excellent (text book) condition.
*Oil filter and oil
*Air filter
*new exhaust
Logically something I did caused the ticking. I recorded (sound) the ticking to be able to measured the time for it to go away and to compare to others recordings.
It slowly lessens and after about 2-3min of idle there is just a faint of ticking left. The sound is not like the bore scoring which I found online(which is a constant tick that doesn't go away), and it makes no sense that it will happen after an oil change either. I don't have a stethoscope to check exactly where it's coming from but the symptoms points to a tappet. I'm guessing the old oil was just thick enough to not drain too much while the new oil drains it and it have to slowly fill up when doing a cold start.
The previous owner used 5w40 Motul 8100 x-cess oil (he gave me a half full bottle of left-overs from last change). I put in M1 0w40, I think this is my mistake. Since I have both 5w40 and 0w40 I did a small test. I drilled a 1mm hole in two plastic cups and fill them with the same amount of oil, one with 5w40 and one with 0w40. At 10 degrees C the 0w40 drips out 30% faster.
The AOS project is going along well, waiting for parts right now. The fan speed controller is a bit on hold since I can't decide how I should build the unit: One central controller or two small located at each fan. I need to take the fans off the car also to better see the options and foremost be able to bench test the system properly.
I went over the spark plugs with a torque wrench this morning since after finding a thread on here which indicated that ticking could come from loose plug.
Before I just tighten by hand estimating the right torque (I never used a torque wrench on the spark plugs before). I found a few which was not tight enough.
They all looked good but I took pictures of them to be able to more clearly compare them. Below is the picture.
After starting there was still a tick but less than before. As usual it went away after around 2min of idle.
Number 5 has slightly more sot on it, but still to my eyes not much at all. I have a bore scope camera on order so will have to wait a week or so before being able to look down the cylinder. Is it possible for sot to form due to badly tightened spark plugs? I'm guessing so and hope this is the case.
I looked thru the receipt from the previous owner and the spark plugs have been in there for roughly 20 000km.
The plugs look ok to me. Have you put a mechanic stethoscope on the engine yet? I didn’t note that in your previous posts. You can put the point on each cylinder and check all around the thing to isolate the source. May save you a lot of time and keep you from throwing extra parts on it.
Those plugs look good to me. There will be some variation because the ECU doesn't know exactly how each cylinder is running so it makes adjustments across the bank as opposed to each individual one. That's just how it is designed. But looks like some of your spark plug booth O rings are leaking a bit.
Thanks for your replies, they are much appreciated.
The spark plug tubes was recently (1 week ago) changed and some oil was dropped, that's why there is a bit of oil on the boot.
Not been over it with a stethoscope, I don't have one, maybe a good investment.
On my list of things to try next is Seafoam in the oil(to dissolve any sludge), 1h drive and then oil change(+ oil pan inspection). Changing to a thicker oil as was before in the engine. The valve train makes more noise than I would like right now(apart from the ticking), I hope some heavier oil can reduce that.
Nick - either buy a mechanic ear stethoscope (cheap) or a medical one (expensive). If you don’t buy the cheap one, you’ll need to buy the expensive one to check your heart each time you start the car.
One thing concerns me. You changed your oil in 5* weather to a thicker oil after a 24hr drain. Oil filter filled? Then started it and let it idle? Did you start and stop (3-5 times)...to build up oil pressure before firing it?
I changed from Motul 8100 5w40 to M1 0W40 (I was a little unfocused when choosing oil. Where I live it seldom goes below 0* centigrade and summer is 35* c), after a 24h drain.
After the change I just started the car directly and idle for around 2min. Stopped and topped up oil. After this I went for a 1h drive.
I've now read it could be good to pull fuse C4 (fuel pump) and circulate oil before starting, which I have been doing since. I run the starter until I have 2.5 bar pressure and then put in the fuse and start. on a side note: Fuel pressure seams to drop to zero after just 24h, is this normal?
No need to over think this. The bearings will still have enough oil on them to be ok even if the case was drained for 24rhs. It's not like they are bone dry when and engine is first fired up after a rebuild.
11-16-2019, 07:04 PM
