to all that want to know what they do..

this will help a lot... and a lot of other things..

https://www.rx8club.com/rx-8-discussion-3/renesis-training-video-100729/

beers

 

the biggest problem with the valves is it is going to be very hard to clean them..

if you run a fuel injector cleaner to clean them you would need to keep the motor over 7500rpm to have the cleaner get to them...

even it you use an induction cleaner... you still have to get to 7500rpm to get the valves to open...

beers

 

yes it can... i have first hand experience with this problem

 

yeah, duh, reading would be good. do you like the fly wheel? do you find it has any down sides other than needing to be revved higher to launch? Do you get any wierd vibrations or it is just as smooth as stock?

 

I've pulled it out the top also, just pulled the upper intake manifold off, Hardest part was getting the engine and transmission to line up used floor jacks on the bottom i had one under the engine and one under the transmission. Not that hard though. Oh yea the hood is too easy and light not to take off while you do this.

 

Every one of the stuck actuators I've ever seen have all used conventional oil. Blaming it on synthetics is pure bs and everyone knows it so NO IT CAN'T!

 

when did i say anything about synthetic oil? You said the ports can't get stuck on a RENESIS... and mine did

 

No, he meant that it isn't the oil that can be blamed for it sticking.
It is carbon build up from combustion blow-back, not oil sludge.

 

Oops. Sorry. I misread that. I had two things in there, you responded to one and I thought it was the other.

It's weird that yours got stuck. It's supposed to rotate them at startup to prevent this from happening. Maybe part of the problem is that they open so high in the rpm range. The RX-7's opened up at 3800 rpm so they were opening far more often. Even a quick rotation every once in a while is apparently not enough to keep them from getting sufficient carbon buildup. I wonder, do they only get stuck or can they get harder to turn and then fry the motor that moves them? that would be a concern of mine.

 

I think the problem is they are only actualted at very high rpms AND with very high engine loads... and lets face it, you can only be at near WOT for so long and the amout of that time you spend above 7800 rpms is not very long lived

(well at least on a street driven only car anyway)

For the record, it seemed mine actually had evidence of corrosion going on.... not sure if it would be the gunk buildup causeing corrosion or if i had a slight coolant leak

 

r0tor --
Is your engine getting (or recently been) replaced?

 

from the bit i have driven it like the flywheel a lot... i dont find it much harder to launch... i have only put 175 miles on it... and i dont notice it now...

note on a side note.... when you replace the clutch with an exedy or an act.. you will have to adjust the clutch ped. as it will release almost at the floor.... i still dont have this perfect...

vibrations... right now none... but aparentlly when the tech took it out for the first ride it was bad... he came back and and said it had a vibration... and paused... as ppf was coming out of my mouth he already had the sockets in his hand...

beers

 

Can you say more on the condition of our engine mounts and water pump? I'm especially interested in the water pump as I believe my water pump is causing my "marbles" sound. (Not everyone else's marbles, just mine, and possibly a couple others.)

 

it had a slight weep... no sound, no liquid on the ground... it would likely fail in the next 10k miles... bearing was still solid..

this was at 55k miles..


beers

 

hasn't been replaced and i haven't taken it in for the recall yet - but since I have no problems and an aftermarket cat it will just be a flash and leave anyway

The real pisser with this problem is the repair bill could be about $1500 cheaper if the boneheads would have given another couple inches of clearance between the manifold and chassis.. but since they didn't, the engine must be pulled out

 

I agree that is crap. It's not like the RX-7's where the sleeves stayed where they were and only the manifold came out.

 

Thank you, that was very helpful. It answered several question I had but didn't know how to ask. That should be mandatory reading for everyone who asks "what's this noise?"

Best of luck with the new engine.

 

Don't bring it up too far - I did that - but a mechanic explained to me that if you don't leave enough slack on the pedal (first part of pedal downward travel) you will be engauging the release bearing all the time leading to premature failure of the bearing.

 

I adjusted my clutch pedal fairly high, which allows me less pedal travel for faster gear changes.

But I agree you can have it too high & reap the issue you mention.

 

It really does.

On the BITOG forum, they are very high on a fuel additive called FP60 from Lube Control (no pun intended). FP60 lubricates the fuel pump and the Upper parts the engine, dissolves carbon, disperses water, acts as a fuel stabilizer, is an antioxidant, and actually improves fuel mileage.

I just ordered some to start using it in each tank. I will also use BG44k every 7500 miles for a good occasional "shock" cleaning as I do in all my cars.

With an engine as prone to this carbon buildup as ours and me kinda being a maintenance nut anyways, I intend to use. Other might want to try it out as well - maybe instead of "premixing" which seems somewhat redundant.

 

I am sceptical of any product makes so many claims - but hey if it does anything usefull be sure to share .

 

I was skeptical as well until I read all the feedback from Terry Dyson, who runs an independent Oil Analysis company, because of impressive Used Oil Analysis he has done with for users of this product and the companion oil product (LC20), he highly recommends these products. He is a regular expert on the BITOG forum and this is one of only two products he recommends (the other being Auto-RX) - he thinks almost all of the rest of them are "snake oil" as most are.

Here is a Link for FP60 info and BITOG site if anyone wants to investigate for themselves:

http://www.lubecontrol.com/fuel.htm

http://www.bobistheoilguy.com/

 

only problem is the valves are only open above 7500 rpm.. so unless you are on a race track it is going to be hard to get them totally clean... but anything will help...

and as to the condition... the tech said it was not that bad... it was soft goo not hard depostits..

beers

 

I agree, but I guess running it to the redline every once in a while may help some.

That's good. I am going to try FP60 and BG44k to try and minimize the buildup as much as I can.

 

I would just hope the hard goo is not the fist stage of the hard stuff which will lock these values.

It dose seem that some high revving is helpful in avoiding this issue. I also wonder if a catch can will help or hurt this issue.