How loud was the noise you heard? Did it get louder with rpm or only at certain loads/rpm's? I have a noise that could be a bad tensioner as well.

What did it do for power and at what boost level?

 

It is a noise like a rattle upon start up, but goes away within 2-3 seconds as oil pressure comes up and pushes the tensioner back where its supposed to be.

The noise was loud enough to concern me and made me consider getting some John Deere stickers to put on the car.

Power numbers are under wraps for a bit yet.... but I'm sure you are still the Mid-A beast.

 

Good to hear that it is running, Chris.

 

Nice meeting you AJ, sorry I wasn't more personable, lots of stress that day.

Mike & Barney - I'm sure I will catch up with you guys soon.

 

I was doing some reading on oils and built engines today, and it seems that oil weight should be determined by the main bearing clearances. Of course the tight the clearances, the lighter the oil, and vice versa. The engine builder may be able to recommend you the best oil for you engine, as he would know what the clearances are. It seems to me that it may not be so much the brand of oil, but more the weight of the oil.


I am no expert, as I have just started doing some research on this topic, but this makes perfect sense.

Maybe some shops that build these engines can chime in.

 

also might not be such a bad idea to check bearings every x amount of miles as well and change em if they show excessive wear, more power made the more wear they have. an extreme example would be top fuel engines, 6000-7000 hp in a 1/4 mile wears the bearings the same as 100k miles on a normal engine. thats why i mentioned in the longevity thread asking what bearings where being used, stock clearance or the .001 extra oil clearance ones. old school small blocks have run looser on clearances the higher the power level for year. bearings and rings that is. clearance on our engines should be between .018 and .025 for bearings, formula directly from federal mogul is .0075-.001 inch clearance per inch of bearing surface diameter which on our cranks is 2.38 inches. seeing as how forged rods expand more then cast as per manufacturers and the problem seems to be above 550 hp im guessing its expansion that is causing issues with high hp engines. personally i would run between .022-.025 on high hp builds, if sleeves where used since they seem to have overheating problems i would say .024 and .026. acl does have bearings that allow .001 extra oil clearance as compared to stock however i cant find what stock is.

Pennzoil also makes a 20w-50 oil that would be excellent for this bearing clearance. when i rebuilt my small block for turbocharging i clearanced the crank for .0022 on the bearings and while i dint get to run the engine the last time i talked to the guy i sold it to it was still running strong with a weiand 6-71 blower with about 11k miles in the past two years. this is on a iron block iron headed chevy 305 bored to 310 and 8.5:1 pistons mind you. no idea what pulley he was running so no idea what the power level was but a build was done identical to this and ran 340 hp at the engine(not bad for a engine from the factory that made 170). overall it makes it a little noisy at startup but thats it, oil pressure might drop a little but theres more volume to provide more "cushion" to keep the parts seperated from each other. once the engine heats cant even tell a difference between a tight clearance/thin oil motor and loose clearance thick oil engine. granted i only have a few engines on under my belt but your gona be hard pressed to get machine shops to give up info. i had to have decking/boring/honing done by a machine shop but clearances i did myself(emery cloth and a flat shoelace i dont recommend doing this for high hp builds......... or anything outside a smallblock) as well as port polishing =/

 

I am not sure if checking clearances could be done with the engine in the car, most likely not. In that case the cost would be prohibitive.

The engine builder is on board with my choice. Blouch Turbo, Forced Performance and Justice Racing all said the Brad Penn is a solid choice for an F/I car with no cats. I read an article in Modified a while back on oil and it said that for F/I applications it is best to get the two numbers as close together as possible, hence the 10w30 choice. My tuner also suggested that better oil will reduce temps slightly and allow for more power in the tune. I was tuned on the break in Motul oil.

 

22lbs of boost and zero smoke on decel

 

i was thinking doing it oneself, i prefer to do my own work some things i just cant do, base wont let me do any welding in hobby shop without state cert. for example. and i just dont have the machines to do engine work =/ if paying someone then yah it kinda blows, ill prob check bearings myself every 10-15k as long as the engine survives, theres a tool that supports the engine on the strut towers and allows removal of the engine cradle/kmember without taking the engine out and would allow a much easier time doing this if a person has access to a lift. jackstands might work though

 

^ I had to use that tool when i had to lower my upper oil pan


This is how it looks

 

yup thats it used it alot doing oil pan gaskets when i still worked in a shop before the army its amazing =D

 

Cass, my G35 APS TT made that strange noise for years. The first time I heard it, scared the crap out of me. Sharif told me it was the tensioner and recommended I just run with it until we had a better reason to pull the timing chain cover. However, I ran with it like that for 3 years without issue and even sold the car with it making that noise. The sound was much louder in the winter months on cold startup or if the car was slightly pointed nose down when parking. Once the engine was running and then turned off and back on, no noise. Only after sitting for some time would it make the noise, kind of like a grinding noise for 1-2 seconds.

My daughters Xterra also does this on very cold mornings, it has 12K miles on it and the car is always parked slightly nose first just because of the driveway.

Get some oil analysis on the 30wt oil you plan to use and post it up. Interested in seeing how it holds up to the stress of VQ motors.

hope this helps - Paul

 

Thanks Paul. I changed the oil today and upon startup the noise is happening all the time now. So, just like that the car is down again until I get this noise sorted out.

The oil was clean, no particles or signs of foriegn materials. Oil pressure is still 90psi @ cold start and 30psi @ warm idle. No smoke out the pipes. I just need this to be a simple fix, I can't take any more FAIL with this car.

 

Def. send a sample to blackstone... just because it 'looks' clean doesn't really tell you much.

 

jeez! my solution, open exhaust. I cant hear shti from the car . Hell my valves might be hitting and turbos bound up, but i cant hear it.

soo nervous about 1st tune as nothing is tested...

hope u can make it to Airstrip. I dont wanna be last!

 

It is a loud *** rattle Rich, believe me I am as nervous as you are, after so many failures I just want this money pit to run without drama for a minute.

 

Pull the little inspection covers off your timing cover and see if the bolts are all tight on your tentioners.

I had the same issue it was just a loose bolt on the passenger side tentioner

 

Cass, what oil filter are you using? There are reports with a few manufacturers about oil filter bachelor seals leaking which is known to cause vslvetrain startup noise.

 

I'm using a Bosch oil filter from Autozone. I had a small leak somewhere and it seemed by the pattern of oil that it may have sprayed past the filter seal under high boost. I tightened this one down a bit more, so we will see. Thanks for the heads up. Is this one of the filters you were speaking of?

 

Ok, I can't stand the waiting and today was 70*+F outside so I got out a few tools and did some discovery.

Here is a pic of the tensioner as it is sitting in the car now:



Notice how it appears completely depressed. Also, I believe it is resting at the point where lock to install it is lined up. I was able to slide an allen wrench right in it. Is this how it is supposed to look at rest?
Here is a pic of the tensioner off of the oil burner used as a core:



It seems that the resting position is not fully depressed, but it also has no resistance on it. When I depress it fully, it does not appear to give as much as the tensioner that is in the car.

Can anyone help me out on this Oh, the tensioner in the car appears to have resistence on it, meaning I couldn't push it in any further and there wasn't slack in the chain to move it to the right easily.